Antifungal Activity of <i>Hyptis spicigera</i> Methanol Leaf Extract and Flavonoid Fraction

Abstract

Control of plant fungal diseases using synthetic fungicides continue to cause major problems to human health and the entire ecosystem. The aim of this research was to investigate the phytochemical and antifungal properties of Hyptis spicigera methanol leaf extract and flavonoid fraction on Aspergillus and Fusarium species, with a view to uncovering effective bio-fungicides for development as substitutes to chemical fungicides. Phytochemical screening revealed the presence of sterols and triterpenes, cardiac glycosides, flavonoids, tannins and alkaloids. The quantitative analysis showed that saponin (690 mg/g GAE), phenolics (220 mg/g GAE) and flavonoids (140 mg/g GAE) were found to be in high concentration. The antifungal effects of H. spicigera methanol extract on F. graminearum (21 mm) was significantly (p<0.05) higher than the control fungicide (Mancozeb). Similarly, the flavonoid fraction was more effective on A. parasitic (18 mm) than the control fungicide used. The extract and fraction exhibited MIC with range 3.13-12.5 mg/mL and MFC 6.25-12.5 mg/mL, indicating promising antifungal efficacies against A. flavus and F. graminearum. Our findings have revealed that H. spicigera flavonoid rich fraction has potential for development as effective bio-fungicide to control plant fungal diseases of the Aspergillus and Fusarium species.