Mycotoxin detection in selected medicinal plants using chromatographic techniques

Mycotoxins are toxic mycological products that when consumed, absorbed or inhaled cause sickness or even the death of humans. Therefore, the present study aimed to evaluate the contamination levels of mycotoxins (aflatoxins, AFB1 , AFB2 , AFG1 , AFG2 , and ochratoxin A, OTA) in selected medicinal herbs and shrubs using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). A total of 15 samples of medicinal herbs and shrubs were selected. Among them, four samples were aflatoxin contaminated while two samples were ochratoxin A contaminated. The highest level of aflatoxin was detected in Justicia adhathoda (4,704.94 ppb) through HPLC (153.4 ppb) and through TLC, while the lowest level of aflatoxin was detected in Pegnum harmala (205.1 ppb) through HPLC. Similarly, the highest level of OTA was detected in Dodonia viscosa (0.53 ppb) through HPLC (0.5 ppb) and through TLC, while the lowest level was detected in J. adhathoda (O.11 ppb) through HPLC (0.4 ppb) and through TLC. The OTA concentration was very low, being negligible and below permissible limits. The present study concludes that there is a potential risk for the consumption of herbal decoctions. Therefore, regular monitoring and proper management of mycotoxins, including aflatoxins and OTA, in herbal medicines are needed to ensure the safety of herbal drugs to protect consumers.

Efficacy and safety of licorice (Glycyrrhiza glabra) in moderately ill patients with COVID-19: a randomized controlled trial

Licorice extract (glycyrrhizin), a potent antiviral, anti-inflammatory, and antioxidant remedy, is a potential therapeutic option for COVID-19. We evaluated the efficacy and safety of licorice in patients with moderate COVID-19. In this study, 60 patients with confirmed COVID-19 were randomly assigned in a 1:1 ratio to receive licorice (at a dose of 760 mg three times a day for seven days) or control groups. The primary outcomes were SPO2, body temperature, and respiratory rate (RR) after the end of the intervention. The findings indicated that SPO2, body temperature, and RR had no significant difference between the groups at the end of the intervention. However, CRP and ALT improved in the licorice group toward the baseline. The number of patients with worse prognoses, LOS, mortality, and the incidence of adverse events were not different between the groups at the end of the study. Licorice had no beneficial effect on the clinical symptoms of COVID-19. Moreover, this intervention demonstrated a safe profile of adverse events. The confirmation of the results of this preparatory trial requires more detailed multiple-center trials with a larger sample size.

Modified Dingchuan Decoction treats cough-variant asthma by suppressing lung inflammation and regulating the lung microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Dingchuan Decoction (MDD) is a Chinese medicine formula containing 11 materials with cough suppression, asthma relief, and anti-inflammatory effects.

AIM OF THE STUDY

This study aimed to evaluate the therapeutic effect of MDD on cough-variant asthma (CVA) and to investigate its mechanism of action.

MATERIALS AND METHODS

The chemical constituents of MDD were analyzed by ultra-performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap HRMS). A guinea pig CVA model was established using an intramuscular injection of ovalbumin (OVA), combined with an intraperitoneal injection of aluminum hydroxide [Al(OH)₃] and nebulized OVA. At the beginning of day 18, the low, medium, and high MDD groups were gavaged with 7.23 g/kg, 14.46 g/kg, and 28.92 g/kg of MDD, respectively, and the positive group was gavaged with 5 mg/kg of prednisone acetate combined with 1 mg/kg of montelukast sodium; the normal and model groups were given an equal volume of distilled water, once a day for 21 days. The cough was induced by 10^-3 mol/L capsaicin solution 1 h after the last administration, and the number of coughs and the latency of coughs were evaluated. Hematoxylin and eosin staining (H&E) was used to observe pathological changes in the lungs and airways. The concentration of inflammatory factors in bronchoalveolar lavage fluid (BALF) was measured by enzyme-linked immunosorbent assay (ELISA). We analyzed the lung microbiota using 16 S ribosomal DNA (16 S rDNA) high-throughput sequencing.

RESULTS

The 38 chemical components were found in MDD, and MDD reduced the number of coughs in guinea pigs with CVA, prolonged cough latency, improved pathological damage to the lungs and airways, regulated inflammatory factor levels in BALF, and modulated the lung microbiota.

CONCLUSIONS

This study demonstrated that treating CVA with MDD may be related to inhibiting lung inflammation and regulating lung microbiota.

Identification of potential anti-pneumonia pharmacological components of Glycyrrhizae Radix et Rhizoma after the treatment with Gan An He Ji oral liquid

Glycyrrhizae Radix et Rhizoma, a traditional Chinese medicine also known as Gan Cao (GC), is frequently included in clinical prescriptions for the treatment of pneumonia. However, the pharmacological components of GC for pneumonia treatment are rarely explored. Gan An He Ji oral liquid (GAHJ) has a simple composition and contains GC liquid extracts and paregoric, and has been used clinically for many years. Therefore, GAHJ was selected as a compound preparation for the study of GC in the treatment of pneumonia. We conducted an in vivo study of patients with pneumonia undergoing GAHJ treatments for three days. Using the intelligent mass spectrometry data-processing technologies to analyze the metabolism of GC in vivo, we obtained 168 related components of GC in humans, consisting of 24 prototype components and 144 metabolites, with 135 compounds screened in plasma and 82 in urine. After analysis of the metabolic transformation relationship and relative exposure, six components (liquiritin, liquiritigenin, glycyrrhizin, glycyrrhetinic acid, daidzin, and formononetin) were selected as potential effective components. The experimental results based on two animal pneumonia models and the inflammatory cell model showed that the mixture of these six components was effective in the treatment of pneumonia and lung injury and could effectively downregulate the level of inducible nitric oxide synthase (iNOS). Interestingly, glycyrrhetinic acid exhibited the strongest inhibition on iNOS and the highest exposure in vivo. The following molecular dynamic simulations indicated a strong bond between glycyrrhetinic acid and iNOS. Thus, the current study provides a pharmaceutical basis for GC and reveals the possible corresponding mechanisms in pneumonia treatment.

