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Aim: Bile acids are suggested to be involved in the antidiarrhetic effect of Goreisan (GRS). This study aimed to investigate the effect of GRS on fecal bile acid levels and composition of the gut microbiota in mice. Correlation analysis was employed to identify the potential gut microbiota associated with the alterations in fecal bile acid levels induced by GRS. Methods: Male C57BL/6 mice were fed a diet supplemented with GRS water extract for 4 weeks. Feces and cecal contents were collected from the mice to determine bile acid levels and analyze bacterial composition. Results: GRS administration significantly increased the levels of fecal secondary bile acids, including ω‐muricholic acid (MCA), hyodeoxycholic acid (HDCA), and lithocholic acid (LCA). In contrast, the levels of primary bile acids, such as β‐MCA, cholic acid (CA), and chenodeoxycholic acid (CDCA) showed a marked decrease. Further analysis revealed a positive correlation between the relative abundance of Alloprevotella, Dehalobacterium PAC001221, and Eubacterium g23 and fecal levels of ωMCA, HDCA, and LCA. Conclusions: GRS was suggested to promote the formation of fecal secondary bile acids in mice, possibly through the enhancement of bacterial 7β‐dehydroxylation and 6β‐epimerization activities. These changes may be involved in the antidiarrhetic action of GRS. Concurrent evaluation of fecal bile acids and gut microbiota presents a promising approach for elucidating the novel mechanisms underlying the effects of kampo formulations, particularly in modulating the microbial metabolism of intestinal bile acids. [ABSTRACT FROM AUTHOR]

BackgroundAlterations in the gut microbiome have been associated with HIV infection, but the relative impact of HIV versus other factors on the gut microbiome has been difficult to determine in cross-sectional studies.MethodsTo address this, we examined the gut microbiome, serum metabolome, and cytokines longitudinally within 27 individuals before and during acute HIV using samples collected from several ongoing cohort studies. Matched control participants (n=28) from the same cohort studies without HIV but at similar behavioral risk were used for comparison.FindingsWe identified few changes in the microbiome during acute HIV infection, but did find alterations in serum metabolites involving secondary bile acid (lithocholate sulfate, glycocholenate sulfate) and amino acid metabolism (3-methyl-2-oxovalerate, serine, cysteine, N-acetylputrescine). Greater microbiome differences, including decreased Bacteroides spp and increased Megasphaera elsdenii, were seen when comparing pre-HIV infection visits to matched at-risk controls. Those who acquired HIV also had elevated inflammatory cytokines (TNF-α, B cell activating factor, IL-8) and bioactive lipids (palmitoyl-sphingosine-phosphoethanolamide and glycerophosphoinositol) prior to HIV acquisition compared to matched controls.InterpretationLongitudinal sampling identified pre-existing microbiome differences in participants with acute HIV compared to matched control participants observed over the same period. These data highlight the importance of increasing understanding of the role of the microbiome in HIV susceptibility.FundingThis work was supported by NIH/NIAID (K08AI124979; P30AI117943), NIH/NIDA (U01DA036267; U01DA036939; U01DA036926; U24DA044554), and NIH/NIMH (P30MH058107; R34MH105272).

Simple Summary: Bile acids (BAs) are compounds made by the liver that act within the intestinal lumen to aid fat digestion. These molecules are also important signals for the intestinal immune system. Primary BAs (e.g., cholic acid) are converted via intestinal bacteria to secondary BAs (e.g., lithocholic acid). The balance between these two classes of BAs is disrupted in dogs with chronic enteropathy, but the impact on gut immunity is unknown. Changes in diet and antibiotic treatment also disrupt gut luminal BAs by altering gut bacterial populations. Primary and secondary BAs are known from studies in other species to exert different effects on innate immune responses, but their role in canine immunity has not been explored. Therefore, we conducted studies to elucidate the effects of primary and secondary BAs on macrophage immune responses in dogs, with the goal of exploring their possible roles in intestinal immunity. We found some shared and some divergent effects of primary versus secondary BAs on canine macrophages. Our findings suggest that the secondary BAs play the dominant role in regulating GI inflammation in dogs. Bile acids (BA) are important metabolites secreted into the intestinal lumen and impacted by luminal microbes and dietary intake. Prior studies in humans and rodents have shown that BAs are immunologically active and that primary and secondary BAs have distinct immune properties. Therefore, the composition of the gut BA pool may influence GI inflammatory responses. The current study investigated the relative immune modulatory properties of primary (cholic acid, CA) and secondary BAs (lithocholic acid, LCA) by assessing their effects on canine macrophage cytokine secretion and BA receptor (TGR5) expression. In addition, RNA sequencing was used to further interrogate how CA and LCA differentially modulated macrophage responses to LPS (lipopolysaccharide). We found that exposure to either CA or LCA influenced LPS-induced cytokine production via macrophages similarly, with suppression of TNF-α secretion and enhancement of IL-10 secretion. Neither BA altered the expression of the BA receptor TGR5. Transcriptomic analysis revealed that CA activated inflammatory signaling pathways in macrophages involving type II interferon signaling and the aryl hydrocarbon receptor, whereas LCA activated pathways related to nitric oxide signaling and cell cycle regulation. Thus, we concluded that both primary and secondary BAs are active modulators of macrophage responses in dogs, with differential and shared effects evident with sequencing analysis. [ABSTRACT FROM AUTHOR]

ABSTRACTChronic alcohol consumption, an important risk factor for diseases and deaths, can cause intestinal microbiota dysbiosis and increase the infection of some opportunistic pathogens. However, the current studies on the effects of alcohol-induced intestinal microbiota dysbiosis on gut colonization of Klebsiella pneumoniae are still scarce. In the present study, we established a binge-on-chronic alcohol model in mice to identify the characteristics of alcohol-induced intestinal microbiome and metabolite dysbiosis using multi-omics and explored the effects and potential mechanisms of these dysbioses on the intestinal colonization of K. pneumoniae. The results show that chronic alcohol consumption alters the diversity and composition of gut microbiota (including bacteria and fungi), decreases the complexity of the interaction between intestinal bacteria and fungi, disturbs the gut metabolites, and promotes the colonization of K. pneumoniae on the gut of mice. The relevance analyses find that alcohol-induced gut microbiome dysbiosis has a strong correlation with the alteration of secondary bile acids. In vitro results suggest that the high concentration of lithocholic acid, a secondary bile acid, could significantly inhibit the proliferation of K. pneumoniae, and the adhesion of K. pneumoniae to Caco-2 cells. Our results indicate that alcohol-induced microbiome dysbiosis contributes to decreased levels of secondary bile acids, which was one of the main reasons affecting the colonization of K. pneumoniae in mice’s intestines. Some secondary bile acids (e.g., lithocholic acid) might be a potential drug to prevent the colonization and spread of K. pneumoniae.IMPORTANCEAlcohol is one of the most commonly misused substances in our lives. However, long-term heavy drinking will increase the colonization of some opportunistic pathogens (e.g., Klebsiella pneumoniae) in the body. Here, we revealed that binge-on-chronic alcohol consumption disrupted the balance between gut bacteria and fungi, induced the gut microbiome and metabolites dysbiosis, and promoted the colonization of K. pneumoniae in the intestine of mice. In particular, alcohol-taking disrupted intestinal bile acid metabolism and reduced the lithocholic acid concentration. However, a high concentration of lithocholic acid can protect against intestinal colonization of K. pneumoniae by inhabiting the bacterial growth and adhesion to the host cell. Hence, regulating the balance of gut microbiota and intestinal bile acid metabolism may be a potential strategy for reducing the risk of K. pneumoniae infection and spread.

The microbiota modulates gut immune homeostasis. Bacteria influence the development and function of host immune cells, including T helper cells expressing interleukin-17A (TH17 cells). We previously reported that the bile acid metabolite 3-oxolithocholic acid (3-oxoLCA) inhibits TH17 cell differentiation1. Although it was suggested that gut-residing bacteria produce 3-oxoLCA, the identity of such bacteria was unknown, and it was unclear whether 3-oxoLCA and other immunomodulatory bile acids are associated with inflammatory pathologies in humans. Here we identify human gut bacteria and corresponding enzymes that convert the secondary bile acid lithocholic acid into 3-oxoLCA as well as the abundant gut metabolite isolithocholic acid (isoLCA). Similar to 3-oxoLCA, isoLCA suppressed TH17 cell differentiation by inhibiting retinoic acid receptor-related orphan nuclear receptor-γt, a key TH17-cell-promoting transcription factor. The levels of both 3-oxoLCA and isoLCA and the 3α-hydroxysteroid dehydrogenase genes that are required for their biosynthesis were significantly reduced in patients with inflammatory bowel disease. Moreover, the levels of these bile acids were inversely correlated with the expression of TH17-cell-associated genes. Overall, our data suggest that bacterially produced bile acids inhibit TH17 cell function, an activity that may be relevant to the pathophysiology of inflammatory disorders such as inflammatory bowel disease.

