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Synthesis, characterization, and theoretical studies of a novel limonene-bis(isoxazole)-thiazolidinone hybrid, prepared from natural D-limonene in five steps, were conducted. The compounds obtained were successfully identified using HRMS, 1H- and 13C-NMR spectral data. Subsequently, in-silico docking and molecular dynamic simulation studies were performed to predict potential interaction modes between the compounds and the active sites of the target hTopo IIα. Both studies indicated that all molecules exhibited good binding affinity towards the hTopo IIα enzyme, similar to the reference drug etoposide, when placed in the enzyme's active site. In addition, in silico ADME/Tox studies were carried out to assess the drug-likeness and pharmacokinetic properties of the molecules. The limonene-bis(isoxazole)-thiazolidinone hybrid derivatives may serve as promising lead compounds for the development of new topoisomerase-targeted anticancer agents. [ABSTRACT FROM AUTHOR]

The excessive use of conventional medications to treat coccidiosis has led to concerns regarding drug residues in tissues and the emergence of multidrug resistance. Essential oils with anti-inflammatory and antioxidant activities may also have anticoccidial effects. The present study investigated the efficacy of D-limonene and its nanoemulsion form against Eimeria tenella in chickens. An in vitro study was conducted to evaluate the sporulation inhibitory effects of D-limonene on Eimeria tenella oocysts. Five D-limonene concentrations (0.625, 1.25, 2.5, 5, and 10% v/v) were tested alongside positive (10% formalin) and negative (2.5% potassium dichromate) controls. Each ELISA plate well was inoculated with 1200 unsporulated oocysts and incubated at 30 °C for 24, 48, and 72 h. Subsequently, samples were microscopically examined to assess sporulation inhibition and calculate the percentage of sporulated oocysts. For the in vivo study, 125 eight-day-old broiler chicks were divided into five groups of 25 birds each. The control negative group remained uninfected and untreated. The control positive group was challenged with 5 × 104 sporulated Eimeria tenella oocysts. The diclazuril group received 0.2 mg/kg diclazuril in their diet two days prior to, and until 10 days post infection. The D-limonene (DL) and D-limonene nanoemulsion (DLN) groups were challenged with 5 × 104 sporulated E. tenella oocysts at 18 days of age and administered 150 mg/L of their respective treatments in drinking water from day eight until the end of the experiment. Results from the in vitro study demonstrated that D-limonene suppressed oocyst sporulation by 50.83% at its highest concentration of 10%. In the in vivo study, both DL and DLN treated groups exhibited a significant reduction in oocyst output per gram of feces (OPG), along with increased body weight and decreased parasite stages in the cecal tissue. Furthermore, these treatments were associated with elevated levels of antioxidant enzymes such as glutathione peroxidase (GPX), catalase (CAT), and superoxide dismutase (SOD), accompanied by a decrease in malondialdehyde (MDA) and nitric oxide (NO) levels. Particularly, DLN treatment remarkably increased the number of goblet cells. In conclusion, D-limonene and its nanoemulsion represent promising alternatives for managing coccidiosis in poultry. They not only effectively control parasites but also promote intestinal health and boost antioxidant defenses. [ABSTRACT FROM AUTHOR]

The majority of conventional osteoarthritis (OA) treatments are based on molecular adjustment of certain signaling pathways associated with osteoarthritis (OA) pathogenesis, however there is a significant need to search for more effective and safe treatments. This study centers around formulating Aceclofenac (ACF) with high bioavailability in combination with Citronellol oil and collagen. The optimal concentrations of Citronellol oil/D-Limonene oil, Tween 80, and Transcutol HP were determined using a pseudoternary phase diagram. The formulated nanoemulsions were studied for thermophysical stability. Thermodynamically stable formula were analyzed for droplet size, zeta potential, and in-vitro permeation. Then, collagen based nanoemulsion were prepared to capitalize on its efficacy in reducing osteoarthritis side effects and characterized for nano size properties. Formulae F10 and F10C were chosen as optimum nanosize formula. Hense, they were prepared and characterized as nanoemulgel dosage form. The nanoemulgel formulae F10NEG1 and F10CNEG1 showed reasonable viscosity and spreadability, with complete drug release after 4 h. These formulae were chosen for further In vivo anti-OA study. Collagen based ACF/citronellol emugel were able to modulate HMGB-1/RAGE/NF-κB pathway, mitigating the production of inflammatory cytokine TNF-α. They were also able to modulate Klotho and miR-499, reducing serum CTXII and COMP, by reducing the cartilage destruction. Histological investigations validated the efficacy, safety, and superiority of Aceclofenac in combination with Citronellol oil and collagen (F10CNEG1) over solo the treated group (F10NEG1 and blank). Hence, the findings of the current work encourage the use of this promising combined formula in treatment of OA patients. [ABSTRACT FROM AUTHOR]

Oranges and eucalyptus trees are abundant sources of waste and pruning, generating secondary streams that can be converted into valuable products. Both species are broadly cultivated in Mexico. Essential oils from orange peels and eucalyptus leaves possess antimicrobial and antioxidant properties, making them useful in various applications. In this study, the essential oils antioxidant potential was determined through radical scavenging activity and ferric reducing capacity, and the total phenolic content was measured. These essential oils also demonstrated inhibition capacity against Escherichia coli and Staphylococcus aureus. GC-MS analysis of the oils revealed the composition of representative compounds, with D-limonene constituting almost 75% of the orange essential oil and 1,8-cineol comprising 15.2% of the eucalyptus oil. The antioxidant test results between essential oils showed that they are similar, except for the FRAP test, where eucalyptus essential oil obtained a value three times higher than orange essential oil. The findings suggest that these essential oils can serve as natural and sustainable alternatives to synthetic antimicrobial and antioxidant agents. [ABSTRACT FROM AUTHOR]

Macroporous polymeric sorbents were synthesized via high internal phase emulsion (HIPE) templating. For this aim, water‐in‐oil (w/o) HIPEs were prepared with 80 vol.% of aqueous internal phase whereas plant‐based β‐myrcene (My) and D‐limonene (Lim) were used as renewable building blocks in the continuous oil phase. Moreover, biocompatible ethylene glycol dimetacrylate (EGDMA) was also added as a crosslinker comonomer. By varying the total volume fraction of My and Lim in the continuous phase composition between 90% and 50%, 14 different HIPE formulations were prepared. After polymerization of HIPE templates 28 different sorbents were obtained depending on the purification procedure (extraction & drying under vacuum or freeze drying). The effect of terpene composition in the obtained sorbents was investigated in terms of cross‐link density (υ), the molecular weight (Mc) and pore morphology. In this context, chemical structures and pore morphologies were characterized by FTIR spectroscopy and SEM analysis, respectively. The Brunauer‐Emmet‐Teller (BET) specific surface area was also measured to determine the relationship between pore morphology and surface area. Based on the characterization results, two sorbents were selected as model for sorption tests. Thereafter, solvent sorption tests were performed by immersing sorbents in either hexane, dichloromethane, deionized water, seawater, solvent/water mixture, or solvent/seawater mixture to determine maximum sorption capacities and determine reusability of the sorbents. Moreover, experimental data was fitted to pseudo‐first order and pseudo second order kinetic models, as well as Freundlich and Langmuir isotherms. In the end, it was found that varying My and Lim ratio is the key parameter of controlling pore morphology and physicochemical properties. Moreover, it was shown that resulting sorbents can be efficiently used in oil/water separation processes repeatedly for several cycles. [ABSTRACT FROM AUTHOR]

