title: Modulatory activity of a Lactobacillus casei strain on 1,2-dimethylhydrazine-induced genotoxicity in rats.
abstract: The present study was designed to investigate the putative antigenotoxic effects of supplementing the diet of rats treated with the colon carcinogen 1,2-dimethylhydrazine hydrochloride (DMH) with a Lactobacillus casei strain using an in vivo approach. The antigenotoxic response was evaluated in colon and liver cells using the alkaline comet assay. Since the balance between the bioactivation and detoxification metabolic pathways is crucial for the formation of toxic and genotoxic metabolites, alterations in the level of some xenobiotic metabolizing enzymes (XME) were studied in liver preparations. In the challenge group (L. casei + DMH), lactobacilli-supplemented diet, there was a decrease in the extent of DMH-induced DNA damage, especially in colon cells. Compared with control rats, there was less basal DNA damage in colon cells of rats fed on a lactobacilli-supplemented diet. These findings are the first to give clear evidence of DNA-protective effects of lactobacilli against basal DNA damage. Moreover, the chemopreventive effects were accompanied by changes in the activities of several XME. The observed decrease in the concentration of nonenzymatic antioxidants (i.e. GSH) and the reduced activity of enzymatic antioxidants (i.e., GST, GPx, and SOD) in liver could reflect an overall reduction in the level of oxidative stress in rats on a diet supplemented with the L. casei suspension compared with control rats (basal state). Thus, the concentrations of GSH and the activities of GST, GPx, and SOD could be downregulated by supplementing the diet with L. casei as a response to an improved antioxidant status.
authors.affiliation: Dipartimento di Specialità Medico-Chirurgiche e Sanità Pubblica, Università degli Studi di Perugia, Via del Giochetto, Perugia, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Villarini
authors.forename: Giovanna
authors.initials: G
authors.lastname: Caldini
authors.forename: Massimo
authors.initials: M
authors.lastname: Moretti
authors.forename: Francesca
authors.initials: F
authors.lastname: Trotta
authors.forename: Rossana
authors.initials: R
authors.lastname: Pasquini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cenci
mesh_terms: D019813:1,2-Dimethylhydrazine / Q000633:toxicity*; D000118:Acetylglucosaminidase / Q000378:metabolism; D000477:Alkylating Agents / Q000633:toxicity*; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D003106:Colon / Q000166:cytology; D020552:Comet Assay; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004249:DNA Damage; D019587:Dietary Supplements; D005243:Feces / Q000201:enzymology; D005966:Glucuronidase / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects; D007780:Lacticaseibacillus casei; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D009153:Mutagens / Q000633:toxicity*; D020011:Protective Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D000477:Alkylating Agents; D002273:Carcinogens; D009153:Mutagens; D020011:Protective Agents; D003577:Cytochrome P-450 Enzyme System; D001617:beta-Glucosidase; D005966:Glucuronidase; D000118:Acetylglucosaminidase; D019813:1,2-Dimethylhydrazine