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Cytochrome P450 monooxygenases in insects have been verified to implicated in insecticide and phytochemical detoxification metabolism. However, the regulation of P450s, which are modulated by signal-regulated transcription factors (TFs), is less well studied in insects. Here, we found that the Malpighian tubule specific P450 gene SlCYP9A75b in Spodoptera litura is induced by xenobiotics. The transgenic Drosophila bioassay and RNAi results indicated that this P450 gene contributes to α-cypermethrin, cyantraniliprole, and nicotine tolerance. In addition, functional analysis revealed that the MAPKs p38, PI3K/Akt, and JAK-STAT activate the transcription factor fushi tarazu factor 1 ( FTZ-F1 ) to regulate CYP9A75b expression. These findings provide mechanistic insights into the contributions of CYP9A genes to xenobiotic detoxification and support the possible involvement of different signaling pathways and TFs in tolerance to xenobiotics in insects.

Survival strategies of human-associated microbes to drug exposure have been mainly studied in the context of bona fide pathogens exposed to antibiotics. Less well understood are the survival strategies of non-pathogenic microbes and host-associated commensal communities to the variety of drugs and xenobiotics to which humans are exposed. The lifestyle of microbial commensals within complex communities offers a variety of ways to adapt to different drug-induced stresses. Here, we review the responses and survival strategies employed by gut commensals when exposed to drugs-antibiotics and non-antibiotics-at the individual and community level. We also discuss the factors influencing the recovery and establishment of a new community structure following drug exposure. These survival strategies are key to the stability and resilience of the gut microbiome, ultimately influencing the overall health and well-being of the host., Competing Interests: Declaration of interests L.M. is listed as a co-inventor on the following patents (or patent applications): EP3838269A (published 23.06.2021) Compounds & Pharmaceutical Compositions for Prevention-Treatment of Dysbiosis, Antidotes for Microbiome Prevention; WO/2019/158559 (published 22.08.2019) Repurposing compounds for the treatment of infections and for modulating the composition of the gut microbiome; and WO/2019/154823 (published in 15.08.2019) In vitro model of the human gut microbiome and uses thereof in the analysis of the impact of xenobiotics., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Anisakiasis is a parasitic disease transmitted through the consumption of raw or undercooked fish and cephalopods that are infected with larvae of Anisakis simplex (sensu stricto) or Anisakis pegreffii. The purpose of this study was to investigate how A. simplex (s. s.) responds to the influence of anthelmintics such as ivermectin (IVM) and pyrantel (PYR). In vitro experiments were conducted using larvae at two developmental stages of A. simplex (s. s.) (L3 and L4) obtained from Baltic herring (Clupea harengus membras). Larvae were cultured with different concentrations of IVM or PYR (1.56, 3.125, and 6.25 μg/mL) for various durations (3, 6, 9, and 12 h) under anaerobic conditions (37 °C, 5% CO 2 ). The gene expression of actin, ABC transporter, antioxidant enzymes, γ-aminobutyric acid receptors, and nicotinic acetylcholine receptors, as well as the oxidative status were analyzed. The results showed that A. simplex (s. s.) L3 stage had lower mobility when cultured with PYR compared to IVM. The analysis of relative gene expression revealed significant differences in the mRNA level of ABC transporters after treatment with IVM and PYR, compared to the control group. Similar patterns were observed in the gene expression of antioxidant enzymes in response to both drugs. Furthermore, the total antioxidant capacity (TAC) and glutathione S-transferase (GST) activity were higher in the treatment groups than in the control group. These findings suggest a relationship between the expression of the studied genes, including those related to oxidative metabolism, and the effectiveness of the tested drugs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Aphis gossypii, a globally distributed and economically significant pest of several crops, is known to infest a wide range of host plants. Heat shock proteins (Hsps), acting as molecular chaperones, are essential for the insect's environmental stress responses. The present study investigated the molecular characteristics and expression patterns of AgHsp70, a heat shock protein gene, in Aphis gossypii. Our phylogenetic analysis revealed that AgHsp70 shared high similarity with homologs from other insects, suggesting a conserved function across species. The developmental expression profiles of AgHsp70 in A. gossypii showed that the highest transcript levels were observed in the fourth instar nymphs, while the lowest levels were detected in the third instar nymphs. Heat stress and exposure to four different xenobiotics (2-tridecanone, tannic acid, gossypol, and flupyradifurone (4-[(2,2-difluoroethyl)amino]-2(5H)-furanone)) significantly up-regulated AgHsp70 expression. Knockdown of AgHsp70 using RNAi obviously increased the susceptibility of cotton aphids to 2-tridecanone, gossypol and flupyradifurone. Dual-luciferase reporter assays revealed that gossypol and flupyradifurone significantly enhanced the promoter activity of AgHsp70 at a concentration of 10 mg/L. Furthermore, we identified the transcription factor heat shock factor (HSF) as a regulator of AgHsp70, as silencing AgHSF reduced AgHsp70 expression. Our results shed light on the role of AgHsp70 in xenobiotic adaptation and thermo-tolerance., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Fly ash application to the soil at lower doses with organic substrates has been advocated by researchers due to its beneficial soil ameliorative properties. But its xenobiotic effects in presence of vermicompost have not yet been studied fully. The hypothesis of the present study was to ascertain the ameliorative effects of fly ash and vermicompost amendment on the soil nematode and earthworm count and change in the soil carbon pool of the rice nursery. The native soil, fly ash, and vermicompost at 0%, 20%, 40%, 60%, 80%, and 100% combinations (by weight) in triplicate were investigated under a factorial complete randomized design. The fly ash affected the earthworm survivability to an extent that the earthworms could not survive in fly ash of concentration greater than 20%. On the contrary, the concentration of vermicompost positively influenced the earthworm and nematode count in the rice rhizosphere. The population of nematodes viz. Rhabditis terricola and Dorylaimids in the rhizosphere of rice nursery was positively linked with the vermicompost concentration, while fly ash had antagonistic effects. The absence of nematodes and earthworms at a higher concentration of fly ash could be linked to the xenobiotic effects of fly ash. However, on mild addition of fly ash and vermicompost (20% each) to the native soil, the carbon stock increased positively to the maximum extent due to the larger surface area of fly ash and its xenobiotic effects limiting respirational carbon loss., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The metagenome of bacteria colonizing the human intestine is a set of genes that is almost 150 times greater than the set of host genes. Some of these genes encode enzymes whose functioning significantly expands the number of potential pathways for xenobiotic metabolism. The resulting metabolites can exhibit activity different from that of the parent compound. This can decrease the efficacy of pharmacotherapy as well as induce undesirable and potentially life-threatening side effects. Thus, analysis of the biotransformation of small drug-like compounds mediated by the gut microbiota is an important step in the development of new pharmaceutical agents and repurposing of the approved drugs. In vitro research, the interaction of drug-like compounds with the gut microbiota is a multistep and time-consuming process. Systematic testing of large sets of chemical structures is associated with a number of challenges, including the lack of standardized techniques and significant financial costs to identify the structure of the final metabolites. Estimation of the compounds' ability to be biotransformed by the gut microbiota and prediction of the structures of their metabolites are possible in silico . However, the development of computational approaches is limited by the lack of information about chemical structures metabolized by microbiota enzymes. The aim of this study is to create a database containing information on the metabolism of drug-like compounds by the gut microbiota. We created the data set containing information about 368 structures metabolized and 310 structures not metabolized by the human gut microbiota. The HGMMX database is freely available at https://www.way2drug.com/hgmmx. The information presented will be useful in the development of computational approaches for analyzing the impact of the human microbiota on metabolism of drug-like molecules.