This study investigated the chemical composition and antibacterial activities of lime Citrus aurantifolia (Cc) and lemon grass Cymbopogon citratus (Ca) essential oils (EOs). Standard methods were used to determine their minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC), and gas chromatography-mass spectrometry was used to determine their composition. Each EO and their combination showed promising results in treating test bacterial infections. Cc EO showed the largest inhibition zone diameter (43 mm) against Staphylococcus aureus and Serratia marcescens, and Ca EO showed the largest (30 mm) and smallest (12 mm) inhibition zone diameters against Bacillus stearothermophilus and S. marcescens, respectively. The combination of Cc EO and Ca EO (1:1) resulted in the largest (45 mm) and smallest (8 mm) inhibition zone diameters against Klebsiella pneumoniae and Salmonella typhimurium, respectively. The MIC of Cc EO ranged from 0.78% to 6.25%, and its MBC ranged from 3.13% to 12.50%. The MIC and MBC of combined Cc EO and Ca EO ranged from 0.78% to 6.25% and from 1.56% to 12.5%, respectively. The major components of Cc EO and Ca EO were neral (44.98%) and D-limonene (56.02%). Overall, the combination of lime and lemon grass EOs performed well compared to streptomycin, making them suitable for treating test bacterial infections. [ABSTRACT FROM AUTHOR]

D‐limonene is a widely used flavouring additive in foods, beverages and fragrances due to its pleasant lemon‐like odour. This study aimed to investigate the effects of D‐limonene on the central nervous system when subjected to chronic restraint stress in rats for 21 days. Forty rats were randomly divided into five groups: i) control, ii) D‐limonene, iii) restraint stress, iv) restraint stress+D‐limonene and v) restraint stress+fluoxetine. Following the induction of restraint stress, the sucrose preference test, the open field test, the novel object recognition test and the forced swimming test were performed. The levels of BDNF, IL‐1β, IL‐6 and caspase‐1 were measured from hippocampal tissue using the ELISA method. Sucrose preference test results showed an increase in consumption rate in the stress+D‐limonene and a decrease in the stress group. The stress+D‐limonene group reversed the increased defensive behaviour observed in the open‐field test compared to the stress group. In the novel object recognition test, the discrimination index of the stress+D‐limonene group increased compared to the stress group. BDNF levels increased in the stress+limonene group compared to the stress group. In contrast, IL‐1β and caspase‐1 levels increased in the stress group compared to the control and decreased in the stress+limonene group compared to the stress group. In this study, D‐limonene has been found to have antidepressant‐like properties, reducing anhedonic and defensive behaviours and the impairing effects of stress on learning and memory tests. It was observed that D‐limonene showed these effects by alleviating neuroinflammation induced by chronic restraint stress in rats. [ABSTRACT FROM AUTHOR]

The Pichia kluyveri, a proliferation commonly found in Sichuan pickles (SCPs), can accelerate the growth and reproduction of spoilage bacteria, causing off-odor development and decay. Although D-limonene, a common natural preservative, effectively restricts P. kluyveri, its inhibitory mechanism remains unclear. This study aimed to elucidate this molecular mechanism by investigating the impact on basic P. kluyveri metabolism. The findings revealed that D-limonene inhibited P. kluyveri growth and disrupted the transcription of the genes responsible for encoding the enzymes involved in cell wall and membrane synthesis, oxidative phosphorylation, glycolysis, and the tricarboxylic acid (TCA) cycle pathway. The results indicated that these events disrupted crucial metabolism such as cell wall and membrane integrity, adenosine triphosphate (ATP) synthesis, and reactive oxygen species (ROS) balance. These insights provided a comprehensive understanding of the inhibitory effect of D-limonene on the growth and reproduction of P. kluyveri while highlighting its potential application in the SCP industry. [ABSTRACT FROM AUTHOR]

Glossogyne tenuifolia (Labill.) Cass. ex Cass (Compositae) is a herbaceous plant that is endemic to Taiwan. Traditional Chinese Medicine has utilized it as a treatment for fever, inflammation, and liver preservation. Recent research has unveiled its bioactivities, including anti-inflammation, anti-cancer, antiviral, antioxidant, anti-fatigue, hepatoprotection, and immune modulation elements. Nevertheless, its effect on skin health remains to be investigated. Thus, we investigated the impact of G. tenuifolia essential oil (GTEO) on forskolin (FRK)-induced melanin biosynthesis and its mechanisms in B16-F10 murine melanoma in vitro. Treatment of GTEO resulted in a substantial decrease in FRK-induced melanin production, accompanied by a significant decrease in tyrosinase mRNA and protein expression levels. Additionally, our data demonstrated that the decrease in tyrosinase expression resulted from the suppression of MITF, as indicated by the reduced movement of MITF into the cell nucleus. Moreover, GTEO prompted a prolonged ERK1/2 activation, leading to the decline of MITF through proteasomal degradation, and it was verified that GTEO had no inhibitory impact on MITF activity in ERK1/2 inhibitor-treated cells. Additional studies demonstrated that α-pinene and D-limonene, which are the primary components in GTEO, showed strong melanin and tyrosinase inhibitory effects, indicating that α-pinene and D-limonene may contribute to its anti-melanogenic effects. Collectively, these data presented compelling proof that GTEO, along with its primary components α-pinene and D-limonene, show great potential as natural sources for developing innovative skin-whitening agents in the field of cosmetics. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) pose significant risks to human health and environmental quality, prompting stringent regulations on their emissions from various industrial processes. Among VOCs, d-limonene stands out due to its low threshold and contribution to malodorous emissions. While biofiltration presents a promising approach for VOC removal, including d-limonene, a comprehensive understanding of its performance and kinetics is lacking. This study aims to comprehensively assess the performance of a lab-scale biotrickling filter in treating gas-phase d-limonene. The experimental results indicate that the biotrickling filter efficiently removed d-limonene, achieving a critical loading rate of 19.4 g m−3 h−1 and a maximum elimination capacity of 31.8 g m−3 h−1 (correspondingly, up to 85% removal) at the condition of 94.2 s of EBRT. Microbial activity played a significant role in biotrickling filter performance, with a strong linear correlation being observed between CO2 production and substrate consumption. The Michaelis–Menten model was employed to represent enzyme-catalyzed reactions, suggesting no inhibition during biotrickling filter operation. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of an essential oil obtained from the fruit of Carum carvi L. (caraway oil), when used as a sensory additive in feed and water for drinking for all animal species. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) Panel concluded that the use of caraway oil is of no concern up to the following concentrations in complete feed: 9 mg/kg for chickens for fattening, 13 mg/kg for laying hens, 12 mg/kg for turkeys for fattening, 16 mg/kg for piglets, 19 mg/kg for pigs for fattening, 24 mg/kg for sows, 35 mg/kg for veal calves (milk replacer), 11 mg/kg for cattle for fattening, 10 mg/kg for dairy cows, sheep, goats, horses and rabbits, 25 mg/kg for salmonids and dogs. These conclusions were extrapolated to other physiologically related species. For cats, ornamental fish and other species, no conclusion can be drawn. The use of caraway oil in animal feed under the proposed conditions of use is safe for the consumer and the environment. The additive under assessment should be considered as an irritant to skin and eyes, and as a respiratory and skin sensitiser. When handling the essential oil, exposure of unprotected users to perillaldehyde may occur. Therefore, to reduce the risk, the exposure of the users should be minimised. Since C. carvi and its preparations were recognised to flavour food and its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary. [ABSTRACT FROM AUTHOR]

The research explored the chemical characteristics of essential oils (EOs) extracted from the peels of four citrus fruits grown in northeastern Peru (lime, sweet lemon, mandarin and orange). The essential oils were extracted by hydrodistillation using a green solvent, and subsequently, their physicochemical profile, bioactive, heat capacity, and RAMAN mapping were determined; in addition, the volatile composition was determined by gas chromatography (GC-MS), and the main phenols by liquid chromatography (UHPLC). The results evidenced that sweet lemon and mandarin essential oils had higher antioxidant activity (1592.38 and 1216.13 μmol TE/g) and total phenolic content (680.78 and 420.28 mg GAE/g). In contrast, sweet lemon peel essential oil had the highest total flavonoid content (23.18 mg QE/g). D-limonene was the most abundant aromatic compound in orange (>67 %), mandarin (>70 %), and sweet lemon (>72 %) EOs; however, in the lime, it was the lowest (37 %). The most abundant component was the cyclobutane, 1,2-bis(1-methylethylethylenyl)-, trans- (32 %).

