Patulin [HRP]

Introduction: Quercetin (QUER) is a bioactive phytochemical belonging to a large group of polyphenolic flavonoid substances and one of the most abundant flavonoids in the human diet. The antioxidant and pro-oxidant activity of QUER has been extensively investigated because of contradictory findings about its ability to protect mammalian cells from cytotoxicity. QUER is concomitant with mycotoxins in numerous food and foodstuffs. In the 80s, experimental approaches started to evaluate in vitro its protective effects against cytotoxicity related to mycotoxin ingest. Objective: The aim of this mini-review was to analyze how QUER treatment modifies mycotoxin effects in in vitro experimental models. Methods: A literature research was performed using the keyword "quercetin", "mycotoxin" and "in vitro", individually or all together, in Scopus, Web of Science and Pubmed. Results: In literature, the tested mycotoxins are described as follows: ochratoxin A, zearalenone and its metabolites alpha- and beta-zearalenol, alternariol, alternariol monomethyl ether, T-2 toxin, patulin, aflatoxin B-1, deoxynivalenol, enniatins and beauvericin. Regarding the experimental models, human hepatocellular (HepG2) and colorectal carcinoma (HCT116 and Caco-2), human peripheral blood mononuclear cells (hPMBC), embryonic kidney (HEK293), Chinese hamster ovary (CHO-K1) and African green monkey kidney (Vero) cell lines were used. Conclusion: QUER showed promising results that made researchers move up to in vivo experiments. As future implementation, a combination of dietary non-enzymatic antioxidant products in food and feed could reduce the effects of mycotoxins on humans and animals.

The blue mold fungus, Penicillium expansum, is a post-harvest apple pathogen that contributes to food waste by rotting fruit and by producing harmful mycotoxins (e.g. patulin). To identify genes controlling pathogen virulence, a random T-DNA insertional library was created from wild-type P. expansum strain R19. One transformant, T625, had reduced virulence in apples, blistered mycelial hyphae, and a T-DNA insertion that abolished transcription of the single copy locus in which it was inserted. The gene, Blistering1, encodes a protein with a DnaJ domain, but otherwise has little homology outside the Aspergillaceae, a family of fungi known for producing antibiotics, mycotoxins, and cheese. Because protein secretion is critical for these processes and for host infection, mass spectrometry was used to monitor proteins secreted into liquid media during fungal growth. T625 failed to secrete a set of enzymes that degrade plant cell walls, along with ones that synthesize the three final biosynthetic steps of patulin. Consequently, the culture broth of T625 had significantly reduced capacity to degrade apple tissue and contained 30 times less patulin. Quantitative mass spectrometry of 3,282 mycelial proteins revealed that T625 had altered cellular networks controlling protein processing in the endoplasmic reticulum, protein export, vesicle-mediated transport, and endocytosis. T625 also had reduced proteins controlling mRNA surveillance and RNA processing. Transmission electron microscopy of hyphal cross sections confirmed that T625 formed abnormally enlarged endosomes or vacuoles. These data reveal that Blistering1 affects internal and external protein processing involving vesicle-mediated transport in a family of fungi with medical, commercial, and agricultural importance.