Effects of <em>Trachyspermum ammi</em> L. (Apiaceae) on serum, urine and hepatic uric acid levels in oxonate-induced rats and <em>in vitro</em> xanthine oxidase inhibition assay

Abstract

Invention of many of the new synthetic drugs is based on the knowledge of traditional system of medicine. <em>Trachyspermum ammi </em>L. (Apiaceae) is traditionally used to treat gout and rheumatism. The study was comprised of <em>in vitro</em> determination of total polyphenolic and flavonoid content, xanthine oxidase inhibition assay and <em>in vivo</em> hypouricemic activity of <em>T. ammi</em> in oxonate induced hyperuricemic rat model. <em>In vivo</em> activity consisted of 11 groups of rats each having 6 animals. All the groups except normal control were treated with potassium oxonate. Allopurinol, <em>T. ammi</em> 250 and 500 mg/kg were administered for one, three and seven days (single dose/day) in different study groups (3×3=9 groups). <em>T. ammi</em> has total phenolic content of 145.17 ± 1.70 gallic acid equivalents/g, and the total flavonoid content of 35 ± 2.20 rutin equivalents/g. <em>T. ammi</em> significantly inhibited xanthine oxidase <em>in vitro</em> (IC₅₀= 68.6±0.2 µg/mL). Oral administration of <em>T. ammi</em> significantly reduced serum and hepatic urate levels in hyperuricemic rats in a time-dependent manner. Furthermore, fractional excretion of uric acid was increased. The results suggested that hypouricemic effects of <em>T. ammi</em> could be explained, at least partly, by inhibiting xanthine oxidase <em>in vitro</em> and due to presence of phenolic and flavonoid contents.