Ethnopharmacological Relevance: Bu-Zhong-Yi-Qi-Tang is a famous traditional Chinese medicine formula that has been prevalent in China for over 700 years to treat spleen-qi deficiency related diseases, such as gastrointestinal and respiratory disorders. However, the bioactive components responsible for regulating spleen-qi deficiency remain unclear and have puzzled many researchers., Aim of the Study: The current study focuses on efficacy evaluation of regulating spleen-qi deficiency and screening the bioactive components of Bu-Zhong-Yi-Qi-Tang., Materials and Methods: The effects of Bu-Zhong-Yi-Qi-Tang were evaluated through blood routine examination, immune organ index, and biochemical analysis. Metabolomics was utilized to analyze the potential endogenous biomarkers (endobiotics) in the plasma, and the prototypes (xenobiotics) of Bu-Zhong-Yi-Qi-Tang in the bio-samples were characterized using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Then, these endobiotics were used as "bait" to predict targets based on network pharmacology and to screen potential bioactive components from the absorbed prototypes in the plasma by constructing an "endobiotics-targets-xenobiotics" association network. Further, the anti-inflammatory activities of representative compounds (calycosin and nobiletin) were validated through poly(I:C)-induced pulmonary inflammation mice model., Results: Bu-Zhong-Yi-Qi-Tang exhibited immunomodulatory and anti-inflammatory activities in spleen-qi deficiency rat, as supported by the observation of increased levels of D-xylose and gastrin in serum, an increase in the thymus index and number of lymphocytes in blood, as well as a reduction in the level of IL-6 in bronchoalveolar lavage fluid. Furthermore, plasma metabolomic analysis revealed a total of 36 Bu-Zhong-Yi-Qi-Tang related endobiotics, which were mainly enriched in primary bile acids biosynthesis, the metabolism of linoleic acid, and the metabolism of phenylalanine pathways. Meanwhile, 95 xenobiotics were characterized in plasma, urine, small intestinal contents, and tissues of spleen-qi deficiency rat after Bu-Zhong-Yi-Qi-Tang treatment. Using an integrated association network, six potential bioactive components of Bu-Zhong-Yi-Qi-Tang were screened. Among them, calycosin was found to significantly reduce the levels of IL-6 and TNF-α in the bronchoalveolar lavage fluid, increase the number of lymphocytes, while nobiletin dramatically decreased the levels of CXCL10, TNF-α, GM-CSF, and IL-6., Conclusion: Our study proposed an available strategy for screening bioactive components of BYZQT regulating spleen-qi deficiency based on "endobiotics-targets-xenobiotics" association network., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Spodoptera frugiperda (fall armyworm, FAW) is an invasive polyphagous lepidopteran pest that has developed sophisticated resistance mechanisms involving detoxification enzymes to eliminate toxic compounds it encounters in its diet including insecticides. Although its inventory of detoxification enzymes is known, the mechanisms that enable an adapted response depending on the toxic compound remain largely unexplored. Sf9 cells were used to investigate the role of the transcription factors, Cap n' collar isoform C (CncC) and musculoaponeurotic fibrosarcoma (Maf) in the regulation of the detoxification response. We overexpressed CncC, Maf or both genes, and knocked out (KO) CncC or its repressor Kelch-like ECH associated protein 1 (Keap1). Joint overexpression of CncC and Maf is required to confer increased tolerance to indole 3-carbinol (I3C), a plant secondary metabolite, and to methoprene, an insecticide. Both molecules induce reactive oxygen species (ROS) pulses in the different cell lines. The use of an antioxidant reversed ROS pulses and restored the tolerance to I3C and methoprene. The activity of detoxification enzymes varied according to the cell line. Suppression of Keap1 significantly increased the activity of cytochrome P450s, carboxylesterases and glutathione S-transferases. RNAseq experiments showed that CncC mainly regulates the expression of detoxification genes but is also at the crossroads of several signaling pathways (reproduction and immunity) maintaining homeostasis. We present new data in Sf9 cell lines suggesting that the CncC:Maf pathway plays a central role in FAW response to natural and synthetic xenobiotics. This knowledge helps to better understand detoxification gene expression and may help to design next-generation pest insect control measures., Competing Interests: Declaration of Competing Interest The authors declare no competing interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Candida glabrata is a prominent opportunistic fungal pathogen of humans. The increasing incidence of C. glabrata infections is attributed to both innate and acquired resistance to antifungals. Previous studies suggest the transcription factor Pdr1 and several target genes encoding ABC transporters are critical elements of pleiotropic defense against azoles and other antifungals. This study utilizes Hermes transposon insertion profiling to investigate Pdr1-independent and Pdr1-dependent mechanisms that alter susceptibility to the frontline antifungal fluconazole. Several new genes were found to alter fluconazole susceptibility independent of Pdr1 ( CYB5 , SSK1 , SSK2 , HOG1 , TRP1 ). A bZIP transcription repressor of mitochondrial function ( CIN5 ) positively regulated Pdr1 while hundreds of genes encoding mitochondrial proteins were confirmed as negative regulators of Pdr1. The antibiotic oligomycin activated Pdr1 and antagonized fluconazole efficacy likely by interfering with mitochondrial processes in C. glabrata . Unexpectedly, disruption of many 60S ribosomal proteins also activated Pdr1, thus mimicking the effects of the mRNA translation inhibitors. Cycloheximide failed to fully activate Pdr1 in a cycloheximide-resistant Rpl28-Q38E mutant. Similarly, fluconazole failed to fully activate Pdr1 in a strain expressing a low-affinity variant of Erg11. Fluconazole activated Pdr1 with very slow kinetics that correlated with the delayed onset of cellular stress. These findings are inconsistent with the idea that Pdr1 directly senses xenobiotics and support an alternative hypothesis where Pdr1 senses cellular stresses that arise only after engagement of xenobiotics with their targets. IMPORTANCE Candida glabrata is an opportunistic pathogenic yeast that causes discomfort and death. Its incidence has been increasing because of natural defenses to our common antifungal medications. This study explores the entire genome for impacts on resistance to fluconazole. We find several new and unexpected genes can impact susceptibility to fluconazole. Several antibiotics can also alter the efficacy of fluconazole. Most importantly, we find that Pdr1-a key determinant of fluconazole resistance-is not regulated directly through binding of fluconazole and instead is regulated indirectly by sensing the cellular stresses caused by fluconazole blockage of sterol biosynthesis. This new understanding of drug resistance mechanisms could improve the outcomes of current antifungals and accelerate the development of novel therapeutics., Competing Interests: The authors declare no conflict of interest.

The efficacy of drugs widely varies in individuals, and the gut microbiota plays an important role in this variability. The commensal microbiota living in the human gut encodes several enzymes that chemically modify systemic and orally administered drugs, and such modifications can lead to activation, inactivation, toxification, altered stability, poor bioavailability, and rapid excretion. Our knowledge of the role of the human gut microbiome in therapeutic outcomes continues to evolve. Recent studies suggest the existence of complex interactions between microbial functions and therapeutic drugs across the human body. Therapeutic drugs or xenobiotics can influence the composition of the gut microbiome and the microbial encoded functions. Both these deviations can alter the chemical transformations of the drugs and hence treatment outcomes. In this review, we provide an overview of (i) the genetic ecology of microbially encoded functions linked with xenobiotic degradation; (ii) the effect of drugs on the composition and function of the gut microbiome; and (iii) the importance of the gut microbiota in drug metabolism., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Controlling Rhipicephalus microplus is among the most significant challenges for livestock production worldwide. The indiscriminate use of acaricides stimulates the selection of resistant tick populations and is therefore ineffective. Understanding the molecular foundations of resistance could help inform the search for new alternatives for tick control. Although the ovary has been suggested as a relevant target organ for tick control, there are few existing studies that focus on tick ovarian tissue. Therefore, we conducted a comparative proteomic analysis on ovaries of R. microplus strains with differential resistance to ivermectin. In resistant ticks, we observed the over-accumulation of proteins involved in several biological processes, including translation, proteolysis, transport, cellular organization, differentiation, and xenobiotic detoxification. We also observed the accumulation of many structural and extracellular proteins such as papilin-like protein, which glycosylation increase its stability-based molecular modeling. Therefore, we propose that ovaries of ivermectin-resistant ticks overcome the negative impact of ivermectin through the activation of detoxification mechanisms and structural proteins associated with the remodeling of the ovary's extracellular matrix. SIGNIFICANCE: Understanding the molecular foundation of ivermectin resistance in Rhipicephalus microplus represents an essential step in cattle farming, which could provide clues and alternatives for tick control. Excessive use of chemicals like ivermectin allows the generation of resistant tick strains in different countries. However, limited molecular information is available concerning the tick's resistance to ivermectin. Detailed proteomics scrutiny in various tick organs will provide more comprehensive molecular information. Thus, we conducted an ovary comparative proteomic-based TMT-SPS-MS3 approach. We highlight in ivermectin-resistant ticks the over-accumulation of structural proteins and enzymes connected to detoxification mechanisms., Competing Interests: Declaration of Competing Interest All the authors of this study attest to not having any conflict of interest in publishing this manuscript., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Endogenous estradiol (E2) exerts diverse physiological and pharmacological activities, commonly used for hormone replacement therapy. However, prolonged and excessive exposure to E2 potentially increases estrogenic cancer risk. Reportedly, CYP1 enzyme-mediated biotransformation of E2 is largely concerned with its balance between detoxification and carcinogenic pathways. Among the three key CYP1 enzymes (CYP1A1, CYP1A2, and CYP1B1), CYP1A1 and CYP1A2 mainly catalyze the formation of nontoxic 2-hydroxyestradiol (2-OH-E2), while CYP1B1 specifically catalyzes the formation of genotoxic 4-hydroxyestradiol (4-OH-E2). 4-OH-E2 can be further metabolized to electrophilic quinone intermediates accompanied by the generation of reactive oxygen species (ROS), triggering DNA damage. Since abnormal alterations in CYP1 activities can greatly affect the bioactivation process of E2, regulatory effects of xenobiotics on CYP1s are essential for E2-associated cancer development. To date, thousands of natural and synthetic compounds have been found to show potential inhibition and/or induction actions on the three CYP1 members. Generally, these chemicals share similar planar polycyclic skeletons, the structural motifs and substituent groups of which are important for their inhibitory/inductive efficiency and selectivity toward CYP1 enzymes. This review comprehensively summarizes these known inhibitors and/or inductors of E2-metabolizing CYP1s based on chemical categories and discusses their structure-activity relationships, which would contribute to better understanding of the correlation between xenobiotic-regulated CYP1 activities and estrogenic cancer susceptibility.

