Effect of Gegen Qinliantang-medicated Serum on Nonalcoholic Steatohepatitis Based on Nrf2/TXNIP Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect of Gegen Qinliantang （GGQLT）-medicated serum on free fatty acid （FFA）-induced nonalcoholic steatohepatitis （NASH） in vitro model of human hepatoma cells HepG2. MethodNASH model of HepG2 cells was established in vitro， and the cells were intervened with different volume fractions of GGQLT-medicated serum and resveratrol. Intracellular lipid deposition in each group was detected by oil red O staining， the level of reactive oxygen species （ROS） in each group were detected by flow cytometry， the levels of glutathione peroxidase （GSH-Px）， superoxide dismutase （SOD）， triglyceride （TG） and malondialdehyde （MDA） in each group were detected by kits. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to measure the mRNA expression levels of nuclear transcription factor （NF）E2-related factor 2 （Nrf2）， heme oxygenase-1 （HO-1）， quinone oxidoreductase 1 （NQO1）， Kelch-like epichlorohydrin-associated protein-1 （Keap1）， NF-κB， thioredoxin interacting protein （TXNIP）， interleukin-1β （IL-1β） in HepG2 cells of each group. The protein expression of Nrf2， TXNIP in cells of each group was detected by Western blot. ResultFFA induced large accumulation of intracellular lipids. Compared with the normal group， the activities of GSH-Px and SOD were significantly decreased （P<0.01） and the contents of TG， ROS and MDA were significantly increased （P<0.05， P<0.01） in the model group. Compared with the model group， all GGQLT groups and resveratrol group could elevate intracellular SOD activity to different degrees （P<0.05， P<0.01） and significantly reduce the levels of intracellular ROS and MDA （P<0.05， P<0.01）， GGQLD high- and medium-dose groups and resveratrol group significantly elevated GSH-Px activity （P<0.01）， GGQLD medium- and low-dose groups and resveratrol group significantly decreased TG content （P<0.05， P<0.01）. Compared with the model group， GGQLT high- and medium-dose groups and resveratrol group could significantly upregulate the mRNA expression levels of Nrf2， HO-1 and NQO1 （P<0.01）， all GGQLT groups and resveratrol group could significantly downregulate the TXNIP protein expression level， as well as significantly downregulate the mRNA expression levels of Keap1， NF-κB （P<0.05， P<0.01）. Nrf2-siRNA transfection of cells revealed that Nrf2 expression was significantly downregulated （P<0.01） in the Nrf2-siRNA group of cells by comparing with NC-siRNA group at the corresponding dose of drugs， and the inhibitory effects of GGQLT and resveratrol on TXNIP， IL-1β were attenuated. ConclusionFFA induces the production of ROS and inflammatory factors in HepG2 cells， and GGQLT can improve the anti-inflammatory and antioxidant capacities of cells， and its mechanism may be related to the regulation of Nrf2/TXNIP signaling pathway， so as to improve NASH.