Quantitative Phytochemical Analysis and Antimicrobial Potential of the Ethanol and Aqueous Extracts of the Leaf, Stem and Root of Chromolaena odorata (Asteraceae)

Abstract

Background: Plants contain secondary metabolites or phytochemicals, which when consumed by humans give therapeutic effect. This study therefore analyzed the phytochemical composition of Chromolaena odorata so as to give an idea of its possible pharmacological potentials. An antimicrobial assay was also carried out to verify claims on its use in the treatment of infectious diseases. Methods: The experimental procedure involved collection of the leaf, stem and root of the plant from the wild, authenticating the samples and drying under shade to facilitate pulverization. Preliminary qualitative and quantitative phytochemical analyses were done using standard methods to reveal the presence and percentage composition of basic phytochemicals. The powder was also macerated in ethanol and water to produce ethanol and aqueous crude extracts that were reconstituted in normal saline to concentrations (mg/ml) of 150, 100, 75 and 50. Clinical isolates of Staphylococcus aureus, Salmonella typhi, Escherichia coli, Aspergillus niger and Candida albicans were screened for sensitivity to the extracts using the agar well diffusion method. Results: The plant parts contain alkaloids, tannins, flavonoids, saponins, terpenoids, phenols, cardiac glycosides, and sterols at varying concentrations. The leaf however had highest concentration of almost all phytochemicals present. The antimicrobial activity of the plant was concentrationdependent in all parts of the plant and both extracts. Aspergillus niger and Candida albicans were most susceptible while Salmonella typhi and Escherichia coli were least susceptible with an average Inhibition Zone Diameter (IZD) of about 8 – 10 mm. Conclusion: The substantial quantity of the basic phytochemicals in Chromolaena odorata could render it a utility plant in therapeutic use. Due to the profound antimicrobial effect as revealed by the IZDs, the plant could be classified as a broad spectrum antimicrobial agent. Thus, the claim on its potency in treatment of infectious diseases by traditional medical practitioners could be said to be justified.