Abstract Background Cancer is a fatal disease that severely affects humans. Designing new anticancer strategies and understanding the mechanism of action of anticancer agents is imperative. Hypothesis/Purpose In this study, we evaluated the utility of metformin and D-limonene, alone or in combination, as potential anticancer therapeutics using the human liver and breast cancer cell lines HepG2 and MCF-7. Study design An integrated systems pharmacology approach is presented for illustrating the molecular interactions between metformin and D-limonene. Methods We applied a systems-based analysis to introduce a drug–target–pathway network that clarifies different mechanisms of treatment. The combination treatment of metformin and D-limonene induced apoptosis in both cell lines compared with single drug treatments, as indicated by flow cytometric and gene expression analysis. Results The mRNA expression of Bax and P53 genes were significantly upregulated while Bcl-2, iNOS, and Cox-2 were significantly downregulated in all treatment groups compared with normal cells. The percentages of late apoptotic HepG2 and MCF-7 cells were higher in all treatment groups, particularly in the combination treatment group. Calculations for the combination index (CI) revealed a synergistic effect between both drugs for HepG2 cells (CI = 0.14) and MCF-7 cells (CI = 0.22). Conclusion Our data show that metformin, D-limonene, and their combinations exerted significant antitumor effects on the cancer cell lines by inducing apoptosis and modulating the expression of apoptotic genes.

Abstract d-limonene is a volatile compound widely used in food flavorings, but it is chemically unstable in the presence of air, light, moisture, and high temperatures. Coacervation is a well-established technique which involves the formation of biopolymer nanocomplexes between negatively charged polysaccharides and positively charged proteins to protect bioactive components. The study shows the effect of pH, protein/polysaccharide ratio and total biopolymer concentration on complex coacervation of defatted wheat germ protein (DWGP) and apple pectin (high methoxyl pectin (HMP)) in the food industry as a carrier and delivery system for d-limonene. DWGP was used for the first time to form coacervate with apple pectin. Turbidity, ζ-potential and particle size of the complex coacervate and their individual biopolymers were examined for preliminary assays of complex coacervation. The optimum condition for DWGP/pectin complex coacervation was found to be at a ratio of 4:1 with a total biopolymer concentration of 1% and a pH of 4.0. The rheological properties of DWGP, pectin, and their coacervate were measured at various pH levels and ratios. The resulting coacervates, used to microencapsulate d-limonene, underwent spray-dried and were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. These findings have the potential to contribute to the development of DWGP/pectin complex coacervates as effective delivery systems for volatile aromas or bioactive compounds. Graphical Abstract

The oriental fruit fly, Bactrocera dorsalis (Hendel), poses a significant threat to the global fruit industry, causing damage to diverse fruits like citrus, mango, and guava. Chemical pesticides have limited effectiveness, and pesticide residues and pesticide resistance are pressing issues. Therefore, it is essential to develop environmentally friendly pest control methods to address this problem. Behavior-modifying chemicals, including male attractants and intersex protein baits, play a critical role in the control of B. dorsalis. The mature host fruit serves as both an oviposition site and food source under natural conditions, making it a potential attraction source for oriental fruit flies. Orange, Citrus sinensis, is a main host of B. dorsalis, and commercial orange juice is a common attractant for the egg laying of B. dorsalis. Although it can both attract and elicit oviposition behaviors in B. dorsalis adults, its active components are still unclear. This study utilized analytical chemistry, behavioral tests, and electrophysiology to identify the active components of commercial orange juice that attract B. dorsalis, with the aim of providing a reference for the development of behavior-modifying chemical-based techniques to control B. dorsalis. Five compounds with a high abundance were identified via a GC-MS, including D-Limonene, butanoic acid ethyl ester, β-myrcene, linalool, and α-terpineol. Behavioral and electrophysiological experiments uncovered that D-Limonene was the active substance that was the main attractant in the mixture of these five substances, evoking a strong electrophysiological response in adult B. dorsalis. D-Limonene strongly attracts adult B. dorsalis only when they are sexually mature, and the attraction is not rhythmic. Olfaction plays a leading role in the attraction of D-Limonene to adult B. dorsalis, and Orco−/− mediates the perception of D-Limonene by B. dorsalis. Overall, D-Limonene is one of the key attractant compounds for B. dorsalis in the volatile compounds of commercial orange juice, offering possible support for the development of behavior-modifying chemical-based technology to control B. dorsalis in the future. [ABSTRACT FROM AUTHOR]

Long-term exposure to arsenic can lead to testicular damage and lower sperm quality in males, which is mediated by increased arsenic-induced oxidative stress and other damage mechanisms. D-Limonene, which is rich in oranges, lemons, oranges, grapes and other natural fruits, can relieve doxorubicin (DOX)-induced kidney injury and CCL4-induced cardiac toxicity by inhibiting oxidative stress and inflammatory response. The antioxidant and anti-inflammatory properties of D-limonene motivate us to further explore whether it can reduce arsenic-induced testicular injury. To verify this scientific hypothesis, testicular pathology, testicular oxidative stress levels and sperm motility were determined after intervention with D-limonene in rats chronically exposed to arsenic. As expected, long-term arsenic exposure caused testicular tissue structure disturbances, increased levels of oxidative stress, and decreased sperm activation, all of which were significantly inhibited due to treatment with D-limonene. In conclusion, our data reveal a previously unproven beneficial effect of D-limonene, namely that D-limonene can inhibit arsenic-induced testicular injury, and also provide theoretical and experimental basis for the application of D-limonene in the treatment of arsenic-induced testicular injury. [ABSTRACT FROM AUTHOR]

The discovery of antibiotics and pesticides has greatly contributed to the social and economic development of human society but, due to the long-term irrational application, it has led to drug-resistant microorganisms, environmental damage, and other hazards, so the selection of alternative natural, safe, and non-hazardous bioactive substances is an effective solution for this problem. D-limonene is a bioactive compound widely present in various plant essential oils, exhibiting excellent broad-spectrum bioactivity and promising prospects for development and clinical application. This review provides a detailed overview of the biological activities of D-limonene, emphasizing its antimicrobial, anthelmintic, insecticidal, and medicinal potential. While nanoencapsulation technology shows promise in improving the physicochemical properties of D-limonene and enhancing its practical applications, it is also crucial to comprehensively evaluate the potential side effects of D-limonene before use. [ABSTRACT FROM AUTHOR]

Background: Cancer is a fatal disease that severely affects humans. Designing new anticancer strategies and understanding the mechanism of action of anticancer agents is imperative. Hypothesis/Purpose: In this study, we evaluated the utility of metformin and D-limonene, alone or in combination, as potential anticancer therapeutics using the human liver and breast cancer cell lines HepG2 and MCF-7. Study design: An integrated systems pharmacology approach is presented for illustrating the molecular interactions between metformin and D-limonene. Methods: We applied a systems-based analysis to introduce a drug–target–pathway network that clarifies different mechanisms of treatment. The combination treatment of metformin and D-limonene induced apoptosis in both cell lines compared with single drug treatments, as indicated by flow cytometric and gene expression analysis. Results: The mRNA expression of Bax and P53 genes were significantly upregulated while Bcl-2, iNOS, and Cox-2 were significantly downregulated in all treatment groups compared with normal cells. The percentages of late apoptotic HepG2 and MCF-7 cells were higher in all treatment groups, particularly in the combination treatment group. Calculations for the combination index (CI) revealed a synergistic effect between both drugs for HepG2 cells (CI = 0.14) and MCF-7 cells (CI = 0.22). Conclusion: Our data show that metformin, D-limonene, and their combinations exerted significant antitumor effects on the cancer cell lines by inducing apoptosis and modulating the expression of apoptotic genes. [ABSTRACT FROM AUTHOR]