A new insight in immunomodulatory impact of botanicals in treating avian coccidiosis

Avian coccidiosis is caused by genus Eimeria (E.) i.e. E. maxima, E. necatrix, E. tenella, E. acervulina, E. brunette and E. mitis and lead to three billion US dollar per year economic loss in poultry industry and reduces the growth performance of birds. To purge undesirable foreign agents, immune system produces a variety of molecules and cells that ultimately neutralize target particles in healthy organisms. However; when this particular system compromises, infection develops and the load of pathogens along with their virulence factors overcome both; innate and adaptive immune systems. Livestock and poultry sectors are important part of agriculture industry worldwide. Due to excessive use of chemotherapeutic agents, pathogens have developed resistance against these agents leading to the great economic losses. Numerous therapeutic approaches are in routine process for the treatment and prevention of various ailments but irrational use of antibiotics/chemicals has raised alarming concerns, like the development of drug resistant strains, residual effects in ultimate users and environmental pollution. These problems have led to the development of alternatives. In this regard, anticoccidial vaccine can be used as an alternative but due to high cost of production, plant derived biological response modifiers and antioxidants compounds are considered as a promising alternative. This review summarizes the immunotherapeutic effects of different compounds particularly with reference to avian coccidiosis.

Liquorice Extract and 18β-Glycyrrhetinic Acid Protect Against Experimental Pyrrolizidine Alkaloid-Induced Hepatotoxicity in Rats Through Inhibiting Cytochrome P450-Mediated Metabolic Activation

Misuse of pyrrolizidine alkaloid (PA)-containing plants or consumption of PA-contaminated foodstuffs causes numerous poisoning cases in humans yearly, while effective therapeutic strategies are still limited. PA-induced liver injury was initiated by cytochrome P450 (CYP)-mediated metabolic activation and subsequent formation of adducts with cellular proteins. Liquorice, a hepato-protective herbal medicine, is commonly used concurrently with PA-containing herbs in many compound traditional Chinese medicine formulas, and no PA-poisoning cases have been reported with this combination. The present study aimed to investigate hepato-protective effects of liquorice aqueous extract (EX) and 18β-glycyrrhetinic acid (GA, the primary bioactive constituent of liquorice) against PA-induced hepatotoxicity and the underlying mechanism. Histopathological and biochemical analysis demonstrated that both single- and multiple-treatment of EX (500 mg/kg) or GA (50 mg/kg) significantly attenuated liver damage caused by retrorsine (RTS, a representative hepatotoxic PA). The formation of pyrrole-protein adducts was significantly reduced by single- (30.3% reduction in liver; 50.8% reduction in plasma) and multiple- (32.5% reduction in liver; 56.5% reduction in plasma) treatment of GA in rats. Single- and multiple-treatment of EX also decreased the formation of pyrrole-protein adducts, with 30.2 and 31.1% reduction in rat liver and 51.8 and 53.1% reduction in rat plasma, respectively. In addition, in vitro metabolism assay with rat liver microsomes demonstrated that GA reduced the formation of metabolic activation-derived pyrrole-glutathione conjugate in a dose-dependent manner with the estimated IC₅₀ value of 5.07 µM. Further mechanism study showed that GA inhibited activities of CYPs, especially CYP3A1, the major CYP isoform responsible for the metabolic activation of RTS in rats. Enzymatic kinetic study revealed a competitive inhibition of rat CYP3A1 by GA. In conclusion, our findings demonstrated that both EX and GA exhibited significant hepato-protective effects against RTS-induced hepatotoxicity, mainly through the competitive inhibition of CYP-mediated metabolic activation of RTS.

Glycyrrhiza glabra alcoholic root extract ameliorates hyperglycemia, hyperlipidemia, and glycation-induced free iron-mediated oxidative reactions

Hyperglycemia-associated oxidative stress leads to various pathophysiological complications in diabetes mellitus. Here, the effects of Glycyrrhiza glabra (G. glabra) root extract of streptozotocin (STZ)-induced diabetic changes and the associated free iron-mediated oxidative reactions were investigated. The animals were divided into five group, Group 1: Control (NC received buffer); Group 2: STZ-induced (DC); Group 3: Control treated with G. glabra root extract (NT, 60 mg/Kg b.w daily for 1 month); Group 4: Diabetic treated with the extract (60 mg/Kg b.w daily for 1 month); Group 5: Diabetic treated with glibenclamide (DTG, 8.6 mg/Kg b.w for 1 month). STZ (i) induced hyperglycemia, abnormal intraperitoneal glucose tolerance test (IPGTT), increased HbA_1c and decreased plasma insulin levels (ii) hyperlipidemia (iii) lowered antioxidant enzyme activities (iv) diminished RBC membrane fluidity (v) enhanced hemoglobin glycation-induced iron release and associated free radical reactions. Treatment with the extract resulted in significant reversal of hyperglycemia (DC: 205.0 ± 7.0 mg/dl vs. DT: 87.5 ± 4.5 mg/dl, p < .05); HbA_1c (DC: 11.5 ± 2.0 vs. DT: 7.5 ± 0.8 vs. DT: 7.5 ± 0.8, p < .05); insulin (DC: 0.3 ± 0.06 vs. DT: 1.25 ± 0.15 μgm/L, p < .05); free iron (DC: 150.4 ± 7.07 vs. DT: 98.8 ± 7.7 μgm/gm of Hb, p < .05); TBARS (DC + H₂ O₂ : 24.62 ± 11.30 vs. DC + H₂ O₂ : 9.82 ± 2.56 mmoles/h, p < .05); carbonyl (DC: 40.40 ± 1.57 vs. DT: 25.50 ± 1.12 mmoles/g of Hb, p < .05) levels and β-cell count/pancreatic islet (DC: 85 ± 15 vs. DT: 125 ± 20, p < .05). Thus, G. glabra extract is quite effective against hyperglycemia and the associated free iron-mediated oxidative stress. PRACTICAL APPLICATIONS: Chronic use of oral hypoglycemic synthetic drugs may produce side effects and drug resistance. Recently, various plant extracts are being researched to explore their antihyperglycemic potential. Here, the effects of this alcoholic powdered root extract on STZ-induced diabetic changes and associated oxidative stress, including hemoglobin-induced free iron-mediated oxidative reactions were examined. The STZ-induced diabetic changes and hemoglobin-glycation-induced free iron-mediated oxidative reactions were alleviated in the Wistar rats after 1-month of treatment with the extract. We have also reported previously that glycyrrhizin, a bioactive constituent of Glycyrrhiza glabra root inhibits peroxidase, esterase activities of hemoglobin and hemoglobin-mediated oxidative damage without affecting oxygen-binding capacity of the protein. This preclinical work further substantiates the potential therapeutic use of the G. glabra whole root extract in the treatment of diabetes mellitus.

