Antioxidant Capacity Evaluation of Crayfish

The hepatopancreas and ovary tissues were weighed and homogenized in precooled saline solution with 10-fold volumes (v/w). These homogenates were centrifuged at 3,500 rpm in 4°C for 10 min (3-18KS, Sigma, Germany) and the supernatants were collected. The supernatants of the hepatopancreas and ovaries and serum were diluted with 0.85% saline solution and follow the instruction and preexperiment for subsequent operations.
The supernatants of hepatopancreas and ovary homogenates were taken to determine the contents of triacylglycerol (TG) (glycerophosphate oxidase-peroxidase method) [23 (link), 24 (link)] and total cholesterol (T-CHO) (cholesterol oxidase-peroxidase method) [25 (link)]. The concentrations of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) (enzymatic method) [26 (link), 27 (link)], malondialdehyde (MDA) (thiobarbituric acid method) [28 (link)], glutathione peroxidase (GSH-Px) (5, 5′-dithiobis-(2-nitrobenzoic acid) method) [29 (link)], superoxide dismutase (SOD) (hydroxylamine method) [30 (link)], and total antioxidant capacity (T-AOC) (Fe³⁺ reduction method) [31 (link)] were detected to evaluate the antioxidant capacity of crayfish fed diets with different phospholipids. All detection was performed by the colorimetric approach of commercial reagent kits (Nanjing Jiancheng Bioengineering Institute, China). The measurements of these parameters were performed by the standard method, and the detection of optical density (OD) values was analyzed by a microplate reader (Epoch, BioTek, USA).