Litchi pericarp is the main byproduct of litchi processing and contains several polyphenols. However, the chemical constituents and the antioxidant effect in litchi pericarp extracts (LPE) have been rarely studied. The result of the quantitative analyses of the major monomers in LPE indicated that procyanidin A2, procyanidin B2, epicatechin, rutin, and catechin were the major polyphenol compounds of LPE. The LPE exhibited high radical scavenging activity, as indicated by the results of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ascorbic acid, 2,2'-Azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) tests. Moreover, administrating D-galactose in mice led to the reduced activity of antioxidant enzymes, aggravated lipid peroxidation, and induced protein oxidation. The results were improved in the aging mice after the LPE treatment was performed. The above results suggest that LPE has an excellent antioxidant effect. Accordingly, litchi pericarp can serve as a promising source of dietary antioxidants.
Keywords: antioxidant effect; chemical constituents; litchi pericarp; mice; polyphenols.