Effect of Phyllanthus amarus Aqueous Extract on Human CYP3A4 Activity in HepG2 Cells

Abstract

Phyllanthus amarus Schum. & Thonn. has been used in traditional medicine for treatment of diverse conditions. Various pharmacological effects of its extracts have been reported such as hepatoprotective, antioxidant, anti-inflammatory, antiviral and anticarcinogenic activities. However, safety data regarding herb-drug interaction of this plant is still marginally reported. Drug interaction issue is one of the major concerns in drug utilization since it may cause therapeutic failure or serious adverse reaction of co-administered medicines. The purpose of this study was to investigate effect of P. amarus aqueous extract on human cytochrome P450 3A4 (CYP3A4) activity in hepatoma HepG2 cells. Cytotoxicity of P. amarus aqueous extract was determined by MTT assay. The result showed that the extract reduced percent cell viability of HepG2 cells with IC₅₀ values of 3.69, 1.76 and 1.24 mg/ml for the incubation periods of 24, 48 and 72 hours, respectively. The extract at concentration of 0.5 mg/ml significantly increased CYP3A4 activity in a time-dependent manner. As compared to the control, CYP3A4 activity was enhanced by 1.64, 2.07 and 2.43 fold following incubation with the extract for 24, 48 and 72 hours, respectively. The inductive effect of the extract found in this study provides an information of herb-drug interaction potential, thus further study in vivo is suggested.