S0121

The T-AOC (S0121, Beyotime Biotechnology, Shanghai, China) and SOD (S0101S, Beyotime Biotechnology, Shanghai, China) level were determined using the commercial kits, following the manufacturers’ instructions.

SOD (expressed as units/mg of protein), Total Antioxidant Capacity (T-AOC) (expressed as mmol/g of protein), and MDA (expressed as nmol/mg of protein) were measured in liver and ileum using commercial kits (S0101S and S0121, Beyotime, Beijing, China; A003-1-2, Nanjing Jiancheng Bioengineering Institute, Nanjing, China). The SOD, T-AOC activity, and MDA level were detected following the manufacturer’s instructions.

The amount of 0.2 g frozen mucosa was precisely weighed and homogenized in 2 mL of ice-cold saline. After being centrifuged at 12,000× g for 10 min at 4 °C, the supernatants were collected to measure the oxidative status. The protein content of the supernatants was measured with a BCA Protein Assay Kit (P0010, Beyotime Biotechnology, Shanghai, China). We assessed malondialdehyde (MDA) content, total antioxidant capacity (T-AOC), catalase (CAT) activity, superoxide dismutase (SOD) activity, and glutathione peroxidase (GSH-Px) activity in the jejunal and ileal mucosae using commercial reagent kits (S0131, S0121, S0051, S0101 and S0056, Beyotime Biotechnology, Shanghai, China). All experimental procedures were performed according to the manufacturer’s instructions. All results were normalized to protein concentration in each sample.

The total antioxidative capability of CSC NPs was measured by using ABTS as a probe (Cat. no. S0121, Beyotime). Briefly, 6.25, 12.5, 25, and 50 µm CSC NPs were added into 96‐well plate (10 µL per well). Then 190 ABTS working solution was added and mixed with CSC NPs solutions, which were incubated at 37 °C for 1 h. The absorbance of mixed solution (A414 nm) was recorded on an UV–vis–NIR spectrophotometer (PerkinElmer EnSpire, Singapore).