A007 2

MDA, SOD, and CAT were measured by using an ELISA kit from Nanjing Jiancheng Company (catalog nos.: AOO3 for SOD, A007-2 for CAT, and A003-1 for MDA, Nanjing, China) according to the manufacturer’s protocol.

To prepare tissue supernatants for antioxidant indicator analysis, ~ 80 mg of pharynx muscle of each sample was homogenized in 0.9% normal saline solution and centrifuged at 2500 r/min for 10 min. Then, the supernatants were immediately used for assessing total protein (TP) amount, malondialdehyde (MDA) concentration, total antioxidative capacity (T-AOC), total superoxide dismutase activity (T-SOD), catalase (CAT) activity, and glutathione (GSH) concentration, using an assay kit (A045-2, A042-1, A003-1, A001-1, A007-2 and A006-1; Nanjing Jiancheng Bioengineering Institute) according to the instructions. TP concentration was determined using the Coomassie brilliant blue staining method, while T-SOD was measured with the xanthine oxidase method, CAT using the ultraviolet method, and GSH and MDA with the dithiol dinitrobenzoic acid method and thiobarbituric acid method, respectively. All these indicators were subsequently measured using an ultraviolet spectrophotometer (DR6000, HACH Inc., USA).