Baicalin Attenuates Methomyl-Induced Oxidative Stress and Tissue Damage in Liver, Kidney, Lung, and Blood of Rats

Methomyl (MET), a broad spectrum carbamate insecticide, is used in agriculture to combat ectoparasites. Baicalin (BAI) is a flavoneglycoside with anti-inflammatory, anticarcinogen and antioxidant effects and is widely found in the plants of the genus Scutellaria. The aim of this study was to determine the effects of BAI on MET-induced subacute intoxication in rats. For this, 48 rats were randomly divided into six groups: I—control; II—BAI 1 (50 mg/kg of body weight (bw)) group; III—BAI 2 (100 mg/kg bw) group; IV—MET (4 mg/kg bw) group; V—BAI 1 + MET group; VI—BAI 2 + MET group. The MET and BAI were administered (via gavage) once a day during 28 days after which blood samples were taken for biochemical analysis and the tissues of liver, kidney and lung were histopathologically examined. It was found that in the MET-treated group the levels of blood urea nitrogen (BUN), creatinine, uric acid, triglyceride, cholesterol, lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) were significantly increased while albumin and total protein levels were decreased in the serum compared to the control. Also, glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) decreased but malondialdehyde (MDA) increased in blood and tissues in the MET-treated group. When the MET-treated group was histopathologically compared with the control group, degeneration in liver and kidney tissues and inflammation in lung tissue were observed. Treatment with BAI resulted in a significant increase of GSH, GPx, GR, GST, SOD, and CAT but a decrease of the MDA levels (p < 0.05). The administration of BAI in two different doses along with MET reduced tissue degeneration and inflammation in a dose-dependent manner. The results of histopathological analysis were consistent with the biochemical data. This suggests that BAI can ameliorate oxidative stress and tissue damage by increasing the levels of antioxidants and reducing reactive oxygen species (ROS) in MET-treated rats.