EFFECT OF SOME PLANT EXTRACTS ON SERUM URIC ACID LEVELS, AND XANTHINE OXIDASE ACTIVITY IN VITRO AND IN OXONATE-INDUCED HYPERURICEMIC RATS

*Hasan F. Al-Azzawie and Samah A. Abd

ABSTRACT

Increased serum uric acid is known to be a major risk related to the development of several oxidative stress diseases. The present study sought to investigate the inhibitory effect of three aqueous plant extract: Olea europaea (Olive), Zingiber officinale (Ginger) and Brassica oleracea (Red cabbage) on Xanthine Oxidase enzyme (XO), the key enzyme involved in purine degradation and uric acid production. The active compounds in extracts were investigated using phytochemical analysis methods which observed that all plant extracts were rich in active compounds, particularly phenolic, flavonoids. Olive leaf extract (OLE), Red cabbage extract (RCE) and Ginger extract (GE) were screened according to their inhibitory effect against xanthine oxidase enzyme in vitro. Results observed that the highest inhibitions were obtained with GE (87.97± 1.45%) followed by OLE and RCE (80.00 ± 2.20 and 53.72 ± 1.76% respectively) compared with standard drug allopurinol (93.00 ± 0.57%). In vivo inhibitory activity of GE at different doses was evaluated in potassium oxonate induced rats (Hyperuricemia model) and in normal healthy rats. Oral administration of ginger extract with (100 and 250 mg/ kg) once a day for 4 weeks to the hyperuricemia rats groups significantly (P<0.05) reduce the mean serum uric acid levels and inhibited XO activity , while GE did not have a significant effect in normal rats groups.

Keywords: Hyperuricaemia, Xanthine Oxidase, Uric Acid, Ginger, Red Cabbage, Olive Flavonoids.