Abstract Background Insulin has been reported to exhibit anti-inflammatory activities in the context of bowel inflammation. However, the role of the interaction between insulin and the microbiota in gut health is unclear. Our goal was to investigate the mechanism of action of insulin in bowel inflammation and the relationship between insulin and the gut microbiota. Methods We used acute and chronic murine models of inflammatory bowel disease (IBD) to evaluate whether insulin influences the progression of colitis. Colonic tissues, the host metabolome and the gut microbiome were analyzed to investigate the relationship among insulin treatment, the microbiome, and disease. Experiments involving antibiotic (Abx) treatment and fecal microbiota transplantation (FMT) confirmed the association among the gut microbiota, insulin and IBD. In a series of experiments, we further defined the mechanisms underlying the anti-inflammatory effects of insulin. Results We found that low-dose insulin treatment alleviated intestinal inflammation but did not cause death. These effects were dependent on the gut microbiota, as confirmed by experiments involving Abx treatment and FMT. Using untargeted metabolomic profiling and 16S rRNA sequencing, we discovered that the level of the secondary bile acid lithocholic acid (LCA) was notably increased and the LCA levels were significantly associated with the abundance of Blautia, Enterorhadus and Rumi-NK4A214_group. Furthermore, LCA exerted anti-inflammatory effects by activating a G-protein-coupled bile acid receptor (TGR5), which inhibited the polarization of classically activated (M1) macrophages. Conclusion Together, these data suggest that insulin alters the gut microbiota and affects LCA production, ultimately delaying the progression of IBD. Graphical Abstract

Averrhoa bilimbi L., (Belimbing wuluh), is traditionally used for various antidiabetic, anti-larvicidal, antioxidant, hypoallergenic, antibacterial, antifungal, and anti-inflammatory treatments. This study evaluated 3 extracts (n-hexane, ethyl acetate, and n-butanol) isolated from starfruit flowers for antidiabetic effects using in vitro and in silico methods. Ethyl acetate extract showed the highest activity, followed by n-hexane and n-butanol extracts in inhibiting α-glucosidase. Each extract has an IC50 value of 89.84, 52.88, and 114.86 µg/mL. The active compounds contained in the ethyl acetate extract were determined using LCMS, and the compounds with the highest retention time were identified as tautomycetin (8.585) and lithocholic acid (8.993). Tautomycetin and lithocholic acid showed promising results in the in silico test. The computational predictions showed that tautomycetin (-6.2 kcal/mol) and lithocholic acid (-10.0 kcal/mol) have better binding affinity values than miglitol (-5.4 kcal/mol). This is the first time the antidiabetic test of starfruit flower extract has been carried out. [ABSTRACT FROM AUTHOR]

Background: Insulin has been reported to exhibit anti-inflammatory activities in the context of bowel inflammation. However, the role of the interaction between insulin and the microbiota in gut health is unclear. Our goal was to investigate the mechanism of action of insulin in bowel inflammation and the relationship between insulin and the gut microbiota. Methods: We used acute and chronic murine models of inflammatory bowel disease (IBD) to evaluate whether insulin influences the progression of colitis. Colonic tissues, the host metabolome and the gut microbiome were analyzed to investigate the relationship among insulin treatment, the microbiome, and disease. Experiments involving antibiotic (Abx) treatment and fecal microbiota transplantation (FMT) confirmed the association among the gut microbiota, insulin and IBD. In a series of experiments, we further defined the mechanisms underlying the anti-inflammatory effects of insulin. Results: We found that low-dose insulin treatment alleviated intestinal inflammation but did not cause death. These effects were dependent on the gut microbiota, as confirmed by experiments involving Abx treatment and FMT. Using untargeted metabolomic profiling and 16S rRNA sequencing, we discovered that the level of the secondary bile acid lithocholic acid (LCA) was notably increased and the LCA levels were significantly associated with the abundance of Blautia, Enterorhadus and Rumi-NK4A214_group. Furthermore, LCA exerted anti-inflammatory effects by activating a G-protein-coupled bile acid receptor (TGR5), which inhibited the polarization of classically activated (M1) macrophages. Conclusion: Together, these data suggest that insulin alters the gut microbiota and affects LCA production, ultimately delaying the progression of IBD. [ABSTRACT FROM AUTHOR]

Less-calcaemic vitamin D receptor (VDR) agonists have the potential to promote osteoblast maturation in a bone regenerative setting. The emergence of lithocholic acid (LCA) as a bona fide VDR agonist holds promise as an adjunct for arthroplasty following reports that it was less calcaemic than calcitriol (1,25D). However, LCA and some earlier derivatives, e.g., LCA acetate, had to be used at much higher concentrations than 1,25D to elicit comparable effects on osteoblasts. However, recent developments have led to the generation of far more potent LCA derivatives that even outperform the efficacy of 1,25D. These new compounds include the cyanoamide derivative, Dcha-150 (also known as AY2-79). In light of this significant development, we sought to ascertain the ability of Dcha-150 to promote human osteoblast maturation by monitoring alkaline phosphatase (ALP) and osteocalcin (OC) expression. The treatment of MG63 cells with Dcha-150 led to the production of OC. When Dcha-150 was co-administered with lysophosphatidic acid (LPA) or an LPA analogue, a synergistic increase in ALP activity occurred, with Dcha-150 showing greater potency compared to 1,25D. We also provide evidence that this synergy is likely attributed to the actions of myocardin-related transcription factor (MRTF)–serum response factor (SRF) gene transcription following LPA-receptor-induced cytoskeletal reorganisation. [ABSTRACT FROM AUTHOR]

Lithocholic acid (LCA) is a classical secondary bile acid formed by the metabolism of gut microbiota. The TGR5 receptor (also known as G protein-coupled receptor 1, GPBAR1) is an important bile acid membrane receptor that mediates a variety of metabolic processes in vivo. In recent years, most studies have focused on the role of bile acid receptors in the intestine and liver. However, there are few reports on its effect on skeletal muscle regeneration, and the specific mechanism remains unclear. Therefore, it is necessary to investigate the mechanism of the TGR5 receptor in the regulation of skeletal muscle regeneration. The results demonstrate that muscle injection with LCA significantly reduces the necrosis rate of injured muscle and improves muscle injury. Moreover, treatment of C2C12 cells with LCA significantly increases AKT/mTOR/FoxO3 phosphorylation through the TGR5 receptor, enhances MyoG transcription and reduces FBXO32 transcription. These findings indicate that LCA can activate the TGR5/AKT signaling pathway, inhibit protein degradation and promote protein synthesis to enhance the myogenic process and promote skeletal muscle regeneration.

In the current study, the conjugate of 3-oxo-lithocholic acid with N-methylpiperazine and paraform was synthesized using the Mannich reaction and evaluated for antiviral activity. This modification resulted in a dramatic increase of antiviral activity combined with a two-fold decrease of toxicity. Together, these effects led to a strong increase of selectivity of compound (SI = 40 vs. 3 for 3 and 2, correspondingly). [ABSTRACT FROM AUTHOR]

Bile acids (BAs) as cholesterol-derived molecules play an essential role in some physiological processes such as nutrient absorption, glucose homeostasis and regulation of energy expenditure. They are synthesized in the liver as primary BAs such as cholic acid (CA), chenodeoxycholic acid (CDCA) and conjugated forms. A variety of secondary BAs such as deoxycholic acid (DCA) and lithocholic acid (LCA) and their derivatives is synthesized in the intestine through the involvement of various microorganisms. In addition to essential physiological functions, BAs and their metabolites are also involved in the differentiation and functions of innate and adaptive immune cells such as macrophages (Macs), dendritic cells (DCs), myeloid derived suppressive cells (MDSCs), regulatory T cells (Treg), Breg cells, T helper (Th)17 cells, CD4 Th1 and Th2 cells, CD8 cells, B cells and NKT cells. Dysregulation of the BAs and their metabolites also affects development of some diseases such as inflammatory bowel diseases. We here summarize recent advances in how BAs and their metabolites maintain gut and systemic homeostasis, including the metabolism of the BAs and their derivatives, the role of BAs and their metabolites in the differentiation and function of immune cells, and the effects of BAs and their metabolites on immuneassociated disorders. [ABSTRACT FROM AUTHOR]