Herb-drug interactions in diabetes mellitus: A review based on pre-clinical and clinical data

Global diabetes epidemic is the major cause of fatality and lethality. As per IDF 2019 report, diabetes caused 4.2 million deaths, approximately 463 million people are living with diabetes and by 2045, this will rise to 700 million. Nowadays, the physicians and common people in both developed and developing countries are using medicinal plants and their formulations to treat diseases with the postulation that organic commodities are safe for consumption. These plants may act as inhibitors or inducers of the Cytochrome P450 or transport and efflux proteins or both and may alter gastrointestinal, renal functions leading to Herb-Drug Interactions. This review intends to focus on the frequently employed medicinal plants, their traditional uses, their Cytochrome P450 inhibition or induction activity, phytochemical, and pharmacological effects, established HDI with the help of in vitro tools, in vivo pharmacokinetics and pharmacodynamics studies to understand the impact of herbs on ADME of the drug and whether it is beneficial, harmful or has no effect respectively. This review will help the physicians and other health care professionals as a reference guide to update their knowledge and expertise about HDI. However, more quality research in this area is needed to evaluate the efficacy of many herbal medicines, thereby reducing side effects and improving the safety of patients.

CYP3A4 mediated pharmacokinetics drug interaction potential of Maha-Yogaraj Gugglu and E, Z guggulsterone

Maha yogaraja guggulu (MYG) is a classical herbomineral polyherbal formulation being widely used since centuries. The aim of this study was to investigate the effect of MYG formulation and its major constituents E & Z guggulsterone on CYP3A4 mediated metabolism. In vitro inhibition of MYG and Guggulsterone isomers on CYP3A4 was evaluated by high throughput fluorometric assay. Eighteen Adult male Sprague–Dawley rats (200 ± 25 g body weight) were randomly divided into three groups. Group A, Group B and Group C were treated with placebo, MYG and Standard E & Z guggulsterone for 14 days respectively by oral route. On 15th day, midazolam (5 mg/kg) was administered orally to all rats in each group. Blood samples (0.3 mL) were collected from the retro orbital vein at 0.25, 0.5, 0.75, 1, 2, 4, 6, 12 and 24 h of each rat were collected. The findings from the in vitro & in vivo study proposed that the MYG tablets and its guggulsterone isomers have drug interaction potential when consumed along with conventional drugs which are CYP3A4 substrates. In vivo pharmacokinetic drug interaction study of midazolam pointed out that the MYG tablets and guggulsterone isomers showed an inhibitory activity towards CYP3A4 which may have leads to clinically significant interactions.

Clinical Pharmacokinetic Drug Interaction Potential of MenoAct851 in Adult, Female Healthy Volunteers

BACKGROUND

MenoAct851 (Varanasi BioResearch Pvt. Ltd., Varanasi, India) is a patented polyherbal formulation developed to manage menopause symptoms that can be taken along with other allopathic medicines.

OBJECTIVE

The present study aims to evaluate the drug interaction potential of MenoAct851 to inhibit cytochrome (CY) P450 in vitro in rats, and to measure its effects on simvastatin pharmacokinetic parameters in healthy human volunteers.

METHODS

CYP450-carbon monoxide assay of MenoAct851 was performed in rat liver microsomes to calculate the percentage inhibition. Fluorometric assays of CYP3A4 and CYP2D6 determined half maximal inhibitory concentration value. A double-blind, randomized, placebo-controlled drug interaction study of MenoAct851 was conducted in 24 healthy adult female volunteers aged 25 to 50 years. The selected volunteers were randomized to receive placebo or MenoAct851 500 mg BID PO for 14 days. On the 15th day, each group received 40 mg single-dose simvastatin. Blood samples were drawn at different intervals to measure simvastatin pharmacokinetic parameters.

RESULTS

The mean (SD) CYP450 concentration of the diluted microsome sample was calculated and found to be 0.405 (0.12) nmol/mg. The inhibitory potential of MenoAct851 (41.16% [1.24%]) was found to be less than ketoconazole. Half maximal inhibitory concentration values of MenoAct851 on CYP3A4 and CYP2D6 were 11.96 (1.04) µg/mL and 15.24 (0.58) µg/mL, respectively, but they were higher than respective positive controls. There was no statistically significant difference between MenoAct851 and placebo groups concerning the pharmacokinetic parameters such as Cmax, Tmax, t½, and mean residence time of simvastatin; however, AUC showed a significant difference (P < 0.05) between the groups.

CONCLUSIONS

MenoAct851 produced weaker interaction potential with CYP3A4 and CYP2D6 substrates based on in vitro assays, but the findings of clinical pharmacokinetic analysis indicate that MenoAct851 increased the AUC of simvastatin and simvastatin hydroxy acid. Therefore, coadministration of MenoAct851 might lead to drug-herb interaction, thereby affecting the therapeutic effect of CYP3A4 substrates. (Curr Ther Res Clin Exp. 2020; 81:XXX-XXX).

COVID-19: Is There Evidence for the Use of Herbal Medicines as Adjuvant Symptomatic Therapy?

BACKGROUND

Current recommendations for the self-management of SARS-Cov-2 disease (COVID-19) include self-isolation, rest, hydration, and the use of NSAID in case of high fever only. It is expected that many patients will add other symptomatic/adjuvant treatments, such as herbal medicines.

AIMS

To provide a benefits/risks assessment of selected herbal medicines traditionally indicated for "respiratory diseases" within the current frame of the COVID-19 pandemic as an adjuvant treatment.

METHOD

The plant selection was primarily based on species listed by the WHO and EMA, but some other herbal remedies were considered due to their widespread use in respiratory conditions. Preclinical and clinical data on their efficacy and safety were collected from authoritative sources. The target population were adults with early and mild flu symptoms without underlying conditions. These were evaluated according to a modified PrOACT-URL method with paracetamol, ibuprofen, and codeine as reference drugs. The benefits/risks balance of the treatments was classified as positive, promising, negative, and unknown.

RESULTS

A total of 39 herbal medicines were identified as very likely to appeal to the COVID-19 patient. According to our method, the benefits/risks assessment of the herbal medicines was found to be positive in 5 cases (Althaea officinalis, Commiphora molmol, Glycyrrhiza glabra, Hedera helix, and Sambucus nigra), promising in 12 cases (Allium sativum, Andrographis paniculata, Echinacea angustifolia, Echinacea purpurea, Eucalyptus globulus essential oil, Justicia pectoralis, Magnolia officinalis, Mikania glomerata, Pelargonium sidoides, Pimpinella anisum, Salix sp, Zingiber officinale), and unknown for the rest. On the same grounds, only ibuprofen resulted promising, but we could not find compelling evidence to endorse the use of paracetamol and/or codeine.

