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Purification, structural identification and in vivo antioxidant activity of Douchi antioxidant peptides

Year: 2026

Type: article

Abstract: In this study, antioxidant peptides were isolated and purified from Tongchuan Douchi through ultrafiltration and gel chromatography. To further assess the in vivo antioxidant activity of the fraction (F3) which had a high DPPH radical scavenging rate, 60 male mice were randomly divided into 6 groups (normal, positive control, model group, and low-, medium-, and high-dose group), and immunosuppression was induced via intraperitoneal cyclophosphamide injection. Hepatorenal function was evaluated by determining organ coefficients and oxidative stress markers including total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels. The results showed that 10 peptides (LLLPH, KDFPPR, DDFFL, ADFYNPK, IIGGI, DTPMIG, SVVDM, LVSPP, C(+57.02)ADLF, and VIVEL) which are rich in hydrophobic amino acids were identified in the fraction F3 by LC-MS/MS. The quantitative analysis of the animal experiments demonstrated that administration of medium and high doses of the F3 fraction significantly ( P < 0.05) improved the liver, kidney, and spleen coefficients in immunosuppressed mice compared to the model group. The high-dose F3 administration significantly increased the SOD and GSH-Px activities while reducing the MDA levels in both hepatic and renal tissues of mice. These results revealed that Douchi-derived peptides can mediate antioxidant effects in vivo by both scavenging free radicals and activating endogenous antioxidant enzymes.

Source: Agricultural Products Processing and Storage

DOI: 10.1007/s44462-026-00066-4