10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 1 2015 (January - March) The study was designed to investigate the possible protective role of aqueous extract of lessThan i greaterThan Cyperus Rotundus lessThan /i greaterThan in mercuric chloride induced renal stress, by using biochemical approaches. The effects of aqueous extract of lessThan i greaterThan Cyperus Rotundus lessThan /i greaterThan on mercuric chloride induced oxidative and renal stress was evaluated by serum creatinine, urea and uric acid levels, kidney tissue lipid peroxidation, GSH levels, GSH-Px and GST activities. Administration of mercuric chloride induced significant increase in serum: creatinine, urea and uric acid concentration showing renal stress. Mercuric chloride also induced oxidative stress, as indicate by decreased kidney tissue of GSH level, GSH-Px and GST activities along with increase the level of lipid peroxidation. Furthermore, treatment with mercuric chloride caused a marked elevation of kidney weight and decreased body weight. aqueous extract of lessThan i greaterThan Cyperus Rotundus lessThan /i greaterThan treatment markedly reduced elevated serum: creatinine, urea and uric acid levels and counteracted the deterious effects of mercuric chloride on oxidative stress markers changes caused by HgCl lessThan sub greaterThan 2 lessThan /sub greaterThan in kidney.Our results indicate that aqueous extract of lessThan i greaterThan Cyperus Rotundus lessThan /i greaterThan could have a beneficial role against mercuric chloride induced nephrotoxicity and oxidative stress in rat. AHLEM BAHI AND YOUCEF NECIB Antioxidant enzymes, mercury, cyperus Rotundus, renal stress. 267-274