Antihypertensive Effect of Trigonella foenum-greacum. Seeds in Experimentally Induced Hypertension in Rats

Abstract

We investigated the antihypertensive effect of a methanol extract (ME) of fenugreek seeds and its methanol fraction (MF) in deoxycorticosterone acetate (DOCA)-salt-induced and fructose-induced hypertensive rats. In the DOCA model, DOCA (15 mg/kg, twice a week; s.c.) was administered in uni-nephrectomized animals for 4 weeks. Methanol extract of fenugreek seeds (30 mg kg−1 day−1; p.o.) and its methanol fraction (15 mg kg−1 day−1; p.o.) were evaluated for their antihypertensive effect. In the fructose model, drinking water was replaced with a 10% fructose solution for 6 weeks to induce hypertension. ME (100 mg kg−1 day−1; p.o.) was assessed for its antihypertensive effect in the fructose model. After completion of the treatment schedule, blood pressure and vascular reactivity to various agonists like serotonin (5-hydroxytryptamine; 5-HT), noradrenaline (NA), and adrenaline (Adr) were recorded in rats of both models. A dose-response curve (DRC) of 5-HT was carried out in isolated rat fundus strip of the fructose-induced hypertensive rats. Chronic administration of ME (30 mg kg−1 day−1; p.o.) and MF (15 mg kg−1 day−1; p.o.) of fenugreek seeds significantly reduced blood pressure in DOCA salt and ME (100 mg kg−1 day−1; p.o.) reduced blood pressure in fructose-induced hypertensive rats. Treatment with ME (100 mg kg−1 day−1; p.o.) in fructose model for 6 weeks shifted the DRC toward the right on rat fundus. Thus, fenugreek seeds exhibit a significant antihypertensive effect. The mechanism of action may partly involve the serotonergic antagonistic property involving the 5-HT2 receptor subtype.