Protective effects of new medicinal mushroom, Grifola gargal singer (higher Basidiomycetes), on induced DNA damage in somatic cells of Drosophila melanogaster.

Grifola gargal is an edible mushroom with attributed antioxidant properties. Different sources of G. gargal materials, i.e., fruit bodies and mycelia grown in liquid or solid media, were used to study its potential protective capacity when somatic mutation and recombination is induced in Drosophila melanogaster using DMBA (7-12-dimethyl-benz(α)anthracene) as promutagen. Heterozygote larvae (white/white+) were grown in media with different concentrations of DMBA. Grifola gargal fruit bodies (GgFB) or mycelia from liquid culture (GgLC) or from solid culture (GgWG), i.e., biotransformed wheat kernel flour, were added to the culture media in combined treatments with DMBA. Water, DMBA solvent, or wheat flour (WF) plus DMBA solvent were used as negative controls. Larval mortality increased from 9% to 11% in negative controls to 31% to 36% in DMBA treatments. The addition of GgFB, GgLC, or GgWG materials produced a protective effect on 25 µmol/vial DMBA-induced mortality. Mutations observed in SMART, as light spots per 100 eyes (LS/100 eyes), increased with increasing doses of DMBA; this was also true when considering the mutation incidence expressed as percentage of eyes exhibiting light spots (% eyes with LS). Interestingly, mycelia from GgFB, GgLC, or GgWG, in the presence of 25 µmol/vial DMBA, showed lower values in SMART of both the total LS/100 eyes and the percentage of eyes with LS. Thus, Grifola gargal materials were not only nontoxic, but in combination with 25 µmol/vial DMBA lowered the mortality induced by the promutagen and showed antimutagenic effects. Protective effects of G. gargal against DMBA are discussed in terms of the onset of desmutagenic and/or bioantimutagenic mechanisms of detoxification in the host organism, probably due to some bioactive compounds known to occur in higher mushrooms.