Antimicrobial Potentials of Uvaria Afzelli Scott-Elliot and Tetracera Alnifolia Willd Crude Extracts on Selected Human Pathogens: An In – Vitro Study

Abstract

The antimicrobial activities of Uvaria afzelii Scott-Elliot root bark and Tetracera alnjfolia Willd leaf and root bark used in folklore medicine for the treatment of respiratory tract infections and superficial mycoses were studied. The chloroform and methanol extracts of the plants were screened against 3 Gram positive and 4 Gram-negative bacteria viz: Staphylococcus aureus UCH 2057, Streptococcus pneumoniae UCH 2034, Bacillus subtillis UCH 2033, Pseudomonas aeruginosa UCH 2058, Klebsiella species UCH 2046, Proteus mirabilis UCH 2055, and Escherichia coli UCH 2052. The activity of the crude extracts were also investigated on Candida albicans UCH STC 2036, Aspergillus niger PHM 1506, Trichophyton mentagrophyte ATCC 4808, Trichophyton rubrum ATCC 2894, Epidermophyton floccosum ATCC 110227 and Microsporum canis ATCC 11622. The agar diffusion and agar dilution methods were used for antimicrobial screening and determination of the minimum inhibitory concentrations (MIC) respectively. The methanol extracts of the plants at 10 mg/mL demonstrated the highest activity against most of the microorganisms tested. The M1C for the susceptible microorganisms ranged between 3.125 mg/mL to 50 mg/mL.

Phytochemical screening of the plant samples revealed the presence of tannins, saponins, cardenolides and alkaloids and the absence of anthraquinones. The test organisms were resistant to the drug controls but were susceptible to the extracts of the plants. The antimicrobial activities of the plants extracts on the microorganisms tested justify their use in folklore medicine for the treatment of respiratory tract infections and superficial mycoses.

Keywords: Antimicrobial activities, phytochemical screening, Uvaria afzelii Scott Elliot, Tetracera alnifolia Willd