Hibiscus sabdariffa L. extracts reduce serum uric acid levels in oxonate-induced rats

Elevated serum levels of uric acid are associated with an increased risk for hyperuricemia, gout, hypertension, cardiovascular disease, and renal failure. Recent attention has focused on the bioactive properties of edible plants in preventing disease. Hibiscus sabdariffa L., a local soft drink material and medicinal herb in Taiwan, is used effectively in native medicines against hypertension, pyrexia, and liver disorders. We investigated the effects of the Hibiscus sabdariffa extract (HSE) on oxonic acid (OA)-induced hyperuricemia in rats. The HSE affected serum uric acid levels and urate enzymes such as uricase and xanthine oxidase (XO). We treated rats intraperitoneally with normal saline and oxonate solution for 1. week and with or without feeding allopurinol (an XO inhibitor) or HSE (1%, 2%, and 5%) for 5. weeks. We observed that treatment with HSE inhibited OA-induced hyperuricemia, with a greater uric acid lowering effect than allopurinol treatment. Our results showed that HSE effectively inhibited OA-induced hyperuricemia by decreasing uric acid and increasing uricase activity, but not by affecting XO activity.