Objective: To discuss the effect of D-limonene on the proliferation and apoptosis of the glioblastoma (GBM) cells, and to clarify its possible mechanism. Methods: The GBM cells were divided into control group (0 mmol·L-1 D-limonene) and 0. 2, 0. 4, 0. 6, 0. 8, and 1. 0 mmol·L-1 D-limonene groups. CCK-8 method was used to detect the inhibitory rates of proliferation of the cells in various groups; clone formation assay was used to detect the clone formation rates of the cells in various groups; Annexin V-FITC/PI method was used to detect the apoptotic rates of the cells in various groups; Western blotting method was used to detect the expression levels of protein kinase B (AKT), B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), and poly adenosine diphosphate (ADP)-ribose polymerase (PARP) proteins in the cells in various groups; imunofluorescence method was used to detect the expression levels of cleaved Caspase-3 protein in the cells in various groups. Fifteen model mice with subcutaneous tumor xenografts were randomly divided into blank group (0 mg·kg-1 ·d-1 D-limonene), low dose of D-limonene group (200 mg·kg-·1 d-1 D-limonene), and high dose of D-limonene group (400 mg· kg·-1 d-1 D-limonene), and there were 5 mice in each group. The inhibitory rates of the tumor in vitro in various groups were calculated; HE staining and immunohistochemical staining were used to observe the morphology of subcutaneous tumor tissue of the mice in various groups and the growth curves of the tumor were drawn; immunohistochemical assay was used to detect the positive expression rates of Ki67 protein in subcutaneous tumor tissue of the mice in various groups; TUNEL staining was used to detect the apoptosis of the tumor cells in various groups. Results: In control group, the cells were spindle-shaped, in good condition, growing closely and adherently, with normal organelles and cytoplasm. After treated for 48 h, the cells in 0. 6 mmol·L-1 D-limonene group showed reduced volume, intact but more permeable cell membranes, shrunken cytoplasm, internal vacuole structures, and some fragments floating in the solution. The cells in 0. 8 and 1. 0 mmol·L-1 D-limonene groups exhibited significant apoptotic bodies and were in an apoptotic state. The CCK-8 results showed that compared with control group, the inhibitory rates of proliferation of the U87, LN229, and GL261 cells in 0. 6, 0. 8, and 1. 0 mmol·L-1 D-limonene groups were significantly increased (P<0. 01), the inhibitory rates of proliferation of the U87 and GL261 cells were significantly increased (P<0. 01). The clone formation assay results showed that compared with control group, the clone formation rates of the U87, LN229, and GL261 cells in 0. 4, 0. 6, and 0. 8 mmol·L-1 D-limonene groups were significantly decreased (P<0. 05 or P<0. 01). The Annexin V-FITC/PI results showed that compared with control group, after treated with D-limonene for 48 h, the apoptotic rates of the LN229 cells in 0. 6, 0. 8, and 1. 0 mmol·L-1 D-limonene groups were significantly increased (P<0. 01). The Western blotting results showed that compared with control group, the expression levels of Bax proteins in the LN229 cells in 0. 6, 0. 8, and 1. 0 mmol·L-1 D-limonene groups were significantly increased (P<0. 01), while the expression levels of AKT and Bcl-2 proteins were significantly decreased (P<0. 01), the expression level of PARP protein in the LN229 cells in 0. 8 and 1. 0 mmol·L-1 D-limonene group was significanthy increased (P<0. 01). The immunofluorescence results showed that compared with control group, the expression levels of cleaved Caspase-3 protein in the LN229 cells in 0. 6, 0. 8, and 1. 0 mmol·L-1 D-limonene groups were significantly increased (P<0. 01). Compared with blank group, the tumor volumes of the mice in low and high doses of D-limonene groups were significantly decreased (P<0. 01). Compared with blank group, the tumor weights of the mice in low and high doses of D-limonene groups were significantly decreased (P<0. 05), and the inhitory rates of tumor were significantly increased (P<0. 05). The tumor cells in blank group were diffusely distributed, with deepened nuclear staining and increased nucleocytoplasmic ratio; a large number of degenerated and necrotic tumor cells were observed in tumor tissue of the mice in low and high doses of D-limonene groups. Compared with blank group, the positive expression rates of Ki67 protein in tumor tissue of the mice in low and high doses of D-limonene groups were significantly decreased (P<0. 01). Compared with blank group, the apoptotic rates of tumor cells of the mice in low and high doses of D-limonene groups were significantly increased (P<0. 01). Conclusion: D-limonene has the inhibitory effect on the proliferation of the GBM cells; its mechanism may be related to the regulation of AKT protein expression and the activation of the Caspase-3 pathway to induce the apoptosis. [ABSTRACT FROM AUTHOR]

Spray-drying is a commonly used method for producing powdered flavors, but the high temperatures involved often result in the loss of volatile molecules. To address this issue, our study focused on a novel approach: developing O/W Pickering emulsions with agri-food byproducts to encapsulate and protect D-limonene during spray-drying and storage. Emulsions formulated with lupin hull, lupin-byproduct (a water-insoluble protein–fiber byproduct derived from the production of lupin protein isolate), and camelina press-cake were subjected to spray-drying at 160 °C. The results revealed that these emulsions exhibited good stability against creaming. The characteristics of the dry emulsions (powders) were influenced by the concentration of byproducts. Quantitative analysis revealed that Pickering emulsions enhanced the retention of D-limonene during spray-drying, with the highest retention achieved using 3% lupin hull and 1% camelina press-cake. Notably, lupin-stabilized emulsions yielded powders with enhanced oxidative stability compared to those stabilized with camelina press-cake. Our findings highlight the potential of food-grade Pickering emulsions to improve the stability of volatile flavors during both processing and storage. [ABSTRACT FROM AUTHOR]

d-limonene is a volatile compound widely used in food flavorings, but it is chemically unstable in the presence of air, light, moisture, and high temperatures. Coacervation is a well-established technique which involves the formation of biopolymer nanocomplexes between negatively charged polysaccharides and positively charged proteins to protect bioactive components. The study shows the effect of pH, protein/polysaccharide ratio and total biopolymer concentration on complex coacervation of defatted wheat germ protein (DWGP) and apple pectin (high methoxyl pectin (HMP)) in the food industry as a carrier and delivery system for d-limonene. DWGP was used for the first time to form coacervate with apple pectin. Turbidity, ζ-potential and particle size of the complex coacervate and their individual biopolymers were examined for preliminary assays of complex coacervation. The optimum condition for DWGP/pectin complex coacervation was found to be at a ratio of 4:1 with a total biopolymer concentration of 1% and a pH of 4.0. The rheological properties of DWGP, pectin, and their coacervate were measured at various pH levels and ratios. The resulting coacervates, used to microencapsulate d-limonene, underwent spray-dried and were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. These findings have the potential to contribute to the development of DWGP/pectin complex coacervates as effective delivery systems for volatile aromas or bioactive compounds. [ABSTRACT FROM AUTHOR]

Microbial biotransformation is an efficient process for making high-value natural products in a controlled and environment friendly manner. Bioconversion of low value monoterpenes to high value products using fungi offers an effective strategy for producing desirable products. Efficient conversion of D-limonene, a monoterpene, into carveol is reported in this study by using an endophytic fungus, Aspergillus flavus IIIMF4012, isolated from the root of Rosa damascena. By optimizing different parameters, isolated strain resulted in the hydroxylation of D-limonene to carveol effectively and the process was carried out at 1 L scale which resulted in the formation of a mixture of carveol isomers (cis- carveol 23.82%, trans- carveol 17.21%). Further, the biotransformation was scaled up in 5 L fermenter and the product was characterized by GC-MS and NMR (1H & 13C). As a result, an efficient procedure was established for biotransforming a low-value molecule i.e., D-limonene into a high-value product i.e.,carveol. [ABSTRACT FROM AUTHOR]

