Salvia plebeia Extract Inhibits Xanthine Oxidase Activity In Vitro and Reduces Serum Uric Acid in an Animal Model of Hyperuricemia

Abstract Hyperuricemia is a clinical condition characterized by an elevated level of serum uric acid and is a key risk factor for the development of gout and metabolic disorders. The existing urate-lowering therapies are often impractical for certain patient populations, providing a rationale to explore new agents with improved safety and efficacy. Here, we discovered that Salvia plebeia extract inhibited the enzyme activity of xanthine oxidase, which is a key enzyme generating uric acid in the liver. In an animal model of hyperuricemia, S. plebeia extract reduced serum urate to the levels observed in control animals. The urate-lowering effect of S. plebeia extract in vivo was supported by the identification of compounds that inhibit xanthine oxidase enzyme activity in vitro. Nepetin, scutellarein, and luteolin contributed significantly to S. plebeia bioactivity in vitro. These compounds showed the highest potency against xanthine oxidase with IC50 values of 2.35, 1.74, and 1.90 µM, respectively, and were present at moderate quantities. These observations serve as a basis for further elaboration of the S. plebeia extracts for the development of new therapeutics for hyperuricemia and related diseases.