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.

Protective Effects of Probiotic Lactobacillus rhamnosus IMC501 in Mice Treated with PhIP

“…PhIP did not show any genotoxic effect in liver cells and, consequently, it was not possible to evaluate potential antigenotoxic properties of the tested Lactobacillus rhamnosus strain in this organ. The beneficial effects reported in the present paper for the challenge lactobacilli/ PhIP are in agreement with previous reports indicating that oral administration of probiotics effectively reduces the extent of induced DNA damage in model animals [12,33,49,54].…”

“…The results of our previous studies have demonstrated the ability of lactobacilli, bacilli, and yeasts to counteract in vitro various food mutagens, among which include 4-nitroquinoline-N-oxide, N-methyl-N'-nitro-N-nitrosoguanidine, heterocyclic amines, and aflatoxin B 1 [4,8,51]. Carcinogenesis studies conducted in laboratory animals have shown that some probiotics (i.e., lactobacilli and bifidobacteria) seem capable of counteracting the DNA damage activity exerted by potent food mutagens (2amino-3-methylimidazo[4,5-f]quinoline, DMH, aflatoxin B 1 , azoxymethane) with consequent reduction of a pre-neoplastic state and protection against tumors induced by these compounds [19,26,39,54]. For these reasons, every strategy reducing mutagen presence may be effective in carcinogenesis prevention.…”

Bacterial Composition, Genotoxicity, and Cytotoxicity of Fecal Samples from Individuals Consuming Omnivorous or Vegetarian Diets

“…The lacto-ovo-vegetarian habit, a less restrictive dietary pattern than the vegan one, was particularly effective in lowering the levels of both FW genotoxicity and cytotoxicity. This finding highlights the possible contribution of this dietary habit in reducing the risk of carcinogenesis at intestinal level and is consistent with our previous studies concerning the antigenotoxic activity of some probiotics and food-borne microorganisms in animal models ( Villarini et al, 2008 ; Dominici et al, 2014 ). Indeed, the capacity of food-borne bacteria and yeasts with acid-bile resistance to significantly reduce the activity of model genotoxins, such as nitroarenes, alkylating agents, mycotoxins, and heterocyclic amines, has been already demonstrated in vitro ( Caldini et al, 2005 ; Cenci et al, 2008 ).…”

“…The diet-related metabolomic features of the digestive tract may endogenously affect the induced expression of fecal microbial enzymes (β-glucuronidase, nitroreductase, azoreductase, 7-α-dehydroxylase) involved in the metabolic activation of pre-carcinogen, and the activity of mucolytic enzymes (β-glucosidase, N -acetyl-β- D -glucosaminidase) that increase colonocyte susceptibility to genotoxic compounds ( Cenci et al, 1993 ; Fotiadis et al, 2008 ; Villarini et al, 2008 ). Furthermore, even secondary bile acids, nitrosamines and fecapentaenes originated by microbial metabolism have genotoxic properties ( de Kok and van Maanen, 2000 ).…”

Administration of lactobacillus casei and bifidobacterium bifidum ameliorated hyperglycemia, dyslipidemia, and oxidative stress in diabetic rats

“…[1415] Probiotic-containing foods have been reported to suppress oxidative stress. It has been shown that Lactobacillus casei decreased the oxidative stress[16] and suppressed the effector functions of CD4 + T-cells, accompanied by reducing the proinflammatory molecules,[17] thus having antioxidant and immunomodulatory effects.…”