Abstract
Inflammation and oxidative stress are two crucial factors mediating liver fibrosis. Stachydrine (STA) is a naturally occurring compound extracted from a medicinal plant Leonuru heterophyllus, which can inhibit the proliferation and induce the apoptosis of breast cancer cells, relieve high glucose-induced endothelial cell senescence and isoproterenol-induced cardiac hypertrophy, and exert antitumor effects. However, its roles in hepatic fibrosis remain largely unknown. We aimed to evaluate the effect of STA on carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats and to elucidate the possible mechanisms. STA alleviated the pathological changes caused by CCl4 injection in livers compared to the normal liver. Hematoxylin-eosin staining further showed that STA treatment remarkably improved the liver histology, as evidenced by mitigated hepatic steatosis, necrosis, and fibrotic septa. STA reduced the liver/body weight ratio and the serum levels of aminotransferase, aspartate aminotransferase and alkaline phosphatase. It also significantly decreased collagen deposition and hydroxyproline level. Both mRNA and protein levels of α-SMA, α1(I)-procollagen and fibronectin were decreased by STA compared to those of the model group. STA significantly inhibited the expressions of inflammatory factors interleukin-6 (IL-6), IL-8, IL-1β, tumor necrosis factor-α, inducible nitric oxide synthase and cyclooxygenase-2. It suppressed oxidative stress by decreasing malondialdehyde level as well as increasing glutathione level and enzymatic activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase. STA also significantly increased the protein expressions of tissue inhibitor of metallopeptidase-1 (TIMP-1) and TIMP-2 but decreased those of matrix metalloproteinase-2 (MMP-2) and MMP-9, indicating excessive basement membrane in the fibrotic liver. Collectively, STA has potent protective effects on the liver, with therapeutic implication for liver fibrosis.