CONCLUSIONS

Our work suggests that several herbal medicines have safety margins superior to those of reference drugs and enough levels of evidence to start a clinical discussion about their potential use as adjuvants in the treatment of early/mild common flu in otherwise healthy adults within the context of COVID-19. While these herbal medicines will not cure or prevent the flu, they may both improve general patient well-being and offer them an opportunity to personalize the therapeutic approaches.

Herb-drug interactions: a mechanistic approach

In India, traditional herbal medicines have been an essential part of therapy for the last centuries. However, a large portion of the general populace is using these therapies in combination with allopathy lacking a proper understanding of possible interactions (synergistic or antagonistic) between the herbal product and the allopathic drug. This is based on the assumption that herbal drugs are relatively safe, i.e. without side effects. We have established a comprehensive understanding of the possible herb-drug interactions and identified interaction patterns between the most common herbs and drugs currently in use in the Indian market. For this purpose, we listed common interactors (herbs and allopathic drugs) using available scientific literature. Drugs were then categorized into therapeutic classes and aligned to produce a recognizable pattern present only if interactions were observed between a drug class and herb in the scientific literature. Interestingly, the top three categories (with highest interactors), antibiotics, oral hypoglycemics, and anticonvulsants, displayed synergistic interactions only. Another major interactor category was CYP450 enzymes, a natural component of our metabolism. Both activation and inhibition of CYP450 enzymes were observed. As many allopathic drugs are known CYP substrates, inhibitors or inducers, ingestion of an interacting herb could result in interaction with the co-administered drug. This information is largely unavailable for the Indian population and should be studied in greater detail to avoid such interactions. Although this information is not absolute, the systematic literature review proves the existence of herb-drug interactions in the literature and studies where no interaction was detected are equally important.

A Comprehensive Review for Phytochemical, Pharmacological, and Biosynthesis Studies on Glycyrrhiza spp

Licorice is extensively applied in food as well as herbal medicine across the world, possessing a substantial share in the global market. It has made great progress in chemical and pharmacological research in recent years. Currently, Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat., and Glycyrrhiza glabra L. were officially used as Gan-Cao according to the Chinese Pharmacopoeia. Accumulating evidence demonstrated three varieties of licorice have their own special compounds except for two quality markers set by Pharmacopoeia, providing great possibility for better understanding their characteristics, evaluating quality of each species and studying biosynthesis mechanisms of species-specific compounds. As a special "guide drug" in clinic, licorice plays an important role in Chinese herbal formulas. The interaction between licorice with other ingredients and their metabolism in vivo should also be taken into consideration. In addition, draft genome annotation, and success of the final step of glycyrrhizin biosynthesis have paved the way for biosynthesis of other active constituents in licorice, a promising beginning of solving source shortage. Accordingly, we comprehensively explored the nearly 400 chemical compounds found in the three varieties of licorice so far, systematically excavated various pharmacological activities, including metabolism via CYP450 system in vivo, and introduced the complete biosynthesis pathway of glycyrrhizin in licorice. The review will facilitate the further research toward this herbal medicine.

Glycyrrhiza glabra L. (Fabaceae/Leguminosae)

Liquorice is a perennial, temperate-zone herb or subshrub, native of India, Pakistan and southern Europe; also cultivated in England, Belgium, France, Germany, Spain, Italy, Greece, Turkey, Russia, South Africa, Egypt, Syria and Iraq. It has also been grown experimentally in the United States. Ancient historical manuscripts from China, India and Greece mention its use for symptoms of viral respiratory tract infections and hepatitis. The plant has also been described by Theophrastus. Licorice from Egypt has been described to be the best, followed by from Iraq and Syria; the root should be decorticated before use. It concocts viscid humours in diseases of liver, bladder and lungs, and expectorates them. It has been used in Iranian herbal medicine for skin eruptions, including dermatitis, eczema, pruritus and cysts, and for treatment of stomach disorders including peptic ulcers. The herb extract inhibits gastric motility in vivo, which is regarded to be an important aspect for its antiulcer activity. Licorice possesses both anti-inflammatory and antiulcer activities; whereas most anti-inflammatory agents are ulcerogenic. Former German Commission E believed it to be effective in the treatment of atopic dermatitis. Licorice root has been used for years to regulate gastrointestinal function in TCM, has been used for generations as an antidote, demulcent, and elixir in folk medicine of China, and is the most commonly used crude drug in Kampo Medicines, the Japanese form of modified TCM, for the treatment of peptic ulcer. Roots contain glycyrrhizin, the main water-soluble constituent that is 50× sweeter than sugar, 2-β-glucuronosyl glucuronic acid, and isoliquiritigenin-4-glucoside. Glycyrrhizin is a nonhemolytic saponin with foaming property, and one of the most potent hydroxyl radical scavengers. No significant effect of deglycyrrhizinised liquorice was observed on gastric ulcer in an RCT of British patients. Treatment of healthy men with licorice for one-week decreased salivary testosterone values by 26% but no significant decrease in free testosterone, and nine healthy women treated with licorice daily for two cycles, had their mean total serum testosterone decreased by 37% at the end of 2nd month. This property could be useful as an adjunct therapy of hirsutism and PCOS.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Natural products in licorice for the therapy of liver diseases: Progress and future opportunities

Liver diseases related complications represent a significant source of morbidity and mortality worldwide, creating a substantial economic burden. Oxidative stress, excessive inflammation, and dysregulated energy metabolism significantly contributed to liver diseases. Therefore, discovery of novel therapeutic drugs for the treatment of liver diseases are urgently required. Licorice is one of the most commonly used herbal drugs in Traditional Chinese Medicine for the treatment of liver diseases and drug-induced liver injury (DILI). Various bioactive components have been isolated and identified from the licorice, including glycyrrhizin, glycyrrhetinic acid, liquiritigenin, Isoliquiritigenin, licochalcone A, and glycycoumarin. Emerging evidence suggested that these natural products relieved liver diseases and prevented DILI through multi-targeting therapeutic mechanisms, including anti-steatosis, anti-oxidative stress, anti-inflammation, immunoregulation, anti-fibrosis, anti-cancer, and drug-drug interactions. In the current review, we summarized the recent progress in the research of hepatoprotective and toxic effects of different licorice-derived bioactive ingredients and also highlighted the potency of these compounds as promising therapeutic options for the treatment of liver diseases and DILI. We also outlined the networks of underlying molecular signaling pathways. Further pharmacology and toxicology research will contribute to the development of natural products in licorice and their derivatives as medicines with alluring prospect in the clinical application.

