Antimicrobial activities of Centella asiatica leaf and root extracts on selected pathogenic micro-organisms

Background and Objective: Centella asiatica belonging to family umbelliferae popularly known as pegagan, is very useful medicinal plant as an antimicrobial. However, the results of the study comparing anti-microbial activities of leaf and root of C. asiatica have not been properly documented. This paper reported on a research on the antimicrobial effect of leaf and root of C. asiatica ethanol, aqueous and chloroform extracts against representative micro-organism. Materials and Methods: The ethanol, aqueous and chloroform extracts of leaf and root of C. asiatica against six bacteria namely, Escherichia coli, Staphylococcus aureus, Staphylococcus albus, Streptococcus pyogenes, Psedomonas aeruginosa, Sreptococcus pneumonia and three fungi: Aspergillus niger, Aspergillus flavus, Microsporium boulardii and one yeast Candida albicans were determined using agar well diffusion and paper disk methods. Results: The results revealed that ethanol was the best extractive solvent for anti-microbial properties of leaf and root of C. asiatica followed in order by chloroform and aqueous. The ethanol extracts C. asiatica root gave the widest zone of inhibition against bacteria using agar well diffusion and the disc plate method. The growth of six bacterial isolates were inhibited by the three extracts except P. aeruginosa and S. pyogenes. Similarly, the growth of three test fungi were inhibited by ethanol and chloroform extracts while the aqueous extract was the least effective on the test fungi. The best antifungal activity was recorded in ethanol extract of C. asiatica root. The minimum inhibitory concentration (MIC) for the ethanol extract was between 5.0 and 20.0 mg mLG1 for fungi. Conclusion: This study revealed that the C. asiatica root demonstrated strong inhibitory effect on the test organisms than C. asiatica leaf. The results therefore established a good support for the use of C. asiatica in traditional medicine.