Protective effect of Lysimachia christinae against acute alcohol-induced liver injury in mice.

Alcohol abuse is one of the main causes of liver disease worldwide and has become a social problem (1). Due to the increased frequency of drinking, incidence of alcoholic liver disease has increased in China, becoming another important risk factor for morbility and mortality in addition to viral hepatitis (2). However, there is no satisfactory therapy for alcoholic liver disease at present except for the combination of abstinence from alcohol and supportive care (3). There is increasing evidence that oxidative stress plays a vital role in pathogenesis of alcoholic liver disease (4-7). During alcohol-induced oxidative stress, reactive oxygen species (ROS) are produced and it is extremely reactive. Such ROS may modify and inactivate lipids, proteins, DNA, and RNA, and thus induce cell dysfunction. To inhibit ROS-induced cell injury, the antioxidant system has been generated in the body. The system includes low-molecular-mass antioxidants such as glutathione, alpha-tocopherol, ascorbic acid and the main antioxidant enzymes such Summary Lysimachia christinae Hance (Primulaceae) is a medicinal plant. The present study was undertaken to investigate protection of L. christinae against acute alcohol-induced liver injury in mice, the related mechanism of oxidative stress and its hepatoprotective chemical compound for the first time. Mice were orally administered alcohol at 6 g/kg 2 h after a 75% ethanol extract of L. christinae (ET) (100, 200, 400 mg/kg), quercetin (2, 4, 8 mg/kg) isolated from L. christinae, or bifendate (150 mg/kg) for seven consecutive days by intragastric administration (i.g.) except the normal group. Serum and liver tissue samples were collected 6 h after alcohol administration and the amount of quercetin in ET was analyzed by high-performance liquid chromatography (HPLC) with a diode array detector (DAD). The results showed that alcohol-induced elevated serum alanine transferase (ALT) and aspartate transaminase (AST) activities were significantly reduced by ET (200, 400 mg/kg), quercetin (4, 8 mg/kg) and bifendate (150 mg/kg), respectively. Further analysis demonstrated that lipid peroxidation (LPO) levels significantly decreased, while glutathione amounts, glutathione-s transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities all increased in livers of ET-, quercetin-, and bifendate-treated mice. Besides, amount of quercetin in ET was 1.03%. Taken together, our results indicate that L. christinae can protect against acute alcoholinduced liver injury in mice, the potential mechanism can be related to inhibiting liver oxidative stress injury, and its main hepatoprotective compound is quercetin, for the first time.