Background: Sensorineural hearing loss has been associated with oxidative stress. However, an antioxidant that passes effectively through the ear remains elusive. Method: Probucol (PB)-based nanoparticles were formed using a spray-drying encapsulation technique, characterized and tested in vitro. Results: Uniform, spherical nanoparticles were produced. The addition of lithocholic acid to PB formulations did not affect drug content or production yield, but it did modify capsule size, surface tension, electrokinetic stability and drug release. Cell viability, bioenergetics and inflammatory profiles were improved when auditory cells were exposed to PB-based nanoparticles, which showed antioxidant properties (p < 0.05). Conclusion: PB-based nanoparticles can potentially protect the auditory cell line from oxidative stress and could be used in future in vivo studies as a potential new therapeutic agent for sensorineural hearing loss. Oxidative stress is an imbalance of cellular processes in which the production of free radicals outweighs the cellular defense mechanism. The association of oxidative stress with the pathophysiology of sensorineural hearing loss (SHL) is well established. SHL development is associated with chronic damage in the structure of the inner ear or auditory nerve. Therefore, potent antioxidants such as probucol could be one way to prevent or treat SHL. However, due to its isolated position, SHL is challenging to treat, imposing a desperate need for refining existing therapeutic methods; one way to do this is by optimizing the formulation using nanoparticles. We aimed to design a novel, stable formulation of PB using polymers and excipients to develop nanoparticles and examine the efficiency of these formulations on the HEI-OC1 stress cell line. We found that the prepared nanoparticle is robust and stable and protects HEI-OC1 from cellular toxicity and oxidative stress. It could be a novel therapeutic agent to treat or prevent SHL. [ABSTRACT FROM AUTHOR]

Key points Efficient procedures for production and regeneration of Gibberella zeae protoplasts were determined. Fungal mutants were obtained with elevated 7β-hydroxylase activity. Mutant G. zeae M23 almost fully converts LCA (4 g/L) to UDCA.

Three groups of bile acid derivatives with acetylenic moieties, such as propargyl, hex-5-ynoyl, and 4,7,10,13-tetraoxahexadec-15-ynoyl ones, were obtained. The cytotoxic activity of the synthesized compounds against hepatocellular carcinoma (HepG2, Huh7), prostate cancer (PC3), and human embryonic kidney (HEK293) cell lines was studied. The parameters enabling estimation of the total lipophilicity of the synthesized bile acid derivatives (logP, TPSA) were calculated. The correlation between the cytotoxic activity and hydrophilic-lipophilic balance of the synthesized compounds was determined. A physicochemical mechanism for the cytotoxic action of bile acid derivatives is proposed. [ABSTRACT FROM AUTHOR]

Bile acids are major components of bile; they emulsify dietary lipids for efficient digestion and absorption and act as signaling molecules that activate nuclear and membrane receptors. The vitamin D receptor (VDR) is a receptor for the active form of vitamin D and lithocholic acid (LCA), a secondary bile acid produced by the intestinal microflora. Unlike other bile acids that enter the enterohepatic circulation, LCA is poorly absorbed in the intestine. Although vitamin D signaling regulates various physiological functions, including calcium metabolism and inflammation/immunity, LCA signaling remains largely unknown. In this study, we investigated the effect of the oral administration of LCA on colitis in a mouse model using dextran sulfate sodium (DSS). Oral LCA decreased the disease activity of colitis in the early phase, which is a phenotype associated with the suppression of histological injury, such as inflammatory cell infiltration and goblet cell loss. These protective effects of LCA were abolished in VDR-deleted mice. LCA decreased the expression of inflammatory cytokine genes, but this effect was at least partly observed in VDR-deleted mice. The pharmacological effect of LCA on colitis was not associated with hypercalcemia, an adverse effect induced by vitamin D compounds. Therefore, LCA suppresses DSS-induced intestinal injury in its action as a VDR ligand. [ABSTRACT FROM AUTHOR]

In the current study, the conjugate of 3-oxo-lithocholic acid with N-methylpiperazine and paraform was synthesized using the Mannich reaction and evaluated for antiviral activity. This modification resulted in a dramatic increase of antiviral activity combined with a two-fold decrease of toxicity. Together, these effects led to a strong increase of selectivity of compound (SI = 40 vs. 3 for 3 and 2, correspondingly).

Bile acids (BA) are important metabolites secreted into the intestinal lumen and impacted by luminal microbes and dietary intake. Prior studies in humans and rodents have shown that BAs are immunologically active and that primary and secondary BAs have distinct immune properties. Therefore, the composition of the gut BA pool may influence GI inflammatory responses. The current study investigated the relative immune modulatory properties of primary (cholic acid, CA) and secondary BAs (lithocholic acid, LCA) by assessing their effects on canine macrophage cytokine secretion and BA receptor (TGR5) expression. In addition, RNA sequencing was used to further interrogate how CA and LCA differentially modulated macrophage responses to LPS (lipopolysaccharide). We found that exposure to either CA or LCA influenced LPS-induced cytokine production via macrophages similarly, with suppression of TNF-α secretion and enhancement of IL-10 secretion. Neither BA altered the expression of the BA receptor TGR5. Transcriptomic analysis revealed that CA activated inflammatory signaling pathways in macrophages involving type II interferon signaling and the aryl hydrocarbon receptor, whereas LCA activated pathways related to nitric oxide signaling and cell cycle regulation. Thus, we concluded that both primary and secondary BAs are active modulators of macrophage responses in dogs, with differential and shared effects evident with sequencing analysis.

Chu-Yun Cheng,1 Guan-Yin Zeng,1 Tong Wang,1 Yan-Hua Su,1 Feng-Dan Xu,2 Hong Luo,1 Hui-Ting Zhong,1 Xiu-Lan Chen1 1Department of Obstetrics, Dongguan Eighth People’s Hospital (Dongguan Children’s Hospital), Dongguan, Guangdong, 523325, People’s Republic of China; 2Department of Neonatal Clinic, Dongguan Eighth People’s Hospital (Dongguan Children’s Hospital), Dongguan, Guangdong, 523325, People’s Republic of ChinaCorrespondence: Chu-Yun Cheng, Department of Obstetrics, Dongguan Eighth People’s Hospital (Dongguan children’s Hospital), No. 68, West Lake 3rd Road, Shilong Town, Dongguan, Guangdong, 523325, People’s Republic of China, Tel +86 13688988412, Email chChu-Yun@126.comObjective: This study aimed to investigate the ability of serum cholic acid (CA) and lithocholic acid (LCA) in the diagnosis and perinatal prognosis assessment of intrahepatic cholestasis of pregnancy (ICP), and the relationship between both indicators and hypoxia-inducible factor-1α (HIF-1α).Methods: Between March 2020 and March 2021, pregnant women with high levels of total bile acid (TBA) in the late pregnancy with TBA ≥ 10 μmol/L and TBA < 10 μmol/L (control group) were included for the retrospective study. Those with TBA ≥ 10 μmol/L were divided into the ICP group and the asymptomatic hypercholanaemia of pregnancy (AHP) group based on ICP symptoms. The comparison of the bile acid profiles, the receiver operating characteristic (ROC) curve analysis, and Pearson correlation analysis were conducted successively.Results: Nine types of bile acids were significantly higher in ICP and AHP than in the control group, while CA and LCA serum levels in the AHP group were significantly lower than those in the ICP group (P < 0.05). The ROC curve analysis showed that LCA, CA, and LCA+CA were all diagnostic indicators for ICP, and LCA+CA displayed the greatest diagnostic value (area under the curve (AUC), 0.923). Subgroup analysis using the LCA+CA cut-off point (3.28 μmol/L) as the subgroup indicator proved that the incidence of adverse perinatal outcomes and the placental HIF-1α positivity were significantly higher in the high LCA+CA group than in the low LCA+CA group (P < 0.05). Pearson correlation analysis revealed significant positive correlations of HIF-1α expression levels to LCA, CA and LCA+CA (r = 0.473, 0.537, 0.619, respectively. P < 0.05 in all).Conclusion: This study confirmed that CA and LCA have a predictive diagnostic value for ICP in pregnant women, and the combined evaluation is associated with adverse perinatal outcomes, and LCA+CA positively correlates to placental HIF-1α expression levels.Keywords: cholic acid, lithocholic acid, intrahepatic cholestasis of pregnancy, hypoxia-inducible factor-1&#x03B1

Background: Bile acids can regulate liver disease progression by affecting the functions of gut microbiota and immune cells. As the most potent natural agonist of G-protein coupled bile acid receptor 5 (TGR5) (expressed in macrophages, HSCs, and monocytes), lithocholic acid (LCA) has multiple functions, such as inhibiting inflammation and regulating metabolism. Therefore, this study aims to investigate the effects of LCA on immune cells and HSCs in liver fibrosis. Methods: A liver fibrosis mouse model was induced by carbon tetrachloride followed by gavage of LCA, and the effects of LCA were evaluated by serum biochemical analysis, liver histology, and western bolt. Plasma cytokine levels and the number of immune cells were determined by cytometric bead array and flow cytometry, respectively. Results: LCA could inhibit the activation of HSCs by inducing apoptosis and reducing the activation of transforming growth factor-β (TGF-β) Smad-dependent and Smad-independent pathways. Meanwhile, LCA inhibited glycolysis and promoted oxidative phosphorylation, leading to the differentiation of macrophages to M2 type and inhibiting their differentiation to M1 type. Furthermore, LCA increased the recruitment of NK cells and reduced the activation of NKT cells. However, these effects of LCA were attenuated after antibiotics reduced the diversity and abundance of the gut microbiota. Conclusions: Gut microbiota and LCA exerted synergistic anti-inflammatory effects on liver fibrosis. The combined intervention of gut microbiota and LCA will be a new strategy for treating liver fibrosis. [ABSTRACT FROM AUTHOR]

