The Effect of Flavonoid Naringenin on Contractile Response of Thoracic Aorta Isolated from Diabetic Rats

Background & Aims: Considering increasing incidence of cardiovascular disorders in diabetes mellitus and some evidence on antioxidant and antidiabetic potentials of naringenin, this study was conducted to evaluate the beneficial effects of ۶-week administration of naringenin on contractile reactivity of isolated thoracic aorta in diabetic rats. Methods: Male Wistar rats were divided into control, naringenin-treated control, diabetic and glibenclamide-treated, and naringenin-treated diabetic groups. For induction of diabetes, streptozotcin (STZ) was administered (۶۰ mg/Kg). Naringenin (۱۰ mg/kg) was administered i.p. one week after diabetes induction in every other day intervals for ۶ weeks. Serum glucose level was measured before naringeninadministration and at ۶th week. Finally, contractile reactivity of thoracic aortic rings to KCl and phenylephrine (PE) was cumulatively determined. Results: Serum glucose level at week ۶ showed a significant decrease in naringenin-treated diabetic group compared to diabetics (P<۰.۰۱). In addition, naringenin-treated diabetic group showed a significantly lower contraction to PE (P<۰.۰۵) as compared to diabetic group and such significant reduction was also observed for KCl (P<۰.۰۵). Meanwhile, there was also a significant difference between control and naringenin-treated control groups regarding their contractile reactivity to PE (P<۰.۰۵). Conclusion: Subchronic administration of naringenin for ۶ weeks could exert an anti-hyperglycemic effect and lowers contractile responsiveness of thoracic aorta rings to KCl and phenylephrine.