Toxic thermoresistant metabolites of Fusarium oxysporum are capable of inducing histopathological alterations in Wistar rats

Hernandes L (1), Marangon AV (1), Salci T (1), Svidzinski TIE (2)

(1) Laboratory of Histology, Department of Morphological Sciences, State University of Maringá (UEM), Maringá, Paraná State, Brazil; (2) Department of Clinical Analysis, Laboratory of Medical Mycology, State University of Maringá (UEM), Maringá, Paraná State, Brazil.

Abstract: The genus Fusarium is known to produce mycotoxins that cause fusariosis in plants, animals and humans. Mycotoxins are among the virulence factors of this genus. Metabolic extracts of Fusarium oxysporum, isolated from a patient with onychomycosis and sterilized by filtration or autoclave, were inoculated intradermally into Wistar rats at concentrations of 0.25, 0.5 and 1 μg/μL, and the effects on their tegument were observed at 24 and 72 hours. After histological procedures and staining by hematoxylineosin, the sections were studied for their inflammatory-reaction intensity and for evidence of injury and tissue distortion. Inflammatory reactions in the dermis and the subcutaneous tissue were observed at all concentrations of the inoculated extract tested. There was a significant influx of neutrophils, mastocytes and lymphocytes, as well as a large quantity of macrophages. Apoptotic bodies and hyperemic blood vessels were observed. This reaction was directly related to the extract concentration, and was most intense in animals that received the 1 mg/μL dose. The maximum peak was observed at 24 hours. The autoclaved metabolic extract produced the same effects as the untreated one, indicating the presence of heat-resistant metabolites. In conclusion, the metabolic extracts obtained from sterilized culture filtrates of F. oxysporum are capable of inducing an inflammatory response within 24 hours in the dermis and subcutaneous tissue of rats.

Key words: fungal skin disease, Fusarium, mycotoxins.

ACKNOWLEDeGMENTS

The authors thank CAPES and CNPq for financial support, and are grateful to Maria Euride Carlo Cancino and Maria dos Anjos Fortunato for technical support.

COPYRIGHT

© CEVAP 2012

SUBMISSION STATUS

Received: June 28, 2011.

Accepted: October 21, 2011.

Abstract published online: October 26, 2011.

Full paper published online: May 31, 2012.

CONFLICTS OF INTEREST

The authors declare no conflicts of interest.

FINANCIAL SOURCE

The Coordination for the Improvement of Higher Education Personnel (CAPES) and The National Council for Scientific and Technological Development (CNPq) provided the financial grants.

ETHICS COMMITTEE APPROVAL

The present study was approved by Ethics Committee for Animal Experimentation of the State University of Maringá, Paraná state, Brazil, under protocol number 080/2010.

CORRESPONDENCE TO

Luzmarina Hernandes, Laboratório de Histologia, Departamento de Ciências Morfológicas, Universidade Estadual de Maringá, Avenida Colombo 5790, Bloco H79, sala 108, Maringá, PR, 87020 900, Brasil. Phone: +55 44 3261 4706. Fax: +55 44 3261 4340. Email: lhernandes@uem.br.