title: Assessment of extracts from red yeast rice for herb-drug interaction by in-vitro and in-vivo assays.
abstract: Red yeast rice (RYR) is made by fermenting the yeast Monascus purpureus over rice. It is a source of natural red food colorants, a food garnish and a traditional medication. Results of the current study demonstrated that polar fractions of the RYR preparations contained herbal-drug interaction activity, which if left unremoved, enhanced P-glycoprotein activity and inhibited the major drug metabolizing cytochromes P450, i,e, CYP 1A2, 2C9 and 3A4. The data from Caco-2 cell absorption and animal model studies further demonstrated that the pharmacokinetic modulation effect by RYR preparations containing the polar fractions ("untreated" preparation) was greater than that from RYR preparations with the polar fractions removed ("treated" preparation). The data indicates a potential for herb-drug interactions to be present in RYR commonly sold as nutritional supplements when the polar fractions are not removed and this should be taken into consideration when RYR is consumed with medications, including verapamil.
authors.affiliation: Eu Yan Sang - Nanyang Polytechnic Laboratory, Block P, 504, 180 AngMo Kio Avenue 8 Singapore 569830, Singapore.
authors.forename: Wai To
authors.initials: WT
authors.lastname: Fung
authors.forename: G
authors.initials: G
authors.lastname: Subramaniam
authors.forename: Joel
authors.initials: J
authors.lastname: Lee
authors.forename: Heng Meng
authors.initials: HM
authors.lastname: Loh
authors.forename: Pak Ho Henry
authors.initials: PH
authors.lastname: Leung
mesh_terms: D000818:Animals; D001688:Biological Products / Q000737:chemistry*; D018938:Caco-2 Cells; D002853:Chromatography, Liquid; D004347:Drug Interactions; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D053719:Tandem Mass Spectrometry
chemical_list: D001688:Biological Products; D010936:Plant Extracts; C117343:red yeast rice