Pharmacognostic Evaluation, Phytochemical Screening and Anti-Candidal Activities of Leaves of Some Medicinal Plants against Candida albicans

Three Nigerian medicinal plants Psidium guajava Linn, Senna siamea Lam, and Senna obtusifolia L were investigated to determine the pharmacognostic characteristics, phytochemical contents and their activities against Candida albicans.  The fresh leaves of each plant were examined for their microscopic characters and then processed. The dried ground leaves were extracted using water and ethanol. The extracts were subjected to phytochemical screening and their anticandida activities were determined using paper disc diffusion method at concentrations of 25mg/ml; 50mg/ml; 100mg/ml; 200mg/ml and 400mg/ml with Ketoconazole as control. The study indicated that the plant extracts contained alkaloids, anthraquinones, flavonoids, saponins, steroids, tannins and terpenoids. Glycoside was found to be absent. The extracts of the plants showed varying mean zones of inhibition (MZI) against C. albicans ranging from 6.00±0.00 to 16.67±1.53mm. The Minimum Inhibitory Concentration (MIC) of the extracts ranged from 10mg/ml to 20mg/ml while the Minimum Fungicidal Concentration (MFC) ranged from 20mg/ml to >80mg/ml with P. guajava having the least MIC and MFC of 10mg/ml and 20mg/ml respectively. The results indicated that MZI of the aqueous and ethanol extracts of P. guajava at a concentration of 400mg/ml had no significant differences at p ≤ 0.05. Further research is recommended for possible combinations of lower doses of the extracts to study their synergistic effects on C. albicans and to explore other potentials of the plants against other pathogens.