[Display omitted] In the study, we aimed to investigate the activity of nanoformulations containing 5-fluorouracil and polymer-magnetic hybrids bearing membrane-penetrating and ligand-receptor-recognizing agents against colorectal cancer cells. The formation and characterization of iron oxide particles covered with polymeric shells comprising lithocholic acid and folic acid moieties are presented. The efficiency of nanoformulations combined by the simple mixing of low doses of 5-fluorouracil with the obtained hybrids was demonstrated against DLD-1 and HT-29 colon cancer cells. The most pronounced cytotoxic potential against HT-29 cells was observed in the cases of particles based on block and randomly arranged copolymers functionalized by FA motifs with depletion of viable cells by approximately 50 % compared to control cells and cells treated by 5-FU applied in free form. In the case of the DLD-1 cell line, the percentage of viable DLD-1 cells decreased by about 30 to 40% after treatment with the block and randomly arranged copolymer decorated by FA-moiety, when compared to 5-FU at the free form and the untreated control. The induction of apoptosis associated with PS-translocation was determined to be the main mechanism of their cytotoxic effects. Moreover, the safety profiles of the nanoformulations were established through hemolysis assay and the analysis of the viability of human colorectal fibroblasts. It was indicated that all tested nanoparticles met the compatibility requirements at the in vitro level. It should be emphasized that in many cases, there was a significant improvement in the compatibility of hybrids with the FA motif compared to non-functionalized hybrids with the addition of 5-FU. These findings suggest that the presence of FA might modulate the toxicity of chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

OleP is a bacterial cytochrome P450 involved in oleandomycin biosynthesis as it catalyzes regioselective epoxidation on macrolide intermediates. OleP has recently been reported to convert lithocholic acid (LCA) into murideoxycholic acid through a highly regioselective reaction and to unspecifically hydroxylate testosterone (TES). Since LCA and TES mainly differ by the substituent group at the C17, here we used X-ray crystallography, equilibrium binding assays, and molecular dynamics simulations to investigate the molecular basis of the diverse reactivity observed with the two steroids. We found that the differences in the structure of TES and LCA affect the capability of these molecules to directly form hydrogen bonds with N-terminal residues of OleP internal helix I. The establishment of these contacts, by promoting the bending of helix I, fosters an efficient trigger of the open-to-closed structural transition that occurs upon substrate binding to OleP and contributes to the selectivity of the subsequent monooxygenation reaction. [Display omitted] • Crystal structures of OleP in complex with steroids were determined • Binding to lithocholic acid efficiently activates the closure of the OleP active site • The C17 substituent in steroids affects the selectivity of the OleP reaction OleP is a cytochrome P450 epoxygenase involved in oleandomycin biosynthesis, and it also hydroxylates lithocholic acid and testosterone. By combining X-ray crystallography, binding assays, and molecular dynamics simulations, Costanzo et al. found that the C17 substituent group of steroids influences the structural transition and reaction selectivity of OleP. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that, in addition to a loss of tolerance, bile acid (BA) modulates the natural history of primary biliary cholangitis (PBC). We focused on the impacts of dietary changes on the immunopathology of PBC, along with alterations in BA composition and gut microbiota. In this study, we have taken advantage of our unique PBC model, a Cyp2c70/Cyp2a12 double knockout (DKO), which includes a human-like BA composition, and develops progressive cholangitis following immunization with the PDC-E2 mimic, 2-octynoic acid (2OA). We compared the effects of a ten-week high-fat diet (HFD) (60 % kcal from fat) and a normal diet (ND) on 2OA-treated DKO mice. Importantly, we report that 2OA-treated DKO mice fed HFD had significantly exacerbated cholangitis, leading to cirrhosis, with increased hepatic expression of Th1 cytokines/chemokines and hepatic fibrotic markers. Serum lithocholic acid (LCA) levels and the ratio of chenodeoxycholic acid (CDCA)-derived BAs to cholic acid-derived BAs were significantly increased by HFD. This was also associated with downregulated expression of key regulators of BA synthesis, including Cyp8b1 , Cyp3a11 , and Sult2a1. In addition, there were increases in the relative abundances of Acetatifactor and Lactococcus and decreases in Desulfovibrio and Lachnospiraceae_NK4A136_group , which corresponded to the abundances of CDCA and LCA. In conclusion, HFD and HFD-induced alterations in the gut microbiota modulate BA composition and nuclear receptor activation, leading to cirrhotic change in this murine PBC model. These findings have significant implications for understanding the progression of human PBC. • High-fat diet (HFD) intake exacerbated cholangitis, affecting cirrhotic change, in mice with a human-like hydrophobic bile acid (BA) composition immunized with 2-octynoic acid. • Alterations in BA composition and the gut microbiota due to HFD intake affected the pathogenesis of autoimmune cholangitis in this murine model. • Chronic overnutrition may be a well-defined factor with clinical implications in patients with primary biliary cholangitis (PBC). • Our new murine model is valuable for elucidating the pathogenesis of PBC. [ABSTRACT FROM AUTHOR]

Lithocholic acid (LCA), a secondary bile acid, has emerged as a potential early diagnostic biomarker for various liver diseases. In this study, we introduce a novel near-infrared (NIR) polymethine dye-based biosensor, capable of sensitive and selective detection of LCA in phosphate buffer and artificial urine (AU) solutions. The detection mechanism relies on the formation of J-aggregates resulting from the interplay of 3,3-Diethylthiatricarbocyanine iodide (DiSC 2 (7)) dye molecules and LCA, which induces a distinctive red shift in both absorption and fluorescence spectra. The biosensor demonstrates a detection limit for LCA of 70 μM in PBS solution (pH 7.4), while in AU solution, it responds to an LCA concentration as low as ∼60 μM. Notably, the proposed biosensor exhibits outstanding selectivity for LCA, effectively distinguishing it from common interferents such as uric acid, ascorbic acid, and glucose. This rapid, straightforward, and cost-effective spectrometer-based method underscores its potential for early diagnosis of liver diseases by monitoring LCA concentrations. [ABSTRACT FROM AUTHOR]

Bariatric surgical procedures such as sleeve gastrectomy (SG) provide effective type 2 diabetes (T2D) remission in human patients. Previous work demonstrated that gastrointestinal levels of the bacterial metabolite lithocholic acid (LCA) are decreased after SG in mice and humans. Here, we show that LCA worsens glucose tolerance and impairs whole-body metabolism. We also show that taurodeoxycholic acid (TDCA), which is the only bile acid whose concentration increases in the murine small intestine post-SG, suppresses the bacterial bile acid-inducible (bai) operon and production of LCA both in vitro and in vivo. Treatment of diet-induced obese mice with TDCA reduces LCA levels and leads to microbiome-dependent improvements in glucose handling. Moreover, TDCA abundance is decreased in small intestinal tissue from T2D patients. This work reveals that TDCA is an endogenous inhibitor of LCA production and suggests that TDCA may contribute to the glucoregulatory effects of bariatric surgery. [Display omitted] • LCA is a metabolic toxin that impairs glucose tolerance • TDCA suppresses the bai operon and inhibits bacterial production of LCA • TDCA treatment improves glucose tolerance in a microbiome-dependent manner • Small intestinal TDCA abundance is decreased in diabetic patients Sleeve gastrectomy decreases the bacterial production of LCA. Chen, Chaudhari et al. show that LCA impairs glucose tolerance and whole-body metabolism. Sleeve gastrectomy increases small intestinal levels of TDCA, which suppresses bacterial bai operon expression and LCA production. TDCA treatment improves glucose regulation in a microbiome-dependent manner. [ABSTRACT FROM AUTHOR]

Less-calcaemic vitamin D receptor (VDR) agonists have the potential to promote osteoblast maturation in a bone regenerative setting. The emergence of lithocholic acid (LCA) as a bona fide VDR agonist holds promise as an adjunct for arthroplasty following reports that it was less calcaemic than calcitriol (1,25D). However, LCA and some earlier derivatives, e.g., LCA acetate, had to be used at much higher concentrations than 1,25D to elicit comparable effects on osteoblasts. However, recent developments have led to the generation of far more potent LCA derivatives that even outperform the efficacy of 1,25D. These new compounds include the cyanoamide derivative, Dcha-150 (also known as AY2-79). In light of this significant development, we sought to ascertain the ability of Dcha-150 to promote human osteoblast maturation by monitoring alkaline phosphatase (ALP) and osteocalcin (OC) expression. The treatment of MG63 cells with Dcha-150 led to the production of OC. When Dcha-150 was co-administered with lysophosphatidic acid (LPA) or an LPA analogue, a synergistic increase in ALP activity occurred, with Dcha-150 showing greater potency compared to 1,25D. We also provide evidence that this synergy is likely attributed to the actions of myocardin-related transcription factor (MRTF)–serum response factor (SRF) gene transcription following LPA-receptor-induced cytoskeletal reorganisation.

