Abstract

The study evaluated the lethal dose LD ₅₀ of the aqueous root extract of Lawsonia inermis; a potent uterine vaso constrictor, usually taken by pregnant women in the first two months of pregnancy to induce spontaneous abortion. The study was carried out to determine the lethal dose of the aqueous root extract to ascertain its safety using Wister rats. Five groups of rats (4 rats per group; including two pregnant females) were administered intraperitoneally (i.p.) doses of the stock aqueous root extract (0.3 g/ml) volumes corresponding to 200,400, 800, 1200 and 1600 mg/Kg Body Weight (BW). The control group was given 0.5 ml of distilled water and observed for 7 to10 days. Various clinical symptoms (physiological changes) like dizziness, loss of appetite, partial paralysis, temporary amnesia and spontaneous abortion in the included pregnant females; were visibly observed in groups treated with 800 to 1600 mg/kg, while groups with 200 to 400 mg/Kg BW and the control remain active and healthy. No mortality was recorded in any of the groups. Conclusions from the result indicate delayed toxicity after ip route administration of the extract at various concentrations. It demonstrated that the aqueous root extract of the L. inermis although, it is active in inducing spontaneous abortion; is slightly toxic and is safe for therapeutic purposes within the dose range. This activity could be related to the various phytochemical compounds proven to be present in the aqueous extract in preliminary phytochemical analysis.

Key words: LD₅₀, spontaneous abortion, Wister rats, intraperitoneally, temporary amnesia, mortality, toxicity.