Naslov
Antioxidant enzymes stimulation in Aspergillus parasiticus by Lentinula edodes inhibits aflatoxin production

Autori
Reverberi, Massimo ; Fabbri, Anna Adele ; Zjalić, Slaven ; Ricelli, Alessandra ; Punelli, Federico ; Fanelli, Corrado

Izvornik
Applied microbiology and biotechnology (0175-7598) 69 (2005), 2; 207-215

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
aflatoxins ; superoxyd dismutase ; catalase ; glutathione peroxidase ; Lentinula edodes

Sažetak
Biosynthesis of aflatoxins, toxic metabolites produced by Aspergillus parasiticus, is correlated to the fungal oxidative stress and cell ageing. In this paper, the mechanism underlying the aflatoxin-inhibiting effect of the Lentinula edodes culture filtrates was studied by analysing their anti-oxidant activity and beta-glucan content. Mushroom beta-glucans are pharmacologically active compounds stimulating anti-oxidant responses in animal cells. L. edodes lyophilised filtrates stimulate A. parasiticus anti-oxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) and aflatoxin inhibition was better correlated with beta-glucan content than with anti-oxidant activity of the filtrates. RT-PCR analyses on treated mycelia showed a delay in the activation of aflR, and norA, genes of aflatoxin cluster and a synchronous activation of hsf2-like, a homologue of a yeast transcription factor involved in oxidative stress responses. The first evidence of hsf2- like in A. parasiticus and its activation during aflatoxin biosynthesis is reported. L. edodes filtrates could play a role as external stimulus affecting the anti-oxidant status in the fungal cell that, in turn, leads to aflatoxin inhibition. In the fungal cell, beta- glucans present in the filtrates could stimulate the activation of transcription factors related to anti-oxidant response and anti-oxidant enzyme activity with a contemporaneous delay of aflatoxin genes transcription, which led to a marked reduction of aflatoxin production. This research suggests new perspectives to set suitable strategies against aflatoxins and L. edodes could be considered a promising tool.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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