The mammalian cytochrome P450 monooxygenase CYP4B1 can bioactivate a wide range of xenobiotics, such as its defining/hallmark substrate 4-ipomeanol leading to tissue-specific toxicities. Similar to other members of the CYP4 family, CYP4B1 has the ability to hydroxylate fatty acids and fatty alcohols. Structural insights into the enigmatic role of CYP4B1 with functions in both, xenobiotic and endobiotic metabolism, as well as its unusual heme-binding characteristics are now possible by the recently solved crystal structures of native rabbit CYP4B1 and the p.E310A variant. Importantly, CYP4B1 does not play a major role in hepatic P450-catalyzed phase I drug metabolism due to its predominant extra-hepatic expression, mainly in the lung. In addition, no catalytic activity of human CYP4B1 has been observed owing to a unique substitution of an evolutionary strongly conserved proline 427 to serine. Nevertheless, association of CYP4B1 expression patterns with various cancers and potential roles in cancer development have been reported for the human enzyme. This review will summarize the current status of CYP4B1 research with a spotlight on its roles in the metabolism of endogenous and exogenous compounds, structural properties, and cancer association, as well as its potential application in suicide gene approaches for targeted cancer therapy.

Background: Saccharolactone is used as a β-glucuronidase inhibitor in in vitro microsomal and recombinant uridine diphosphoglucuronosyl transferases (rUGTs) incubations to enhance glucuronide pathway and, thereby, formation of glucuronide metabolites. We investigated its effect on CYP mediated metabolism of drugs (compound-174, phenacetin and quinidine) using human liver microsomes (HLM) supplemented with Phase-1 and Phase-2 co-factors., Methods: Compounds were incubated in HLM supplemented with co-factors to assess Phase-1 (NADPH) and Phase-2 (NADPH, alamethicin, saccharolactone and UDPGA) metabolism. CYP phenotype assay for compound-174 was conducted in HLM (± 1-ABT) and human recombinant CYP isoforms. CYP inhibition profile of saccharolactone was also generated in HLM., Results: The metabolism of compound-174, phenacetin and quinidine in HLM significantly decreased in reactions containing additional components like alamethicin, saccharolactone and UDPGA and indicated that the addition of saccharolactone inhibited the metabolism. Phenacetin and quinidine are known substrates of CYP1A2 and CYP3A4 isoforms. The metabolism of compound- 174 was significantly inhibited in the presence of 1-ABT in HLM, and CYP3A4 and CYP2C8 isoforms were found to be the predominant isoforms responsible for its metabolism. Further evaluation of CYP inhibition in HLM indicated saccharolactone to be a strong inhibitor of CYP1A2, 2D6, 3A4 and 2C8 isoforms with IC 50 values of less than 4 mM., Conclusion: The findings indicated that saccharolactone being a strong inhibitor of CYP1A2, 2D6, 3A4 and 2C8 isoforms (IC 50 < 4 mM), resulted in significant inhibition of the metabolism of compound-174, phenacetin and quinidine in HLM and caution should be exercised in using it with proper titration of the concentrations., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen, the leading cause of acute and chronic infections in immunocompromised patients, frequently with high morbidity and mortality rates. The xenobiotic response element (XRE) family proteins are the second most common transcriptional regulators (TRs) in P. aeruginosa. However, only a few XRE-like TRs have been reported to regulate multiple bacterial cellular processes, encompassing virulence, metabolism, antibiotic synthesis or resistance, stress responses, and phage infection, etc. Our understanding of what roles these XRE-like small regulatory proteins play in P. aeruginosa remains limited. Here, we aimed to decipher the role of a putative XRE-type transcriptional regulator (designated LfsT) from a prophage region on the chromosome of a clinical P. aeruginosa isolate, P8W. Southern blot and reverse transcription quantitative PCR (RT-qPCR) assays demonstrated that LfsT controlled host sensitivity to the phage PP9W2 and was essential for efficient phage replication. In addition, electrophoretic mobility shift assays (EMSAs) and transcriptional lacZ fusion analyses indicated that LfsT repressed the lysogenic development and promoted the lytic cycle of phage PP9W2 by binding to the promoter regions of the gp71 gene (encoding a CI-like repressor) and several vital phage genes. Combined with RNA-seq and a series of phenotypic validation tests, our results showed that LfsT bound to the flexible palindromic sites within the promoters upstream of several genes in the bacterial genome, regulating fatty acid (FA) metabolism, spermidine (SPD) transport, as well as the type III secretion system (T3SS). Overall, this study reveals novel regulatory roles of LfsT in P. aeruginosa, improving our understanding of the molecular mechanisms behind bacterium-phage interactions. IMPORTANCE This work elucidates the novel roles of a putative XRE family TR, LfsT, in the intricate regulatory systems of P. aeruginosa. We found that LfsT bound directly to the core promoter regions upstream of the start codons of numerous genes involved in various processes, including phage infection, FA metabolism, SPD transport, and the T3SS, regulating as the repressor or activator. The identified partial palindromic motif NAACN(5,8)GTTN recognized by LfsT suggests extensive effects of LfsT on gene expression by maintaining preferential binding to nucleotide sites under evolutionary pressure. In summary, these findings indicate that LfsT enhances metabolic activity in P. aeruginosa, while it reduces host resistance to the phage. This study helps us better understand the coevolution of bacteria and phages (e.g., survival comes at a cost) and provides clues for designing novel antimicrobials against P. aeruginosa infections.

Wildlife is exposed to a wide range of xenobiotics in the natural environment. In order to appropriately assess xenobiotic-induced toxicity in wildlife, it is necessary to understand metabolic capacities. Carnivores, in general, have low metabolic abilities, making them vulnerable to a variety of chemicals. Raccoons (Procyon lotor) in the wild have been found to have high levels of xenobiotics. However, little is known about the metabolic capacity of the cytochrome P450 (CYP) enzymes in this species. Thus, this study used liver samples to investigate the characteristics of CYP enzymes in wild raccoons. In 22 wild raccoons, CYP concentrations in hepatic microsomes were examined. To better understand the properties of CYP-dependent metabolism, in vitro metabolic activity studies were performed using ethoxyresorufin, pentoxyresorufin and testosterone as substrates. In addition, three raccoons were fed commercial dog food in the laboratory for one week, and the effects on CYP-dependent metabolism were investigated. In comparison to other mammalian species, raccoons had very low concentrations of CYP in their livers. In an in vitro enzymatic analysis, raccoons' ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin O-depentylase (PROD) metabolic capacities were less than one-fifth and one-tenth of rats', respectively. These results indicate the possible high risk in raccoons if exposed to high levels of environmental xenobiotics because of their poor CYP activity. In this study, the features of CYP-dependent metabolism in wild raccoons are described for the first time.

Depending on their chemical structure, insecticides enter the insect body either through the cuticle or by ingestion (mode of entry [MoE]), and, naturally, harm or even kill insects through different mechanisms (modes of action). In parallel, they trigger a systemic detoxification response, especially by activation of detoxification gene expression. We monitored the acute genetic alterations of known xenobiotic response target genes against five different insecticides with two most common MoEs (contact toxicity and stomach toxicity), found that: 1. only a few genes were detected responding to acute exposure to insecticides (LD 90 ); 2. The expression of cyp12d1 was upregulated in all experiments, except for dichlorodiphenyltrichloroethane exposure, suggesting that cyp12d1 is a general first response gene of the xenobiotic response; 3. The contact and stomach entries did not show any notable difference, both MoEs induced the response of JNK signaling pathway, possibly serving as the driver of the response of cyp12d1 and a few other genes. In conclusion, the changes in gene expression levels were relatively modest and no significant differences were found between the two MoEs, so the insecticide entry route does not seem to have an impact on the detoxification response. However, the two MoEs of the same insecticide showed different efficiencies in our test. Thus, the study of these two MoEs will help to develop more efficient release and management methods for the use of such insecticides., (© 2022 Wiley Periodicals LLC.)

