title: Food borne yeasts as DNA-bioprotective agents against model genotoxins.
abstract: Yeasts isolated from Italian beverages and foods (wine and cheeses) were identified as Saccharomyces cerevisiae and Debaryomyces hansenii by sequencing the D1/D2 domain of the 26S rRNA gene and differentiated, at strain level, by microsatellite PCR fingerprinting and RAPD-PCR. All the strains showed antioxidant activity, as demonstrated by their ability to scavenge the free radical diphenyl-1-picrylhydrazyl (DPPH). Furthermore, tested strains revealed high in vitro inhibitory activity against two model genotoxins, 4-nitroquinoline-1-oxide (4-NQO) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), as showed by short-term methods with different target cells: SOS-Chromotest with Escherichia coli PQ37 and Comet assay with HT-29 enterocytes. High inhibitory activity towards 4-NQO was associated with cell viability, while heat-inactivated cells showed a reduced antigenotoxic capability. Surprisingly, high inhibition of MNNG genotoxicity was observed even with heat-treated cells. Moreover, the strains able to inhibit the genotoxins induced some changes in the spectroscopic properties of the original compound. This result perfectly agrees with the information obtained by the two bioassays. Interestingly, strains characterized for antioxidant and antigenotoxic properties, also presented acid-bile tolerance, indicating that food autochthonous yeasts could be expected to reach gut in viable form and thus prevent genotoxin DNA damage in situ.
authors.affiliation: Dipartimento Biologia Cellulare e Ambientale, Università di Perugia, Via del Giochetto, I-06122 Perugia, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Trotta
authors.forename: Giovanna
authors.initials: G
authors.lastname: Caldini
authors.forename: Luca
authors.initials: L
authors.lastname: Dominici
authors.forename: Ermanno
authors.initials: E
authors.lastname: Federici
authors.forename: Rosanna
authors.initials: R
authors.lastname: Tofalo
authors.forename: Maria
authors.initials: M
authors.lastname: Schirone
authors.forename: Aldo
authors.initials: A
authors.lastname: Corsetti
authors.forename: Giovanna
authors.initials: G
authors.lastname: Suzzi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cenci
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000378:metabolism* / Q000633:toxicity; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology; D002611:Cheese / Q000382:microbiology; D020552:Comet Assay; D004247:DNA; D004249:DNA Damage / Q000187:drug effects; D005609:Free Radicals; D008769:Methylnitronitrosoguanidine / Q000378:metabolism* / Q000633:toxicity; D009153:Mutagens / Q000737:chemistry / Q000633:toxicity; D012335:RNA, Ribosomal / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification / Q000378:metabolism*; D014920:Wine / Q000382:microbiology; D015003:Yeasts / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D009153:Mutagens; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; D008769:Methylnitronitrosoguanidine; D015112:4-Nitroquinoline-1-oxide; D004247:DNA