Interaction between phytotherapy and oral anticancer agents: prospective study and literature review

Cancer is becoming more prevalent in elderly patient. Due to polypharmacy, older adults with cancer are predisposed to drug-drug interactions. There is also an increasing interest in the use of complementary and alternative medicine (CAM). Thirty to seventy percent of patients with cancer have used CAM. Through pharmaceutical counseling sessions, we can provide advices on herb-drug interactions (HDI). All the patients seen in pharmaceutical counseling sessions were prospectively included. Information was collected during these sessions: prescribed medication (oral anticancer agents (OAA) and other drugs), CAM (phytotherapy especially), and use of over-the-counter (OTC) drugs. If pharmacist considered an interaction or an intervention clinically relevant, the oncologist was notified. Then, a literature review was realized to identify the potential HDI (no interactions, precautions for use, contraindication). Among 201 pharmacist counseling sessions, it resulted in 104 interventions related to 46 HDI, 28 drug-drug interactions and 30 others (wrong dosage, omission…). To determine HDI, we review 73 medicinal plants which are used by our patients with cancer and 31 OAA. A total of 1829 recommendations were formulated about 59 (75%) medical plants and their interaction with an OAA. Herb-drug interactions should not be ignored by healthcare providers in their management of cancer patients in daily practice.

RP-HPLC analysis of methanol extract of Viscum articulatum

BACKGROUND

Viscum articulatum Burm. (Family: Loranthaceae) is commonly known as mistletoe. In ayurveda, the plant parts are used in "Kapha", "Vata", diseases of the blood, ulcer, and epilepsy. The plant parts are also used in urinary tract infection and wound infection. The plant contains five triterpenoids such as α-amyrin, lupeol, betulin, betulinic acid and oleanolic acid, exhibiting several pharmacological activities including antimicrobial, anti-HIV, antitumor, antiviral activity.

OBJECTIVE

To ensure the content of uniformity of oleanolic acid, a RP-HPLC method has been developed for estimation of oleanolic acid in V. articulatum aerial part.

MATERIAL AND METHODS

The RP-HPLC method was carried out in reverse phase C₁₈ column, using methanol and water as mobile phase in the ratio of 95:5 (v/v), at the flow rate of 1 mL/min. The pH of aqueous phase was adjusted 3.2 with 1% (v/v) glacial acetic acid. The λ_max was set at 210 nm.

RESULTS

The retention time of oleanolic acid was found at 21.5 ± 0.05 min. The linearity of the response was found to be 10-800 μg/mL. The coefficient of determinants of oleanolic acid was found to be (r²) 0.995 and equation Y = 19462X + 16,172. The LOD and LOQ were found to be for oleanolic acid (1.96% w/w) 0.197 ± 0.63 and 0.623 ± 0.87 μg/mL, respectively. The developed method was accurate, specific, precise and reproducible.

CONCLUSION

This RP-HPLC may be useful for quantitative estimation of the chemical constituents present in the plant extract as well as the quality assessment of the herbal product.

Inhibitory Effect of Japanese Traditional Kampo Formula Frequently Prescribed in Gynecological Clinics on CYP3A4

Recently, the use of herbal medicines has become popular, and information on drug interactions between herbal medicines and chemical drugs is needed in clinics. In Japan, the number of patients taking Japanese traditional Kampo medicines has been increasing, and the proper drug information about herb-drug interaction is highly demanded. The most established herb-drug interaction is the case of grapefruit juice (GFJ) via the inhibition on CYP3A4 expressed in the small intestine. In the present study, we compared the inhibitory titer on CYP3A4 between the target Kampo products and GFJ used as positive control. We evaluated the inhibitory effects of GFJ and three extracts of Kampo formulas frequently used in gynecological clinics on CYP3A4 in vitro and calculated the related titer of one-time dosage of Kampo formulas to GFJ in order to predict its effect on clinics. Although the extracts of these three Kampo formulas and the most of crude drug components in the formulas exhibited the inhibitory effects on CYP3A4 in some levels, the possibilities of tokishakuyakusan and keishibukuryogan to cause drug interaction can be quite low; however, it is possible that the excessive dosage of kamishoyosan may cause drug interaction with the substrate of CYP3A4 in clinics.

Evaluation of herb-drug interaction of a polyherbal Ayurvedic formulation through high throughput cytochrome P450 enzyme inhibition assay

ETHNOPHARMACOLOGICAL RELEVANCE

Arishtas are Ayurvedic formulation made with decoction of herbs. Arjunarishta formulation is being used in Ayurveda for cardio-protective activity. Ashwagandharishta formulation possesses antioxidant, anti-atherosclerotic and anti-stress properties. Ridayarishta, a novel empirical formulation was prepared using combination of selected ingredients from these two formulations to support healthy heart functions and to reduce stress.

AIM OF THE STUDY

Aim of the Study was to investigate herb-drug interaction (HDI) of Ridayarishta formulation through human hepatic cytochrome P450 (CYP450) enzyme inhibition assay.

MATERIALS AND METHODS

Ridayarishta formulation was phyto-chemically standardized against arjunolic acid, arjunetin, berberine, piperine, resveratrol and withaferin-A using high performance thin layer chromatography (HPTLC) analysis. The formulation was standardized with respect to ethanol by gas chromatographic (GC) analysis. HDI was evaluated with Ridayarishta formulation and amlodipine besilate, atenolol, atorvastatin, metformin, glipizide glimepiride cocktail using high throughput CYP450 enzyme inhibition assay; against CYP1A2, 2C19, 2D6 and 3A4 isozymes.

