PROTECTIVE EFFECT OF SOME PLANT EXTRACTS ON HYPERURICEMIA IN EXPERIMENTAL ANIMALS

Hyperuricemia (elevated serum levels of uric acid) is a key risk factor for the development of gout, and has been linked to renal dysfunction, cardiovascular diseases, hypertension, diabetes and metabolic syndrome. Hyperuricemia was induced by oxonic acid (uricase inhibitor) in experimental rats to evaluate the protective effect of alcoholic extracts from parsley shoots, celery seeds and fig leaves. The rats were divided into 6 groups, and the first one served as a normal control group. Three groups of rats were given various plant extracts (celery, parsley and fig) by oral administration using a stomach tube at a dose of 250 mg/kg. A positive control group of rats was administered orally the hypouricemic drug, allopurinol (xanthine oxidase inhibitor) at a dose of 100 mg/kg. A negative control group did not receive any plant extracts or drugs. The various plant extracts and the drug were administered for the rats every day for 9 days. On the 10th day, all groups except the normal control received a single dose of oxonic acid (250 mg/kg) by intraperitoneal injection to induce hyperuricemia. After two hours of hyperuricemia induction by oxonic acid injection, blood samples were collected from all rat groups. The protective effects of various plant extracts were monitored through measurement of uric acid and other blood biochemical analyses for the rats as well as assay of xanthine oxidase enzyme in liver tissues. The data indicated a significant (P<0.05) increase in the levels of uric acid, urea, creatinine and potassium, and a significant (P<0.05) decrease in the levels of total calcium in serum of hyperuricemic rats (negative control) compared to the normal control group. These results indicated that oxonic acid caused hyperuricemia and renal dysfunction in the nega tive control group. The protective effects of various plant extracts were established by appearance the levels of uric acid and other kidney function tests near to their normal values which appeared in the normal control group. The different plant extracts exhibited protective effects against hyperuricemia in variant efficacies compared to allopurinol. These efficacies were in the following order: fig > allopurinol > celery ≈ parsley. Comparatively, the different plant extracts exhibited inhibitory effects on the activity of liver xanthine oxidase enzyme in variant efficacies compared to allopurinol. These efficacies were in the following order: allopurinol > fig > celery ≈ parsley. It can be noticed that fig extract was the most effective treatment against hyperuricemia while allopurinol was the strongest inhibitor against xanthine oxidase activity.