UHPLC-MS/MS and GC-MS screening of Synedrella nodiflora (L.) Gaertn. and its remedial effect in carbon tetrachloride (CCl)-induced HepG2 cells against oxidative stress and apoptosis.

Synedrella nodiflora (L.) Gaertn. is known for its medicinal properties in Malaysian traditional practice. Our previous study reported the prophylactic effect of S. nodiflora in protecting carbon tetrachloride (CCl)-induced hepatic injury in rats. This study aimed to identify the potential bioactive compounds in the same aqueous extract of S. nodiflora and to determine its remedial effect against CCl-induced oxidative stress and apoptosis in human HepG2 cells. Aqueous extract of S. nodiflora used in the previous prophylactic study was characterized using UHPLC-MS/MS and GC-MS to screen the extended phytochemical profile. HepG2 cells were exposed to CCl and post-treated with S. nodiflora (0-100 μg/mL) to determine the efficacy of the extract in repairing the damage, unlike the previous preventive study. The results of UHPLC-MS/MS of S. nodiflora aqueous extract showed putative annotations of glycosides, flavonoids, phenolics, terpenoids, and vitamins among the major phytochemicals present. The in vitro results exhibited improved HepG2 cell viability and reduced cellular ROS levels with increasing concentrations of S. nodiflora against CCl. The concentration of cytochrome C release and caspase 3 activity were reduced (p < 0.01) in CCl-induced HepG2 cells upon treatment with S. nodiflora. The activity of antioxidant enzyme superoxide dismutase (SOD) and reduced glutathione (GSH) levels were improved (p < 0.01) whereas malondialdehyde (MDA) levels were reduced (p < 0.01) by S. nodiflora in CCl-induced HepG2 cells. The levels of inflammatory cytokines TNF-α, IL-8, and IL-1β were suppressed in CCl-induced HepG2 cells by S. nodiflora. The findings suggest that the putatively annotated bioactive compounds of S. nodiflora may have reversed the oxidative stress and apoptosis induced by CCl in HepG2 cells.