The effect of casing and gypsum on the yield and psychoactive tryptamine content of Psilocybe cubensis (Earle) Singer.

Psychedelic fungi have experienced a surge in interest in recent years. Most notably, the fungal secondary metabolite psilocybin has shown tremendous promise in the treatment of various psychiatric disorders. The mushroom species that produce this molecule are poorly understood. Here we sought to examine for the first time, the response of a psilocybin-producing species Psilocybe cubensis to casing (peat moss and vermiculite) and supplementation with gypsum (calcium sulfate dihydrate), two common practices in commercial mushroom cultivation. Mycelial samples of genetically authenticated P. cubensis were used to inoculate popcorn grain bags. The fully colonized bags of popcorn grain (0.15 kg) were transferred to bins of 0.85 kg pasteurized horse manure, with or without 1 cm thick layer of casing and/or 5 % gypsum. Our results indicate that the use of a casing layer significantly increases the biological efficiency (161.5 %), by approximately four fold, in comparison to control (40.5 %), albeit with a slight delay (∼2 days) for obtaining fruiting bodies and a somewhat reduced total tryptamine content (0.85 %) as gauged by High Performance Liquid Chromatography measurements. Supplementation with both casing and gypsum, however, appears to promote maximal yields (896.6 g/kg of dried substrate), with a biological efficiency of 89.6 %, while also maintaining high total tryptamine expressions (0.95 %). These findings, revealing methods for maximizing yield of harvest and expressions of psychoactive tryptamines, may prove useful for both home growers and commercial cultivators of this species, and ultimately support the growth of a robust industry with high quality natural products.

Dibenzyl trisulfide induces caspase-independent death and lysosomal membrane permeabilization of triple-negative breast cancer cells.

The Petiveria alliacea L. (P. alliacea) plant is traditionally used in folklore medicine throughout tropical regions of the world to treat arthritis, asthma, and cancer. Dibenzyl trisulfide (DTS) is one of the active ingredients within the P. alliacea plant. Triple-negative breast cancer (TNBC) is associated with a poor prognosis, particularly among women of West African ancestry, due in part to limited effective therapy. Though potent anticancer actions of DTS have been reported in a TNBC cell line, the mechanism of DTS-mediated cytotoxicity and cell death remains ill-defined. In the current study, we show that DTS exhibits cytotoxicity in a panel of triple-negative breast cancer (TNBC) cells derived from patients of European and West African ancestry. We found that DTS inhibits proliferation and migration of CRL-2335 cells derived from a patient of West African ancestry. DTS induces the expression of pro-apoptotic genes BAK1, GADD45a, and LTA in CRL2335 cells though it primarily promotes caspase-independent CRL-2335 cell death. DTS also promotes destabilization of the lysosomal membrane resulting in cathepsin B release in CRL-2335 cells. Finally, Kaplan-Meier survival curves reveal that higher expression of BAK1 and LTA in tumors from patients with TNBC is associated with longer relapse-free survival. Collectively, our data suggest that DTS confers promising antitumor efficacy in TNBC, in part, via lysosomal-mediated, caspase-independent cell death to warrant furthering its development as an anticancer agent.

Potential chemopreventive, anticancer and anti-inflammatory properties of a refined artocarpin-rich wood extract of Artocarpus heterophyllus Lam.

