In-vitro Antifungal Activity of Ethanol Plant Extracts of Moringa oleifera, Vernonia amygdalina and Ocimum gratissimum against Some Clinical Candida Species

Vaginal candidiasis, primarily caused by microorganisms belonging to the Candida genus, is a common fungal infection prevalent among millions of women worldwide and can lead to significant morbidity. The treatment of Candida infections has often relied on antifungal drugs such as azoles and echinocandins. However, the emergence of resistance among Candida species to these drugs poses a significant challenge to effective treatment. This study was, thus, aimed at evaluating the in vitro antifungal activity of ethanol extracts of some selected medicinal plants against Candida species isolated from high vaginal swabs of some women attending a hospital in Enugu State, Nigeria. Six (6) isolates resistant to three or more commercial antifungal drugs were selected for this study. These isolates include Candida tropicalis (2), Candida albicans (2), Candida Parapsilosis (1) and Candida krusei (1). The plants used were Moringa oleifera leaves, Vernonia amygdalina and Ocimum gratissimum. The leaves were dried, pulverized and 300g of each was extracted using ethanol in a Soxhlet extractor at 70°C for 6hrs. The concentrated extract of each plant was reconstituted in Dimethyl sulfoxide and different concentrations of 400 mg/ml, 200 mg/ml, 100 mg/ml, 50 mg/ml, 25 mg/ml and 12.25 mg/ml were obtained using double fold serial dilution. The susceptibility of the Candida species to the ethanol plant extracts was carried out using the agar well diffusion method. The results showed that the Extract of Moringa oleifera had the highest inhibition zone diameter (19 mm) at 200 mg/ml against resistant Candida albicans1, followed by the extract of Vernonia amygdalina and Ocimum gratissimum with inhibition zone diameters of 18.67 mm and 18 mm at 100 mg/ml and 200 mg/ml respectively. Candida tropicalis1 was sensitive to all the plant extracts at all concentrations, while Candida parapsilosis was resistant to the extract of Ocimum gratissimum at all concentrations. The activity of the extracts of Moringa oleifera and Ocimum gratissimum against Candida tropicalis1 was concentration dependent. This study also revealed that Candida krusei was resistant to all the extracts of the plants at the highest concentration of 200 mg/ml. The antifungal activities of these plant extracts implies these plants have great therapeutic potential that can be harnessed. This study, thus, recommends that these plants be investigated further for possible use in the formulation of antifungal drugs especially, against those diseases caused by Candida species that have developed resistance to the commonly used antifungal drugs.