Phytochemical characterization and antifungal potentials of Melia azedarach Linn leave aqueous extract to inhibit aflatoxins biosynthesis in food during storages

Abstract

The current study was aimed to assess the chemical compositions of Melia azedarach Linn (Chinaberry) leaves aqueous extracts. Additionally, the extracts were also tested to investigate its antifungal potentials against Aspergillus flavus and Aspergillus parasiticus. Leaf extract of M. azedarach was obtained by maceration technique, subsequently analyzed using UV-Visible Spectrophotometer, Fourier Transform Infrared (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS). The total phenolic and flavonoids contents were; 67.5 ± 0.4 mg GAE/g DW and 12.7 ± 0.2 mg QE /g DW respectively. The presence phytochemicals were confirmed from various functional groups recorded in FT-IR spectra. The results were further validated through GC-MS analysis where a total of 18 compounds were identified with seven major compounds; namely 1-Butanol, 3-methyl-, acetate (11.53%), followed by coumaran (10.04%), (R, S)-2-propyl-5-oxohexanal (7.07%), 10-octadecenoic acid, methyl ester (5.16%) and 5,7-Octadien-2-one, 3-acetyl (3.06%). The extract exhibited antifungal activities against two major aflatoxin-producing fungi, A. flavus and A. parasiticus. The aqueous extract (31.25 to 500 mg mL-1) was active to inhibit the spore germination, mycelial growth, biomass production and aflatoxin biosynthesis. Spore germination was significantly reduced, with maximum inhibition of 83% against A. flavus and 85% against A. parasiticus at 500 mg mL-1. Mycelial growth and fungal biomass were markedly declined with increasing trend in extract concentration. The recorded biomass inhibition was 73.2% and 76.9% respectively against A. flavus and A. parasiticus. The extract also significantly suppressed the aflatoxin production in the selected fungal strains at higher concentrations, exceeded from 75% with respect to aflatoxins BI, BJ, GI, and GJ. The findings suggest that M. azedarach leaves extract is a valuable source of bioactive compounds possessing strong antifungal and anti-aflatoxigenic properties and could be considered as a promising natural alternative for controlling aflatoxins contamination in agricultural food sectors.