Colorectal cancer (CRC) represents the third leading cause of death among cancer patients below the age of 50, necessitating improved treatment and prevention initiatives. A crude methanol extract from the wood pulp of Artocarpus heterophyllus was found to be the most bioactive among multiple others, and an enriched extract containing 84% (w/v) artocarpin (determined by HPLC-MS-DAD) was prepared. The enriched extract irreversibly inhibited the activity of human cytochrome P450 CYP2C9, an enzyme previously shown to be overexpressed in CRC models. In vitro evaluations on heterologously expressed microsomes, revealed irreversible inhibitory kinetics with an IC50 value of 0.46 µg/mL. Time- and concentration-dependent cytotoxicity was observed on human cancerous HCT116 cells with an IC50 value of 4.23 mg/L in 72 h. We then employed the azoxymethane (AOM)/dextran sodium sulfate (DSS) colitis-induced model in C57BL/6 mice, which revealed that the enriched extract suppressed tumor multiplicity, reduced the protein expression of proliferating cell nuclear antigen, and attenuated the gene expression of proinflammatory cytokines (Il-6 and Ifn-γ) and protumorigenic markers (Pcna, Axin2, Vegf, and Myc). The extract significantly (p = 0.03) attenuated (threefold) the gene expression of murine Cyp2c37, an enzyme homologous to the human CYP2C9 enzyme. These promising chemopreventive, cytotoxic, anticancer and anti-inflammatory responses, combined with an absence of toxicity, validate further evaluation of A. heterophyllus extract as a therapeutic agent.

Selective cytotoxic and anti-metastatic activity in DU-145 prostate cancer cells induced by Annona muricata L. bark extract and phytochemical, annonacin.

BACKGROUND: Annona muricata L. was identified as a popular medicinal plant in treatment regimens among cancer patients in Jamaica by a previously conducted structured questionnaire. Ethnomedically used plant parts, were examined in this study against human prostate cancer cells for the first time and mechanisms of action elucidated for the most potent of them, along with the active phytochemical, annonacin. METHODS: Nine extracts of varying polarity from the leaves and bark of A. muricata were assessed initially for cytotoxicity using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on PC-3 prostate cancer cells and the ethyl acetate bark (EAB) extract was identified as the most potent. EAB extract was then standardized for annonacin content using High-performance Liquid Chromatography - Mass Spectrometry (HPLC-MS) and shown to be effective against a second prostate cancer cell line (DU-145) also. The mode of cell death in DU-145 cells were assessed via several apoptotic assays including induction of increased reactive oxygen species (ROS) production, reduction of mitochondrial membrane potential, activation of caspases and annexin V externalization combined with morphological observations using confocal microscopy. In addition, the potential to prevent metastasis was examined via inhibition of cell migration, vascular endothelial growth factor (VEGF) and angiogenesis using the chorioallantoic membrane assay (CAM). RESULTS: Annonacin and EAB extract displayed selective and potent cytotoxicity against the DU-145 prostate carcinoma cells with IC50 values of 0.1 ± 0.07 µM and 55.501 ± 0.55 µg/mL respectively, without impacting RWPE-1 normal prostate cells, in stark contrast to chemotherapeutic docetaxel which lacked such selectivity. Docetaxel's impact on the cancerous DU-145 was improved by 50% when used in combination with EAB extract. Insignificant levels of intracellular ROS content, depolarization of mitochondrial membrane, Caspase 3/7 activation, annexin V content, along with stained morphological evaluations, pointed to a non-apoptotic mode of cell death. The extract at 50 µg/mL deterred cell migration in the wound-healing assay, while inhibition of angiogenesis was displayed in the CAM and VEGF inhibition assays for both EAB (100 µg /mL) and annonacin (0.5 µM). CONCLUSIONS: Taken together, the standardized EAB extract and annonacin appear to induce selective and potent cell death via a necrotic pathway in DU-145 cells, while also preventing cell migration and angiogenesis, which warrant further examinations for mechanistic insights and validity in-vivo.

Hypotensive and antihypertensive effects of an aqueous extract from Guinep fruit (Melicoccus bijugatus Jacq) in rats.

