Antiaflatoxigenic effects of selected antifungal peptides
Autor: | R B Sashidhar, Manju S. Devi |
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Rok vydání: | 2019 |
Předmět: |
Aflatoxin
Antifungal Agents Physiology DPPH Antimicrobial peptides Conidiation 030209 endocrinology & metabolism Aspergillus flavus Biochemistry Antioxidants 03 medical and health sciences Cellular and Molecular Neuroscience chemistry.chemical_compound 0302 clinical medicine Endocrinology Aflatoxins Humans Mycotoxin ABTS biology Chemistry food and beverages biology.organism_classification Aspergillus parasiticus Oxidative Stress Peptides Reactive Oxygen Species 030217 neurology & neurosurgery |
Zdroj: | Peptides. 115:15-26 |
ISSN: | 0196-9781 |
Popis: | Aflatoxins are potent carcinogenic mycotoxins produced as secondary metabolites mainly by the fungi Aspergillus flavus and Aspergillus parasiticus. Control measures to curtail the contamination of aflatoxin in food products is still a challenge. Although there are several reports on the antifungal peptides, there is no specific study on the action of antifungal peptides on aflatoxin synthesis. This work details the effect of four antimicrobial peptides (AMPs) - PPD1 (FRLHF), 66-10 (FRLKFH), 77-3 (FRLKFHF) and D4E1 (FKLRAKIKVRLRAKIKL) on the aflatoxin production by A. flavus and A. parasiticus. Results of the investigations suggests that AMPs at near minimum inhibitory concentrations (MIC) were effectively inhibiting aflatoxins, without hindering the growth of the fungi. These AMPs, at concentrations near MIC, induced membrane permeabilisation, without inducing cellular leakage. The involvement of oxidative stress for the aflatoxin synthesis was reversed by the antioxidant nature of the peptides as evidenced by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay, reactive oxygen species production, malondialdehyde and antioxidant enzymes analysis. Quantitative real time polymerase chain reaction (RT-qPCR) analysis of the aflatoxin gene cluster showed that 'aflR' and its downstream genes expressions were significantly down regulated. Conidiation of the fungi were negatively influenced by the peptides as evidenced by scanning electron microscopy analysis and RT-qPCR. mRNA levels of Manganese-superoxide dismutase (Mn-SOD) showed a decrease in the expression in RT-qPCR. The effect of these peptides on aflatoxin inhibition provides insight into their use as novel antiaflatoxigenic molecules. |
Databáze: | OpenAIRE |
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