Ocimum basillicum protective effect against Hg2+- induced hematologic disorders and genetic birth defects in Wistar rats

Human indiscriminate exposure to heavy metal contaminants such as mercury through long-term ingestion of contaminated drinking water with notable attendant health burdens has been widely reported. In this study, the protective potential of Ocimum basillicum aqueous leaf extract was examined on mercury-induced hematologic disorders and chromosome aberrations in wistar rats. Mercury chloride (1.5mg/kg bd. wt.) and Ocimum basillicum leaf extract (100 mg/kg bd. wt.) were administered alone (group B) and simultaneously (group C) to the rats by gavage consecutively for 14-days. The control (group A) was fed with distilled water only while animals in group D were administered the extract alone. The hematologic assay was conducted using hematology-analyzer while the chromosomal aberrations were examined with the use of micronucleus assay. The results from micronucleus assay show that mercury is a pro-oxidant capable of inducing clastogenic effect in rats where mercury chloride caused significant (P<0.05) increase in frequency of micronucleated polychromatic erythrocytes (MPCEs) in group B (10.75 ± 1.25d) animals compared with the control (0.50 ± 0.29^a) while appreciable reduction in frequency of MPCEs in group C (4.01 ± 0.90^bc) animals was observed. However, significant (P<0.05) decrease in hematologic parameters was observed in group B animals fed with mercury chloride when compared with others in group C and D. This study indicates that mercury is a potential clastogen which could possibly induce chromosome aberration and hematologic disorders in rats as observed in group B animals while Ocimum basillicum is suggested to have demonstrated metal chelating ability against the mercury chloride where it offered protective effect to animals in group C.