Anti-Bacterial Effect of Different Fractionations of Acetic Acid Leaf Extract of Parinari curatellifolia

Abstract

The research was aimed at determining the anti-bacterial effect of different fractions of acetic acid leaf extract of Parinari curatellifolia. The research was conducted in laboratory unit of peace specialist hospital, Yola, Nigeria between May and November, 2011. Different solvent extracts of the leaf were prepared using the soxhlet apparatus. Disc diffusion method was used to test for the anti-bacterial activities of the different solvent extracts. The Minimum Inhibitory Concentration (MIC) of the acetic acid extract which gave the highest zones of inhibition against the microbial isolates used revealed that the MIC for Streptococcus pyogenes and Pseudomonas sp is 5mg/ml while that for Klebsiella sp and Staphylococcus aureus is 50mg/ml The acetic acid extract was fractionated with different solvents using the column chromatography. Four fractions (TiA, TiB, TiC, and TiD) were obtained from the column. Fraction TiC gave the highest zone of inhibition ranging from 10.0±0.6 to 17.3±0.9 against the test organisms. This is significantly (P=0.5) different from the crude acetic acid extract with inhibition zones ranging from 20.0±0.6 to 28.3±0.3. Inhibition zones were measured using a metre rule. Fraction TiB did not have any anti-bacterial activity against all the test organisms. Fraction TiC gave three bands on thin layer chromatography with Rf values of 0.38, 0.36, and 0.23. The activities of the separated fractions were lower compared to the crude extract. This may be due to synergistic effect of various secondary metabolites present in the crude extract. Results were discussed in respect to the anti-bacterial effect of the different fractions.