African Journal of Biotechnology Vol. 6 (13), pp. 1544-1548, 4 July 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Antibacterial activities and toxicological potentials of crude ethanolic extracts of Euphorbia hirta

J. N. Ogbulie¹*, C. C. Ogueke², I. C. Okoli³ and B. N Anyanwu¹

¹Department of Industrial Microbiology, Federal University of Technology, Owerri. P. M. B. 1526 Owerri, Nigeria.

²Department of Food Science and Technology, Federal University of Technology, Owerri, P. M. B. 1526 Owerri, Nigeria.

³Department of Animal Science Technology, Federal University of Technology, Owerri, P. M. B. 1526 Owerri, Nigeria.

*Corresponding author. E-mail: ogbujuan@yahoo.com.

Accepted 28 May, 2007

Leaves of Euphorbia hirta used in traditional medicine for the treatments of boils, wounds and control of diarrhoea and dysentery were extracted by maceration in ethanol. The agar diffusion method was used to determine the antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Bacillus subtilis at different concentrations while toxicological studies was carried out through intraperitoneal injection of albino rat with varying concentrations of the extract. Antibacterial sensitivity test indicated that the extract inhibited the growth of S. aureus, E. coli, B. subtilis and P.  aeruginosa to varying degrees while S. typhi was not affected. Minimum inhibitory concentration (MIC), of the extract against E. coli, S aureus, P. aeruginosa and B. subtilis were 58.09, 22.55, 57.64 and 74.61 mg/ml respectively. Hematological analyses revealed that there was no significant difference (p = 0.05) between the total red blood cells (RBC), white blood cells (WBC), hemoglobin (Hb) and mean corpuscular hemoglobin concentration (MCHC) values of the rats used as control and those treated with the different concentrations of the extract. Also, the erythrocyte sedimentation rate (ESR) and mean corpuscular volume (MCV) values were significantly different at certain concentrations of the extract administered which indicates that the plant extract is heamatologically not toxic to rats. The plant extract was found to contain tannins, alkaloids and flavonoids which may be responsible for its antimicrobial properties. The results justify the traditional use of the plant in the treatment of sores, boils, wounds and control of dysentery and diarrhoea.

Key words: Euphorbia hirta, ethanolic extract, agar diffusion, inhibition,   toxicity.