Effects and mechanisms of kidney bean peptides on uric-lowering activity in oteracil potassium-induced hyperuricemia rats

In the present study, the stability of kidney bean-derived DWYDIK (Asp-Trp-Tyr-Asp-Ile-Lys) after acid and alkali treatment and in vitro simulated gastrointestinal digestion were determined. Next, the uric acid-lowering activity and mechanisms of kidney bean peptides (KBPs) and DWYDIK were studied in vivo. We found that DWYDIK had certain tolerance to digestive enzymes. KBPs and DWYDIK significantly inhibited the activity of xanthine oxidase, reduced creatinine content, improved the changes of glomerular morphological, cellular vacuolar degeneration and inflammatory cell infiltration in kidney, and recovered intestinal tissue damages in hyperuricemia rats (p < 0.05). Besides, KBPs and DWYDIK also significantly down-regulated Glucose transporter 9 and Urate transporter 1 (p < 0.05), whereas the expression of Organic anion transporter 1 and the excretion of uric acid were upregulated by DWYDIK. Overall, KBPs and DWYDIK exert promising potentials as a safe therapeutic alternatives to conventional drugs in treating hyperuricemia.