Vasorelaxant and anti-platelet aggregation effects of aqueous Ocimum basilicum extract

Aim of the study: In this work the endothelium-dependant vasorelaxant and anti-platelet aggregation activities of an aqueous extract from Ocimum basilicum were studied. Materials and methods: The vasorelaxant effect was undertaken in thoracic aorta from three experimental groups of rats: one of them (NCG) fed with standard diet, the second (HCG) with hypercholesterolemic diet (HCD) and the third (BTG) with hypercholesterolemic diet together with an intragastric administration of Ocimum basilicum extract at a dose of 0.5 g/kg body weight for a period of 10 weeks. The in vitro antiplatelet aggregation of Ocimum basilicum extract was studied using thrombin (0.5 U/ml) and ADP (5 mu M) as agonists. Results: The results show that the HCD statistically decreases vascular relaxation in HCG compared to NCG (p < 0.001) and increases the vascular responses to phenylephrine (p < 0.02). Ocimum basilicum extract exerts a significant vasorelaxant effect at 10(-5) M (p < 0.01) and 10(-4) M carbachol (p = 0.001). The plant extract also tends to suppress the elevated contractions induced by HCD (p = 0.05). The extract inhibits ADP-induced platelet aggregation by 13%, 28.2%, 30.5%, 44.7% and 53% at a dose of 1, 2, 3, 4 and 5 g/l, respectively. Thrombin-induced platelet activation was also reduced by 15%, 23%, 40%, 38.4%, and 42% at the same doses of extract described above. Conclusion: The use of Ocimum basilicum as medicinal plant could be beneficial for cardiovascular system. (C) 2009 Elsevier Ireland Ltd. All rights reserved.