Summary: D‐limonene is an important flavouring ingredient with a wide range of applications. However, its high volatility and low stability have severely impacted its application in the food industry. To address these limitations, temperature‐flavour release control system is expected to be established to reduce the loss of D‐limonene during processing and storage, as well as to control its release by temperature. The aim of the current study is to construct an oleogel system to encapsulate D‐limonene using carnauba wax as a gelling agent and palm oils (POs) as the base oil. POs with 24 °C, 38 °C, 42 °C, 48 °C, and 52 °C melting points were selected to systematically investigate the effects of the base oil melting point on the crystal morphology, interactions, physicochemical properties, microstructure, and D‐limonene release of the oleogels. The enthalpy of melting, enthalpy of crystallisation, hardness, stickiness, and gel strength increased in oleogels prepared using POs with a higher melting point. In addition, the oil‐binding capacity (OBC) (>95%) of the oleogels increased with the base oil melting point, while the fat crystal distribution became more homogeneous and denser. Based on the influence that extraction temperature has on the concentration of released D‐limonene (a lower concentration of aroma was released from high‐melting‐point POs oleogels at low temperatures (<1.9 mg mL−1), whereas the control group released >2.5 mg mL−1), suitable POs can be selected to achieve the release or retention of the aroma. These results demonstrate that a temperature‐responsive flavour delivery system can be prepared with different PO melting points. The molecular dynamics of flavour release revealed that storage temperature and fat crystalline state impact the cumulative release rate of D‐limonene. [ABSTRACT FROM AUTHOR]

The aim of this research was to investigate the effects of d-limonene on decreasing post-operative adhesion in rats and to understand the mechanisms involved. Peritoneal adhesions were induced by creating different incisions and excising a 1 × 1 cm section of the peritoneum. The experimental groups included a sham group, a control group in which peritoneal adhesions were induced without any treatment, and two treatment groups in which animals received d-limonene with dosages of 25 and 50 mg/kg after inducing peritoneal adhesions. Macroscopic examination of adhesions showed that both treatment groups had reduced adhesion bands in comparison to the control group. Immunohistochemical assessment of TGF-β1, TNF-α, and VEGF on day 14 revealed a significant increment in the level of immunopositive cells for the mentioned markers in the control group, whereas administration of limonene in both doses significantly reduced levels of TGF-β1, TNF-α, and VEGF (P < 0.05). Induction of peritoneal adhesions in the control group significantly increased TGF-β1, TNF-α, and VEGF on days 3 and 14 in western blot evaluation, while treatment with limonene significantly reduced TNF-α level on day 14 (P < 0.05). Moreover, VEGF levels in both treatment groups significantly reduced on days 3 and 14. In the control group, a significant increment in the levels of MDA and NO and a notable decline in the levels of GPX, CAT was observed (P < 0.05). Limonene 50 group significantly reduced MDA level and increased GPx and CAT levels on day 14 (P < 0.05). In summary, d-limonene reduced adhesion bands, inflammatory cytokines, angiogenesis, and oxidative stress. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bactrocera minax is a devastating pest of citrus fruits. However, there have been no effective control measures before. Few reports on the sex pheromones of B. minax are available. RESULTS: In this study, nine of the volatile compounds in adult females were identified using headspace solid‐phase microextraction (HS‐SPME) in combination with gas chromatography–mass spectrometry (GC–MS). Among them, d‐limonene, caprolactam, 2‐Nitro‐1H‐imidazole, and creatinine could evoke antennal responses in males. Field bioassays showed that only d‐limonene could lure male flies, with a relative lure rate of 78.18% in all tested samples, which was significantly higher than that of paraffin oil control, while all volatile compounds did not have any lure effective to female flies. Moreover, d‐limonene was diluted with paraffin oil into differential concentrations, the lure effect on males was better at 100, 500, and 800 μL d‐limonene mL−1 than pure d‐limonene (1000 μL mL−1). The relative male lure rate of d‐limonene at 100 μL mL−1 was 85.88%, which was significantly higher than that of food−baits (14.12%) on day 3. However, d‐limonene was unattractive to female and male Bactrocera dorsalis and Zeugodacus tau. Further kinetic analysis showed that female adults released d‐limonene around 15‐day post eclosion. Electroantennography 1 results showed that 500 μL mL−1 d‐limonene evoked the strongest responses to antennae of 10‐ to 25‐day‐old male flies. CONCLUSION: Our results indicated that d‐limonene could be a sex pheromone from female flies of B. minax, and it could be used as a male‐specific sex attractant for B. minax. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of an essential oil obtained from the fruit of Carum carvi L. (caraway oil), when used as a sensory additive in feed and water for drinking for all animal species. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) Panel concluded that the use of caraway oil is of no concern up to the following concentrations in complete feed: 9 mg/kg for chickens for fattening, 13 mg/kg for laying hens, 12 mg/kg for turkeys for fattening, 16 mg/kg for piglets, 19 mg/kg for pigs for fattening, 24 mg/kg for sows, 35 mg/kg for veal calves (milk replacer), 11 mg/kg for cattle for fattening, 10 mg/kg for dairy cows, sheep, goats, horses and rabbits, 25 mg/kg for salmonids and dogs. These conclusions were extrapolated to other physiologically related species. For cats, ornamental fish and other species, no conclusion can be drawn. The use of caraway oil in animal feed under the proposed conditions of use is safe for the consumer and the environment. The additive under assessment should be considered as an irritant to skin and eyes, and as a respiratory and skin sensitiser. When handling the essential oil, exposure of unprotected users to perillaldehyde may occur. Therefore, to reduce the risk, the exposure of the users should be minimised. Since C. carvi and its preparations were recognised to flavour food and its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.

Introduction: During non-surgical endodontic retreatment, gutta-percha (GP) solvents are indispensable in difficult cases when used with mechanical removal, however studies comparing their efficacy against different types of GP are limited. The purpose of this study was to investigate the softening effect of three solvents on the conventional (CGP), cross-linked carrier-based (CLGP), and thermoplasticized (TGP) and compare the effect of time on the softening effect of the solvents. Methods: Tested GP were embedded in cuboidal blocks of stone with their upper surfaces exposed (1 mm diameter). Three commercial GP solvents based on D-Limonene (DL), Eucalyptol oil (EO), and orange oil (OO) were added to the exposed GP before an indenter (weight = 1Kg) was applied. Using a digital camera, the indentation depth was measured (mm) directly after applying the solvent and indenter (T = 0), and after 1, 2, and 3 min of application (T = 1,2,3). The means of indentation depth were calculated and compared using a two-way analysis of variance and Tukey’s post-hoc test to assess the effect of the types of solvent, GP for each application duration, and Friedman’s test to evaluate the effect of application duration on the softening effect of solvents. Results: The type of GP (F = 261.43, p

This article discusses a case report of an 8-year-old girl who experienced shortness of breath and an itchy nose when brushing her teeth with different brands of toothpaste. Skin prick tests and open patch tests revealed that she had an immediate-type allergy to an aroma mixture called Optamint®, which contained the substances d-limonene and anethole. These substances are commonly used as fragrance and flavoring agents in various products. The findings suggest that fragrance ingredients in toothpaste can cause immediate-type allergies, and it is important to identify the specific allergens in order to address the issue. [Extracted from the article]

Purpose: Ticks infestation has a negative impact against human and animal health through blood sucking, transmission of blood-borne diseases and also caused economic losses. Methods: In the present study the adulticidal, ovicidal and larvicidal activity of d-limonene nanoemulsion (DLN) were evaluated against two tick species; Rhipicephalus annulatus and Rhipicephalus sanguineus. Nanoemulsion form of d-limonene was prepared, and its characteristics were evaluated using a UV spectrophotometer and zeta droplet size measurement. Acetylcholinesterase activity was determined. Results: The results revealed significant adulticidal effect with low LC50 and LC90 for d-limonene pure form (DL) against both adult tick spp. (R. annulatus and R. sanguineus) ((0.958 and 1.559%) and (2.26 and 3.51%), respectively). DLN LC50 and LC90 values were ((1.277 and 2.396) and (3.97 and 7.28), respectively) against R. annulatus and R. sanguineus, respectively. DL and DLN showed significant ovicidal effect against R. sanguineus at high concentrations (10 and 5%). In larval packet test, LC50 and LC90 values of DL were ((1.53 and 2.22%) and (6.81 and 12.07%), respectively) against R. annulatus and R. sanguineus, respectively, while LC50 and LC90 values of DLN were ((6.48 and 11.26%) and (7.82 and 13.59%), respectively) against R. annulatus and R. sanguineus, respectively. Significant acetylcholinesterase inhibition percentage was detected for both ticks spp. which treated by DL and DLN. Conclusion: Pure DL is more effective than DLN form against R. annulatus and R. sanguineus. [ABSTRACT FROM AUTHOR]

