Effect of Aqueous and Ethanolic Extracts of Ocimum gratissimum on the Histology of the Spleen, Haematological Indicies of Wistar Rats and its Antimicrobial Properties

The effects of the aqueous and ethanolic extracts of Ocimum gratissimum (Linn) on the haematological indices and histology of the spleen of adult Wistar rats, as well as its antimicrobial properties were investigated in this study. Ocimum gratissimum (Linn) is widely distributed in tropical and warm temperate regions and is commonly called “fever plant”. Twenty five adult wistar rats with weight range of 180-220 g were used. They were randomised into 5 groups. Group 1 was given normal saline 2 mL/kg Group 2 and 3; 500 mg/kg of aqueous and ethanolic extracts respectively while groups 4 and 5 1000 mg/kg of aqueous and ethanolic extracts respectively. Administration was orally for 14 days. Pure strains of Escherichia coli, Staphylococcus aureus and Salmonella typhi were used for the antibacterial test with concentrations at 2 and 4% for each extract. The plates were then incubated at 37oC for 24 h. The study showed that the extracts of Ocimum gratissimum had no antimicrobial effect at these concentrations; however, there was increased white pulp in the spleen more at concentrations of 1000 mg/kg for both extracts. Also, at 1000 mg/kg there was a significant increase in the RBC and lymphocyte count and a decrease in neutrophil count at (p<0.05).