Previously-designed amphiphilic scorpion-like macromolecule (AScM) nanoparticles (NPs) showed elevated potency to counteract oxidized low-density lipoprotein (oxLDL) uptake in atherosclerotic macrophages, but failed to ameliorate oxLDL-induced inflammation. We designed a new class of composite AScMs incorporating lithocholic acid (LCA), a natural agonist for the TGR5 receptor that is known to counteract atherosclerotic inflammation, with two complementary goals: to simultaneously decrease lipid uptake and inhibit pro-inflammatory cytokine secretion by macrophages. LCA was conjugated to AScMs for favorable interaction with TGR5 and was also hydrophobically modified to enable encapsulation in the core of AScM-based NPs. Conjugates were formulated into negatively charged NPs with different core/shell combinations, inspired by the negative charge on oxLDL to enable competitive interaction with scavenger receptors (SRs). NPs with LCA-containing shells exhibited reduced sizes, and all NPs lowered oxLDL uptake to

Background: Hepatic sarcopenia is one of many complications associated with chronic liver disease (CLD) and has a high mortality rate; however, the liver-muscle axis is not fully understood. Therefore, few effective treatments exist for hepatic sarcopenia, the best of which being branched-chain amino acid (BCAA) supplementation to help increase muscle mass. Our aim was to investigate the molecular mechanism(s) of hepatic sarcopenia focused on bile acid (BA) composition. Methods: The correlation between serum BA levels and psoas muscle mass index (PMI) was examined in 73 CLD patients. Gastrocnemius muscle phenotype and serum BA levels were assessed in CLD rats treated with BCAA. Mouse skeletal muscle cells (C2C12) were incubated with lithocholic acid (LCA), G-protein-coupled receptor 5 (TGR5) agonist or TGR5 antagonist to assess skeletal muscle hypertrophy. Results: In human CLD, serum LCA levels were the sole factor positively correlated with PMI and were significantly decreased in both the low muscle mass group and the deceased group. Serum LCA levels were also shown to predict patient survival. Gastrocnemius muscle weight significantly increased in CLD rats treated with BCAA via suppression of protein degradation pathways, coupled with a significant increase in serum LCA levels. LCA treated C2C12 hypertrophy occurred in a concentration-dependent manner linked with TGR5-Akt pathways based upon inhibition results via a TGR5 antagonist. Conclusions: Our results indicate LCA-mediated skeletal muscle hypertrophy via activation of TGR5-IGF1-Akt signaling pathways. In addition, serum LCA levels were associated with skeletal muscle mass in cirrhotic rats, as well as CLD patients, and predicted overall patient survival. Funding: This research was supported by JSPS KAKENHI Grant Number 22K08011 and 21H02892, and AMED under Grant Number JP21fk0210090 and JP22fk0210115. Maintaining cirrhotic rats were partially supported by Otsuka Pharmaceutical Company.

Simple Summary: Vitamin D3 is mainly synthesized in the skin after exposure to sunlight and plays a fundamental role in the absorption of calcium and phosphate. Lithocholic acid increases intestinal calcium absorption in vitamin D-deficient rats. The plateau zokor, which lives underground throughout its life, and plateau pika are unique animal species on the Qinghai-Tibet Plateau. To investigate how animals that are rarely exposed to sunlight deal with the expected deficit in vitamin D3 levels and the effect of hypoxia on vitamin D3 metabolism, the levels of key biomarkers related to vitamin D3 metabolism, and the mRNA and protein levels of enzymes involved in key pathways were measured. Plateau zokor was deficient in vitamin D3 and has a higher level of lithocholic acid, but its calcium levels were within the normal range. The levels of vitamin D3 and the expression levels of vitamin D3 metabolism-related genes CYP2R1 and CYP27B1 decreased with increasing altitude in plateau pika. Plateau zokor was deficient in vitamin D3, and lithocholic acid appears to substitute it. In addition, hypoxia suppresses vitamin D3 in plateau pika by down-regulating the expression of vitamin D3 metabolism-related genes. Vitamin D3 (D3) is produced endogenously from 7-dehydrocholesterol by irradiation and is an important secosteroid for the absorption of calcium and phosphate. Lithocholic acid (LCA) increases intestinal paracellular calcium absorption in a vitamin D receptor-dependent manner in vitamin D-deficient rats. The plateau zokor (Myospalax baileyi), a strictly subterranean species, and plateau pika are endemic to the Qinghai-Tibet Plateau. To verify whether the zokors were deficient in D3 and reveal the effects of hypoxia on D3 metabolism in the zokors and pikas, we measured the levels of 25(OH)D3, calcium, and LCA, and quantified the expression levels of D3 metabolism-related genes. The results showed an undetectable serum level of 25(OH)D3 and a significantly higher concentration of LCA in the serum of plateau zokor, but its calcium concentration was within the normal range compared with that of plateau pika and Sprague-Dawley rats. With increasing altitude, the serum 25(OH)D3 levels in plateau pika decreased significantly, and the mRNA and protein levels of CYP2R1 (in the liver) and CYP27B1 (in the kidney) in plateau pika decreased significantly. Our results indicate that plateau zokors were deficient in D3 and abundant in LCA, which might be a substitution of D3 in the zokor. Furthermore, hypoxia suppresses the metabolism of D3 by down-regulating the expression of CYP2R1 and CYP27B1 in plateau pika. [ABSTRACT FROM AUTHOR]

Ursodeoxycholic acid (UDCA) is a highly demanded pharmaceutical steroid widely used in medicine. An ascomycete Gibberella zeae VKM F-2600 is capable of producing UDCA by 7β-hydroxylation of lithocholic acid (LCA). The present study is aimed at the improvement of the fungus productivity. The original procedures for the protoplast obtaining followed by UV mutagenesis and screening of ketoconazole-resistant mutant clones have been applied. The highest yield of G. zeae protoplasts was obtained when using the mycelium in the active growth phase, ammonium chloride as an osmotic stabilizer and treatment of the fungal cells by the lytic enzymes cocktail from Trichoderma hurzanium. The conditions for effective protoplast regeneration and the UV-mutagenesis were found to provide 6–12% survival rate of the protoplasts with superior number of possible mutations. Three of 27 ketoconazole-resistant mutant clones obtained have been selected due to their increased biocatalytic activity towards LCA. The mutant G. zeae M23 produced 26% more UDCA even at relatively high LCA concentration (4 g/L) as compared with parent fungal strain, and the conversion reached 88% (w/w). The yield of UDCA reached in this study prefers those ever reported. The results contribute to the knowledge on ascomycete mutagenesis, and are of importance for biotechnological production of value added cholic acids. Key points: Efficient procedures for production and regeneration of Gibberella zeae protoplasts were determined. Fungal mutants were obtained with elevated 7β-hydroxylase activity. Mutant G. zeae M23 almost fully converts LCA (4 g/L) to UDCA. [ABSTRACT FROM AUTHOR]

Patients with liver diseases not only experience the adverse effects of liver-metabolized drugs, but also the unexpected adverse effects of renally excreted drugs. Bile acids alter the expression of renal drug transporters, however, the direct effects of bile acids on drug transport remain unknown. Renal drug transporter organic anion-transporting polypeptide 4C1 (OATP4C1) was reported to be inhibited by chenodeoxycholic acid. Therefore, we predicted that the inhibition of OATP4C1-mediated transport by bile acids might be a potential mechanism for the altered pharmacokinetics of renally excreted drugs. We screened 45 types of bile acids and calculated the IC50, Ki values, and bile acid–drug interaction (BDI) indices of bile acids whose inhibitory effect on OATP4C1 was >50%. From the screening results, lithocholic acid (LCA), glycine-conjugated lithocholic acid (GLCA), and taurine-conjugated lithocholic acid (TLCA) were newly identified as inhibitors of OATP4C1. Since the BDI index of LCA was 0.278, LCA is likely to inhibit OATP4C1-mediated transport in clinical settings. Our findings suggest that dose adjustment of renally excreted drugs may be required in patients with renal failure as well as in patients with hepatic failure. We believe that our findings provide essential information for drug development and safe drug treatment in clinics. [ABSTRACT FROM AUTHOR]

