Hepatoprotective effect of phenylethanoid glycosides from Incarvillea compacta against CCl4-induced cytotoxicity in HepG2 cells

Abstract

The extraction and solvent partition of roots of Incarvillea compacta, a traditional Tibetan folk medicine, and repeated column chromatography and preparative high-performance liquid chromatography for n-butanol fraction yielded four phenylethanoid glycosides, crenatoside (1), 3′′′-O-methylcrenatoside (2), leucoseceptoside A (3), and martynoside (4). The chemical structures were identified on the basis of spectroscopic data analyses including NMR and MS. All compounds were isolated for the first time from the plant. Compound 1 exerted better 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity. In addition, compounds 1–4 were evaluated for their hepatoprotective activity on carbon tetrachloride (CCl4)-induced liver injury in HepG2 cells. Pretreatment of HepG2 cells with compound 1–4 significantly increased the viability on CCl4-induced cell death. Furthermore, compounds 1–4 also alleviated CCl4-induced hepatotoxicity by enhancement of the antioxidant enzyme activities of superoxide dismutase and reduction of the malondialdehyde content, intracellular ROS as well as NF-κB transactivation. Our results suggest that phenylethanoid glycosides ameliorate CCl4-induced cell injury, and this protection was likely due to antioxidative activity and down-regulation of NF-κB.