Melicoccus bijugatus Jacq (Mb) has been reported to have cardiovascular modulatory effects. In this study, we evaluated the antihypertensive effects and mechanism of action of Mb on NG-Nitro-L-arginine Methyl Ester (L-NAME) and Deoxycorticosterone Acetate (DOCA) rat models. Aqueous extract of Mb fruit (100 mg/kg) was administered for 6 weeks to rats by gavage and blood pressure was recorded. Effects of the extract on vascular reactivity was evaluated using isolated organ baths, and tissues were collected for biochemical and histological analysis. The systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were significantly (P < 0.05) reduced with extract (100 mg/kg) administration and treatment compared to the hypertensive models. Mb (100 µg/mL) reduced the vascular contractility induced by phenylephrine (PE), and caused a dose-dependent relaxation of PE-induced contraction of aortic vascular rings. The vasorelaxation properties seemed to be endothelium dependent, as well as nitric oxide (NO) and guanylyl cyclase, but not prostaglandin dependent. Histomicrograph of transverse sections of the ventricles from the Mb group did not show abnormalities. The extract significantly (P < 0.05) reduced an L-NAME induced elevation of cardiac output and Creatine Kinase Muscle-Brain (CKMB), but had no significant impact on the activities of arylamine N-acetyltransferase. In conclusion, Mb significantly decreased blood pressure in hypertensive models. The extract possesses the ability to induce endothelium dependent vasodilation, which is dependent on guanylyl cyclase but not prostaglandins.

Chemical composition and biological activities of the essential oil from Cleome rutidosperma DC.

Cleome rutidosperma DC, commonly known in Jamaica as 'consumption-weed' is a plant traditionally used in folklore for treating tuberculosis and other infectious and chronic ailments. We evaluate for the first time the chemical composition and biological activities of the essential oil components of the complete aerial parts of this plant. The essential oil obtained by steam distillation (0.02%) was analyzed by a combination of gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectroscopy (GC-MS) and retention index (RI). The volatile oil of C. rutidosperma was dominated by oxygenated diterpenes (67.6%); with (Z)-phytol (65.1%) being the single most abundant constituent. C. rutidosperma aerial essential oil exhibited moderate inhibition against the activity of recombinant arylamine N-acetyltransferase (NAT) from Mycobacterium marinum (IC50 22.20 ±â€¯1.80 µg/µL), while, racemic phytol had an inhibition with an IC50 of 22.33 µg/µL ±â€¯0.50 µg/µL, thus accounting for the NAT inhibition imparted by the crude oil. Inhibition of NAT, a key enzyme in mycobacterial growth may be the pathway in which phytol, shown in this study to interact with the active site using in-silico methods, renders its previously demonstrated anti-tubercular properties. The phytol rich essential oil also demonstrated antimicrobial activity against all nine human pathogenic bacteria and the fungus strain assayed, with the most significant inhibitory activity against Bacillus cereus and justifies the need for further evaluation and development of the essential oils from this plant.

Inhibition of Cytochrome P450 Activities by Extracts of Hyptis verticillata Jacq.: Assessment for Potential HERB-Drug Interactions.

Understanding the potential for adverse drug reactions (ADRs), from herb-drug interactions, is a key aspect of medicinal plant safety, with particular relevance for public health in countries where medicinal plant use is highly prevalent. We undertook an in-depth assessment of extracts of Hyptis verticillata Jacq., via its impact on activities of key cytochrome P450 (CYP) enzymes (CYPs 1A1, 1A2, 1B1, 3A4 and 2D6), its antioxidant properties (determined by DPPH assays) and chemical characterisation (using LC-MS). The dried plant aqueous extract demonstrated potent inhibition of the activities of CYPs 1A1 (7.6 µg/mL), 1A2 (1.9 µg/mL), 1B1 (9.4 µg/mL) and 3A4 (6.8 µg/mL). Further analysis of other crude extracts demonstrated potent inhibition of CYP1A2 activity for a dried plant ethanol extract (1.5 µg/mL), fresh plant ethanol extract (3.9 µg/mL), and moderate activity for a fresh plant aqueous extract (27.8 µg/mL). All four extracts demonstrated strong antioxidant activity, compared to the positive control (ascorbic acid, 1.3 µg/mL), with the dried plant ethanol extract being the most potent (1.6 µg/mL). Analysis of the dried plant aqueous extract confirmed the identity of seven phytochemicals, five lignans and two triterpenes. Individual screening of these phytochemicals against the activity of CYP1A2 identified yatein as a moderate inhibitor (71.9 µM), likely to contribute to the plant extract's potent bioactivity. Further analysis on the impact of this plant on key drug metabolizing enzymes in vivo appears warranted for likely ADRs, as well as furthering development as a potential chemopreventive agent.

