effect of crataegus spp branchlet feeding on endothelium-dependent contractile and relaxatory response of thoracic aorta from diabetic rats

ABSTRACT

Diabetes mellitus is accompanied with higher incidence of cardiovascular disorders. There is some evidence on antidiabetic and cardiovascular improving potential of Crataegus spp [CS]. Thus, the endothelium-dependent effect of oral administration of CS branchlet for 6 weeks on contractile and relaxatory response of thoracic aorta from diabetic rats was investigated. Male Wistar rats were divided into control, CS-treated control, diabetic, CS-treated diabetic, and glibenclamide-treated diabetic groups. Treated groups received CS-mixed pelleted food at a weight ratio of 6.25%. Body weight and serum glucose level was measured before the study and at weeks 3 and 6. At the end of study, contractile reactivity of thoracic aortic rings to KC1 and phenylephrine and relaxatory response to acetylcholine and sodium nitroprusside was determined using isolated tissue setup. Serum glucose level significantly decreased in CS-treated diabetic group [p<0.01] versus untreated diabetics. In addition, endothelium-intact CS-treated diabetic group showed a significantly lower contraction to KC1 and phenylephrine [p<0.05] as compared to diabetic group and endothelium removal abolished this response. Meanwhile, relaxation response of endothelium-intact rings to acetylcholine was significantly higher in CS-treated diabetic group as compared to diabetics [p<0.05]. In addition, there were no significant changes amongst the groups regarding relaxatory response to sodium nitroprusside. Chronic oral administration of CS through affecting endothelial-related agents could decrease contractile response and enhance relaxatory response in aortic tissue of diabetic rat and this may be beneficial in prevention of long-term vascular complications of diabetes