Zerumbone (ZER) is a phytochemical with antioxidant and antiproliferative properties. This study evaluated the cytoxicity of ZER combined with chemotherapeutic agents and the expression of mRNA genes related to cell cycle, cell death, xenobiotic metabolism, DNA damage, and endoplasmic reticulum (ER) stress in HepG2/C3A cells. ZER was cytotoxic (IC 50 , 44.31 μM). ZER-induced apoptosis was related to BBC3 and ERN1 upregulation (ER stress), and its antiproliferative effects were attributable to MYC, IGF1, and NF-kB mRNA inhibition. ZER-induced G 2 /M arrest and DNA damage was associated with mRNA expression of cell cycle (CDKN1A) and DNA damage (GADD45A) genes. Increased CYP1A2 and CYP2C19 mRNA expression suggested ZER metabolization, and reduced CYP1A1 and CYP2D6 expression indicated a longer time of action of ZER in the cell, enhancing its pharmacological effect. ZER downregulated TP53, PARP1, BIRC5 (apoptosis), and MAP1LC3A (autophagy). In apoptosis assay, the data of the association treatments with ZER suggested antagonism. In cytotoxicity assay, the data of the association treatments with ZER suggested synergism action to cisplatin and antagonism action to doxorubicin and 5-fluorouracil. Thus, ZER has potential for application in chemotherapy as it modulates mRNA targets; however, it may not have the desired efficiency when combined with other chemotherapeutic agents., Competing Interests: Declaration of Competing Interest The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Introduction: Selective serotonin reuptake inhibitors (SSRIs) are commonly used medication for the treatment of depression during pregnancy. Their use may affect various biological molecules such as enzymes which regulate placental hormonal production and xenobiotic metabolism. Our aim was to investigate the effect of maternal SSRI use on activities of three placental enzymes., Methods: We analyzed activities of xenobiotic metabolism enzymes cytochrome P450 1A1 (CYP1A1), aromatase (CYP19A1), and glutathione-S-transferase (GST) from placental microsomal and cytosolic subcellular fractions. Term placentas were collected from 47 SSRI users and 49 control women participating Kuopio Birth cohort (KuBiCo) during the years 2013-2015. Among SSRI users, escitalopram was the most widely used SSRI medication., Results: The mean enzyme activities of all studied enzymes were lower in SSRI users compared to controls. A statistically significant difference was observed in the enzyme activities of CYP19A1 (p = 0.001) and CYP1A1 (p = 0.002) between the study groups after adjusting for use of additional medication, gestational diabetes, sex of the newborn and gestational weeks at delivery. SSRI use had no significant effect on placental GST enzyme activity., Discussion: Our results indicate that SSRI medication alters placental enzyme activities. This may lead disturbances in maternal steroid hormone balance as well as in xenobiotic metabolism and may provide risk for both developing fetus and pregnant women., Competing Interests: Declaration of competing interest None., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Cerebral ischemia (CI) is associated with high global incidence and risk; therefore, its rapid and reliable therapeutic management is essential for protecting patients' lives and improving health. Senkyunolide H (SH) is remarkably effective against phlebosclerosis, oxidation, and apoptosis. Blood-brain barrier is the main obstacle impeding the delivery of drugs and xenobiotics to brain areas. Drugs' loading in nanoparticles can overcome the blood-brain barrier obstacle and thus directly and completely act on brain tissue, and such a loading can also change the half-life of drugs in vivo and lower the dosage requirement of drugs. In this study, we loaded the SH in lipid nanoparticles to improve its delivery to the brain for the therapy of CI. Thus, this study preliminarily analyzed the mechanism of SH-loaded nanoparticles in CI. The SH-loaded lipid nanoparticles were prepared and characterized with electron microscopy and PS potentiometery. The SH-loaded nanoparticles were intraperitoneally administered to CI-induced rats and brain tissue water content, and neuronal apoptosis and autophagy-associated proteins were determined. Our assays revealed SH-loaded nanoparticle's ability to reduce nerve injury and brain tissue water content in rats with CI and inhibit the apoptosis and autophagy of their neuronal cells (NCs). Additionally, under intervention with SH-loaded nanoparticles, P13K/AKT/mTOR pathway-associated proteins in brain tissue of rats decreased. As the assay results showed, SH-loaded nanoparticles can suppress the autophagy of NCs through medicating P13K/AKT/mTOR pathway and lower apoptosis, thus delivering the effect of treating CI. Results of this study indicate SH-loaded nanoparticles as promising strategy for delivery SH to brain areas for treating CI., Competing Interests: The authors declare no competing interests., (Copyright © 2022 Bei Zhao et al.)

Renal tissue plays a crucial function in maintaining homeostasis, making it vulnerable to xenobiotic toxicity. Pueraria montana has more beneficial potential against the various diseases and has long history used as a traditional Chinese medicine. But its effect against the renal cancer not scrutinize. The goal of this study is to see if Pueraria montana can protect rats from developing kidney tumors caused by diethylnitrosamine (DEN) and ferric nitrite (Fe-NTA). Wistar rats was selected for the current study and DEN (use as an inducer) and Fe-NTA (promoter) for induction the renal cancer. For 22 weeks, the rats were given orally Pueraria montana (12.5, 25, and 50 mg/kg) treatment. At regular intervals, the body weight and food intake were calculated. The rats were macroscopically evaluated for identification of cancer in the renal tissue. The renal tumor makers, renal parameters, antioxidant enzymes, phase I and II enzymes, inflammatory cytokines and mediators were estimated at end of the experimental study. Pueraria montana treated rats displayed the suppression of renal tumors, incidence of the tumors along with suppression of tumor percentage. Pueraria montana treated rats significantly (p < 0.001) increased body weight and suppressed the renal weight and food intake. It also reduced the level of renal tumor marker ornithine decarboxylase (ODC) and [3H] thymidine incorporation along with suppression of renal parameter such as uric acid, blood urea nitrogen (BUN), urea and creatinine. Pueraria montana treatment significantly (p < 0.001) altered the level of phase enzymes and antioxidant. Pueraria montana treatment significantly (p < 0.001) repressed the level of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and improved the level of interleukin-10 (IL-10). Pueraria montana treatment suppressed the level of prostaglandin (PGE 2 ), cyclooxygenase-2 (COX-2), nuclear kappa B factor (NF-κB) and transforming growth factor beta 1 (TGF-β1). Pueraria montana suppressed the inflammatory necrosis, size the bowman capsules in the renal histopathology. Pueraria montana exhibited the chemoprotective effect via dual mechanism such as suppression of inflammatory reaction and oxidative stress.

Ficus dubia latex is recognized as a remedy in Asian traditional medicine with various therapeutic effects. The present study aimed to determine the preventive action of Ficus dubia latex extract (FDLE) on 1,2-dimethylhydrazine (DMH)-induced rat colorectal carcinogenesis and its mechanisms. The experiment included an initiation model in which rats were orally administered with FDLE daily for 1 week before DMH injection until the end of the experiment, while only after DMH injection until the end in the post-initiation model. The results firstly indicated that FDLE treatment could reduce the level of methylazoxymethanol (MAM) in rat colonic lumen by inhibition of the activities of both phase I xenobiotic metabolizing enzymes in the liver and β-glucuronidase in the colon, leading to reduced DNA methylation in colonic mucosal cells, related to the number of ACF in the initiation stage. Besides, FDLE modulated the inflammation which could suppress the growth and induce apoptosis of aberrant colonic mucosal cells, leading to retardation of ACF multiplicity. Therefore, FDLE showed the ability to suppress the DMH-induced rat ACF formation and inflammation promoted growth of ACF. In conclusion, FDLE had the potential to prevent carcinogens-induced rat colorectal carcinogenesis in the initiation stage., (© 2022. The Author(s).)

Background: Despite the well-known detrimental effects of cigarette smoke (CS), little is known about the complex gene expression dynamics in the early stages after exposure. This study aims to investigate early transcriptomic responses following CS exposure of airway epithelial cells in culture and compare these to those found in human CS exposure studies., Methods: Primary bronchial epithelial cells (PBEC) were differentiated at the air-liquid interface (ALI) and exposed to whole CS. Bulk RNA-sequencing was performed at 1 h, 4 h, and 24 h hereafter, followed by differential gene expression analysis. Results were additionally compared to data retrieved from human CS studies., Results: ALI-PBEC gene expression in response to CS was most significantly changed at 4 h after exposure. Early transcriptomic changes (1 h, 4 h post CS exposure) were related to oxidative stress, xenobiotic metabolism, higher expression of immediate early genes and pro-inflammatory pathways (i.e., Nrf2, AP-1, AhR). At 24 h, ferroptosis-associated genes were significantly increased, whereas PRKN, involved in removing dysfunctional mitochondria, was downregulated. Importantly, the transcriptome dynamics of the current study mirrored in-vivo human studies of acute CS exposure, chronic smokers, and inversely mirrored smoking cessation., Conclusion: These findings show that early after CS exposure xenobiotic metabolism and pro-inflammatory pathways were activated, followed by activation of the ferroptosis-related cell death pathway. Moreover, significant overlap between these transcriptomic responses in the in-vitro model and human in-vivo studies was found, with an early response of ciliated cells. These results provide validation for the use of ALI-PBEC cultures to study the human lung epithelial response to inhaled toxicants., (© 2022. The Author(s).)

