Inhibition of cytochrome P450 3A4 by Thai herbal teas and fruit juices

Abstract

The liver specific Cytochrome P450 3A4 (CYP3A4) enzyme plays an important role in metabolism of more than 30% of pharmaceutical drugs. However, inhibition of CYP3A4 activity by herbal or fruit constituents, the herb-drug interaction, could lead to various unpredicted side effects. In this study, the effect of popularly used herb and fruit juices were investigated on bacterially expressed and purified CYP3A4 enzyme in vitro. The remaining activities of CYP3A4 enzyme (testosterone 6ß-hydroxylation activity) at 10% v/v concentration of Thai herbs and fruit juices were determined. Among tested plant extracts (Anova, p-value < 0.05), Zingiber officinale and Averrhoa carambola juices could potently inhibit the human CYP3A4 by 80%, followed by Punica granatum, Citrus reticulate, Citrus aurantifolia and Citrus sinensis juices, (60-80%) respectively. According to the results, co-treatment of diseases by mentioned Thai herbs and fruit juices with pharmaceutical drug should be in caution, as the herb-drug interaction may lead to unpredictable outcome of treatment.