Endothelium-dependent vasorelaxing activity of aqueous extracts of lyophilized seeds of Casimiroa edulis (AECe) on rat mesenteric arterial bed.

The vasorelaxing activity of the aqueous extracts of Casimiroa edulis seeds F(AECe) on mesenteric arterial bed (MAB) of rats was studied. MAB precontracted with methoxamine was mounted on a tissue bath and exposed to plant extracts (bolus 50, 500, 2500 and 5000 microg). The bolus injections of AECe significantly inhibited, in a concentration-dependent manner, the maximal contractile response induced by methoxamine (30 microm) in MAB. After endothelium removal, the vascular ability of Casimiroa edulis aqueous extract was significantly changed. Treatment with an inhibitor of NO synthase (L-NOA, 10 microM) also modified the AECe effect. The guanilate cyclase inhibitor methylene blue (MB, 100 microM) inhibited the AECe-induced vasodilatation. These results suggest the involvement of NO of endothelial source (or related factors) in this vasodilator effect.