Bioactivity of five components of Chinese herbal formula Jiangzhi granules against hepatocellular steatosis

OBJECTIVE: This study aims to evaluate the bioactivity of five components of the traditional Chinese medicine complex prescription Jiangzhi granules against hepatocellular steatosis. METHODS: The five major components, including protopanaxadiol, tanshinone IIA, emodin, chlorogenic acid, and nuciferine, were extracted from Jiangzhi granules. Their cytotoxicity was assessed to determine the safe dose of each component for HepG2 cells. HepG2 cellular steatosis was induced using 1 mmol/L of free fatty acids (FFAs) for 24 h, and then treated with each component at high, intermediate, and low doses (500, 50, and 5 mu mol/L), respectively for another 24 h. The effects on HepG2 steatosis were observed directly under optical phase microscopy, or through oil red O staining and Nile red assays. In addition, the levels of reactive oxygen species (ROS) in the steatotic HepG2 cells with and without high-dose protopanaxadiol treatment were measured using fluorescent dye 2',7'-dichlorodihydrofluorescein diacetate staining. RESULTS: No obvious cytotoxicity was observed in the HepG2 cells incubated with each of the five components at up to 500 mu mol/L. At 24 h after incubation with FFAs, the HepG2 cells swelled and many lipid droplets accumulated. The lipid content was attenuated after 24 h of incubation with protopanaxadiol, tanshinone IIA, and emodin at 500 or 50 mu mol/L (P < 0.05), especially with 500 mu mol/L protopanaxadiol ( P < 0.01). In addition, the ROS level was elevated in steatotic cells, but decreased after intervention with 500 mu mol/L protopanaxadiol (P < 0.05). CONCLUSION: Protopanaxadiol, tanshinone IIA, and emodin alleviate hepatocellular steatosis in a dose-dependent manner, and oxidative stress regulation may partially contribute to the effects of protopanaxadiol.