Polysaccharide isolated from Dioscorea septemloba improves hyperuricemia and alleviates renal fibrosis through gut-kidney axis in mice

Hyperuricemia (HUA) is a common metabolic disorder that often accompanies kidney diseases such as tubule damage and renal interstitial fibrosis. The preventive and therapeutic effects of Dioscorea septemloba, an anti-HUA herb, polysaccharide of which was considered as the main active ingredient on HUA, need to be explored. The major polysaccharide component, BXP, was purified from Dioscorea septemloba, with an average molecular weight of 10.432 kDa. Structural analysis inferred that BXP backbone was composed of t-β-D-Glcp-(1 → 4)-α-D-Glcp-(1 → 4)-α-D-Glcp-(1 → 4, 3)-β-D-Glcp-(1→, along with the side chain of →1)-α-D-Glcp-(6, 4 → 3, 4)-β-D-Glcp-(1→. The HUA mouse model was further established to clarify the underlying effect of BXP on HUA alleviation. As results shown, BXP decreased serum uric acid by inhibiting XOD and regulating urate transporter expression (GLUT9, OAT3, OAT1, URAT1 and ABCG2) in HUA mice, as well as relieving kidney and liver damage. Moreover, results of microbiome and metabolomics indicated that BXP improved the abundance of gut bacteria and reversed the Lipids-related metabolism disorder caused by HUA. This study indicated that BXP had potential to alleviate HUA and kidney disease through the gut-kidney axis in mice.