The translational value of high-throughput toxicity testing will depend on pharmacokinetic validation. Yet, popular in vitro airway epithelia models were optimized for structure and mucociliary function without considering the bioactivation or detoxification capabilities of lung-specific enzymes. This study evaluated xenobiotic metabolism maintenance within differentiated air-liquid interface (ALI) airway epithelial cell cultures (human bronchial; human, rhesus, and mouse tracheal), isolated airway epithelial cells (human, rhesus, and mouse tracheal; rhesus bronchial), and ex vivo microdissected airways (rhesus and mouse) by measuring gene expression, glutathione content, and naphthalene metabolism. Glutathione levels and detoxification gene transcripts were measured after 1-h exposure to 80 µM naphthalene (a bioactivated toxicant) or reactive naphthoquinone metabolites. Glutathione and glutathione-related enzyme transcript levels were maintained in ALI cultures from all species relative to source tissues, while cytochrome P450 monooxygenase gene expression declined. Notable species differences among the models included a 40-fold lower total glutathione content for mouse ALI trachea cells relative to human and rhesus; a higher rate of naphthalene metabolism in mouse ALI cultures for naphthalene-glutathione formation (100-fold over rhesus) and naphthalene-dihydrodiol production (10-fold over human); and opposite effects of 1,2-naphthoquinone exposure in some models-glutathione was depleted in rhesus tissue but rose in mouse ALI samples. The responses of an immortalized bronchial cell line to naphthalene and naphthoquinones were inconsistent with those of human ALI cultures. These findings of preserved species differences and the altered balance of phase I and phase II xenobiotic metabolism among the characterized in vitro models should be considered for future pulmonary toxicity testing.

Pentaclethra macroloba (Willd.) Kuntze seeds oil has been used as a topical healing agent, applied mainly to parturients and snake bites. The objective was to investigate the effects of pracaxi oil (POP) on HepG2/C3A cells under cytogenotoxicity, cell cycle and apoptosis influence, and expression of metabolism and other related cell types proliferation genes. Cytotoxicity was analyzed by MTT test and apoptosis and cell cycle interferences by flow cytometry. To identify genotoxicity were used comet and micronucleus tests. RT-qPCR investigated gene expression. PO chemical characterization has shown two significant triterpenes, identified as oleanolic acid and hederagenin. The results showed that the PO did not reduce cell viability at concentrations ranging from 31 to 500 μg/ml. Comet and micronucleus assays revealed the absence of genotoxic effects, and flow cytometry showed no cell cycle or apoptosis disturbance. RT-qPCR indicated that PO up-regulated genes related to metabolism (CYP3A4, CYP1A2, CYP1A1), cell proliferation (mTOR), and oxidative stress (GPX1). The data indicate that PO has no cytogenotoxic effects and suggest that it activated the PI3/AKT/mTOR cascade of cell growth and proliferation. Inside the cells, the PO activated xenobiotic metabolizing genes, responsible for reactive oxygen species (ROS) generation, can neutralize ROS with increased GPX1 gene expression without genetic damage, interruption of the cell cycle, or induction of apoptosis., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The pregnane X receptor (PXR) is a master xenobiotic-sensing receptor in response to toxic byproducts, as well as a key regulator in intermediary lipid metabolism. Therefore, the present study was conducted to investigate the potential role of PXR in mediating the lipid dysregulation and xenobiotic responses under Cu-induced stress in largemouth bass ( Micropterus salmoides ). Four groups of largemouth bass (52.66 ± 0.03 g) were treated with control, Cu waterborne (9.44 μmol/L), Cu+RIF (Rifampicin, 100 mg/kg, PXR activator), and Cu+KET (Ketoconazole, 20 mg/kg, PXR inhibitor) for 48 h. Results showed that Cu exposure significantly elevated the plasma stress indicators and triggered antioxidant systems to counteract Cu-induced oxidative stress. Acute Cu exposure caused liver steatosis, as indicated by the significantly higher levels of plasma triglycerides (TG), lipid droplets, and mRNA levels of lipogenesis genes in the liver. Liver injuries were detected, as shown by hepatocyte vacuolization and severe apoptotic signals after Cu exposure. Importantly, Cu exposure significantly stimulated mRNA levels of PXR, suggesting the response of this regulator in the xenobiotic response. The pharmacological intervention of PXR by the agonist and antagonist significantly altered hepatic mRNA levels of PXR, implying that RIF and KET were effective agents of PXR in largemouth bass. Administration of RIF significantly exacerbated liver steatosis, and such alterations were dependent on the regulations on pparγ and cd36 rather than srebp1 signaling, which suggested that PXR-PPARγ might be another pathway for Cu-induced lipid deposition in fish. Whereas, KET administration showed reverse effects on lipid metabolism as indicated by the lower hepatic TG levels, suppressed mRNA levels of pparγ and cd36 . Activation of PXR stimulated autophagy and inhibited apoptosis, leading to lower hepatic vacuolization; while inhibition of PXR showed higher apoptotic signals, inhibition of autophagic genes and stimulation of apoptotic genes. Taken together, PXR played a cytoprotective role in Cu-induced hepatotoxicity through regulations on autophagy and apoptosis. Overall, our data has demonstrated for the first time on the dual roles of PXR as a co-regulator in mediating xenobiotic responses and lipid metabolism in fish, which implying the potential of PXR as a therapy target for xenobiotics-induced lipid dysregulation and hepatotoxicity., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Li, Gong, Wang, Yu, Tian, Xia, Li, Zhang and Xie.)

Sweet potato leaves (SPL) are a valuable source of phytonutrients with nutritional and various health-promoting benefits. This study evaluated the effects of green and purple SPL supplementation on hepatic xenobiotic-metabolizing enzymes (XME) and membrane transporters, and benzo[ a ]pyrene (B[ a ]P) metabolism and B[ a ]P accumulation in rats. The experiments were conducted in standard and B[ a ]P-treated rat models. The first experiment showed that rats fed a diet containing 5% (w/w) green or purple SPL for two weeks showed increased hepatic activity of cytochrome P-450 (CYP)1A1/1A2 and glutathione S-transferase. Green SPL supplementation also increased the CYP2C, CYP2D and CYP3A and multidrug resistance-associated protein 2 levels in the liver. Notably, green and purple SPL induced nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 protein expression and reduced oxidative stress in the liver. The second experiment was to evaluate the effects of green and purple SPL supplementation on B[ a ]P metabolism and B[ a ]P accumulation in rats. Rats were fed SPL diets (the same as experiment I) for two weeks. When rats were exposed to a single dose (25 mg per kg BW) of B[ a ]P, green SPL had no effect on B[ a ]P-induced elevation of CYP1A1 activity but induced GST activity in the intestinal mucosa and the liver. Green SPL also increased hepatic UDP-glucuronosyltransferase activity and reduced B[ a ]P levels in the plasma, liver, and intestinal mucosa. A lower plasma 8-hydroxy-2'-deoxyguanosine level was found after B[ a ]P treatment only in the green SPL group. This study suggests that, in the standard rat model, green and purple SPL may increase Nrf2-mediated antioxidant activity and facilitate the xenobiotic detoxification process by increasing hepatic XME and transporters. When exposed to B[ a ]P, however, only green SPL consumption may increase hepatic B[ a ]P metabolism and lower the B[ a ]P level in the liver by increasing phase II detoxifying enzyme activities.

The concept of hepatic induction of drug-metabolizing cytochrome P450s (P450s) by xenobiotics, including therapeutic drugs, was proposed in the early 1960s. A polycyclic aromatic hydrocarbon and phenobarbital have been the two major inducers used to investigate this induction mechanism. Currently, the mechanisms mediated by aryl hydrocarbon receptor and constitutive androstane receptor are well-established. In addition to mammals, insects and fungi also express P450s and induce them following exposure to insecticides. These inductions may have environmental consequences. Finding the molecular mechanism regulating these inductions will be of major interest in the future. SIGNIFICANCE STATEMENT: This paper summarizes present and future of investigations into induction of drug-metabolizing enzymes., (Copyright © 2022 by The American Society for Pharmacology and Experimental Therapeutics.)

Activation of constitutive androstane receptor (CAR) transcription factor by xenobiotics promotes hepatocellular proliferation, promotes hypertrophy without liver injury, and induces drug metabolism genes. Previous work demonstrated that lymphocyte-specific protein-1 (LSP1), an F-actin binding protein and gene involved in human hepatocellular carcinoma, suppresses hepatocellular proliferation after partial hepatectomy. The current study investigated the role of LSP1 in liver enlargement induced by chemical mitogens, a regenerative process independent of tissue loss. 1,4-Bis [2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP), a direct CAR ligand and strong chemical mitogen, was administered to global Lsp1 knockout and hepatocyte-specific Lsp1 transgenic (TG) mice and measured cell proliferation, hypertrophy, and expression of CAR-dependent drug metabolism genes. TG livers displayed a significant decrease in Ki-67 labeling and liver/body weight ratios compared with wild type on day 2. Surprisingly, this was reversed by day 5, due to hepatocyte hypertrophy. There was no difference in CAR-regulated drug metabolism genes between wild type and TG. TG livers displayed increased Yes-associated protein (YAP) phosphorylation, decreased nuclear YAP, and direct interaction between LSP1 and YAP, suggesting LSP1 suppresses TCPOBOP-driven hepatocellular proliferation, but not hepatocyte volume, through YAP. Conversely, loss of LSP1 led to increased hepatocellular proliferation on days 2, 5, and 7. LSP1 selectively suppresses CAR-induced hepatocellular proliferation, but not drug metabolism, through the interaction of LSP1 with YAP, supporting the role of LSP1 as a selective growth suppressor., (Copyright © 2022 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Lipofuscin is a representative biomarker of aging that is generated naturally over time. Remofuscin (soraprazan) improves age-related eye diseases by removing lipofuscin from retinal pigment epithelium (RPE) cells. In this study, the effect of remofuscin on longevity in Caenorhabditis elegans and the underlying mechanism were investigated. The results showed that remofuscin significantly (p < 0.05) extended the lifespan of C. elegans (N2) compared with the negative control. Aging biomarkers were improved in remofuscin-treated worms. The expression levels of genes related to lysosomes (lipl-1 and lbp-8), a nuclear hormone receptor (nhr-234), fatty acid beta-oxidation (ech-9), and xenobiotic detoxification (cyp-34A1, cyp-35A1, cyp-35A2, cyp-35A3, cyp-35A4, cyp-35A5, cyp-35C1, gst-28, and gst-5) were increased in remofuscin-treated worms. Moreover, remofuscin failed to extend the lives of C. elegans with loss-of-function mutations (lipl-1, lbp-8, nhr-234, nhr-49, nhr-8, cyp-35A1, cyp-35A2, cyp-35A3, cyp-35A5, and gst-5), suggesting that these genes are associated with lifespan extension in remofuscin-treated C. elegans. In conclusion, remofuscin activates the lysosome-to-nucleus pathway in C. elegans, thereby increasing the expression levels of xenobiotic detoxification genes resulted in extending their lifespan., (© 2022. The Author(s).)