RESULTS

Contents of arjunolic acid, arjunetin, berberine, piperine, resveratrol and withaferin-A in Ridayarishta formulation were found to be 1.76±0.12, 1.51±0.09, 1.85±0.05, 3.2±0.12, 1.21±0.08, and 2.16±0.09ppm, respectively. Quantity of ethanol in Ridayarishta was found to be 7.95±0.023% (V/V). Ridayarishta showed significantly higher (P<0.001) IC₅₀ value against CYP1A2 (IC₅₀-13.80±1.96µg/mL), 2C19 (IC₅₀-14.343±2.28µg/mL), 2D6 (IC₅₀-0.897±0.28µg/mL) and 3A4 (IC₅₀-32.057±2.51µg/mL) compared to positive controls such as furafylline, tranylcypromine, quinidine and ketoconazole respectively. Cocktail of herbal formulation and cardio protective, antihypertensive, anti-diabetic drugs showed significantly (P<0.001and P<0.01) less or negligible HDI.

CONCLUSION

Ridayarishta formulation alone and cocktail with amlodipine besilate, atenolol, atorvastatin, metformin, glipizide, glimepiride had negligible or insignificant effect on CYP450 inhibition. It may be concluded that consumption of Ridayarishta along with selective cardio protective, antihypertensive and anti-diabetic conventional medicine is safe with negligible or without any significant CYP450 (CYP1A2, 2C19, 2D6 and 3A4) inhibition mediated HDI.

Safety assessment of selected medicinal food plants used in Ayurveda through CYP450 enzyme inhibition study

BACKGROUND

Andrographis paniculata, Bacopa monnieri and Centella asiatica are mentioned in Ayurveda for the management of neurodegenerative disorders. These plants and their phytomolecules, such as andrographolide, bacoside A and asiaticoside, were studied for their inhibition potential on pooled CYP450 as well as human CYP3A4, CYP2D6, CYP2C9 and CYP1A2 by CYP-CO complex assay and fluorogenic assay respectively followed by IC₅₀ determination. Quantification of bioactive compounds present in the extracts was done by RP-HPLC. Heavy metal content in the selected medicinal plants was determined by atomic absorption spectroscopy.

RESULT

CYP-CO complex assay indicated significantly less inhibition potential than standard inhibitor (P < 0.05 and above). A. paniculata showed highest inhibitory activity against CYP3A4 and CYP2D6 (IC₅₀ = 63.06 ± 1.35 µg mL^-1 ; 88.80 ± 3.32 µg mL^-1 ), whereas C. asiatica and B. monnieri showed least inhibitory activity against CYP1A2 (IC₅₀ = 288.83 ± 1.61 µg mL^-1 ) and CYP2C9 (184.68 ± 3.79 µg mL^-1 ), respectively. In all cases the extract showed higher inhibition than the single bioactive compounds. The heavy metals content in the plant extracts were within the permissible limits.

CONCLUSION

The findings suggested that selected food plants and bioactive compounds contributed negligible interaction potential with CYP isozymes and may not possess any harmful effect with regard to their therapeutic application. © 2016 Society of Chemical Industry.

Effects of traditional herbal formulae on human CYP450 isozymes

OBJECTIVE

To assess the effects of traditional herbal formulae Sijunzi Decoction (, Sagunja-tang, SJZD), Siwu Decoction (, Samul-tang, SWD), Bawu Decoction (, Palmul-tang, BWD) and Shiquan Dabu Decoction (, Sipjeondaebo-tang, SDD) on the activities of human cytochrome P450 (CYP450), a drug-metabolizing enzyme.

METHODS

Herbal formula water extracts were filtered and lyophilized after the powder extracts were dissolved in distilled water. The activities of major human CYP450 isozymes (CYP3A4, CYP2C19, CYP2D6 and CYP2E1) were measured using in vitro fluorescence-based enzyme assays. The inhibitory effects of the herbal formulas on the activities of CYP450 were characterized as half maximal inhibition concentration (IC₅₀) values.

RESULTS

All the tested herbal formulae inhibited CYP2C19 activity (IC₅₀: SJZD, 83.28 μg/mL; SWD, 235.54 μg/mL; BWD, 166.82 μg/mL; SDD, 178.19 μg/mL); SJZD (IC₅₀ = 196.46 μg/mL), SWD (IC₅₀ = 333.42 μg/mL) and SDD (IC₅₀ = 163.42 μg/mL) inhibited CYP2E1-mediated metabolism; whereas BWD exhibited comparatively weak inhibition of CYP2E1 (IC₅₀ = 501.78 μg/mL). None of the four herbal formulas significantly affected CYP3A4 or CYP2D6.

CONCLUSIONS

These results suggest that SJZD, SWD, BWD and SDD could potentially inhibit the metabolism of co-administered synthetic drugs whose primary route of elimination is via CYP2C19. In addition, clinically relevant pharmacokinetic interactions could occur when SJZD, SWD or SDD is co-administered with drugs metabolized by CYP2E1. Our findings provide information for the safety and effective clinical use of these four classic herbal formulas.

Interaction potential of Trigonella foenum graceum through cytochrome P450 mediated inhibition

Objective:

The seeds of Trigonella foenum-graecum (TFG) (family: Leguminosae) are widely consumed both as a spice in food and Traditional Medicine in India. The present study was undertaken to evaluate the inhibitory effect of standardized extract of TFG and its major constituent trigonelline (TG) on rat liver microsome (RLM) and cytochrome P450 (CYP450) drug metabolizing isozymes (CYP3A4 and CYP2D6), which may indicate the possibility of a probable unwanted interaction.

Materials and Methods:

Reverse phase-high performance liquid chromatography method was developed to standardize the hydroalcoholic seed extract with standard TG. The inhibitory potential of the extract and TG was evaluated on RLM and CYP isozymes using CYP450-carbon monoxide (CYP450-CO) complex assay and fluorescence assay, respectively.

Results:

The content of TG in TFG was found to be 3.38% (w/w). The CYP-CO complex assay showed 23.32% inhibition on RLM. Fluorescence study revealed that the extract and the biomarker had some inhibition on CYP450 isozymes e.g. CYP3A4 and CYP2D6 (IC₅₀ values of the extract: 102.65 ± 2.63–142.23 ± 2.61 µg/ml and TG: 168.73 ± 4.03–180.90 ± 2.49 µg/ml) which was very less compared to positive controls ketoconazole and quinidine. Inhibition potential of TFG was little higher than TG but very less compared to positive controls.

Conclusions:

From the present study, we may conclude that the TFG or TG has very less potential to inhibit the CYP isozymes (CYP3A4, CYP2D6), so administration of this plant extract or its biomarker TG may be safe.

CYP450 mediated inhibition potential of Swertia chirata: An herb from Indian traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

An Ayurvedic herb, Swertia chirata (SC) have been used in treating various ailments such as hyperglycemia, leishmania, liver infections, inflammation, abdominal pain, bacterial infection, malaria etc. in Indian Systems of Medicine (ISM).

