[Protective effects of aqueous extracts from Sedum sarmentosum growing under different light intensity on CCl_4-induced damage in HepG2 cells].

To explore the effect of light intensity in cultivating environment on the hepetoprotective activity of Sedum sarmentosum, S. sarmentosum were planted under five water treatments for 60 days, namely 100% full sunlight(G1), 77% full sunlight(G2), 60% full sunlight(G3), 38% full sunlight(G4), and 16% full sunlight(G5) and CCl_4 drug-induced liver injury model in vitro was used. Cell viability, cell cycle, and cell apoptosis were individually detected by MTT, PI single staining, and Annexin-V FITC/PI double staining assays. Additionally, ALT, AST and antioxidant index in supernatant were determined by colorimetry. And the relationship among the protective effects, chemical composition and antioxidant activity were also analyzed. The results showed that S. sarmentosum aqueous extract could significantly improve the HepG2 cell viability. Among the five S. sarmentosum groups, the cell viability of G1(100% full sunlight) treatment was the highest, and the cell apoptosis was the least. Meanwhile, the level of ALT, AST, and MDA in G1 was the lowest, but it achieved the highest level of SOD and GSH. Moderate light shading(60% full light) also improved the effect of protecting liver and reducing the enzyme. It was found that cell viability was positively correlated with ferricion reducing capacity. ALT activity was positively correlated with isorhamnetin content. Taken together, different light intensity had great influence on hepatoprotective effect of S. sarmentosum, which may be related to its antioxidant capacity. From the perspective of hepetoprotective activity, S. sarmentosum should be planted under full light.