Synergistic Antifungal Analysis of Carica papaya Leaf and Solanum melongena Peel Ethanolic Extracts Against Candida albicans

Abstract

Infectious diseases are responsible for most mortalities and morbidities globally. They are estimated to cause 17 million deaths annually. Candida albicans is a microflora found in mucous membranes of the gastrointestinal tract and vagina. Though a commensal organism, it can cause either oropharyngeal or vaginal candidiasis in immunocompromised states. It thus, is a common opportunistic infection especially in patients living with HIV/AIDS. Management of candidiasis requires use of antifungal agents but some are costly or drug-resistant. Therefore, there is need for exploration of novel and affordable treatment modalities. Medicinal plants offer alternative therapeutic modalities. Against this backdrop, we sought to evaluate synergistic antifungal activity of ethanolic extract of Carica papaya leaves and Solanum melongena fruit peel against Candida albicans. Ethical approval was sought from School of pharmacy, Kabarak University Research Ethics Committee (KUREC) and National commission for science, technology, and innovation (NACOSTI).  Experimental research design was employed. Green leaves of Carica papaya were obtained from the school’s herbarium while the eggplant fruit was purchased from Nakuru town market. The sample plants were dried and powdered. Phytochemical analysis was carried out and antifungal activity evaluated via disk diffusion method. Phytochemical studies showed presence of tannins, alkaloids and flavonoids in both plants. Anthraquinone glycosides were absent in both samples. Carica papaya and Solanum melongena ethanolic extracts respectively showed activity against Candida albicans at different concentrations with zones of inhibition of 8.34mm and 7.98mm, respectively, at the highest concentrations. S. melongena extracts showed a lower zone of inhibition against Candida albicans compared to C. papaya extracts. Combined ethanolic extracts of   Solanum melongena and Carica papaya showed higher activity at all concentrations than individual extracts, implying synergism between the two plant extracts. The difference in zones of inhibition was significant at different concentrations(P<0.05).

Conclusion: The study findings have demonstrated that Carica papaya and Solanum melongena extracts have remarkable antifungal activity against Candida albicans. This makes them potential efficacious antifungal agents against Candida albicans.