title: Effect of natural compounds on Fusarium graminearum complex.
abstract: BACKGROUND
  A search is underway for new solutions to counter farm loss caused by fungal contamination of grains, since the active agents of fungicides can remain in the environment and contribute to the development of resistant and toxigenic species. In this study, the antifungal activity of natural compounds (γ-oryzanol, phenolic extract of neem seeds and of rice bran) was assessed on three toxigenic strains of Fusarium graminearum isolated from wheat, rice and barley. Their efficacy was compared to that of synthetic fungicides. The halo diameters were measured and the susceptible pathways were determined by the levels of structural compounds and activities of enzymes involved in the primary metabolism of the microorganisms. Moreover, mycotoxin production and gene expression were examined.
  
  
  RESULTS
  Phenolic extracts were more effective at inhibiting F. graminearum than was γ-oryzanol, as evidenced by the minimum inhibitory concentration. This work contributed to the elucidation of the mechanism of action of natural antifungal agents.
  
  
  CONCLUSIONS
  Natural antifungals effectively inhibited fungal growth, especially via the inactivation of the enzymatic systems of F. graminearum. Natural antifungals inhibited mycotoxin production by the fungi. A correlation between the levels of deoxynivalenol and the expression of Tri5 gene was observed, indicating that the natural compounds could be considered alternatives to synthetic antifungals. © 2015 Society of Chemical Industry.
authors.affiliation: Laboratory of Mycotoxins and Food Science, Chemical and Food School, Federal University of Rio Grande, RS, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Heidtmann-Bemvenuti
authors.affiliation: Laboratory of Mycotoxins and Mycotoxigenic Fungi, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Sabina Moser
authors.initials: SM
authors.lastname: Tralamazza
authors.affiliation: Laboratory of Mycotoxins and Food Science, Chemical and Food School, Federal University of Rio Grande, RS, Brazil.
authors.forename: Cláudia Fetter
authors.initials: CF
authors.lastname: Jorge Ferreira
authors.affiliation: Laboratory of Mycotoxins and Mycotoxigenic Fungi, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Benedito
authors.initials: B
authors.lastname: Corrêa
authors.affiliation: Laboratory of Mycotoxins and Food Science, Chemical and Food School, Federal University of Rio Grande, RS, Brazil.
authors.forename: Eliana
authors.initials: E
authors.lastname: Badiale-Furlong
mesh_terms: D000821:Animal Feed / Q000382:microbiology*; D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology*; D004032:Diet / Q000662:veterinary*; D005516:Food Microbiology; D005670:Fusarium / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D015870:Gene Expression / Q000187:drug effects; D005800:Genes, Fungal; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D010936:Plant Extracts
keywords: ergosterol; glucosamine; neem seeds; phenolic extract; rice bran; γ-oryzanol