Adejo GO and Atawodi SE
The acute toxicity and dose-response studies of methanol extracts of the fruit (MFE), leaf (MLE), bark (MBE) and root (MRE) of Morinda lucida were investigated in adult male albino rats (Wistar strain) weighing between 180 – 250g. They were orally administered (p.o) with the various extracts by observing Lorke’s method. The median lethal dose (LD50) was greater than 5000 mg/kg for all the extracts tested and without any observable sign of toxicity. The genotoxic and geno-protective properties of all the MFE, MLE, MBE and MRE on pUC18 plasmid DNA were also studied, in the presence of Fenton’s reagent using the plasmid nicking assay method. While MFE, MBE and MRE offered better protection to pUC18 plasmid DNA at lower doses particularly at 10 μg/μl, MLE was genotoxic at all the doses as evidenced by the presence of DNA linear forms. While parts of Morinda lucida showed no visible toxicity even at very high doses, they proved to be genotoxic to pUC18 plasmid DNA at higher concentrations.
