Licorice, Doum, and Banana Peel Extracts Inhibit <i>Aspergillus flavus</i> Growth and Suppress Metabolic Pathway of Aflatoxin B1 Production
Nesrine H. Youssef,
Sameer H. Qari,
Saleh Matar,
Najwa A. Hamad,
Eldessoky S. Dessoky,
Moustafa M. Elshaer,
Sherien Sobhy,
Ahmed Abdelkhalek,
Hossam M. Zakaria,
Ahmed A. Heflish,
Ibrahim A. Elsamra,
Said I. Behiry
Affiliations
Nesrine H. Youssef
Microbiology and Mycotoxins Labs, Regional Center for Foods and Feeds, Agricultural Researches Center, Alexandria 12619, Egypt
Sameer H. Qari
Biology Department, Al-Jumum University College, Umm Al-Qura University, Mecca 25376, Saudi Arabia
Saleh Matar
Chemical Engineering Department, Faculty of Engineering, Jazan University, Jazan 45142, Saudi Arabia
Najwa A. Hamad
Plant Protection Department, Faculty of Agriculture, Omar Al-Mukhtar University, Al Bayda 00218-84, Libya
Eldessoky S. Dessoky
Department of Biology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
Moustafa M. Elshaer
Department of Microbiology at Specialized Medical Hospital, Mansoura University, Mansoura 35516, Egypt
Sherien Sobhy
Plant Protection and Biomolecular Diagnosis Department, ALCRI, City of Scientific Research and Technological Applications, New Borg El Arab City 21934, Alexandria, Egypt
Ahmed Abdelkhalek
Plant Protection and Biomolecular Diagnosis Department, ALCRI, City of Scientific Research and Technological Applications, New Borg El Arab City 21934, Alexandria, Egypt
Hossam M. Zakaria
Agricultural Genetic Engineering Research Institute, Agricultural Research Center, Giza 12619, Egypt
Three different concentrations of four (ethanol, acetone, methanol, and diethyl ether) extracts of licorice, doum, and banana peel were evaluated for antifungal and antimycotoxigenic efficiency against a maize aflatoxigenic fungus, Aspergillus flavus. Among them, the licorice diethyl ether 75% extract was intensely active, showing the best wet and dry weight inhibition and exhibiting the highest efficacy ratio (91%). Regarding aflatoxin B1 (AFB1) production, all the plant extracts tested were effective against AFB1 production after one month of maize storage, with average efficacy ratios ranging from 74.1% to 97.5%. At the same time, Thiram fungicide exhibited an efficacy ratio of 20.14%. The relative expression levels of three structural genes (aflD, aflP, and aflQ) and two regulatory genes (aflR and aflS) were significantly downregulated when compared to untreated maize grains or Thiram-treated maize grains. The doum diethyl ether 75% peel extract showed the highest total phenolic content (60.48 mg GAE/g dry extract wt.) and antioxidant activity (84.71 μg/mL). GC–MS analysis revealed that dimethoxycinnamic acid, aspartic acid, valproic acid, and linoleic acid might imbue the extracts with antioxidant capacities in relation to fungal growth and aflatoxin biosynthesis. Finally, the results suggest that the three plant extracts can be considered a promising source for developing potentially effective and environmentally safer alternative ways to control aflatoxin formation, thus creating a potentially protective method for grain storage.
