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 μmol/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 500μmol/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 μmol/L （P 〈 0.05）, especially with 500 μmol/L protopanaxadiol （P 〈 0.01）. In addition, the ROS level was elevated in steatotic cells, but decreased after intervention with 500μmol/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. ：

Inhibitory effect of schisandrin B on free fatty acid-induced steatosis in L-02 cells

AIM:To investigate the effects of schisandrin B (Sch B) on free fatty acid (FFA)-induced steatosis in L-02 cells.METHODS:Cellular steatosis was induced by incubating L-02 cells with a FFA mixture (oleate and palmitate at the ratio of 2:1) for 24 h.Cytotoxicity and apoptosis were evaluated by 3-(4,5-dmethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and Annexin V/propidium iodide staining,respectively.Cellular total lipid was determined using a photocolorimetric method after Nile red staining,and triglyceride content was measured using an enzymatic kit.To study the effects of Sch B on steatosis,L-02 cells were treated with Sch B (1-100 μmol/L) in the absence or presence of 1 mmol/L FFA for 24 h,and cellular total lipid and triglyceride levels were measured.To explore the mechanisms of action of Sch B in the steatotic L-02 cells,mRNA levels of several regulators of hepatic lipid metabolism including adipose differentiation related protein (ADRP),sterol regulatory element binding protein 1 (SREBP-1),peroxisome proliferator-activated receptor (PPAR)-α and PPAR-γ were measured by quantitative real-time polymerase chain reaction (PCR),and protein levels of ADRP and SREBP-1 were measured by immunoblotting.RESULTS:Treatment with 1 mmol/L FFA for 24 h induced intracellular lipid accumulation in L-02 cells comparable to that in human steatotic livers without causing apparent apoptosis and cytotoxicity.Sch B mitigated cellular total lipid and triglyceride accumulations in the steatotic L-02 cells in a dose-dependent manner.Quantitative real-time PCR and Western blot analyses revealed that treatment of L-02 cells with 100 μmol/L Sch B reverted the FFA-stimulated up-regulation of ADRP and SREBP-1.CONCLUSION:Sch B inhibits FFA-induced steatosis in L-02 cells by,at least in part,reversing the up-regulation of ADRP and SREBP-1.