2,3,5,4-Tetrahydroxystilbene-2-O-Β-D-Glucoside Inhibiting Hepatocytes Injury Through Reducing the Expression of Tumor Necrosis Factor-a in LPSStimulated Kupffer Cells via Regulating PPAR-γ/NFκB

2,3,5,4'-Tetrahydroxystilbene-2-O-Β-D-Glucoside (TSG), a main bioactive component of polygonum multiflorum Thumb, exerts anti-oxidant, antitumor, anti-inflammatory effects. However, the protective effects of TSG on hepatocytes through anti-inflammatory effects have rarely been investigated. Mouse liver macrophages (Kupffer cells, KUP5 cells) were primed with various concentrations of TSG before Lipopolysaccharide (LPS) treatment, and AML12 hepatocytes were cultured with the supernatants of KUP5 cells. The results showed that TSG inhibits the expression of iNOS in KUP5 cells. Meanwhile, Tumor Necrosis Factor-a (TNF-a) and interleukin-1Β (IL-1Β) expression in KUP5 cells were reversed after TSG treatment. Additionally, the expression of Peroxisome Proliferators-Activated Receptors-γ (PPAR-γ) was up-regulated while the phosphorylation of p65 and IκB-a were decreased in KUP5 cells after TSG treatment. Furthermore, GW9662 (PPAR-γ antagonist) treatment could eliminate the anti-inflammatory effects of TSG. In AML12 hepatocytes, the level of AST, ALT, and apoptosis was decreased after being cultured with the supernatants of KUP5 cells pretreated with TSG. Moreover, TNF-a neutralization of KUP5 cells supernatants could decrease the level of AST, ALT, and AML12 hepatocyte apoptosis. These results indicate that TSG activates PPAR-γ, thereby decreasing nuclear factor kappa-B (NFκB) activation and reducing the release of TNF-a in macrophages to protect hepatocytes from injury. Our study may help further understand the protective effects of TSG on hepatocytes by suppressing liver inflammation.