Endothelium independent calcium channel blocking pathways mediate antihypertensive effect of morus nigra

Present study was conducted to validate the folkloric claims of morus nigra l. (moraceae) using invasive blood pressure measuring and ex vivo vasorelaxant experimental techniques. Intravenous administration of mn. Aq in 0.01-30 mg/kg doses caused significant decrease in mean arterial pressure and heart rate in fructose-induced hypertensive rats. It also showed relaxation in high k⁺ [80 mm] and pe (1µm) mediated aortic contraction with ec₅₀ 1.25 and 3.72mg/ml values, respectively. Vaso-relaxant effect of mn.aq was partially blocked in presence of l-name with ec50, 5.32mg/ml value, but showed concentration dependent significant inhibition of ligand gated and voltage gated ca⁺² channels and intracellular ca⁺² release, similar to verapamil. Findings of current study designate that aqueous fraction of m. Nigra possesses antihypertensive activity with concentration-dependent vaso-relaxant effect predominantly mediated through endothelial-independent calcium channel blocking pathways accompanied by partial involvement of endothelium-dependent nos mediated relaxation.