Oxidative stress is a crucial factor associated with fatty liver disease, which raises the possibility of using antioxidants to improve liver steatosis. Tanshinone IIA (TSIIA) is a traditional Chinese medicine that has been reported to have antioxidant effects in vitro. The present study aimed to investigate whether TSIIA possesses antioxidant effects in vivo and whether TSIIA was able to improve liver steatosis. Hence, the ability of TSIIA to protect rats from liver disease was explored, particularly in regard to antioxidant activity. Rats were fed a high-lipid diet for 90 days, causing severe liver steatosis, both morphologically and biochemically. An increase in reactive oxygen species (ROS) in the liver was exhibited in addition to significantly elevated serum lipids and malondialdehyde (MDA). Furthermore, hepatocyte apoptosis was measured by Hoechst staining, reverse transcription-quantitative polymerase chain reaction and western blot analysis and an increase in hepatocyte apoptosis rate was indicated in mice on a high-fat diet. Following intraperitoneal injection of TSIIA (10 mg/kg/day), liver steatosis was significantly inhibited. In rats receiving TSIIA treatment, less ROS were indicated in the liver and significantly decreased levels of MDA (P<0.05) in serum were exhibited, whereas significantly increased activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX) were observed (P<0.05 and P<0.01, respectively). In addition, the rate of hepatocyte apoptosis was significantly decreased in the TSIIA group (P<0.01). However, TSIIA elicited no effect on serum lipid profiles. These results suggest that TSIIA attenuates oxidative stress by decreasing ROS and MDA production and enhancing the activity of T-SOD and GSH-PX, which may contribute to the inhibition of apoptosis and amelioration of liver steatosis.
Keywords: apoptosis; fatty liver; free radical species; glutathione peroxidase; tanshinone IIA; total superoxide dismutase.