Reliance on medicinal plant therapy among cancer patients in Jamaica.

PURPOSE: Patients' perspective of their treatment regime plays a vital role in its success. Recognizing the high prevalence of medicinal plant usage among Jamaicans at large, we investigated the engagement of such remedies by cancer patients, with the aim of uncovering self-medicating habits, perceptions and details of utilized plants. METHODS: A structured, interviewer-based questionnaire was administered to 100 patients attending the oncology and urology clinics at the University Hospital of the West Indies in Kingston, Jamaica. A method of convenience sampling was employed and the data were analyzed using summary statistics and statistical significance tests. RESULTS: A large proportion (n = 80, 80%) of interviewed patients, engaged medicinal plants in their treatment regimes. Such habits were independent of person's education, economic status and were higher among the 55-74 age groups (p < 0.05) compared with younger patients. The use of herbs was hinged on the patient's strong sense of tradition and positive perspective of herbal efficacy (88%), fueled by anecdotal accounts from fellow patients. Majority of such users (74.7%) were under concomitant treatment with a prescription medicine, and worryingly, only 15% of patients made their oncologists aware. Annona muricata L. and Petiveria alliacea L. were the most commonly used plants for treating breast and prostate cancers, respectively. CONCLUSION: A large proportion of Jamaican cancer patients use medicinal plants in self-medicating practices and their perceptions and habits need to be considered by physicians, in the design of safe and effective care regimes.

Aqueous extract from leaf of Artocarpus altilis provides cardio-protection from isoproterenol induced myocardial damage in rats: Negative chronotropic and inotropic effects.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Artocarpus altilis (Parkinson ex F.A.Zorn, Fosberg) (Moraceae) are used in the management of hypertension; this study assessed the cardio-protective effects of the leaf extract on isoproterenol (ISO) induced myocardial damage in rats. MATERIAL AND METHODS: Twenty (20) adult male Sprague-Dawley rats (175-230g) were divided into 5 groups. Group 1 (Control), 2 (AA) received 50mg/Kg Artocarpus altilis (AA) only; 3 (ISO) received 85mg/Kg ISO only; 4 (ISO+AA/50) and 5 (ISO+AA/100) received 50 and 100mg/Kg AA respectively for 6 days, after induced with ISO twice (85mg/Kg) at a 24-h period. Blood pressure readings were taken before and after the administering of ISO using the tail cuff method. ECG was performed on anaesthetized rats. Cardiac contractility was measured in isolated right atrial muscles. Assessment of myocardial infarct (MI) size, heart/body weight ratio, biochemical, hematological and histo-morphological parameters were conducted at the end of seven days. An aqueous extract from leaves of A. altilis was analyzed for organic compounds using UHPLC mass spectrometry. RESULTS: ISO induced myocardial damage through an elevation of the heart rate (HR), infarct size and ECG distortions. Treatment with AA significantly (p˂0.05) reduced heart/body weight ratio (49%), MI (96%), HR (27%), sympathovagal imbalance (36%) and serum cardiac biomarkers (AST, LDH, HDL, triglycerides and CCK) caused by ISO. AA decreased the beat frequency of isolated right atrium (11%) cause by ISO, an action similar to propranolol (beta-adrenergic antagonist; 20%), but showed no significant changes in the QTc intervals of the ECG (suggesting no cardio-toxic drug-herb interactions), Thirty nine compounds were detected using high resolution LC-MS analysis (HPLC-Orbitrap-APCI-MS) in the extract. Pure compounds, as gallic acid and rutin, presented a higher negative chronotropic effect, similar to propranolol. CONCLUSION: Oral administration of aqueous extract of Artocarpus artilis has cardio-protective functions in myocardial injury, in part, by decreasing the HR, reduced contractility and infarct size. These findings may explain the cardio-protective use of A. altilis in traditional medicine.

