Phytochemical Screening And Antimicrobial Activity Of Four Nigerian Medicinal Plants:- Amakwe, Ogadinma C.

ABSTRACT

The antimicrobial activity and phytochemical screening of the leaves of Piper guineense Schumach, Psidium guajava Linn, Gongrenema latifolium Endl and Terminalia catappa Linn was carried out. The four plant species indicated the presence of alkaloid, phenol, tannin, spaonin and flavonoid which are bioactive component. The percentage of the phytochemcials are as follows alkaloid (0.46.139%), phenol (0.37-1.66%, saponin (0.31-0.67%), flavonoid (0.23-0.55%) and tannin (0.13-037%). The antimicrobial activity of the ethanolic and aqueous extracts of the leaves of the plant species were tested against four microorganisms, Candida albican, Klebsiella pneumonia, Escherchia coli and Bacillus subtilis. The sensitivity of the microorganisms was determined using disk diffusion method. Ethanolic plant extract and aqueous extract inhibited the growth of these pathogens. The zone of inhibition of the growth of these microorganisms by the plant extract depends on the concentration of the extract. Ethanolic plant extract had high sensitivity than the aqueous plant extract which shows less. Gongronema latifolium contained more alkaloids (1.39±0.03%) than other phytochemicals and Terminalia catappa had less tannin (0.13±0.00%) than other phytochemicals. The ethanolic extracts of Gongronema latifolium had the highest inhibitory activity (24.00±2.00mm) which shows more sensitivity against the test organisms while the aqueous extracts of Terminalia catappa has low inhibitory activity (8.33±0.58mm) which showed less sensitivity against the test organism. This result reveals that these plant species have potentials as source of raw materials in the pharmaceutical industry.