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

• Published in: Journal of ethnopharmacology 2014-05, Vol.153 (3), p.674-681
• Main Authors: Harwansh, Ranjit K., Mukherjee, Kakali, Bhadra, Santanu, Kar, Amit, Bahadur, Shiv, Mitra, Achintya, Mukherjee, Pulok K.
• Format: Article
• Language: English
• Subjects: Alkenes - pharmacology; Animals; Ayurveda; Chromatography, High Pressure Liquid; Cytochrome P-450 CYP2D6 - metabolism; Cytochrome P-450 CYP3A - metabolism; Cytochrome P-450 Enzyme Inhibitors - pharmacology; Cytochrome P450; Dose-Response Relationship, Drug; Herb-Drug Interactions; Herb–drug interaction; Microsomes, Liver - metabolism; Piperidines - pharmacology; Rasayana; Rats; Spices; Trikatu
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2014.03.023

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. 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. 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. Different concentrations of the trikatu formulation and its individual components showed significantly (p