Lithocholic acid (LCA) is a monohydroxy bile acid produced by intestinal flora, which has been found to be associated with a variety of hepatic and intestinal diseases. LCA is previously considered to be toxic, however, recent studies revealed that LCA and its derivatives may exert anti-inflammatory and anti-tumor effects under certain conditions. LCA goes through enterohepatic circulation along with other bile acids, here, we mainly discuss the effects of LCA on the gut-liver axis, including the regulation of gut microbiota, intestinal barrier, and relevant nuclear receptors (VDR, PXR) and G protein-coupled receptor five in related diseases. In addition, we also find that some natural ingredients are involved in regulating the detoxification and excretion of LCA, and the interaction with LCA also mediates its own biological activity. [ABSTRACT FROM AUTHOR]

Imidazolium salts (IMSs) are the subject of many studies showing their anticancer activities. In this research, a series of novel imidazolium salts substituted with lithocholic acid (LCA) and alkyl chains of various lengths (S1–S10) were evaluated against colon cancer cells. A significant reduction in the viability and metabolic activity was obtained in vitro for DLD-1 and HT-29 cell lines when treated with tested salts. The results showed that the activities of tested agents are directly related to the alkyl chain length, where S6–S8 compounds were the most cytotoxic against the DLD-1 line and S4–S10 against HT-29. The research performed on the xenograft model of mice demonstrated a lower tendency of tumor growth in the group receiving compound S6, compared with the group receiving 5-fluorouracil (5-FU). Obtained results indicate the activity of S6 in the induction of apoptosis and necrosis in induced colorectal cancer. LCA-based imidazolium salts may be candidates for chemotherapeutic agents against colorectal cancer. [ABSTRACT FROM AUTHOR]

Deoxynivalenol (DON) is a secondary metabolite of fungi. Ingestion of feed containing DON causes severe intestinal damage in humans and animals, possibly due to cholesterol-enriched lipid raft abnormalities. Cholic acid (CA) and lithocholic acid (LCA) are metabolites of cholesterol transformation, which have been proven to benefit epithelial cell proliferation and reduce intestinal inflammation and lesions. Therefore, we aimed to study the protective roles of CA and LCA administration on the DON-exposed intestinal epithelial cells (IPI-2I) and the underlying mechanisms involved in cholesterol metabolism. We found that LCA pretreatment, but not CA, alleviated the reduction of cell numbers caused by DON exposure. Furthermore, we demonstrate that LCA restored the DON-induced cell apoptosis by reducing the cleaved caspase 3 and cleaved PARP-1 expression. DON-increased cellular cholesterol and bile acid contents were significantly reduced when LCA was co-treated. Further transcriptomic analysis revealed that the aberrant cholesterol homeostasis genes profile was observed in the cells exposed to DON or pretreated with LCA. We also validated that the key genes involved in cholesterol biosynthesis and transformation (cholesterol to bile acids) were strongly inhibited by the LCA treatment in the DON-exposed cells. Together, this study demonstrated that LCA ameliorated DON-caused toxic apoptosis in IPI-2I cells by maintaining cholesterol metabolism. We suggest that as an endogenous metabolite, LCA may be used as a therapeutic and/or integrated into a dietary intervention against mycotoxin toxicity. [ABSTRACT FROM AUTHOR]

Mycophenolate mofetil (MMF) is one of the most used immunosuppressive drugs in organ transplantation, but frequent gastrointestinal (GI) side effects through unknown mechanisms limit its clinical use. Gut microbiota and its metabolites were recently reported to play a vital role in MMF-induced GI toxicity, but the specific mechanism of how they interact with the human body is still unclear. Here, we found that secondary bile acids (BAs), as bacterial metabolites, were significantly reduced by MMF administration in the gut of mice. Microbiome data and fecal microbiota transfer model supported a microbiota-dependent effect on the reduction of secondary BAs. Supplementation of the secondary BA lithocholic acid alleviated MMF-induced weight loss, colonic inflammation, and oxidative phosphorylation damage. Genetic deletion of the vitamin D3 receptor (VDR), which serves as a primary colonic BA receptor, in colonic epithelial cells (VDR ΔIEC ) abolished the therapeutic effect of lithocholic acid on MMF-induced GI toxicity. Impressively, we discovered that paricalcitol, a Food and Drug Administration-approved VDR agonist that has been used in clinics for years, could effectively alleviate MMF-induced GI toxicity. Our study reveals a previously unrecognized mechanism of gut microbiota, BAs, and VDR signaling in MMF-induced GI side effects, offering potential therapeutic strategies for clinics., Competing Interests: Declaration of competing interest The authors of this manuscript have no conflicts of interest to disclose as described by the American Journal of Transplantation., (Copyright © 2024. Published by Elsevier Inc.)

Background and Aim: Elobixibat is a locally acting inhibitor of the ileal bile acid transporter. We compared bile acid metabolism between healthy subjects and patients with chronic constipation and assessed changes in the bile acid profile after elobixibat administration in the latter group. Methods: Healthy subjects (n = 10) and patients with chronic constipation (n = 19) were assessed as inpatients for 7 days, during which they received meals containing ~60 g/day of fat. Patients with chronic constipation remained as inpatients for a further 7 days for once‐daily elobixibat administration. Assessments included concentrations of fecal and serum bile acids, serum 7α‐hydroxy‐4‐cholesten‐3‐one (C4) and fibroblast growth factor 19, and bowel movements and constipation symptoms. Results: Fecal total and primary bile acids were significantly lower in patients with chronic constipation versus healthy subjects. Serum C4 and fibroblast growth factor 19 levels were comparable between groups. Elobixibat treatment increased fecal total and primary bile acids and decreased levels of fecal lithocholic acid and serum total as well as secondary bile acids in patients with chronic constipation. Bowel movements and other constipation‐related symptoms were also improved by elobixibat to levels almost comparable with those of healthy subjects. Conclusions: Despite comparable C4 levels, patients with chronic constipation demonstrated decreased levels of fecal bile acids versus healthy subjects. Elobixibat treatment increased fecal bile acid excretion and reduced serum bile acid concentrations. The improvement of constipation after elobixibat treatment was associated with increased total bile acids, particularly primary bile acids. [ABSTRACT FROM AUTHOR]

Listeria monocytogenes (L. monocytogenes) is an important Gram-positive food-borne pathogen that severely threatens public health. A checkerboard microdilution method was performed to evaluate the synergistic effect of lithocholic acid (LCA) with Gentamicin (Genta) against L. monocytogenes. BacLight LIVE/DEAD staining, scanning electron microscopy and biofilm inhibition assays were further used to explore the bactericidal effect and antibiofilm effect of this combination on L. monocytogenes. Additionally, the synergistic effects of LCA derivatives with Genta were also evaluated against L. monocytogenes, S.aureus and S. suis. The results indicated that a synergistic bactericidal effect was observed for the combined therapy of LCA at the concentration without affecting bacteria viability, with Genta. Additionally, LCA in combination with Genta had a synergistic effect against Gram-positive bacteria (L. monocytogenes, S. aureus and S. suis) but not against Gram-negative bacteria (E. coli, A. baumannii and Salmonella). BacLight LIVE/DEAD staining and scanning electron microscopy analysis revealed that the combination of LCA with Genta caused L. monocytogenes membrane injury, leading to bacteria death. We found that 8 μg/mL LCA treatment effectively improved the ability of Genta to eradicate L. monocytogenes biofilms. In addition, we found that chenodeoxycholic acid, as a cholic acid derivative, also improved the bactericidal effect of Genta against Gram-positive bacteria. Our results indicate that LCA represents a broad-spectrum adjuvant with Genta for infection caused by L. monocytogenes and other Gram-positive pathogens. [ABSTRACT FROM AUTHOR]

The vitamin K antagonist is a commonly prescribed effective oral anticoagulant with a narrow therapeutic range, and the dose requirements for different patients varied greatly. In recent years, studies on human intestinal microbiome have provided many valuable insights into disease development and drug reactions. A lot of studies indicated the potential relationship between microbiome and the vitamin K antagonist. Vitamin K is absorbed by the gut, and the intestinal bacteria are a major source of vitamin K in human body. A combined use of the vitamin K antagonist and antibiotics may result in an increase in INR, thus elevating the risk of bleeding, while vitamin K supplementation can improve stability of anticoagulation for oral vitamin K antagonist treatment. Recently, how intestinal bacteria affect the response of the vitamin K antagonist remains unclear. In this review, we reviewed the research, focusing on the physiology of vitamin K in the anticoagulation treatment, and investigated the potential pathways of intestinal bacteria affecting the reaction of the vitamin K antagonist.