An amphotropic liquid crystal polyacetylene derivative with pyrimidine–type two-ringed mesogenic core, exhibiting both thermotropic and lyotropic liquid crystallinity, was synthesized in this study. The polyacetylene derivative showed a lyotropic liquid crystal in d-limonene. The cis configuration of the main chain was confirmed via1H NMR. Heat treatment induced cis–trans isomerization of the as-prepared polymer. Gas-phase iodine doping of the polymer initiated a chemical interaction between the polyene and iodine, acting as an electron acceptor, generating charge carriers (radical cations, solitons) detected with the electron spin resonance spectroscopy. Moreover, gas phase doping of the polymer induced cis–trans isomerization. [ABSTRACT FROM AUTHOR]

During non-surgical endodontic retreatment, gutta-percha (GP) solvents are indispensable in difficult cases when used with mechanical removal, however studies comparing their efficacy against different types of GP are limited. The purpose of this study was to investigate the softening effect of three solvents on the conventional (CGP), cross-linked carrier-based (CLGP), and thermoplasticized (TGP) and compare the effect of time on the softening effect of the solvents. Tested GP were embedded in cuboidal blocks of stone with their upper surfaces exposed (1 mm diameter). Three commercial GP solvents based on D-Limonene (DL), Eucalyptol oil (EO), and orange oil (OO) were added to the exposed GP before an indenter (weight = 1Kg) was applied. Using a digital camera, the indentation depth was measured (mm) directly after applying the solvent and indenter (T = 0), and after 1, 2, and 3 min of application (T = 1,2,3). The means of indentation depth were calculated and compared using a two-way analysis of variance and Tukey's post-hoc test to assess the effect of the types of solvent, GP for each application duration, and Friedman's test to evaluate the effect of application duration on the softening effect of solvents. The type of GP (F = 261.43, p < 0.001), type of solvent (F = 3.57, p = 0.015), and application duration (F = 53.088, p < 0.001) were all found to significantly affect GP softening. DL exhibited the highest and only significant effect on CGP after 1 min (p < 0.05), while OO had the only significant effect against CLGP when applied for at least 2 min (p < 0.05). Both OO and EO had significant softening effects on TGP instantly or after 1 min of application, respectively. The results of this study revealed that the softening effect of GP solvents varies depending on their type, their application duration, and the type of GP. [ABSTRACT FROM AUTHOR]

Meloidogyne spp. are important parasitic nematodes affecting a variety of plants worldwide. We investigated the nematicidal properties of specific compounds found in bio-fumigant plants, particularly linalool, nonanal, methylene chloride, and 2-Decanal. Laboratory findings revealed that methylene chloride and 2-Decenal effectively reduced populations of second-stage juveniles (J2s). Additionally, the research explored the effects of tomato (Solanum lycopersicum L.) on M. incognita J2s, observing that tomato leaves significantly increased J2 mortality for all time measurements and different temperatures, while the opposite results were observed for root-stems. In the study, leaf treatment resulted in a maximum mortality response (MRmax) and half-maximal effective concentration (EC50) of approximately 100% and 4.0 µg/mg, respectively, at a temperature of 35 °C by week 8. In contrast, the root-stems treatment showed an MRmax of 13.5% and an EC50 of 3.0 ± 1.7 µg/mg. GC-MS analysis identified key compounds in tomato leaves and root-stems, such as α-pinene, d-limonene, and linalool. The results suggest that tomato leaves have potential as effective bio-fumigants for controlling root-knot nematodes. [ABSTRACT FROM AUTHOR]

Glossogyne tenuifolia (Labill.) Cass. ex Cass (Compositae) is a herbaceous plant that is endemic to Taiwan. Traditional Chinese Medicine has utilized it as a treatment for fever, inflammation, and liver preservation. Recent research has unveiled its bioactivities, including anti-inflammation, anti-cancer, antiviral, antioxidant, anti-fatigue, hepatoprotection, and immune modulation elements. Nevertheless, its effect on skin health remains to be investigated. Thus, we investigated the impact of G. tenuifolia essential oil (GTEO) on forskolin (FRK)-induced melanin biosynthesis and its mechanisms in B16-F10 murine melanoma in vitro. Treatment of GTEO resulted in a substantial decrease in FRK-induced melanin production, accompanied by a significant decrease in tyrosinase mRNA and protein expression levels. Additionally, our data demonstrated that the decrease in tyrosinase expression resulted from the suppression of MITF, as indicated by the reduced movement of MITF into the cell nucleus. Moreover, GTEO prompted a prolonged ERK1/2 activation, leading to the decline of MITF through proteasomal degradation, and it was verified that GTEO had no inhibitory impact on MITF activity in ERK1/2 inhibitor-treated cells. Additional studies demonstrated that α-pinene and D-limonene, which are the primary components in GTEO, showed strong melanin and tyrosinase inhibitory effects, indicating that α-pinene and D-limonene may contribute to its anti-melanogenic effects. Collectively, these data presented compelling proof that GTEO, along with its primary components α-pinene and D-limonene, show great potential as natural sources for developing innovative skin-whitening agents in the field of cosmetics.

The Pichia kluyveri, a proliferation commonly found in Sichuan pickles (SCPs), can accelerate the growth and reproduction of spoilage bacteria, causing off-odor development and decay. Although D-limonene, a common natural preservative, effectively restricts P. kluyveri, its inhibitory mechanism remains unclear. This study aimed to elucidate this molecular mechanism by investigating the impact on basic P. kluyveri metabolism. The findings revealed that D-limonene inhibited P. kluyveri growth and disrupted the transcription of the genes responsible for encoding the enzymes involved in cell wall and membrane synthesis, oxidative phosphorylation, glycolysis, and the tricarboxylic acid (TCA) cycle pathway. The results indicated that these events disrupted crucial metabolism such as cell wall and membrane integrity, adenosine triphosphate (ATP) synthesis, and reactive oxygen species (ROS) balance. These insights provided a comprehensive understanding of the inhibitory effect of D-limonene on the growth and reproduction of P. kluyveri while highlighting its potential application in the SCP industry.

Volatile organic compounds (VOCs) pose significant risks to human health and environmental quality, prompting stringent regulations on their emissions from various industrial processes. Among VOCs, d-limonene stands out due to its low threshold and contribution to malodorous emissions. While biofiltration presents a promising approach for VOC removal, including d-limonene, a comprehensive understanding of its performance and kinetics is lacking. This study aims to comprehensively assess the performance of a lab-scale biotrickling filter in treating gas-phase d-limonene. The experimental results indicate that the biotrickling filter efficiently removed d-limonene, achieving a critical loading rate of 19.4 g m−3 h−1 and a maximum elimination capacity of 31.8 g m−3 h−1 (correspondingly, up to 85% removal) at the condition of 94.2 s of EBRT. Microbial activity played a significant role in biotrickling filter performance, with a strong linear correlation being observed between CO2 production and substrate consumption. The Michaelis–Menten model was employed to represent enzyme-catalyzed reactions, suggesting no inhibition during biotrickling filter operation.

