Phytochemical Screening and Antimicrobial Activity of Chromolaena odorata Leaf Extract against Selected Microorganisms

Aims: The increasing microbial drug resistance in recent times has necessitated the search for an alternative antimicrobial agents derived from natural sources. Chromolaena odorata L. (Asteraceae) is one of such natural sources that has been reported to possess healing properties. In this study, the phytochemical constituents and antimicrobial properties of C. odorata leaf extract were investigated.

Methodology: The leaves of C. odorata were collected from Babcock University garden, authenticated, prepared and extracted following standard procedures with methanol and ethyl-ether as extraction solvents. Phytochemical screening was carried out according standard protocol while antimicrobial screening was performed according to agar well diffusion method on the following organisms: Pseudomonas aeruginosa (ATCC19582), Shigella flexneri (KZN), Klebsiella pneumoniae (ATCC 10031), Enterococcus faecalis (ATCC 29212), Enterococcus cloacae (ATCC 13047), Proteus vulgaris ATCC 6830, Escherichia coli (ATCC 25922) Enterococcus faecalis (KZN) and Neurospora crassa.

Results: Of the nine phytochemicals screened (terpenoids, steroids, flavonoids, alkaloids, saponins, tannins, phlobatannin, phenols and anthraquinones), only one (phlobatannin) was absent in both solvent extracts. The antimicrobial activity of the extracts indicated least and highest zones of inhibition of 9 and 23 mm against Shigella flexneri (KZN) and Shigella sonnei (ATCC19930) respectively and fungicidal potency of 100% within 24 h on Neurospora crassa.

Conclusion: Chromolaena odorata extract possesses antimicrobial activity and thus, represents a promising source for medicines of which when carefully tapped and explored has enormous therapeutic potentials.