Glaucarubulone glucoside from Castela macrophylla suppresses MCF-7 breast cancer cell growth and attenuates benzo[a]pyrene-mediated CYP1A gene induction.

Quassinoids often exhibit antioxidant and antiproliferative activity. Emerging evidence suggests that these natural metabolites also display chemopreventive actions. In this study, we investigated the potential for the quassinoid glaucarubulone glucoside (Gg), isolated from the endemic Jamaican plant Castela macrophylla (Simaroubaceae), to display potent cytotoxicity and inhibit human cytochrome P450s (CYPs), particularly CYP1A enzymes, known to convert polyaromatic hydrocarbons into carcinogenic metabolites. Gg reduced the viability of MCF-7 breast adenocarcinoma cells (IC50 = 121 nm) to a greater extent than standard of care anticancer agents 5-fluorouracil, tamoxifen (IC50 >10 µm) and the tamoxifen metabolite 4-hydroxytamoxifen (IC50 = 2.6 µm), yet was not cytotoxic to non-tumorigenic MCF-10A breast epithelial cells. Additionally, Gg induced MCF-7 breast cancer cell death. Gg blocked increases in reactive oxygen species in MCF-10A cells mediated by the polyaromatic hydrocarbon benzo[a]pyrene (B[a]P) metabolite B[a]P 1,6-quinone, yet downregulated the expression of genes that promote antioxidant activity in MCF-7 cells. This implies that Gg exhibits antioxidant and cytoprotective actions in non-tumorigenic breast epithelial cells and pro-oxidant, cytotoxic actions in breast cancer cells. Furthermore, Gg inhibited the activities of human CYP1A according to non-competitive kinetics and attenuated the ability of B[a]P to induce CYP1A gene expression in MCF-7 cells. These data indicate that Gg selectively suppresses MCF-7 breast cancer cell growth without impacting non-tumorigenic breast epithelial cells and blocks B[a]P-mediated CYP1A induction. Taken together, our data provide a rationale for further investigations of Gg and similar plant isolates as potential agents to treat and prevent breast cancer. Copyright © 2017 John Wiley & Sons, Ltd.

Possible mechanisms of action of the aqueous extract of Artocarpus altilis (breadfruit) leaves in producing hypotension in normotensive Sprague-Dawley rats.

CONTEXT AND OBJECTIVES: Artocarpus altilis (Parkinson) Fosberg (Moraceae) (breadfruit) leaves are used as an antihypertensive remedy. We investigated the possible mechanisms of action of its aqueous extract and its effect on cytochromes P450 (CYP) enzyme activities. MATERIALS AND METHODS: Intravenous administration of an aqueous leaf extract (20.88-146.18 mg/kg) of A. altilis on mean arterial pressure and heart rate were recorded via cannulation of the carotid artery on anaesthetized normotensive Sprague-Dawley rats. Recordings of the contractile activity of the aortic rings to the extract (0.71-4.26 mg/mL) were studied using standard organ bath techniques. Inhibitions of human CYP3A4 and CYP2D6 enzyme activities were evaluated by means of a fluorometric assay in 96 well plates using heterologously expressed microsomes. RESULTS: A. altilis caused significant (p < 0.05) hypotensive and bradycardiac responses unaffected by atropine (2 mg/kg) and mepyramine (5 mg/kg), but attenuated by propranolol (1 mg/kg) and N(G)-nitro-L-arginine methyl ester (5 mg/kg). The extract (0.71-4.26 mg/mL) significantly (p < 0.05) relaxed phenylephrine (10⁻9-10⁻4 M) and 80 mM KCl-induced contractions in endothelium intact and denuded aortic rings; and caused a significant (p < 0.05) rightward shift of the Ca²âº dose-response curves in Ca²âº-free Kreb's solution. Moderate inhibitions of cytochrome P450s (CYP3A4 and CYP2D6) enzyme activities with IC50 values of 0.695 ± 0.187 and 0.512 ± 0.131 mg/mL, respectively, were produced. CONCLUSION: A. altilis exhibits negative chronotropic and hypotensive effects through α-adrenoceptor and Ca²âº channel antagonism. Drug adversity effects are unlikely if the aqueous leaf extract is consumed with other medications reliant on CYP3A4 and CYP2D6 metabolism. This study thus provides scientific evidence for the use of the breadfruit in the treatment of hypertension.