ABSTRACTAtemoya (Annona squamosa x A. cherimola hybrid) is a typical climacteric fruit that has a high respiration rate after harvest, short storage life, and is highly susceptible to fruit cracking and rot. Therefore, this study was intended to apply D-limonene nanoemulsion coating on fruit to prolong the storage life, reduce spoilage, and facilitate the expansion of the market. Green mature atemoya fruit coated with different concentrations of D-limonene nanoemulsion (0.25%, 0.5%, 1.0%, 1.5%, and control) was stored in a 14°C refrigerator for relevant analysis and investigation. The results showed that the use of 0.25% D-limonene nanoemulsion inhibited the browning on the fruit surface, and reduced physiological metabolisms. The browning phenomenon on the fruit surface increased as the D-limonene concentration ratio increases. Since the high concentration caused damage to the peel cells, 0.25% D-limonene was chosen as optimum for atemoya coating. The fruit of atemoya maintained green peel color (L × 28.6, a × 6.63, b × 12.3) after storage at 14°C for 21 days with 0.25% D-limonene nanoemulsion coating. At the same time, after 0.2% D-limonene nanoemulsion coating, the weight loss rate was about % less than that of the control group (0.25% treatment was 11.3%; control was 14.2%) and high pectin content (0.25% treatment was 16.9 mg AGA g−1AIS−1; control was 9.89 mg AGA g−1AIS−1). Coating of D-limonene nanoemulsion can reduce the physiological response of atemoya fruits after harvesting, prolong the storage time, and increase the feasibility of their export. From the experimental results, D-limonene showed the potential to be widely used in fruit preservation agents in the future.

d-limonene nanoemulsion (NE) previously showed satisfactory potential for storage stability and might be a safety carrier for transdermal drug delivery systems (TDDSs). Curcumin has been widely studied for health promotion, food safety, and functions. This study evaluated the application of d-limonene NE carrier for curcumin embedding and the transdermal absorption effect. Results revealed that the droplet size of curcumin NE affected the cumulative concentration of transdermal absorption following the descending order of hydrophilic-lipophilic balance (HLB) 11 > 8 > 5 > 3 > microemulsion (p

The polystyrene film as a formaldehyde-free adhesive for plywood production was developed from polystyrene foam waste (PSF) and D-limonene, extracted from orange peel waste. The influence of the weight ratio of solvent (D-limonene) to foam in the range of 1, 1.5 and 2 (w/w) on the properties of adhesive film and plywood panels was studied. In addition, the effects of pressing temperatures of 150°C, 165°C and 180°C on the properties of the plywood were investigated. The adhesive film was characterized by measuring the melt flow index, the average molecular weight of the polymers and by FTIR. The bonding quality of the adhesive films was investigated by shear strength tests. Integrated gel permeation chromatography has also shown that the average molecular weight of PSF is drastically reduced by doubling the solvent content. Shear strength and bending properties were also significantly reduced by doubling the weight ratio of solvent to foam. The mechanical properties of plywood are positively affected with increasing press temperature to 165°C. In general, plywood bonded with an adhesive film prepared with a solvent to foam weight ratio of 1 and press temperature of 165°C was fulfilled the requirement according to EN314-2 for interior use. [ABSTRACT FROM AUTHOR]

D-limonene, derived from citrus essential oils, holds significant therapeutic potential but faces challenges due to its high volatility, especially in pharmaceutical formulations. This study investigates microemulsions as a promising delivery system for volatile compounds, emphasizing their thermal protection for D-limonene. The formulation development was guided by a pseudo-ternary phase diagram and involved assays with different surfactants. Microemulsions were achieved solely with Labrasol® (Gattefossé Brasil, São Paulo, Brazil), encompassing concentrations of 7.1% to 30.8% D-limonene, 28.6% to 57.1% Labrasol®, and 20.0% to 64.3% water. All formulations were homogeneous, transparent, and presented low viscosity, with adequate D-limonene content, indicating that the production is feasible at room temperature. While the formulations demonstrated robust physical stability under mechanical stress, they exhibited destabilization at temperatures exceeding 50 °C. In terms of oxidative stability, pure D-limonene exhibited an induction period of 4.88 min, whereas microemulsions extended this period by four to eight times. Notably, the induction period of the microemulsions remained practically unchanged pre and post-heating (70 °C), suggesting the formulation's ability to enhance the D-limonene thermal stability. This highlights the value of oxidative stability analysis as a quicker tool than conventional oxidative tests, while affirming microemulsions as a viable encapsulation strategy for D-limonene protection against elevated temperatures. [ABSTRACT FROM AUTHOR]

Diabetes mellitus is a major public health problem worldwide. Oxidative stress plays a pivotal role in the pathogenesis of diabetes as it is one of the inevitable outcomes of the cellular process. The present study aims to investigate the putative antihyperglycemic, antihyperlipidemic and antioxidant efficacy of limonene and vitamin E in comparison with metformin, a standard drug for therapy of diabetes. Diabetes was induced by a single intraperitoneal injection of 150 mg/kg of alloxan. There was a significant (P<0.05) increase in body weight of rats treated with limonene, vitamin E and combinatory therapy of limonene and vitamin E compared to the untreated diabetic group which showed decrease in weight. Combinatory therapy treatment of limonene and vitamin E showed significant difference (P<0.05) when compared with the groups treated with limonene, vitamin E and metformin. The combinatory therapy also reduced blood glucose levels, significantly (P < 0.05) compared to non-diabetic treated group treated with limonene and the group treated with metformin. Treatment with limonene and vitamin E, significantly (P< 0.05) ameliorated diabetic effect on MDA concentration and SOD activity. Pathological lesions observed in the pancreas treated with limonene, vitamin E and combinatory therapy of limonene and vitamin E showed normal tissue architecture compared to group treated with metformin. It was concluded that limonene and vitamin E exerted significant anti-diabetic and anti-hyperglycaemic effects in alloxan-induced diabetic rats. [ABSTRACT FROM AUTHOR]

Diaspis echinocacti (Bouché) is a significant pest affecting various cactus pear species worldwide. Over the past three years, this scale insect was able to build up a considerable population and had now reached a pest status in Morocco. To control this pest, insecticides with different modes of action were evaluated in laboratory and greenhouse. In laboratory bioassays, d-limonene at 30-150 cc/hl, mineral oil at 700-2400 cc/hl, potassium salts of fatty acid at 15-60 cc/hl, and pyriproxyfen at 8-37 cc/hl were evaluated against first instar nymphs and adult females of the cochineal, while only d-limonene applied at 150 cc/hl, mineral oil applied at 2000 and 2400 cc/hl, and potassium salts of fatty acid applied at 60 cc/hl were used in greenhouse tests. In laboratory tests, mineral oil at 2400 cc/hl, d-limonene at 150 cc/hl, and potassium salts of fatty acid at 60 cc/hl were the most effective against nymphs and adult females of the cochineal 48 hours after exposure to insecticide treatments, resulting in LT50 values of 24, 24 and 48 h (nymphs), and 48 h (adult females), respectively. Under greenhouse conditions, mineral oil at 2400 cc/hl and d-limonene at 150 cc/hl showed significantly higher mortality rates [70 and 67% (nymph) and 45 and 42% mortality (adult female), respectively] and a high potential for degrading waxy carapace covering the body of the cochineal. Effective control of this harmful pest depends on a justified use of these two insecticides (mineral oil and d-limonene) and requires the development of an integrated management approach.

The oriental fruit fly, Bactrocera dorsalis (Hendel), poses a significant threat to the global fruit industry, causing damage to diverse fruits like citrus, mango, and guava. Chemical pesticides have limited effectiveness, and pesticide residues and pesticide resistance are pressing issues. Therefore, it is essential to develop environmentally friendly pest control methods to address this problem. Behavior-modifying chemicals, including male attractants and intersex protein baits, play a critical role in the control of B. dorsalis. The mature host fruit serves as both an oviposition site and food source under natural conditions, making it a potential attraction source for oriental fruit flies. Orange, Citrus sinensis, is a main host of B. dorsalis, and commercial orange juice is a common attractant for the egg laying of B. dorsalis. Although it can both attract and elicit oviposition behaviors in B. dorsalis adults, its active components are still unclear. This study utilized analytical chemistry, behavioral tests, and electrophysiology to identify the active components of commercial orange juice that attract B. dorsalis, with the aim of providing a reference for the development of behavior-modifying chemical-based techniques to control B. dorsalis. Five compounds with a high abundance were identified via a GC-MS, including D-Limonene, butanoic acid ethyl ester, β-myrcene, linalool, and α-terpineol. Behavioral and electrophysiological experiments uncovered that D-Limonene was the active substance that was the main attractant in the mixture of these five substances, evoking a strong electrophysiological response in adult B. dorsalis. D-Limonene strongly attracts adult B. dorsalis only when they are sexually mature, and the attraction is not rhythmic. Olfaction plays a leading role in the attraction of D-Limonene to adult B. dorsalis, and Orco−/− mediates the perception of D-Limonene by B. dorsalis. Overall, D-Limonene is one of the key attractant compounds for B. dorsalis in the volatile compounds of commercial orange juice, offering possible support for the development of behavior-modifying chemical-based technology to control B. dorsalis in the future.

