Background: hypertension is still a big challenge and is a key risk factor for cardiovascular disease which is the leading cause of death in the world. Objective: to determine the effects of Allopurinol in high-fat diet-induced hypertensive rats. Materials and Methods: Rats were divided into six groups, five groups of Sprague-Dawley male rats were fed a high-fat diet for six weeks and one group fed standard chow. Drugs were given for seven days, one group (n = 5) was only given a high-fat diet and CMC 0,5% orally, one group (n = 5) was given a high-fat and ISDN 3,6 mg/200 g BW orally, one group (n = 6) was given a high-fat diet and Allopurinol dose of 9 mg / 200 g BW orally, one group (n = 5) were given a high-fat diet and Allopurinol dose of 18 mg / 200 g BW orally, and one group (n = 6) were given a high-fat diet and Allopurinol dose of 36 mg / 200 g BW orally. Results: Allopurinol significantly reduced blood pressure in all three dose groups (p <0.05). The dose group of Allopurinol and ISDN gave similar results to the blood pressure and glucose levels measured on the last day of administration of the drug. Conclusion: Based on these results, Allopurinol has a potential effect as an antihypertensive agent.

Key words: Blood pressure, high-fat diet, Allopurinol, hypertension, off-label.