Effects of Oligonol®, an oligomerized polyphenol formulated from lychee fruit, on serum concentration and urinary excretion of uric acid

Epidemiological observations and laboratory studies have suggested that polyphenols possess anti-inflammatory, anti-microbial, anti-carcinogenic, and antioxidant properties. However, studies assessing the effects of polyphenols on uric acid metabolism in vivo are scarce. Herein, we investigated whether a phenolic substance, Oligonol®, has effects on uric acid metabolism. In six healthy male volunteers, Oligonol® significantly decreased 1-h uric acid excretion and fractional uric acid clearance, which was accompanied by a decreased serum concentration of uric acid. In addition, an in vitro experiment showed that Oligonol® inhibited buttermilk xanthine oxidase activity in a dose-dependent manner. Together, these results suggest that Oligonol® lowers serum uric acid through inhibition of xanthine oxidase, and may be effective for prevention and treatment of hyperuricemia and/or gout.

Research highlights
► Effects of polyphenols on uric acid metabolism were investigated.
► Oligonol®, a phenolic substance, decreased uric acid in serum and urine.
► Oligonol® inhibited xanthine oxidase activity in an in vitro study.
► Oligonol® may be beneficial for individuals with mild hyperuricemia.