Evaluation of the antifungal efficacy of Mitracarpus scaber extracts and Ocimum gratissimum oil against clinical isolates of fungi

Dermatophytes and Candida albicans are widespread with increasing prevalence and pose a grave threat to public health globally. Ocimum gratissimum and Mitracarpus scaber have been used in Southeastern Nigeria for several purposes, including antimicrobial effects, and have exhibited inhibition of growth to fungi. This study aimed to evaluate and ascertain the antifungal potential of these extracts against dermatophytes and Candida albicans. A total of 50 samples of dermatophytes and Candida albicans previously isolated from clinical samples at two different Hospitals, in the Southeast of Nigeria were used. The clinical samples were vaginal discharge, sputum, swab samples from the endocervix, urine, groin, mouth thrush, and palm. These organisms were all identified using standard mycological identification and characterization techniques. The sensitivity of selected fungi to the extracts (ethanolic extract of M. scaber and O. gratissimum oil) and ketoconazole was evaluated using a modified cup-agar diffusion plate method. The minimum inhibitory concentration (MIC) of the extracts was determined by the agar dilution method. Their minimum fungicidal concentration (MFC) and killing rates against the isolates were also determined. The organisms remain an important etiological agent in this species, implicated in several kinds of infections. The result showed that the activity of the O. gratissimum oil was comparable with that of the conventional drugs, indicating the potential in this extract. The MIC values for Candida isolates were consistently lower against O. gratisimum compared to ketoconazole. The MFC results indicated that O. gratissimum oil had a greater biocidal effect against most of the test organisms in contrast to ketoconazole. The killing rate study also indicated that the oil has very good activity against the isolates. O. gratissimum oil holds great potential for use in treating a wider spectrum of fungal pathogens.