5-Hydroxy-1-methylhydantoin (HD-003) is an antioxidant potentially for the treatment of renal failure. A creatinine metabolite, 5-Hydroxy-1-methylhydantoin , a hydroxyl radical scavenger, has previously been shown to confer renoprotection by inhibiting the progression of chronic kidney disease in rats. 5-Hydroxy-1-methylhydantoin is a novel anti-oxidant drug completely suppressed the expression of B2-kinin receptors (B2KR) in response to high glucose (25 mM) stimulation in VSMC and was also shown to attenuate the effects of BK on VSMC remodeling. 5-Hydroxy-1-methylhydantoin inhibited the BK-induced increase in MAPK phosphorylation and attenuated the increase in connective tissue growth factor (CTGF) protein levels in VSMC. These findings suggest that 5-Hydroxy-1-methylhydantoin may confer vascular protection against high glucose concentrations and BK-stimulation to ameliorate vascular injury and remodeling through its anti-oxidant properties.