The comparative effects of different fractions of hydroalcoholic extract of Cynodon dactylon (L.) pers. rhizome on hemodynamic and contractility function of isolated rat heart

Abstract

Objectives: The rhizomes of Cynodon dactylon (L.) pers. are used for the treatment of heart failure in folk medicine. The purpose of this study was to investigate the effect of different fractions of hydroalcoholic extract of C.dactylon rhizomes on contractility and hemodynamic factors of isolated rat hearts to find out the most effective fraction. Methods: Study was carried out on male wistar rats weighing between 200-250 g those were randomly divided into 5 groups (n=6). Hydroalcoholic extract of dried rhizomes was prepared by maceration method. In addition, the methanolic fractions of 20, 40, 60, 80 and 100% were prepared by solid phase extraction method and then three concentrations of each fraction (50, 75 and 125 ?g/g tissue) were examined. Rats were anaesthetized by injection of sodium pentobarbital (50 mg/kg, i.p.), then hearts were removed by opening the thorax, mounted on langendorff apparatus and different concentrations of each fraction were perfused with Krebs solution and hemodynamic factors and left ventricular contractility were studied. Results: The results indicated that fraction 40% and 50 ?g/g tissue of fraction 60% produced a significant increase in the studied factors (LVSP p<0.001, LVEDP p<0.05, HR p<0.01, dp/dtmax p<0.001 and dp/dt/p p<0.001). Conclusion: The methanolic fraction of C. dactylon obtained by 40 and 60% methanol had the strongest inotropic effect on heart and can be used in treatment of cardiovascular diseases like heart failure. In order to relate the cardiac effects of C.dactylon to particular phytochemicals, further investigations should be done.