Comparative Study of Antimicrobial Potentials of Leaf and Root Extracts of Calliandra portoricensis (Jacq)-benth (Fabaceae) on Some Human Pathogens

Abstract

The plant Calliandra portoricesis had been widely used over the years in traditional medicine. Such uses included; treatment of swollen gum, tooth ache and inflammation, worm expeller, viperean venom antidote and more. This investigation was aimed at screening and anti-microbial evaluation of various leaf and root extracts of the plant. By this, explore substitution of root with leaf as excessive root harvesting could lead to shrub extinction. The dried and pulverized samples were subjected to successive extraction using solvents of varying polarities; n-hexane, ethyl acetate and 70% aqueous methanol. The respective extracts were concentrated en vacuo in a rotatory evaporator at temperature not exceeding 40°C. Seven human pathogens were selected comprising the G +ve, G-ve, fungi, group that was known to acquire resistance easily and nosocomial strains namely; Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, Streptococus fecalis, Candida albican and Aspergillus nigar. Ciprofloxacin and fluconazole solutions served as the control reference standards. Agar well diffusion assay method was used and the Inhibition Zone Diameters (mm) of growth were measured to assess activities for all the extracts. The Minimum Inhibitory Concenyrations (MIC) and Total Activity (TA) were also determined. The experimental values indicated that both leaf and root materials of this plant exhibited anti bacterial and anti fungal properties on the selected human pathogens especially with respect to the reference control standards at P ≤ 0.05. Except for anthraquinones, the leaf though exhibited weaker activities than root for same quantity of materials showed close similarity in activity pattern. In this sense, with an appropriate quantitative adjustments, leaf material could effectively substitute the root for antimicrobial purposes.