Effects of aqueous extract of Polygoni Multiflori Radix and its main constituents on expression of mRNA of CYP1A2, CYP2C9, and CYP2E1 in human liver L02 cells / 中草药

ABSTRACT

Objective To analyze the main chemical constituents and their contents in aqueous extract of Polygoni Multiflori Radix (PMR, root of Polygonum multiflorum), and to elucidate the effects of aqueous extract of PMR and its main constituents on the expression of the mRNA of CYP1A2, CYP2C9, and CYP2E1 in human liver L02 cells. Methods The main chemical constituents and their content in aqueous extract of PMR were determined by HPLC. The cytotoxicity of aqueous extract of PMR and its main constituents on L02 cells was determined by MTT assay. The mRNA expression of CYP1A2, CYP2C9, and CYP2E1 in L02 cells were detected by quantitative real-time PCR. Results There were four main well-separated chromatographic peaks standing for tetrahydroxy stilbene glucoside, emodin-8-O-β-D-glucoside, emodin and physcion in aqueous extract of PMR. The content of thesecomponents in aqueous extract of PMR was (1.14 ± 0.03)%, (0.106 9 ± 0.001 6)%, (0.010 8 ± 0.000 9)%, (0.003 55 ± 0.000 19)%, respectively. The cytotoxicity of aqueous extract of PMR and emodin on L02 cells at 24 h was dose-dependent, and the concentration of 50% inhibition was 7.290 mg/mL and 0.082 mmol/L respectively. Tetrahydroxy stilbene glucoside, emodin-8-O-β-D-glucoside and physcion did not show significant cytotoxicity on L02 cells in the experimental concentrations. Aqueous extract of PMR and emodin significantly inhibited the expression of mRNA of CYP1A2, CYP2C9, and CYP2E1 in L02 cells. Emodin-8-O-β-D-glucoside inhibited the expression of mRNA of CYP1A2 and CYP2C9. Tetrahydroxy stilbene glucoside inhibited the expression of mRNA of CYP1A2 but activated the expression of mRNA of CYP2C9. Physcion inhibited the expression of mRNA of CYP1A2 and CYP2C9 in a dose-dependent manner, but inhibited the expression of mRNA of CYP2E1 in low concentration and activitated the expression of mRNA of CYP2E1 in high concentration. Conclusion The inhibition of aqueous extract of PMR on the expression of mRNA of CYP1A2, CYP2C9, and CYP2E1 in L02 cells is the combined effect of all components in it. The main four components all inhibit the expression of mRNA of CYP1A2. The anthraquinone is the main component inhibiting the expression of mRNA of CYP2C9. The free anthraquinone is the main component inhibiting the expression of mRNA of CYP2E1.