For cereal bran, rating of antioxidant capacity and screening of xanthine oxidase inhibitor

Based on the free radical scavenging rate and xanthine oxidase (XOD) inhibition rate, the basic properties of different cereal bran were analyzed, and the key XOD inhibitor in bran extract was screened by ultrafiltration centrifugation combined with liquid chromatography. The effectiveness of ferulic acid (FA) in the regulation of hyperuricemia was evaluated by basic physiological indexes, expression of inflammatory factors and expression of urate transporter. The analysis of the basic properties of maize bran showed that the free phenol content of maize bran is 221.17 ± 8.03 mg GAE/100 g DW, and the bound phenol content is 245.88 ± 5.31 mg GAE/100 g DW, which is the highest among five kinds of cereal bran. The antioxidant capacity of bran was evaluated according to ABTS free radical scavenging rate and DPPH free radical scavenging rate. The IC₅₀ value of maize bran bound phenol was 0.23 μg/mL for ABTS and 2.76 μg/mL for DPPH. Eight potential XOD inhibitors were detected in maize bran bound phenol and among which FA had the highest XOD inhibition rate. Animal experiments demonstrated that FA could effectively alleviate slow weight gain, suppress the increased expression of inflammatory factors, and correct the abnormal expression of urate transporters in hyperuricemia-induced mice. The results can provide a basis that cereal bran as a dietary supplement and functional food take hyperuricemia regulation effect in the future.