Scope: CYP3A4 is the most important drug-metabolizing enzyme regulated via the vitamin D receptor (VDR) in the intestine. However, less is known about VDR in the regulation of CYP3A4 and other drug-metabolizing enzymes in the liver., Methods and Results: This study investigates whether 1α,25-dihydroxyvitamin D 3 (1α,25(OH) 2 D 3 ) regulates major cytochrome P450 enzymes, selected phase I and II enzymes, and transporters involved in xenobiotic and steroidal endobiotic metabolism in 2D and 3D cultures of human hepatocytes. The authors found that 1α,25(OH) 2 D 3 increases hepatic CYP3A4 expression and midazolam 1'-hydroxylation activity in 2D hepatocytes. The results are confirmed in 3D spheroids, where 1α,25(OH) 2 D 3 has comparable effect on CYP3A4 mRNA expression as 1α-hydroxyvitamin D 3 , an active vitamin D metabolite. Other regulated genes such as CYP1A2, AKR1C4, SLC10A1, and SLCO4A1 display only mild changes in mRNA levels after 1α,25(OH) 2 D 3 treatment in 2D hepatocytes. Expression of other cytochrome P450, phase I and phase II enzyme, or transporter genes are not significantly influenced by 1α,25(OH) 2 D 3 . Additionally, the effect of VDR activation on CYP3A4 mRNA expression is abolished by natural dietary compound sulforaphane, a common suppressor of pregnane X receptor (PXR) and constitutive androstane receptor (CAR)., Conclusion: This study proposes that VDR or vitamin D supplementation is unlikely to significantly influence liver detoxification enzymes apart from CYP3A4., (© 2022 Wiley-VCH GmbH.)

Eugenol, a plant-derived component possessing small side effects, has an insecticidal activity to Tribolium castaneum; however, the underlying molecular mechanisms of eugenol acting on T. castaneum are currently unclear. Here, a nerve conduction carboxylesterase and a detoxifying glutathione S-transferase were significantly inhibited after eugenol exposure, resulting in the paralysis or death of beetles. Then, RNA-sequencing of eugenol-exposed and control samples identified 362 differentially expressed genes (DEGs), containing 206 up-regulated and 156 down-regulated genes. RNA-seq data were validated further by qRT-PCR. GO analysis revealed that DEGs were associated with 1308 GO terms of which the most enriched GO terms were catalytic activity, and integral component of membrane; KEGG pathway analysis showed that these DEGs were distributed in 151 different pathways, of which some pathways associated with metabolism of xenobiotics or drug were significantly enriched, which indicated that eugenol most likely disturbed the processes of metabolism, and detoxication. Moreover, several DEGs including Hexokinase type 2, Isocitrate dehydrogenase, and Cytochrome b-related protein, might participate in the respiratory metabolism of eugenol-exposed beetles. Some DEGs encoding CYP, UGT, GST, OBP, CSP, and ABC transporter were involved in the xenobiotic or drug metabolism pathway, which suggested that these genes of T. castaneum participated in the response to eugenol exposure. Additionally, TcOBPC11/ TcGSTs7, detected by qRT-PCR and RNA-interference against these genes, significantly increased the mortality of eugenol-treated T. castaneum, providing further evidence for the involvement of OBP/GST in eugenol metabolic detoxification in T. castaneum. These results aid eugenol insecticidal mechanisms and provide the basis of insect control., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The gastrointestinal tract (GIT) is exposed to xenobiotics, including drugs, through both: local (oral) and systemic routes. Despite the advances in drug discovery and in vitro pre-clinical models, there is a lack of appropriate translational models to distinguish the impact of these routes of exposure. Changes in intestinal permeability has been observed in different gastrointestinal and systemic diseases. This study utilized one such xenobiotic, arsenic, to which more than 200 million people around the globe are exposed via their food, drinking water, work environment, soil, and air. The purpose of this study was to establish an in vitro model to mimic gastrointestinal tract exposure to xenobiotics via oral or intravenous routes. To achieve this, we compared the route (mimicking oral and intravenous exposure to GIT and the dose response (using threshold approach) of trivalent and pentavalent inorganic arsenic species on the permeability of in vitro cultured polarized T84 cells, an example of intestinal epithelial cells. Arsenic treatment to polarized T84 cells via the apical and basolateral compartment of the trans-well system reflected oral or intravenous routes of exposure in vivo, respectively. Sodium arsenite, sodium arsenate, dimethyl arsenic acid sodium salt (DMA V ), and disodium methyl arsonate hydrate (MMA V ) were assessed for their effects on intestinal permeability by measuring the change in trans-epithelial electrical resistance (TEER) of T-84 cells. Polarized T-84 cells exposed to 12.8 µM of sodium arsenite from the basolateral side showed a marked reduction in TEER. Cytotoxicity of sodium arsenite, as measured by release of lactate dehydrogenase (LDH), was increased when cells were exposed via the basolateral side. The mRNA expression of genes related to cell junctions in T-84 cells was analyzed after exposure with sodium arsenite for 72 h. Changes in TEER correlated with mRNA expression of focal-adhesion-, tight-junction- and gap-junction-related genes (upregulation of Jam2, Itgb3 and Notch4 genes and downregulation of Cldn2, Cldn3, Gjb1, and Gjb2) . Overall, exposure to sodium arsenite from the basolateral side was found to have a differential effect on monolayer permeability and on cell-junction-related genes as compared to apical exposure. Most importantly, this study established a preclinical human-relevant in vitro translational model to assess the changes in permeability and cytotoxicity during exposure, mimicking oral or intravenous routes.

In vitro evolution and whole genome analysis were used to comprehensively identify the genetic determinants of chemical resistance in Saccharomyces cerevisiae. Sequence analysis identified many genes contributing to the resistance phenotype as well as numerous amino acids in potential targets that may play a role in compound binding. Our work shows that compound-target pairs can be conserved across multiple species. The set of 25 most frequently mutated genes was enriched for transcription factors, and for almost 25 percent of the compounds, resistance was mediated by one of 100 independently derived, gain-of-function SNVs found in a 170 amino acid domain in the two Zn 2 C 6 transcription factors YRR1 and YRM1 (p < 1 × 10 -100 ). This remarkable enrichment for transcription factors as drug resistance genes highlights their important role in the evolution of antifungal xenobiotic resistance and underscores the challenge to develop antifungal treatments that maintain potency., (© 2022. The Author(s).)

Cytochrome P450 enzymes (CYPs) that metabolize xenobiotics are expressed and active in the brain. These CYPs contribute to the metabolism of many centrally acting compounds, including clinically used drugs, drugs of abuse, and neurotoxins. Although CYP levels are lower in the brain than in the liver, they may influence central substrate and metabolite concentrations, which could alter resulting centrally-mediated responses to these compounds. Additionally, xenobiotic metabolizing CYPs are highly variable due to genetic polymorphisms and regulation by endogenous and xenobiotic molecules. In the brain, these CYPs are sensitive to xenobiotic induction. As a result, CYPs in the brain vary widely, including among humans, and this CYP variation may influence central metabolism and resulting response to centrally acting compounds. It has been demonstrated, using experimental manipulation of CYP activity in vivo selectively within the brain, that CYP metabolism in the brain alters central substrate and metabolite concentrations, as well as drug response and neurotoxic effects. This suggests that variability in xenobiotic metabolizing CYPs in the human brain may meaningfully contribute to individual differences in response to, and effects of, centrally acting drugs and neurotoxins. This chapter will provide an overview of CYP expression in the brain, endogenous- and xenobiotic-mediated CYP regulation, and the functional impact of CYP-mediated metabolism of drugs and neurotoxins in the brain, with a focus on experimental approaches in mice, rats, and non-human primates, and a discussion regarding the potential role of xenobiotic metabolizing CYPs in the human brain., Competing Interests: Conflict of interest R.F.T has consulted for Quinn Emanuel and Ethismos Research Inc on unrelated topics. M.R.S has no conflicts to declare., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Environmental factors including diet, sedentary lifestyle and exposure to pollutants largely influence human health throughout life. Cellular and molecular events triggered by an exposure to environmental pollutants are extremely variable and depend on the age, the chronicity and the doses of exposure. Only a fraction of all relevant mechanisms involved in the onset and progression of pathologies in response to toxicants has probably been identified. Mitochondria are central hubs of metabolic and cell signaling responsible for a large variety of biochemical processes, including oxidative stress, metabolite production, energy transduction, hormone synthesis, and apoptosis. Growing evidence highlights mitochondrial dysfunction as a major hallmark of environmental insults. Here, we present mitochondria as crucial organelles for healthy metabolic homeostasis and whose dysfunction induces critical adverse effects. Then, we review the multiple mechanisms of action of pollutants causing mitochondrial toxicity in link with chronic diseases. We propose the Aryl hydrocarbon Receptor (AhR) as a model of "exposome receptor", whose activation by environmental pollutants leads to various toxic events through mitochondrial dysfunction. Finally, we provide some remarks related to mitotoxicity and risk assessment.

