Lychee Peel Extract Ameliorates Hyperuricemia by Regulating Uric Acid Production and Excretion in Mice

Lychee peel generated during the industrial processing of lychee fruit are currently disposed of as agricultural waste. This study investigates the primary components of lychee peel extract (LPE) and the regulatory mechanisms of LPE on reducing uric acid (UA). Mice were injected with hypoxanthine and potassium oxonate to induce hyperuricemia and concurrently orally administered LPE. The analysis of the LPE composition reveals a predominance of polyphenolic compounds, including (-)-epicatechin, (-)-epigallocatechin, and procyanidin A2. In vitro tests have demonstrated that the LPE significantly inhibits the activity of xanthine oxidase (XOD). In vivo studies showed that LPE can reduce UA levels in hyperuricemia mice. Further mechanistic insights indicate that LPE inhibits hepatic XOD activity, thereby reducing UA synthesis within the organism. It also decreases the protein expression of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9), which leads to diminished UA reabsorption and increased excretion of UA. Additionally, LPE enhances the activity of superoxide dismutase (SOD) while simultaneously reducing malondialdehyde (MDA) contents, thereby improving antioxidant capacity in mice. Our findings indicate that LPE not only inhibits the production of UA but also promotes its elimination, positioning it as a promising candidate for UA-lowering agents.