The prevalence of herbal medicine home use and concomitant use with pharmaceutical medicines in Jamaica.

ETHNOPHARMACOLOGICAL RELEVANCE: The work described in this paper aimed to study the prevalence of herbal medicine use in treating illness and concomitant use with pharmaceutical medicines in Jamaica. MATERIALS AND METHODS: A survey using a structured questionnaire was administered by a trained interviewer to randomly selected adults in systematically selected households within randomly selected urban and rural clusters. Categorical data analysis was performed using Stata version 10 software. RESULTS: 91.4%(372/407) of selected people agreed to participate. 72.6%(270/372) self-medicated with herbs within the previous year. Commonly treated were illnesses of the respiratory system (RS, 77.8%(210/270)), gastro-intestinal tract (GIT, 53.3%(144/270)) and health maintenance using tonics (29.6%(80/270)). 26.7%(72/270) of respondents used pharmaceuticals concomitantly with medicinal plants. Commonly treated were illnesses of the RS (20.4%(55/270)), GIT (13.7%(37/270)) and hypertension (10.0%(27/270)). 19.4% (14/72) of physicians knew of such practices. There was significant association of herb use with/without drugs with age (p<0.001), employment status (p<0.001), religion (p=0.004), gender (p=0.02) and educational level (p=0.031). Thus prevalence of herb use alone was greatest amongst people aged 35-44 and 45-54 years; those employed; Rastafarians; those without health insurance; males and people who had completed secondary education. Whilst prevalence of concomitant herb-drug use was greater amongst people aged 65 years and older; those retired; those of religions other than Rastafarians and Christians, females and people who had attained primary education and below. CONCLUSIONS: Self-medication with herbs in Jamaica is highly prevalent and highest for self-limiting conditions of the RS, GIT and health maintenance with tonics. Concomitant herb and drug use is highest for self-limiting conditions of the RS, GIT and hypertension, and the use of combined therapy highlights the need for investigations on potential drug-herb interactions. Physicians have limited awareness and knowledge of such concomitant usage, further highlighting the need for increased dialogue with patients, knowledge of medicinal plants and their uses and a heightened pharmacovigilance to avoid adversities that may arise from potential drug-herb interactions.

The prevalence of herbs use in conjunction with conventional medicines in Jamaica.