The routes of uptake and efflux should be considered when developing new drugs so that they can effectively address their intracellular targets. As a general rule, drugs appear to enter cells via protein carriers that normally carry nutrients or metabolites. A previously developed pipeline that searched for drug transporters using Saccharomyces cerevisiae mutants carrying single-gene deletions identified import routes for most compounds tested. However, due to the redundancy of transporter functions, we propose that this methodology can be improved by utilizing double mutant strains in both low- and high-throughput screens. We constructed a library of over 14,000 strains harboring double deletions of genes encoding 122 nonessential plasma membrane transporters and performed low- and high-throughput screens identifying possible drug import routes for 23 compounds. In addition, the high-throughput assay enabled the identification of putative efflux routes for 21 compounds. Focusing on azole antifungals, we were able to identify the involvement of the myo- inositol transporter, Itr1p, in the uptake of these molecules and to confirm the role of Pdr5p in their export. IMPORTANCE Our library of double transporter deletion strains is a powerful tool for rapid identification of potential drug import and export routes, which can aid in determining the chemical groups necessary for transport via specific carriers. This information may be translated into a better design of drugs for optimal absorption by target tissues and the development of drugs whose utility is less likely to be compromised by the selection of resistant mutants.

Severe outcomes of COVID-19 are associated with pathological response of the immune system to the SARS-CoV-2 infection. Emerging evidence suggests that an interaction may exist between COVID-19 pathogenesis and a broad range of xenobiotics, resulting in significant increases in death rates in highly exposed populations. Therefore, a better understanding of the molecular basis of the interaction between SARS-CoV-2 infection and chemical exposures may open opportunities for better preventive and therapeutic interventions. We attempted to gain mechanistic knowledge on the interaction between SARS-CoV-2 infection and chemical exposures using an in silico approach, where we identified genes and molecular pathways affected by both chemical exposures and SARS-CoV-2 in human immune cells (T-cells, B-cells, NK-cells, dendritic, and monocyte cells). Our findings demonstrate for the first time that overlapping molecular mechanisms affected by a broad range of chemical exposures and COVID-19 are linked to IFN type I/II signaling pathways and the process of antigen presentation. Based on our data, we also predict that exposures to various chemical compounds will predominantly impact the population of monocytes during the response against COVID-19.

Arthropod Glutathione S-transferases (GSTs) constitute a large family of multifunctional enzymes that are mainly associated with xenobiotic or stress adaptation. GST-mediated xenobiotic adaptation takes place through direct metabolism or sequestration of xenobiotics, and/or indirectly by providing protection against oxidative stress induced by xenobiotic exposure. To date, the roles of GSTs in xenobiotic adaptation in the Colorado potato beetle (CPB), a notorious agricultural pest of plants within Solanaceae, have not been well studied. Here, we functionally expressed and characterized an unclassified-class GST, LdGSTu1. The three-dimensional structure of the LdGSTu1 was solved with a resolution up to 1.8 Å by X-ray crystallography. The signature motif VSDGPPSL was identified in the "G-site", and it contains the catalytically active residue Ser14. Recombinant LdGSTu1 was used to determine enzyme activity and kinetic parameters using 1-chloro-2, 4-dinitrobenzene (CDNB), GSH, p-nitrophenyl acetate (PNA) as substrates. The enzyme kinetic parameters and enzyme-substrate interaction studies demonstrated that LdGSTu1 could catalyze the conjugation of GSH to both CDNB and PNA, with a higher turnover number for CDNB than PNA. The LdGSTu1 enzyme inhibition assays demonstrated that the enzymatic conjugation of GSH to CDNB was inhibited by multiple pesticides, suggesting a potential function of LdGSTu1 in xenobiotic adaptation.

The genus Spodoptera (Lepidoptera: Noctuidae) comprises some of the most polyphagous and destructive agricultural pests worldwide. The success of many species of this genus is due to their striking abilities to adapt to a broad range of host plants. Superfamilies of detoxification genes play a crucial role in the adaption to overcome plant defense mechanisms mediated by numerous secondary metabolites and toxins. Over the past decade, a substantial amount of expression data in Spodoptera larvae was produced for those genes in response to xenobiotics such as plant secondary metabolites, but also insecticide exposure. However, this information is scattered throughout the literature and in most cases does not allow to clearly identify candidate genes involved in host-plant adaptation and insecticide resistance. In the present review, we analyzed and compiled information on close to 600 pairs of inducers (xenobiotics) and induced genes from four main Spodoptera species: S. exigua, S. frugiperda, S. littoralis and S. litura. The cytochrome P450 monooxygenases (P450s; encoded by CYP genes) were the most upregulated detoxification genes across the literature for all four species. Most of the data was provided from studies on S. litura, followed by S. exigua, S. frugiperda and S. littoralis. We examined whether these detoxification genes were reported for larval survival under xenobiotic challenge in forward and reverse genetic studies. We further analyzed whether biochemical assays were carried out showing the ability of corresponding enzymes and transporters to breakdown and excrete xenobiotics, respectively. This revealed a clear disparity between species and the lack of genetic and biochemical information in S. frugiperda. Finally, we discussed the biological importance of detoxification genes for this genus and propose a workflow to study the involvement of these enzymes in an ecological and agricultural context., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The blood-brain barrier (BBB) is a physical structure whose main function is to strictly regulate access to circulating compounds into the central nervous system (CNS). Vegetable-derived phenolic compounds have been widely studied, with numerous epidemiologic and interventional studies confirming their health-related bioactivities across multiple cells, organs and models. Phenolics are non-essential xenobiotics, and should theoretically be unable to cross the BBB. The present work summarizes current experimental evidence that reveals that not only are phenolic compounds able to cross the BBB and bioaccumulate in the brain, but there is some stereoselectivity, which suggests the presence of specific transporters that allow them to reach the brain. Some molecules cross the BBB intact, while others do so only after being biotransformed or metabolized elsewhere. Once inside the CNS, they prevent or counter oxidative stress, which maintains the molecular, cellular, structural and functional integrity of the brain, and subsequently, overall human health.

Candida albicans is a leading human fungal pathogen, which can cause superficial infections or life-threatening systemic disease in immunocompromised individuals. The ability to transition between yeast and filamentous forms is a major virulence trait of C. albicans, and a key regulator of this morphogenetic transition is the molecular chaperone Hsp90. To explore the mechanisms governing C. albicans morphogenesis in response to Hsp90 inhibition, we performed a functional genomic screen using the gene replacement and conditional expression collection to identify mutants that are defective in filamentation in response to the Hsp90 inhibitor, geldanamycin. We found that transcriptional repression of genes involved in mitochondrial function blocked filamentous growth in response to the concentration of the Hsp90 inhibitor used in the screen, and this was attributable to increased resistance to the compound. Further exploration revealed that perturbation of mitochondrial function reduced susceptibility to two structurally distinct Hsp90 inhibitors, geldanamycin and radicicol, such that filamentous growth was restored in the mitochondrial mutants by increasing the compound concentration. Deletion of two representative mitochondrial genes, MSU1 and SHY1, enhanced cellular efflux and reduced susceptibility to diverse intracellularly acting compounds. Additionally, screening a C. albicans efflux pump gene deletion library implicated Yor1 in the efflux of geldanamycin and Cdr1, in the efflux of radicicol. Deletion of these transporter genes restored sensitivity to Hsp90 inhibitors in MSU1 and SHY1 homozygous deletion mutants, thereby enabling filamentation. Taken together, our findings suggest that mitochondrial dysregulation elevates cellular efflux and consequently reduces susceptibility to xenobiotics in C. albicans., (© The Author(s) 2021. Published by Oxford University Press on behalf of Genetics Society of America. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The mussel Mytilus galloprovincialis is one of the most important aquaculture species in Europe. Its main production problem is the accumulation of toxins during coastal blooms, which prevents mussel commercialization. P-glycoprotein (ABCB1/MDR1/P-gp) is part of the multixenobiotic resistance system in aquatic organisms, and okadaic acid, the main DSP toxin, is probably a substrate of the P-gp-mediated efflux. In this study, the presence and possible role of P-gp in the okadaic acid detoxification process was studied in M. galloprovincialis . We identified, cloned, and characterized two complete cDNAs of mdr1 and mdr2 genes. MgMDR1 and MgMDR2 predicted proteins had the structure organization of ABCB full transporters, and were identified as P-gp/MDR/ABCB proteins. Furthermore, the expression of mdr genes was monitored in gills, digestive gland, and mantle during a cycle of accumulation-elimination of okadaic acid. Mdr1 significantly increased its expression in the digestive gland and gills, supporting the idea of an important role of the MDR1 protein in okadaic acid efflux out of cells in these tissues. The expression of M. galloprovincialis mrp2 , a multidrug associated protein (MRP/ABCC), was also monitored. As in the case of mdr1 , there was a significant induction in the expression of mrp2 in the digestive gland, as the content of okadaic acid increased. Thus, P-gp and MRP might constitute a functional defense network against xenobiotics, and might be involved in the resistance mechanisms to DSP toxins.