AIM OF THE STUDY

Study was designed to investigate the inhibition potential of the standardized SC extract along with its bioactive molecule ursolic acid on hepatic drug metabolizing isozymes (CYP3A4 and CYP2D6) and further some heavy metals were also analysed of the plant material.

MATERIALS AND METHODS

The hydro-alcoholic extract was standardized with standard ursolic acid by reverse phase-high performance liquid chromatography (RP-HPLC) method and the heavy metals content were analyzed through atomic absorption spectroscopy (AAS). The effect of extract on rat liver microsome (RLM) and individual CYP isozymes (CYP3A4 and CYP2D6) was investigated through CYP450-CO complex assay and fluorescence microplate assay respectively.

RESULTS

The content of ursolic acid was found to be 2.66% (w/w) in the SC extract and heavy metal contents along with trace elements were within the prescribed limits as per WHO guidelines. The inhibitory potential of SC extract on RLM was found to be 23.64±1.80%. CYP3A4 and CYP2D6 inhibitory effect of SC and ursolic acid (IC50: 197.49±2.68, 211.45±3.54 and IC50: 229.25±2.52, 212.66±1.26 µg/mL) was less as compared to that known inhibitors, ketoconazole and quinidine respectively.

CONCLUSIONS

The current study revealed that S. chirata has less inhibition potential with two major drug metabolizing isozymes CYP3A4 and CYP2D6. SC extract and ursolic acid showed significantly (P<0.001) less inhibitory potential on RLM. The Ayurvedic herb (SC) has shown less inhibitory activity in a concentration dependent manner against the tested two CYP450 enzymes. The tested heavy metals and trace elements present SC was within limit. Therefore, the traditional use of S. chirata may be safe in respect of both tested isozymes.

Peony-Glycyrrhiza Decoction, an Herbal Preparation, Inhibits Clozapine Metabolism via Cytochrome P450s, but Not Flavin-Containing Monooxygenase in In Vitro Models

Our previous studies have shown the therapeutic efficacy and underlying mechanisms of Peony-Glycyrrhiza Decoction (PGD), an herbal preparation, in treating antipsychotic-induced hyperprolactinemia in cultured cells, animal models, and human subjects. In the present study, we further evaluated pharmacokinetic interactions of PGD with clozapine (CLZ) in human liver microsomes (HLM), recombinantly expressed cytochrome P450s (P450s), and flavin-containing monooxygenases (FMOs). CLZ metabolites, N-demethyl-clozapine and clozapine-N-oxide, were measured. PGD, individual peony and glycyrrhiza preparations, and the two individual preparations in combination reduced production of CLZ metabolites to different extents in HLM. While the known bioactive constituents of PGD play a relatively minor role in the kinetic effects of PGD on P450 activity, PGD as a whole had a weak-to-moderate inhibitory potency toward P450s, in particular CYP1A2 and CYP3A4. FMOs are less actively involved in mediating CLZ metabolism and the PGD inhibition of CLZ. These results suggest that PGD has the capacity to suppress CLZ metabolism in the human liver microsomal system. This suppression is principally associated with the inhibition of related P450 activity but not FMOs. The present study provides in vitro evidence of herb-antipsychotic interactions.

Herb-drug interaction between an anti-HIV Chinese herbal SH formula and atazanavir in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

With the prevalent use of highly active antiretroviral therapy (HAART) for AIDS patients since 1996, the mortality of HIV/AIDS patients has been remarkably decreased. With long-term use of HAART, drug resistance and side effects of antiretrovirals have been frequently reported, which not only reduce the efficacy, but also decreases the tolerance of patients. Traditional herbal medicine has become more popular among HIV/AIDS patients as adjuvant therapy to reduce these adverse effects of HAART. SH formula is a Chinese herbal formula consisting of five traditional Chinese herbs including Morus alba L., Glycyrrhiza glabra L., Artemisia capillaris Thumb., Astragalus membranaceus Bge., and Carthamus tinctorius L. SH formula is clinically used for HIV treatment in Thailand. However, the possible pharmacokinetic interactions between these Chinese herbs and antiretroviral drugs have not been well documented. The aim of this study was to investigate the potential herb-drug interaction between SH herbal Chinese formula and the antiretroviral drug atazanavir (ATV).

MATERIALS AND METHODS

The combination effect of SH formula and ATV on HIV protease was studied in HIV-1 protease inhibition assay in vitro. The inhibition of SH formula on rat CYP3A2 was assessed by detecting the formation of 1'-OH midazolam from midazolam in rat liver microsomes in vitro. The in vivo pharmacokinetic interaction between SH formula and ATV was investigated by measuring time-dependent plasma concentrations of ATV in male Sprague-Dawley rats with liquid chromatography-mass spectrometry.

RESULTS

Through the in vitro HIV-1 protease inhibition assay, combination of SH formula (41.7-166.7 μg/ml) and ATV (16.7-33.3 ng/ml) showed additive inhibition on HIV-1 protease activity than SH formula or ATV used alone. In vitro incubation assay indicated that SH formula showed a weak inhibition (IC50=231.2 µg/ml; Ki=98.2 µg/ml) on CYP3A2 activity in rat liver microsomes. In vivo pharmacokinetic study demonstrated that SH formula did not affect the metabolism of ATV in rats.

CONCLUSIONS

Our study demonstrated for the first time that there is no metabolism-based herb-drug interaction between SH formula and ATV in rats, but this combination enhances the inhibition potentials against HIV protease activity. This observation may support the combinational use of anti-HIV treatment in human.

Effect of Coleus forskohlii and its major constituents on cytochrome P450 induction

Coleus forskohlii Briq. has been used traditionally for the treatment of several ailments since antiquity in Ayurveda. In the present study, an approach has been made to evaluate the effect of C. forskohlii and its major constituents on cytochrome P450 (CYP3A, CYP2B, and CYP2C) mRNA expression in rat hepatocytes. To gain better understanding of the herb-drug interaction potential of the chemical constituents present in C. forskohlii, the extract was subjected to column chromatography followed by standardization with respect to forskolin, 1-deoxyforskolin, and 1,9-dideoxyforskolin using reversed-phase high-performance liquid chromatography (RP-HPLC). Hepatocytes were treated with extracts, fractions, and phytoconstituents, followed by extraction and purification of total mRNA. Study of mRNA expression was carried out through reverse transcription polymerase chain reaction, followed by agarose gel electrophoresis. Results revealed that the test substances did not show any significant mRNA expression compared to the control against CYP3A, CYP2B, and CYP2C. Positive controls such as dexamethasone and rifampin showed significantly high (p < 0.001) induction potential compared to the control. It can be concluded that C. forskohlii and its major constituents may not be involved in CYP450 induction-based drug interaction.

