Antifungal Activity of Terminalia avicennioides in Drosophila melanogaster as an Infectious Model

摘要

Background and Objective: Conventional antifungal agents have become less effective against fungal pathogens especially, Aspergillus fumigatus and Aspergillus flavus because of the toxicity and resistance. This has prompted the search for novel prototype antifungals from higher plants. The present study determined the antifungal activity of leave, stem bark and root extracts of Terminalia avicennioides in vitro and in vivo against Aspergillus fumigatus , Aspergillus flavus and Aspergillus terreus in Drosophila melanogaster . Materials and Methods: In the in vitro and in vivo evaluation of antifungal potentials of the extracts was measured using the microdilution method in a 96-well diffusion method. Survival of Drosophila melanogaster (Drs-LacZ III) challenged with A. fumigatus , A. flavus and A. terreus by ingestion method was used to evaluate in vivo activity. Results: Antifungal activity increased in a concentration dependent manner. There was increased activity with increased concentrations. A. fumigatus , A. flavus and A. terreus was more susceptible to dichloromethane followed by ethyl acetate extract of the leave and roots of T. avicennioide. MIC of 0.32- 0.18 mg mLG1 was recorded against test organisms after 24 and 48 h with Amphotericin B as standard antifungal drug and with the petroleum ether, ethyl acetate, dichloromethane and ethanol leave, stem bark and root extracts. Survival rate increased by more than 50% in flies treated with dichloromethane and ethyl acetate leave and root extract of T. avicennioides. Drosomycin, an AMP increased as fungal infection progressed. Conclusion: The antifungal results in vitro and in vivo validated the use of this plant in traditional medicine in the treatment of fungal infections. These results have stressed the need for isolation and characterization of the active compound and the elucidation of the mechanisms of action of secondary metabolites on the immune response of Drosophila melanogaster.