Human bodies encompass very important symbiotic and mutualistic relationships with tiny creatures known as microbiota. Trillions of these tiny creatures including protozoa, viruses, bacteria, and fungi are present in and on our bodies. They play important roles in various physiological mechanisms of our bodies. In return, our bodies provide them with the habitat and food necessary for their survival. In this review, we comprehend the gut microbial species present in various regions of the gut. We can get benefits from microbiota only if they are present in appropriate concentrations, as if their concentration is altered, it will lead to dysbiosis of microbiota which further contributes to various health ailments. The composition, diversity, and functionality of gut microbiota do not remain static throughout life as they keep on changing over time. In this review, we also reviewed the various biotic and abiotic factors influencing the quantity and quality of these microbiota. These factors serve a significant role in shaping the gut microbiota population., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2021 Haseeb Anwar et al.)

Rice bran oil (RBO) comprises various nutrients and phytochemicals which exhibit several health benefits. There are no studies regarding the functional effects of different colours of RBO. This study was aimed to compare the constituents and antioxidant activities of white rice bran oil (WRBO) and coloured rice bran oil (CRBO). Each RBO showed similar free fatty acid profiles. However, greater amounts of vitamin E, phytosterols, carotenoids, and chlorophylls were found in CRBO, which had lower γ -oryzanol content than WRBO. Oxidative stress was induced in male mice by an overdose of acetaminophen (APAP) at 300 mg/kg body weight. The mice were then fed with RBO at the equivalent dose to 100 mg/kg body weight of γ -oryzanol three hours later and sacrificed six hours after APAP treatment. The administration of 100 mg γ -oryzanol equivalent in CRBO ameliorated APAP-induced hepatotoxicity in mice more strongly than 100 mg γ -oryzanol equivalent in WRBO, as evidenced by the significant reduction of serum ALT, hepatocellular necrosis, and hepatic lipid peroxidation. CRBO could improve xenobiotic-metabolizing and antioxidant enzyme activities, including glutathione S -transferase, superoxide dismutase, glutathione peroxidase, and glutathione reductase, and also increase mRNA expression of various antioxidant-responsive genes. Vitamin E, phytosterols, carotenoids, and chlorophyll might be the protective compounds in CRBO that alleviate APAP-induced hepatotoxicity through the interruption of APAP metabolism and the activation of antioxidant systems at both transcriptional and enzymatic levels. These findings might provide a protective role of CRBO on oxidative stress associated with several degenerative diseases., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2021 Warunyoo Phannasorn et al.)

Mechanism-based inactivation (MBI) refers to the metabolic bioactivation of a xenobiotic by cytochrome P450s to a highly reactive intermediate which subsequently binds to the enzyme and leads to the quasi-irreversible or irreversible inhibition. Xenobiotics, mainly drugs with specific functional units, are the major sources of MBI. Two possible consequences of MBI by medicinal compounds are drug-drug interaction and severe toxicity that are observed and highlighted by clinical experiments. Today almost all of these latent functional groups (e.g., thiophene, furan, alkylamines, etc.) are known, and their features and mechanisms of action, owing to the vast experimental and theoretical studies, are determined. In the past decade, molecular modeling techniques, mostly density functional theory, have revealed the most feasible mechanism that a drug undergoes by P450 enzymes to generate a highly reactive intermediate. In this review, we provide a comprehensive and detailed picture of computational advances toward the elucidation of the activation mechanisms of various known groups with MBI activity. To this aim, we briefly describe the computational concepts to carry out and analyze the mechanistic investigations, and then, we summarize the studies on compounds with known inhibition activity including thiophene, furan, alkylamines, terminal acetylene, etc. This study can be reference literature for both theoretical and experimental (bio)chemists in several different fields including rational drug design, the process of toxicity prevention, and the discovery of novel inhibitors and catalysts.

The liver is an important organ and plays a key role in the regulation of metabolism and in the secretion, storage, and detoxification of endogenous and exogenous substances. The impact of food and nutrition on the pathophysiological mechanisms of liver injury represents a great controversy. Several environmental factors including food and micronutrients are involved in the pathogenesis of liver damage. Conversely, some xenobiotics and micronutrients have been recognized to have a protective effect in several liver diseases. This paper offers an overview of the current knowledge on the role of xenobiotics and micronutrients in liver damage.

Humans are chronically exposed to mixtures of xenobiotics referred to as endocrine-disrupting chemicals (EDCs). A vast body of literature links exposure to these chemicals with increased incidences of reproductive, metabolic, or neurological disorders. Moreover, recent data demonstrate that, when used in combination, chemicals have outcomes that cannot be predicted from their individual behavior. In its heterodimeric form with the retinoid X receptor (RXR), the pregnane X receptor (PXR) plays an essential role in controlling the mammalian xenobiotic response and mediates both beneficial and detrimental effects. Our previous work shed light on a mechanism by which a binary mixture of xenobiotics activates PXR in a synergistic fashion. Structural analysis revealed that mutual stabilization of the compounds within the ligand-binding pocket of PXR accounts for the enhancement of their binding affinity. In order to identify and characterize additional active mixtures, we combined a set of cell-based, biophysical, structural, and in vivo approaches. Our study reveals features that confirm the binding promiscuity of this receptor and its ability to accommodate bipartite ligands. We reveal previously unidentified binding mechanisms involving dynamic structural transitions and covalent coupling and report four binary mixtures eliciting graded synergistic activities. Last, we demonstrate that the robust activity obtained with two synergizing PXR ligands can be enhanced further in the presence of RXR environmental ligands. Our study reveals insights as to how low-dose EDC mixtures may alter physiology through interaction with RXR-PXR and potentially several other nuclear receptor heterodimers., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

Breast Cancer Resistance Protein (BCRP) is an efflux transporter responsible for causing multidrug resistance (MDR). It is known to expel many potent antineoplastic drugs, owing to its efflux function. Efflux of chemotherapeutics because of BCRP develops resistance to many drugs, leading to failure in cancer treatment. BCRP plays an important role in physiology by protecting the organism from xenobiotics and other toxins. It is a half-transporter affiliated to the ATP- binding cassette (ABC) superfamily of transporters, encoded by the gene ABCG2 and functions in response to adenosine triphosphate (ATP). Regulation of BCRP expression is critically controlled at molecular levels, which help in maintaining the balance of xenobiotics and nutrients inside the body. Expression of BCRP can be found in brain, liver, lung cancers and acute myeloid leukemia (AML). Moreover, it is also expressed at high levels in stem cells and many cell lines. This frequent expression of BCRP has an impact on the treatment procedures and, if not scrutinized, may lead to the failure of many cancer therapies., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

The cytosolic sulfotransferase (SULT) enzymes are found in human liver, kidney, intestine, and other tissues. These enzymes catalyze the transfer of the -SO 3 group from 3'-phospho-adenosyl-5'-phosphosulfate (PAPS) to a nucleophilic hydroxyl or amine group in a drug substrate. SULTs are stable as dimers, with a highly conserved dimerization domain near the C-terminus of the protein. Crystal structures have revealed flexible loop regions in the native proteins, one of which, located near the dimerization domain, is thought to form a gate that changes position once PAPS is bound to the PAPS-binding site and modulates substrate access and enzyme properties. There is also evidence that oxidation and reduction of certain cysteine residues reversibly regulate the binding of the substrate and PAPS or PAP to the enzyme thus modulating sulfonation. Because SULT enzymes have two substrates, the drug and PAPS, it is common to report apparent kinetic constants with either the drug or the PAPS varied while the other is kept at a constant concentration. The kinetics of product formation can follow classic Michaelis-Menten kinetics, typically over a narrow range of substrate concentrations. Over a wide range of substrate concentrations, it is common to observe partial or complete substrate inhibition with SULT enzymes. This chapter describes the function, tissue distribution, structural features, and properties of the human SULT enzymes and presents examples of enzyme kinetics with different substrates., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)