Comparative inhibitory potential of selected dietary bioactive polyphenols, phytosterols on CYP3A4 and CYP2D6 with fluorometric high-throughput screening

Cytochrome P450 (CYP450) inhibition by the bioactive molecules of dietary supplements or herbal products leading to greater potential for toxicity of co-administered drugs. The present study was aimed to compare the inhibitory potential of selected common dietary bioactive molecules (Gallic acid, Ellagic acid, β-Sitosterol, Stigmasterol, Quercetin and Rutin) on CYP3A4 and CYP2D6 to assess safety through its inhibitory potency and to predict interaction potential with co-administered drugs. CYP450-CO complex assay was carried out for all the selected dietary bioactive molecules in isolated rat microsomes. CYP450 concentration of the rat liver microsome was found to be 0.474 nmol/mg protein, quercetin in DMSO has shown maximum inhibition on CYP450 (51.02 ± 1.24 %) but less when compared with positive control (79.02 ± 1.61 %). In high throughput fluorometric assay, IC50 value of quercetin (49.08 ± 1.02-54.36 ± 0.85 μg/ml) and gallic acid (78.46 ± 1.32-83.84 ± 1.06 μg/ml) was lower than other bioactive compounds on CYP3A4 and CYP2D6 respectively but it was higher than positive controls (06.28 ± 1.76-07.74 ± 1.32 μg/ml). In comparison of in vitro inhibitory potential on CYP3A4 and CYP2D6, consumption of food or herbal or dietary supplements containing quercetin and gallic acid without any limitation should be carefully considered when narrow therapeutic drugs are administered together.

The effects of Glycyrrhizae uralenis and its major bioactive components on pharmacokinetics of daphnetin in Cortex daphnes in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhizae uralenis (GU) is often prescribed together with Cortex daphnes (CD) in traditional Chinese medicinal practice to increase the efficacy of CD on the treatment of rheumatoid arthritis (RA), but the reasons were still unknown. In order to clarify the rationality of herbaceous compatibility between CD and GU, the comparative evaluations on pharmacokinetic behaviors of daphnetin (a predominantly active ingredient in CD) after intragastric administration of CD and CD-GU (combination of CD and GU) extract were studied. In addition, the effects of glycyrrhizin and liquiritin, active ingredients of Glycyrrhiza triterpenes and Glycyrrhiza flavones respectively, on the pharmacokinetics of daphnetin were also investigated.

MATERIALS AND METHODS

Five groups of rats were orally administered with CD extract, CD-GU extract, pure daphnetin, co-administration of daphnetin and glycyrrhizin as well as co-administration of daphnetin and liquiritin at the same single dose of daphnetin (20 mg/kg). The rat plasma concentrations of daphnetin were determined by our developed UPLC-MS/MS method. The pharmacokinetics of daphnetin in above groups were investigated and compared.

RESULTS

Comparing with oral administration of CD extract, AUC and Tmax of daphnetin significantly increased after giving CD-GU (p<0.05). In addition, in comparison to daphnetin alone, co-administration of daphnetin with liquiritin significantly increased the AUC and Cmax of daphnetin for ~1.5-fold, while co-administered with glycyrrhizin showed limited impact on the pharmacokinetics of daphnetin.

CONCLUSIONS

In this study, it was found that liquiritin, one of the major components of GU, significantly enhanced the bioavailability of the main component daphnetin in CD. In addition, the bioavailability of daphnetin in the CD-GU prescription was also significantly higher than that in CD alone, which could be due to liquiritin. Such results explained the mechanism of the increased efficacy in treating RA with the combined use of CD and GU.

Cytochrome P450 inhibitory potential and RP-HPLC standardization of trikatu--a Rasayana from Indian Ayurveda

ETHNOPHARMACOLOGICAL RELEVANCE

Trikatu is a very well known 'Rasayana' in Ayurveda and widely used as a polyherbal ayurvedic formulation in India. It consists of three well known plants, viz., Piper longum (PL), Piper nigrum (PN) and Zingiber officinale (ZO) in equal ratio. Trikatu has been prescribed for cough, cold, fever, asthma, respiratory problems and improvement of digestive disorders. The aim of the present study was to investigate the effect of individual ingredients of trikatu namely PL, PN, and ZO and formulations [Marketed formulation (MF) and laboratory formulation (LF)] on drug metabolizing enzymes (CYP3A4 and CYP2D6), to assess its herb-drug interaction potential through cytochrome P450 inhibition assays. Further this work was aimed to develop an RP-HPLC method for the identification and quantification of piperine and 6-gingerol in the crude drug trikatu.

MATERIALS AND METHODS

Enzyme inhibition effect of LF, MF, PL, PN and ZO was explored through CYP450-CO complex assay using rat liver microsomes (RLM) and a fluorescence screening method using individual isoenzymes (CYP3A4 and CYP2D6). The RP-HPLC method was developed for the identification and quantification of piperine and 6-gingerol in LF, MF and individual plant materials at the concentration of 1mg/mL.

RESULTS

RP-HPLC analysis confirmed the presence of piperine and 6-gingerol in LF and MF [Piperine: 7.89±2.12% (w/w) (MF), 6.70±2.13% (w/w) (LF)]; [6-gingerol: 5.3±1.21% (w/w) (MF), 4.95±2.34% (w/w) (LF)]. Inhibitory potential of MF and LF in CYP450-CO complex assay was found to be 37.54±3.12% (MF) and 35.12±2.31% (LF) and against CYP2D6 and CYP3A4 was estimated to be IC50 251.30±3.98 and 245.23±1.92μg/mL and IC50 225.50±1.02 and 223.254±0.92μg/mL respectively.

CONCLUSIONS

Different concentrations of the trikatu formulation and its individual components showed significantly (p<0.001) less inhibitory activity on individual isoenzymes as compared to the positive control. The crude drug exhibited inhibitory potential against the CYP450 enzymes in a concentration dependent manner. Outcome of the present study demonstrated that trikatu has less interaction potential with drug metabolizing enzymes.