The effect of oral administration of chard on contractile reactivity of isolated aorta in diabetic rats

Background: Chard (Beta vulgaris L. var. Cicla) administration could improve the activity of antioxidant systems such as gluthatione and has a hypoglycemic and hypolipidemic property. Objective: To evaluate the effect of oral administration of chard on the contractile reactivity of isolated aorta in diabetic rats. Methods: This experimental study was conducted at the School of Medicine, Shahed University in 2003. Male Wistar rats were divided into control, chard-treated control, diabetic, and chard-treated diabetic groups. For induction of diabetes, streptozotcin (STZ) was intraperitoneally administered (60 mg/Kg). Chard-treated groups received chard mixed with standard pelleted food at a weight ratio of 1/15. After one month, contractile reactivity of aortic rings to KCl and noradrenaline was determined using isolated tissue setup. Findings: Serum glucose level showed a significant increase (409/4 and 401/3 mg/dl) in diabetic group at 2nd and 4th weeks (P<0.001), while this increase was less obvious in chard-treated diabetic group (274/5 and 161/2 mg/dl) (P<0.01 and P<0.001 for 2nd and 4th weeks, respectively). In addition, the latter group showed a lower contraction to KCl (P<0.05) and noradrenaline (P<0.01) as compared to diabetic group (0/76 and 1.41 g/mm2 of the aortic ring). Meanwhile, there was no significant difference between control and chard-treated control groups regarding contractile reactivity. Conclusion: Oral administration of chard for one month could attenuate the contractile responsiveness of the vascular system and may prevent the development of hypertension in diabetic rats.