METHODS AND RESULTS: Five pathogen: antagonist inoculum ratios (100:0, 75:25, 50:50, 25:75, and 0:100) were employed. Non-aflatoxigenic Aspergillus flavus Af1KD and Af5TD, and Penicillium janthinellum were used against aflatoxin B1 (AFB1) and aflatoxin B2 (AFB2) by A. flavus. Against OTA by A. niger, and fumonisin B1 (FB1) and fumonisin B2 (FB2) by Fusarium verticillioides and F. proliferatum, respectively, the antagonists Trichoderma asperelloides, T. asperellum, and T. harzianum were used. Non-aflatoxigenic A. flavus Af1KD was the most effective against AFB1 and AFB2 at all tested ratios and substrates. All Trichoderma spp. were effective against OTA by A. niger on grain corn agar at all tested ratios. Trichoderma asperelloides and T. asperellum were effective against FB1 and FB2 produced by F. verticillioides at all tested ratios and substrates. Trichoderma asperelloides was effective against FB1 and FB2 by F. proliferatum at all tested ratios and substrates.
CONCLUSION: The native biocontrol candidates were effective against mycotoxigenic fungi and mycotoxin production on grain corn agar and grain corn kernels, and could be developed into biocontrol agents.
METHODS: The phenolic compounds of PKC were obtained by solvent extraction and the product rich in phenolic compounds was labeled as phenolic-enriched fraction (PEF). This fraction was evaluated for its phenolic compounds composition. The antioxidant activity of PEF was determined by using 1,1-diphenyl-2-picryl-hydrazil scavenging activity, ferric reducing antioxidant power, inhibition of ß-carotene bleaching, and thiobarbituric acid reactive substances assays. The cytotoxicity assay and molecular biomarkers analyses were performed to evaluate the cytoprotective effects of PEF towards aflatoxin B1 (AFB1)-induced cell damage.
RESULTS: The results showed that PEF contained gallic acid, pyrogallol, vanillic acid, caffeic acid, syringic acid, epicatechin, catechin and ferulic acid. The PEF exhibited free radical scavenging activity, ferric reducing antioxidant power, ß-carotene bleaching inhibition and thiobarbituric acid reactive substances inhibition. The PEF demonstrated cytoprotective effects in AFB1-treated chicken hepatocytes by reducing the cellular lipid peroxidation and enhancing antioxidant enzymes production. The viability of AFB1-treated hepatocytes was improved by PEF through up-regulation of oxidative stress tolerance genes and down-regulation of pro-inflammatory and apoptosis associated genes.
CONCLUSIONS: The present findings supported the proposition that the phenolic compounds present in PKC could be a potential cytoprotective agent towards AFB1 cytotoxicity.