PHYTOCHEMICAL SCREENING AND INSECTICIDAL ACTIVITY OF ENDOPHYTIC FUNGAL EXTRACTS FROM STEM BARK OF Azadirachta indica AGAINST Anopheles gambiae

Abstract

Mosquitoes are the vectors of several life-threatening diseases in humans such as malaria, yellow fever, chikungunya fever, e.t.c. The present study explored the insecticidal effect of three endophytic fungal extracts isolated from the stem bark of Azadirachta indica on larvicidal, pupicidal and adulticidal activity against Anopheles gambiae and their phytochemical constituents. Aspergillus specie (AI-1), Mucor specie (AI-2) and Penicillium specie (AI-3) were isolated from the stem bark of Azadirachta indica and identified based on the morphological characteristics of the colonies and microscopically using lacto phenol cotton blue staining technique. The ethyl acetate extract was obtained by liquid-liquid extraction of the fermented fungus in potato dextrose broth medium. Results of qualitative phytochemical screening of the extracts revealed the presence of saponins in all the extracts, cardiac glycosides and phenols are present in AI-1 and AI-3. Alkaloids, Tannins and terpenoids were detected only in AI-1, steroids and anthraquinones were found only in AI-2 and AI-3 respectively. The extract of AI-1 was also observed to record the highest insecticidal activity against Anopheles gambiae with LC₅₀ values of 143.88, 272.70 and 418.23 ppm for larvicidal, pupicidal and adulticidal respectively, AI-3 showed significant activity with LC₅₀ values of 155.14, 336.21 and 612.62 ppm accordingly while AI-2 proved to be less active. These results suggest that ethyl acetate extract of Aspergillus specie (AI-1) have the potential to be used as an eco-friendly approach for vector control program.