Phytochemical and pharmacological evaluation of the anti-hypertensive effect of Theobroma Cacao

Abstract

Background: This study evaluated the effects of chloroform and ethanol extracts of Theobroma Cacao (T.Cacao) in nitro-L-arginine, methyl esters (L-NAME)-induced hypertensive rats. The acute toxicity and phytochemical analyses of the extracts were carried out using standard methods while hemodynamic parameters of hypertensive rats treated with the extracts were assayed using invasive and non-invasive methods of blood pressure measurements. The percentage yield of the extract was 3.25% (ethanol) and 15.77% (chloroform). The phytochemical analyses revealed the presence of flavonoids, alkaloids, steroids, saponins, anthraquinone, tannins and, cardiac glycosides. Concurrent administration of the extracts with L-NAME showed a significant (p<0.05) decrease in systolic blood pressure, diastolic blood pressure, pulse pressure, and mean arterial pressure in the treated rats compared with the untreated rats. The mechanism of action showed that ethanol extract led to significant (p<0.05) decreases in systolic blood pressure, diastolic blood pressure, pulse pressure and mean arterial pressure also in the presence of muscarinic antagonist (atropine). The isolated rat thoracic aorta showed a slight decrease at each concentration but not statistically significant (p<0.05), it was statistically significant at 50mg/ml while in the presence of high KCl, there were significant (p<0.05) decreases at each of the concentrations compared with the control. The observed results showed that consumption of T. cacao within the experimental dose prevented an increase in hemodynamic status of Wistar rats. Thus, if these results are extrapolated to man, consumption of T. cacao should be encouraged.