UNLABELLED: Due to the global rise in the popularity of herbal medicines, adversities resulting from concomitant use of both prescription drugs and herbs are becoming an increasingly important public health issue. OBJECTIVES: To estimate the prevalence of the use of herbal medicines among persons on prescription medicines in Jamaica. Findings are thought to aid in estimates of the risk of adversities from drug-herb interactions through laboratory investigations and to provide awareness among policy makers responsible for the design of appropriate pharmacovigilance systems in the country. METHODS: A survey was conducted in eighteen pharmacies throughout Jamaica and patients or parents/carers of children who were on at least one prescription medicine were administered a structured questionnaire by trained interviewers. RESULTS: Of 399 persons invited to participate in the study 365 (91.5% response rate) agreed to do so and were included in the study. This study population consisted of 306 adults and 60 children and of that 243 adults (80.6%) and 45 children (75.6%) engaged in the concomitant use of herbs and drugs. Patients with a variety of disease conditions, in both rural and urban environs engaged in concomitant herb-drug use. Persons with higher salary (P<0.1) and those with health insurance (P<0.02) tended to have a lower prevalence of herb-drug concomitant use. Among persons indicating such practices the most commonly cited reason for concurrent use of prescription medicine and herbal preparations was the belief that there was no harm in taking both (269, 94.0%) followed by the belief that the prescription medicine alone was not adequate cure (211, 71%). Only 55 (18%) respondents who practised such co-medication indicated that their doctors knew of their use of herbal preparations. CONCLUSION: There is a high prevalence of herb-drug concomitant use in Jamaica, and an awareness within the medical community and those monitoring adversities would serve well to mitigate risks from potential drug-herb interactions.

Inhibition of CYP1A1 by Quassinoids found in Picrasma excelsa.

Infusions of the plant Picrasma excelsa, known as Jamaican bitterwood tea, are commonly consumed to lower blood sugar levels in diabetics who are already on prescription medicines. We therefore investigated the inhibition properties of this tea against a panel of cytochrome P450 (CYP) enzymes, which are primarily responsible for the metabolism of a majority of drugs on the market. The two major ingredients, quassin and neoquassin, were then isolated and used for further characterization. Inhibition of the activities of heterologously expressed CYP microsomes (CYPs 2D6, 3A4, 1A1, 1A2, 2C9, and 2C19) was monitored, and the most potent inhibition was found to be against CYP1A1, with IC (50) values of 9.2 microM and 11.9 microM for quassin and neoquassin, respectively. The moderate inhibition against the CYP1A1 isoform by quassin and neoquassin displayed partial competitive inhibition kinetics, with inhibition constants ( K(i)) of 10.8 +/- 1.6 microM, for quassin and competitive inhibition kinetics, with a K(i) of 11.3 +/- 0.9 microM, for neoquassin. We then docked these two inhibitors into the active site of a model of CYP1A1, which provided insight at the atomic level into the structure-activity relationship of quassinoids with respect to this important CYP isoform known to be an activator of carcinogens, thus providing a useful basis for the search for more potent inhibitors of CYP1A1 that may have implications in chemoprotection.

Herbal interactions involving cytochrome p450 enzymes: a mini review.

The metabolism of a drug can be altered by another drug or foreign chemical, and such interactions can often be clinically significant. Cytochrome P450 (CYP) enzymes, a superfamily of enzymes found mainly in the liver, are involved in the metabolism of a plethora of xenobiotics and have been shown to be involved in numerous interactions between drugs and food, herbs and other drugs. The observed induction and inhibition of CYP enzymes by natural products in the presence of a prescribed drug has (among other reasons) led to the general acceptance that natural therapies can have adverse effects, contrary to the popular beliefs in countries where there is an active practice of ethnomedicine. Herbal medicines such as St. John's wort, garlic, piperine, ginseng, and gingko, which are freely available over the counter, have given rise to serious clinical interactions when co-administered with prescription medicines. Such adversities have spurred various pre-clinical and in vitro investigations on a series of other herbal remedies, with their clinical relevance remaining to be established. Although the presence of numerous active ingredients in herbal medicines, foods and dietary supplements complicate experimentation, the observable interactions with CYP enzymes warrant systematic studies, so that metabolism-based interactions can be predicted and avoided more readily. This article highlights the involvement of CYP enzymes in metabolism-related drug-herb interactions and the importance of gaining a mechanism-based understanding to avoid potential adverse drug reactions, in addition to outlining other contributory factors, such as pharmacogenetics and recreational habits that may compound this important health issue.