Diuretic and hypotensive effects of Nigella sativa on the spontaneously hypertensive rat

Nigella sativa (ranunculaceae) is used in Arab folk medicine as a diuretic and hypotensive plant. We report here the diuretic and hypotensive effects of dichloromethane extract of Nigella saliva seeds in the spontaneously hypertensive rat (SHR). An oral dose of Nigella sativa extract (0.6 ml/kg/day) and furosemide (5 mg/kg/day) increased significantly the diuresis by 16 and 30 per cent respectively after 15 days of treatment; urinary excretion of Cl-, Na+, K+ and urea is also increased. Simultaneously, the mean arterial pressure decreased respectively by 22 and 18 per cent in the Nigella sativa treated rat and nifedipine treated rat (0.5 mg/kg/day). In conclusion, the diuretic activity observed in the SHR rat treated with Nigella sativa seeds may be partially responsible for its diuretic action; it seems that other pathways may also be involved in their cardiovascular effects.