Yahong Zheng,1 Chengcheng Yue,1 Hui Zhang,1 Haoran Chen,1 Yanyan Liu,1 Jiabin Li1– 4 1Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China; 2Department of Infectious Diseases, The Chaohu Affiliated Hospital of Anhui Medical University, Hefei, People’s Republic of China; 3Anhui Center for Surveillance of Bacterial Resistance, Hefei, People’s Republic of China; 4Institute of Bacterial Resistance, Anhui Medical University, Hefei, People’s Republic of ChinaCorrespondence: Jiabin LiDepartment of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Jixi Road No. 218, Hefei, 230022, People’s Republic of ChinaTel +86-551-62922713Fax +86-551-62922281Email lijiabin@ahmu.edu.cnPurpose: Klebsiella pneumoniae-induced liver abscess and baiacterem is a serious infectious disease with high mortality. Secondary bile acids (SBAs) are produced by intestinal flora through the metabolism of primary bile acids and play a role in promoting or inhibiting inflammation in some diseases. However, the immunomodulatory role of SBAs in bacterial infections of the liver remains unclear. This study aimed to investigate the anti-inflammatory and liver-protective effects of SBAs in K. pneumoniae-infected mice.Methods: The absolute concentrations of deoxycholic acid (DCA) and lithocholic acid (LCA) in feces and serum were analyzed, and intestinal flora alterations between K. pneumoniae-infected and healthy control mice were examined. The effect of SBAs was investigated by analyzing the survival, tissue bacterial load, histopathology, and inflammatory factor levels in SBA-treated mice. The expression of crucial proteins implicated in the NF-κB pathway, as well as the G-protein-coupled bile acid receptor TGR5, was detected.Results: The content of SBAs in feces and serum of the K. pneumoniae-infected group was significantly reduced, and significant changes in the composition of the intestinal flora were detected. The intestinal flora are directly related to the synthesis of SBAs. Ruminococcaceae levels in K. pneumoniae-infected mice were significantly lower than in healthy control mice. Oral administration of SBAs improved the survival and liver pathology of K. pneumoniae-infected mice, and reduced the bacterial load and the level of inflammatory factors. SBAs down-regulated the expression of key proteins in the NF-κB inflammatory signaling pathway, including the phosphorylation of IκBα and NF-κB p50 and the nuclear translocation of NF-κB p65. The protective effect of SBAs may be dependent on high TGR5 expression.Conclusion: SBAs downregulate the NF-κB inflammatory signaling pathway through TGR5, protecting the liver and inhibiting inflammation in K. pneumoniae-induced liver abscess and bacteremia.Keywords: Klebsiella pneumoniae liver abscess, deoxycholic acid, lithocholic acid, inflammation, nuclear factor-κB

[Display omitted] • Carboxyl isosteric analogues of lithocholic acid were designed and synthesized. • Sulfate analogues selectively target the N -specific ST6GAL1 over O-specific ST3GAL1. • Sulfate derivative inhibited breast cancer cell migration, adhesion, and invasion. • Antimetastatic activity may be due to suppression of FAK/paxillin signaling pathway. The naturally occurring bile acid lithocholic acid (LCA) has been a crucial core structure for many non-sugar-containing sialyltranferase (ST) inhibitors documented in literature. With the aim of elucidating the impact of the terminal carboxyl acid substituent of LCA on its ST inhibition, in this present study, we report the (bio)isosteric replacement-based design and synthesis of sulfonate and sulfate analogues of LCA. Among these compounds, the sulfate analogue SPP-002 was found to selectively inhibit N -glycan sialylation by at least an order of magnitude, indicating a substantial improvement in both potency and selectivity when compared to the unmodified parent bile acid. Molecular docking analysis supported the stronger binding of the synthetic analogue in the enzyme active site. Treatment with SPP-002 also hampered the migration, adhesion, and invasion of MDA-MB-231 cells in vitro by suppressing the expression of signaling proteins involved in the cancer metastasis-associated integrin/FAK/paxillin pathway. In totality, these findings offer not only a novel structural scaffold but also valuable insights for the future development of more potent and selective ST inhibitors with potential therapeutic effects against tumor cancer metastasis. [ABSTRACT FROM AUTHOR]

Cytochrome P450 enzyme with 7β-hydroxylation capacity has attracted widespread attentions due to the vital roles in the biosynthesis of ursodeoxycholic acid (UDCA), a naturally active molecule for the treatment of liver and gallbladder diseases. In this study, a novel P450 hydroxylase (P450 FE) was screen out from Fusarium equiseti HG18 and identified by a combination of genome and transcriptome sequencing, as well as heterologous expression in Pichia pastoris. The biotransformation of lithocholic acid (LCA) by whole cells of recombinant Pichia pastoris further confirmed the C7β-hydroxylation with 5.2% UDCA yield. It was firstly identified a fungal P450 enzyme from Fusarium equiseti HG18 with the capacity to catalyze the LCA oxidation producing UDCA. The integration of homology modeling and molecular docking discovered the substrate binding to active pockets, and the key amino acids in active center were validated by site-directed mutagenesis, and revealed that Q112, V362 and L363 were the pivotal residues of P450 FE in regulating the activity and selectivity of 7β-hydroxylation. Specifically, V362I mutation exhibited 2.6-fold higher levels of UDCA and higher stereospecificity than wild-type P450 FE. This advance provided guidance for improving the catalytic efficiency and selectivity of P450 FE in LCA hydroxylation, indicative of the great potential in green synthesis of UDCA from biologically toxic LCA. [Display omitted] • The strategy of combining genome and transcriptome sequencing effectively reduced the workload of traditional large-scale genome screening. • A novel cytochrome P450 enzyme (P450 FE) with the 7β-hydroxylase capacity was discovered from Fusarium equiseti HG18. • Heterologous expression of P450 FE was successfully achieved in Pichia pastoris. • Q112, V362 and L363 were the key amino acid residues regulated the 7β-hydroxylation activity and selectivity of P450 FE. [ABSTRACT FROM AUTHOR]

Bile acids are major components of bile; they emulsify dietary lipids for efficient digestion and absorption and act as signaling molecules that activate nuclear and membrane receptors. The vitamin D receptor (VDR) is a receptor for the active form of vitamin D and lithocholic acid (LCA), a secondary bile acid produced by the intestinal microflora. Unlike other bile acids that enter the enterohepatic circulation, LCA is poorly absorbed in the intestine. Although vitamin D signaling regulates various physiological functions, including calcium metabolism and inflammation/immunity, LCA signaling remains largely unknown. In this study, we investigated the effect of the oral administration of LCA on colitis in a mouse model using dextran sulfate sodium (DSS). Oral LCA decreased the disease activity of colitis in the early phase, which is a phenotype associated with the suppression of histological injury, such as inflammatory cell infiltration and goblet cell loss. These protective effects of LCA were abolished in VDR-deleted mice. LCA decreased the expression of inflammatory cytokine genes, but this effect was at least partly observed in VDR-deleted mice. The pharmacological effect of LCA on colitis was not associated with hypercalcemia, an adverse effect induced by vitamin D compounds. Therefore, LCA suppresses DSS-induced intestinal injury in its action as a VDR ligand.

Obese subjects have a high baseline of genotoxic stress, but the underlying mechanism is poorly understood. Given that obesity is associated with high bile acids (BA) and low folate, we aimed to determine the interactive effect of folate deficient or supplementation to the genotoxicity and cytotoxicity of BA in human colon and liver cells. NCM460 and L-02 cells were cultured in folate-deficient (22.6 nM) and replete (2260 nM) Roswell Park Memorial Institute (RPMI)-1640 medium with or without 50 μM deoxycholic acid (DCA) or lithocholic acid (LCA) for 7 days. Moreover, these cells were cultured in folate supplemented (5.65, 11.3 and 22.6 μM) and standard (2.26 μM) medium with 200 μM DCA or LCA for 7 days. Genotoxicity and cytotoxicity were measured using the cytokinesis-block micronucleus cytome assay. Our results showed that under folate-replete condition, 50 μM DCA or LCA significantly increased the rate of micronuclei (MN) in NCM460 and L-02 cells. Significantly, the MN-inducing effect of 50 μM DCA or LCA was further enhanced by folate deficiency. Interestingly, folate supplementation exerted a dose-dependent manner to significantly decrease the rates of MN, nucleoplasmic bridges, nuclear buds, apoptosis, and necrosis induced by 200 μM DCA or LCA in NCM460 and L-02 cells. In conclusion, the genotoxicity of moderate BA (50 μM) was exacerbated by folate deficiency and folate supplementation could efficiently protect cells against the genotoxicity and cytotoxicity of high BA (200 μM). [ABSTRACT FROM AUTHOR]

A systematic study with phase 1 and phase 2 metabolites of cholesterol and Vitamin D was conducted to determine whether their biological activity is mediated by the Vitamin D receptor (VDR). The investigation necessitated the development of novel synthetic routes for lithocholic acid (LCA) glucuronides (Gluc). Biochemical and cell-based assays were used to demonstrate that hydroxylated LCA analogs were not able to bind VDR. This excludes VDR from mediating their biological and pharmacological activities. Among the synthesized LCA conjugates a novel VDR agonist was identified. LCA Gluc II increased the expression of CYP24A1 in DU145 cancer cells especially in the presence of the endogenous VDR ligand 1,25(OH)2D3.Furthermore, the methyl ester of LCA was identified as novel VDR antagonist. For the first time, we showed that calcitroic acid, the assumed inactive final metabolite of Vitamin D, was able to activate VDR-mediated transcription to a higher magnitude than bile acid LCA. Due to a higher metabolic stability in comparison to Vitamin D, a very low toxicity, and high concentration in bile and intestine, calcitroic acid is likely to be an important mediator of the protective Vitamin D properties against colon cancer.

