Publication Title:Oscar Mayunzu, D. Shitanda, F. Okalebo and L. Simiyu. Evaluation of the Antimicrobial and Antioxidant properties of Extracts of Mondia whytei roots. Pakistan Journal of Nutrition 9 (X): XX-XX, 2010. Pakistan Journal of Nutrition 9 (x): xx-xx, 2010 ISBN 1680-5194 © Asian Network for Scientific Information, 2010 Corresponding Author: O. Mayunzu, BEED, Jomo Kenyatta University of Agriculture and Technology, Kenya 1 Evaluation of the Antimicrobial and Antioxidant Properties of Extracts of Mondia whytei Roots O. Mayunzu1, D. Shitanda1, F. Okalebo2 and L. Simiyu1 1BEED, Jomo Kenyatta University of Agriculture and Technology, Kenya 2School of Pharmacy, University of Nairobi, Nairobi, Kenya
Abstract: Aqueous, ethanol and methanol extracts of Mondia whytei (M. whytei) root barks were screened for their inhibitory effects on some fungal and bacterial strains. Staphylococcus aureus (S. aureus) (ATCC25923), Escherichia coli (E. coli) 0157:H7 (PSSCMI 0032), Bacillus subtillus, Candida albicans and Asparagus niger were used as test organisms. The water extract lacked significant activity against all organisms except Staphylococcus. aureus where the water extract exhibited the highest activity. However,
the ethanol extract had significant activity against Candida albicans and Asperigillus niger with minimuminhibitory values of 58.59 and 14.65 μg/ml respectively. Methanol had high Minimum Inhibitory Concentration (MIC) values of less than 14.65 and 14.7 μg/ml for Asperigillus niger and E. coli respectively. From the results it was concluded that activity varied with the solvent used. Contrary to previous reports, the plant seems to lack significant antibacterial activity except against E. coli. The popularity of a herbal recipe is not always a measure for its potency. However, M. whytei had antifungal activity since the ethanol and methanol extracts showed significant activity against the tested strains of fungi. The antioxidant activity of the extracts was also evaluated using the DPPH free radical scavenging assay. M. whytei exhibited substantial inhibition of the DPPH activity with EC50 of 413 mg/l for the crude extracts. The results suggest that M. whytei has significant antioxidant activity as demonstrated by the DPPH assay. This antioxidant activity of the crude extracts can be attributed to the presence of 2-Hydroxy-4-Methoxybenzaldehyde that is a known antioxidant in the root extracts.
Key words: Aqueous, ethanol extract, methanol extract