The discovery of antibiotics and pesticides has greatly contributed to the social and economic development of human society but, due to the long-term irrational application, it has led to drug-resistant microorganisms, environmental damage, and other hazards, so the selection of alternative natural, safe, and non-hazardous bioactive substances is an effective solution for this problem. D-limonene is a bioactive compound widely present in various plant essential oils, exhibiting excellent broad-spectrum bioactivity and promising prospects for development and clinical application. This review provides a detailed overview of the biological activities of D-limonene, emphasizing its antimicrobial, anthelmintic, insecticidal, and medicinal potential. While nanoencapsulation technology shows promise in improving the physicochemical properties of D-limonene and enhancing its practical applications, it is also crucial to comprehensively evaluate the potential side effects of D-limonene before use.

Spray-drying is a commonly used method for producing powdered flavors, but the high temperatures involved often result in the loss of volatile molecules. To address this issue, our study focused on a novel approach: developing O/W Pickering emulsions with agri-food byproducts to encapsulate and protect D-limonene during spray-drying and storage. Emulsions formulated with lupin hull, lupin-byproduct (a water-insoluble protein–fiber byproduct derived from the production of lupin protein isolate), and camelina press-cake were subjected to spray-drying at 160 °C. The results revealed that these emulsions exhibited good stability against creaming. The characteristics of the dry emulsions (powders) were influenced by the concentration of byproducts. Quantitative analysis revealed that Pickering emulsions enhanced the retention of D-limonene during spray-drying, with the highest retention achieved using 3% lupin hull and 1% camelina press-cake. Notably, lupin-stabilized emulsions yielded powders with enhanced oxidative stability compared to those stabilized with camelina press-cake. Our findings highlight the potential of food-grade Pickering emulsions to improve the stability of volatile flavors during both processing and storage.

The objective of this study was to develop novel invaethosomes (I-ETS) and invaflexosomes (I-FXS) to enhance the dermal delivery of clotrimazole (CZ). Twenty model CZ-loaded I-ETS and I-FXS formulations were created according to a face-centered central composite experimental design. CZ-loaded vesicle formulations containing a constant concentration of 0.025% w/v CZ and various amounts of ethanol, d-limonene, and polysorbate 20 as penetration enhancers were prepared using the thin film hydration method. The physicochemical characteristics, skin permeability, and antifungal activity were characterized. The skin permeability of the experimental CZ-loaded I-ETS/I-FXS was significantly higher than that of conventional ethosomes, flexosomes, and the commercial product (1% w/w CZ cream). The mechanism of action was confirmed to be skin penetration of low ethanol base vesicles through the disruption of the skin microstructure. The optimal I-ETS in vitro antifungal activity against C. albicans differed significantly from that of ETS and the commercial cream (control). The response surface methodology predicted by Design Expert® was helpful in understanding the complicated relationship between the causal factors and the response variables of the 0.025% w/v CZ-loaded I-ETS/I-FXS formulation. Based on the available information, double vesicles seem to be promising versatile carriers for dermal drug delivery of CZ. [ABSTRACT FROM AUTHOR]

Transglutaminase (TG) cross-linked whey proteins are used to prepare a D -limonene emulsion, which can solve the problems of easy oxidation and poor water solubility of D -limonene. TG cross-linking can improve the emulsion stability of whey protein isolate (WPI). SDS PAGE results showed that TG cross-linked WPI and limonene were emulsified under high-pressure homogenization to form the emulsion (WPI-TG-Oil), which had more molecular polymers. The adsorption rate of interfacial protein of the WPI-TG-Oil emulsion was significantly increased by 5.15 % compared to the WPI limonene emulsion cross-linked with TG (WPI-Oil-TG). After a 10-day storage interval, the CDs and POV showed that the WPI-TG-Oil emulsion had the strongest oxidation stability and a thickened interfacial layer. It was also noted that WPI-TG-Oil was difficult to hydrolyze during the digestion process due to the large degree of cross-linking and many high molecular weight polymers. The WPI-TG-Oil emulsion was more stable with a high molecular weight and improved the overall properties. Moreover, these findings provide basic theoretical and technical support for improving the stability of D -limonene emulsions. The most suitable processing method was TG-crosslinked WPI to form a stable emulsion, which improved the physiochemical and emulsifying properties of its emulsion for potential uses in food, cosmetics, and other industries. [Display omitted] • TG cross-linking and emulsification were crucial for D -limonene emulsion. • WPI-TG-Oil had more molecular polymers than WPI-Oil-TG. • WPI-TG-Oil emulsion had the strongest oxidation stability. [ABSTRACT FROM AUTHOR]

Breast cancer one of the most common diseases in women, has a high death and morbidity rate. Tamoxifen being very much effective in the chemoprevention of breast cancer has been shown to develop resistance during the course of treatment making it difficult for patient's survival. By combining tamoxifen with naturally occurring substances having similar activities, might control the toxicity and increase the susceptibility towards the treatment. As a natural compound, D-limonene has been reported to inhibit the growth of certain malignancies significantly. The main goal of our work is to investigate the combinatorial antitumor effects of D-limonene and tamoxifen in MCF-7 cells, as well as understand the potential underlying anticancer mechanism. MTT assays, colony formation assays, DAPI and Annexin V-FITC labeling, flow cytometer analysis, and western blot analysis were used to explore the details of anticancer mechanism. The combined effects of tamoxifen with D-limonene have shown significant decrease in the cell viability of MCF 7 cells. According to flow cytometer analyses and Annexin V/PI staining, D-limonene has been found to increase tamoxifen-mediated apoptosis as compared to the treatment alone in these cells. Additionally, cell growth has been found to be arrested at G1 phase by regulating cyclin D1 and cyclin B1. Our research consequently provided the first evidence that combining D-limonene and tamoxifen might increase the anticancer efficacy by inducing apoptosis in MCF 7 breast cancer cells. This combinatorial treatment strategy demands more research which might fulfill the need for improved treatment efficacy in controlling breast cancer. [ABSTRACT FROM AUTHOR]

Breast cancer is the most common type of cancer and the second most common cause of death. Influential and widely accepted breast cancer prevention strategies are still elusive. Aspirin and other nonsteroidal anti-inflammatory drugs, such as ibuprofen, are frequently recommended to treat fever, pain, and inflammation. Studies have shown that these medications also have anticancer effects. A key target of tumor-targeted therapy has been discovered in recent years, and it is the PI3K/AKT/mTOR signalling pathway. In order for tumour cells to proliferate, develop, migrate, and survive, the PI3K/AKT/mTOR signalling system is essential. So, using in silico analysis, we chose to determine whether the NSAID Diclofenac and other phytochemicals have anticancer properties and also act as PI3K/AKT/mTOR inhibitors. We conducted docking analyses for the drugs diclofenac, piperine, naringin, eugenol, d-limonene, cinnamaldehyde, and curcumin versus the FDA-approved AKT/PI3K and mTOR inhibitors alpelisib, rapamycin, and afuresertib. Both bioactivity and ADMET profiling were done for these drugs. We concluded from our in silico analysis that diclofenac, d-limonene, and piperine do not contradict any of Lipinski's rules and can be effective AKT/PI3K/mTOR inhibitors. [ABSTRACT FROM AUTHOR]