Vasorelaxant properties of acid and neutral fractions of Dimerocostus strobilaceus Kuntze used by Kuna Indians of Panama.

BACKGROUND

Dimerocostus strobilaceus is used by the Kuna Indians of Panama for the treatment of hypertension and other cardiovascular diseases.

OBJECTIVE

We investigated the vascular effects of acid and neutral fractions obtained from methanol and dichloromethane extracts of Dimerocostus strobilaceus.

METHODS

The acid and neutral methanol fractions (A-MeOH and N-MeOH) or acid and neutral dichlorometanic fractions (A-DCM and N-DCM) were tested using isolated rat aortic rings with or without endothelium pre-contracted by phenylephrine. We examined the ability of these different fractions at different concentrations to modify vascular responses induced by angiotensin II using endothelium-denuded aortic rings from Spontaneously Hypertensive Rats (SHR).

RESULTS

In aortic rings with intact endothelium A-MeOH, N-MeOH and A-DCM fractions produced a concentration-dependent vasorelaxation (62.4 +/- 5.2, 64.5 +/- 5.0 and 63.7 +/- 5.0%, respectively), whereas the N-DCM fraction did not produce any vasorelaxant effect. Maximal relaxation evocated by vasoactive fractions was substantially inhibited on aortic rings without endothelium.Our study demonstrates that A-MeOH, N-MeOH, A-DCM and N-DCM significantly reduce contractile responses induced by angiotensin-II on aortic rings.

CONCLUSIONS

Our findings may contribute to a better understanding of the potential link between vascular properties observed with Dimerocostus strobilaceus and their ethnobotanical use.