Antihypertensive activity of Gossypin against L-NAME induced hypertension in rats

ABSTRACTGossypin (3,5,7,3,4-pentahydroxy-8-o-glucoside) a bioflavonoid was  evaluated for protection against  L-NAME(L-NG-Nitroarginine methylester) induced hypertension in albino rats, based on its effects on body weight of animals and arterial blood pressure. Male adult albino rats (220-2600gm)were used in this study. The hypertensive activity was measured using AD 8 channel Lab chart solution instrument. The activity was carried out in acute and chronic models .In acute studies animals were divided into 5 equal groups of five rats each. group I was the normal group received normal saline and group II as control group received L-NAME (20mg/kg i.v after 30 minutes of arterial cannulation .Group III as standard received losartan (10 mg/kg b.w.i.v) after increase in B.P produced by L-NAME while group IV, V. received gossypin at a dose of 5,10, mg/kg b.w i.p after inducing hypertension. In chronic studies animals were divided into 6 equal groups of 6 animals each. Group I normal group received normal saline orally for 4wks and group II received L-NAME (40mg/kg p.o )for 4 wks Group III as STD group received losartan (20mg/kg p.o) while group IV.V.VI  as treated groups received Gossypin( 5,10,20,mg/kg b.w p.o)for 4 wks. After last dose the animals were examined for weight variation and B.P determination by invasive method using AD instrument. The left carotid artery was cannulated for B.P measurement and femoral vein for drug administration. The hypertension induced   by  L-NAME  was  indicated  by  elevated  levels in systolic B.P and decrease in body weight of animals. In acute hypertension, L-NAME increases systolic B.P and mean B.P and decrease in heart rate which was administrated through carotid artery after 30 mins of stabilization of B.P.  There was increase in systolic and mean B.P and decrease in heart rate. The drug was administered by I.P shows significant reduction in elevated b.p which was observed for 2hrs.In chronic hypertension L-NAME induced group show