Lithocholic acid (LCA) is a secondary bile acid that is selectively toxic to human neuroblastoma, breast and prostate cancer cells, whilst sparing normal cells. We previously reported that LCA inhibited cell viability and proliferation and induced apoptosis and necrosis of androgen-dependent LNCaP and androgen-independent PC-3 human prostate cancer cells. In the present study, we investigated the roles of endoplasmic reticulum (ER) stress, autophagy and mitochondrial dysfunction in the toxicity of LCA in PC-3 and autophagy deficient, androgen-independent DU-145 cells. LCA induced ER stress-related proteins, such as CCAAT-enhancer-binding protein homologous protein (CHOP), and the phosphorylation of eukaryotic initiation factor 2-alpha (p-eIF2α) and c-Jun N-terminal kinases (p-JNK) in both cancer cell-types. The p53 upregulated modulator of apoptosis (PUMA) and B cell lymphoma-like protein 11 (BIM) levels were decreased at overtly toxic LCA concentrations, although PUMA levels increased at lower LCA concentrations in both cell lines. LCA induced autophagy-related conversion of microtubule-associated proteins 1A/1B light chain 3B (LC3BI-LC3BII), and autophagy-related protein ATG5 in PC-3 cells, but not in autophagy-deficient DU-145 cells. LCA (>10 µM) increased levels of reactive oxygen species (ROS) concentration-dependently in PC-3 cells, whereas ROS levels were not affected in DU-145 cells. Salubrinal, an inhibitor of eIF2α dephosphorylation and ER stress, reduced LCA-induced CHOP levels slightly in PC-3, but not DU-145 cells. Salubrinal pre-treatment increased the cytotoxicity of LCA in PC-3 and DU-145 cells and resulted in a statistically significant loss of cell viability at normally non-toxic concentrations of LCA. The late-stage autophagy inhibitor bafilomycin A1 exacerbated LCA toxicity at subtoxic LCA concentrations in PC-3 cells. The antioxidant α-tocotrienol strongly inhibited the toxicity of LCA in PC-3 cells, but not in DU-145 cells. Collectively, although LCA induces autophagy and ER stress in PC-3 cells, these processes appear to be initially of protective nature and subsequently consequential to, but not critical for the ROS-mediated mitochondrial dysfunction and cytotoxicity of LCA. The full mechanism of LCA-induced mitochondrial dysfunction and cytotoxicity in the similarly sensitive DU-145 cells remains to be elucidated.

In the present study, a polymeric micelle based on amphiphilic block copolymer, namely poly(methacrylated methyl lithocholate)‐block‐poly(oligoethylene glycol methacrylate) (PMML‐b‐POEGMA) bearing bile acid moiety is prepared via sequential photo‐initiated free radical polymerizations, and its drug carrying capacity is investigated using doxorubicin hydrochloride (DOX) as a model drug. For this purpose, two‐step procedure is applied in the presence of phenylbis (2,4,6‐trimethylbenzoyl)phosphine oxide (BAPO) as bifunctional photo initiator. Based on spectroscopic and chromatographic analyses, the desired amphiphilic block copolymer (PMML‐b‐POEGMA) is successfully synthesized by wavelength‐selective free radical photopolymerization under mild conditions. Finally, the DOX drug is loaded into the PMML‐b‐POEGMA micelles and then drug release behavior is investigated at two different pH (5.5 and 7.4) values. It is concluded from the results that PMML‐b‐POEGMA micelles may be used as an efficient nanocarrier to deliver conventional anti‐cancer drugs for combination chemotherapy. [ABSTRACT FROM AUTHOR]

Functional bowel disorders such as irritable bowel syndrome (IBS) are common, multifactorial and have a major impact on the quality of life of individuals diagnosed with the condition. Heterogeneity in symptom manifestation, which includes changes in bowel habit and visceral pain sensitivity, are an indication of the complexity of the underlying pathophysiology. It is accepted that dysfunctional gut-brain communication, which incorporates efferent and afferent branches of the peripheral nervous system, circulating endocrine hormones and local paracrine and neurocrine factors, such as host and microbially-derived signaling molecules, underpins symptom manifestation. This review will focus on the potential role of hepatic bile acids in modulating gut-to-brain signaling in IBS patients. Bile acids are amphipathic molecules synthesized in the liver, which facilitate digestion and absorption of dietary lipids. They are also important bioactive signaling molecules however, binding to bile acid receptors which are expressed on many different cell types. Bile acids have potent anti-microbial actions and thereby shape intestinal bacterial profiles. In turn, bacteria with bile salt hydrolase activity initiate the critical first step in transforming primary bile acids into secondary bile acids. Individuals with IBS are reported to have altered microbial profiles and modified bile acid pools. We have assessed the evidence to support a role for bile acids in the pathophysiology underlying the manifestation of IBS symptoms. [ABSTRACT FROM AUTHOR]

Functional bowel disorders such as irritable bowel syndrome (IBS) are common, multifactorial and have a major impact on the quality of life of individuals diagnosed with the condition. Heterogeneity in symptom manifestation, which includes changes in bowel habit and visceral pain sensitivity, are an indication of the complexity of the underlying pathophysiology. It is accepted that dysfunctional gut-brain communication, which incorporates efferent and afferent branches of the peripheral nervous system, circulating endocrine hormones and local paracrine and neurocrine factors, such as host and microbially-derived signaling molecules, underpins symptom manifestation. This review will focus on the potential role of hepatic bile acids in modulating gut-to-brain signaling in IBS patients. Bile acids are amphipathic molecules synthesized in the liver, which facilitate digestion and absorption of dietary lipids. They are also important bioactive signaling molecules however, binding to bile acid receptors which are expressed on many different cell types. Bile acids have potent anti-microbial actions and thereby shape intestinal bacterial profiles. In turn, bacteria with bile salt hydrolase activity initiate the critical first step in transforming primary bile acids into secondary bile acids. Individuals with IBS are reported to have altered microbial profiles and modified bile acid pools. We have assessed the evidence to support a role for bile acids in the pathophysiology underlying the manifestation of IBS symptoms.

High temperature and humidity in the environment are known to be associated with discomfort and disease, yet the underlying mechanisms remain unclear. We observed a decrease in plasma glucagon-like peptide-1 levels in response to high-temperature and humidity conditions. Through 16S rRNA gene sequencing, alterations in the gut microbiota composition were identified following exposure to high temperature and humidity conditions. Notably, changes in the gut microbiota have been implicated in bile acid synthesis. Further analysis revealed a decrease in lithocholic acid levels in high-temperature and humidity conditions. Subsequent in vitro experiments demonstrated that lithocholic acid increases glucagon-like peptide-1 secretion in NCI-H716 cells. Proteomic analysis indicated upregulation of farnesoid X receptor expression in the ileum. In vitro experiments revealed that the combination of lithocholic acid with farnesoid X receptor inhibitors resulted in a significant increase in GLP-1 levels compared to lithocholic acid alone. In this study, we elucidate the mechanism by which reduced lithocholic acid suppresses glucagon-like peptide 1 via farnesoid X receptor activation under high-temperature and humidity condition., (© 2024. The Author(s).)

The aim of this article is to introduce the topic of newly designed peptides as well as their biological activity. We designed nine encoded peptides composed of six amino acids. All these peptides were synthesized with C-terminal amidation. To investigate the importance of increased hydrophobicity at the amino end of the peptides, all of them were subsequently synthesized with palmitic or lithocholic acid at the N-terminus. Antimicrobial activity was tested on Gram-positive and Gram-negative bacteria and fungi. Cytotoxicity was measured on HepG2 and HEK 293 T cell cultures. Peptides bearing a hydrophobic group exhibited the best antimicrobial activity. Lipopeptides with palmitic or lithocholic acid (PAL or LCA peptides) at the N-terminus and with C-terminal amidation were highly active against Gram-positive bacteria, especially against strains of Staphylococcus aureus and Candida tropicalis. The LCA peptide SHP 1.3 with the sequence LCA-LVKRAG-NH 2 , had high efficiency on HepG2 human liver hepatocellular carcinoma cells (97%)., (© 2024. The Author(s).)