Antifungal Activity and Biosafety Assessment of Vernonia adoensis

Abstract

Dermatophytes and other pathogenic fungi species are neglected tropical infections that grow on skin, hair, nails, mucous membranes, appendages and other body surfaces, causing various diseases in over a billion people annually. Common treatments are not only inaccessible but there are rising incidences of resistance to these antifungals. Vernonia adoensis, a plant indigenous to tropical and subtropical regions and prevalent in Southern Africa has widely been used as an effective treatment for fungal infections in traditional medicine in Southern Africa, however its toxicity profile and effectivity against pathogenic fungi remains unscientifically systematically validated. In this study, the phytochemical constituents of pharmacological relevance were identified through wet chemical analysis techniques, the toxicity profile was determined through OECD guidelines as well as Draize dermal irritation and skin sensitivity tests, the antifungal activity was assessed through the agar well diffusion method against Aspergillus fumigatus, with miconazole as a standard. The anti-inflammatory activity was determined through the egg albumin test with diclofenac as a standard. It was confirmed in this study that lyophilized hydroethanolic extracts from V. adoensis possess numerous phytoconstituents of pharmacological relevance including flavonoids, alkaloids, and terpenoids. The extracts demonstrated significant inhibitory effects against Aspergillus fumigatus comparable to miconazole. Our findings indicate that the lyophilized extracts were non-toxic at doses up to 5000 mg/kg, and the skin irritation tests confirmed that V adoensis has negligible skin irritation potential. The extracts also demonstrated considerable anti-inflammatory activity at doses within the toxicity safety zone. Based on the foregoing it was concluded that Vernonia adoensis possess relevant, pharmacologically active metabolites with regards to common end points of fungal infections. The hydroethanolic extracts possess no adverse dermal sensitivity issues and is toxicologically safe according to the Hodge and Sterner toxicity scale. V. adoensis therefore presents a safer, efficacious alternative as an antifungal agent for pharmacological use.