Title

Blood pressure-lowering and vascular modulator effects of Acorus calamus extract are mediated through multiple pathways.

Document Type

Article

Department

Biological and Biomedical Sciences

Abstract

This investigation was aimed to provide a pharmacologic basis 10 the Medicinal Use of Acorus calamus in cardiovascular disorders. In normotensive anesthetized rats, crude extract of Acorus calamus and its ethylacetate and nHexane fractions caused a fall in mean arterial pressure. In rabbit aorta rings. crude extract Was More potent against high K(+) (80 mM), ethylacetate against phenylephrine ( 1 mu M), whereas nHexane fraction was equipotent against both precontractions, Crude extract exhibited a vasoconstrictor effect oil baseline. Pretreatment of aortic rings With crude extract and its fractions shifted Ca(+2) concentration-response curves to the right, similar to verapanil. Crude extract and ethylacetate fraction suppressed phenylephrine peak formation in Ca(+2)-free medium. In rat aorta preparations, crude extract exhibited endothelium-independent relaxation with a vasodilatory effect against high K(+). nHexane fraction caused all endothelium-dependent N omega-nitro-L-arginine methyl ester-sensitive vasorelaxant along with ryanodine-sensitive vasoconstrictor effect on baseline tension and partially inhibited high K(+), although ethylacetate fraction caused an endothelium-independent relaxant and endothelium-dependent vasoconstrictor effect. These data indicate that crude extract possesses a combination of effects. relaxant effects mediated possibly through Ca(+2), antagonism in addition to a nitric oxide pathway, although the associated vasoconstrictor effects may be meant by nature to offset excessive vasodilatation, thus providing a pharmacologic rationale to its cardiovascular medi-cinal uses.

Publication

Journal of Cardiovascular Pharmacology