Original ResearchProbiotic Pediococcus pentosaceus strain GS4 alleviates azoxymethane-induced toxicity in mice
Introduction
Colorectal cancer is the third most common form of cancer, making up about 10% of all cases [1], and is known to be triggered by adenomatous polyposis generated in the colon due to distinct factors, including diet and chemical intoxication [2], [3], [4]. Different inflammation-related diseases like inflammatory bowel disease, Crohn disease, and ulcerative colitis are considered high-risk factors for the development of colon cancer, which may subsequently metastasize into the liver and kidney [5], [6]. Although different targeted therapies including chemotherapies are available for colon cancer and inflammatory diseases [7], their uses get relatively restricted because they are generally associated with gastrointestinal adverse effects [8]. Moreover, antibiotics that are used to overcome the gastrointestinal adverse effects associated with chemotherapy also have adverse effects on gut microbiota [9], so there was a necessity to develop a novel therapeutic approach that can avoid these adverse effects on the gut microbiota, combat cancer, and also ameliorate the probability of prognosis in the secondary target organs. In recent times, the probiotic therapy has been gaining a lot of attention as an active research front for the mitigation of toxicity generated by the carcinogenic azoxymethane (AOM).
Azoxymethane intoxication generally occurs in the liver, kidney, and intestine as secondary targeted organs [10] and is widely used to generate multiple-organ toxic models in rodents [11]. Azoxymethane is metabolically activated with hydroxylation of a methyl group by cytochrome P450 2EI to produce methyl azoxymethanol which is further transformed to a highly reactive alkylating species methyl diazonium, which causes inflammation [12]. Many studies have shown that the AOM model could also be used as a hepatotoxic model, where acute liver failure occurs. This was examined by the elevation of hepatic enzymes such as alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) [13]. Besides liver failure, inflammation caused by AOM intoxication can lead to structural deformities and impaired brush border membrane (BBM) in the intestine; this can often result in insufficient production of intestinal disaccharidases (sucrase, maltase, and lactase) and intestinal ALP (i-ALP) [14], [15]. Furthermore, the deregulation of disaccharide metabolism in the intestine leads to a condition called malabsorption [15]. There is enough scientific evidence to support the fact that AOM toxicity reduces the microbial load in the gut and thus leads to dysbiosis [16], [17]. Sustained dysbiosis leads to many systemic diseases and disorders, including diabetes, obesity, irritable bowel syndrome, and colon cancer [17]. Thus, if the gut microbial load could be elevated in these conditions by probiotic intervention, then there could certainly be a mitigation of these inflammatory processes.
Probiotic is an important component of functional food which offers several benefits to the host either by reducing the impact of carcinogens or through xenobiotic metabolism or by producing health-promoting metabolites. Probiotic cures different types of liver diseases without causing adverse effects [18]. Studies have shown probiotics (eg, Lactobacillus rhamnosus LC705 and Propionibacterium freudenreichii subsp Shermanii) in the hepatoprotective role which can symbiotically reduce the toxicity generated by aflatoxin in the liver [19]. Similarly, Enterococcus lactis IITRHR1 has demonstrated its potential in lowering the level of different serum biomarker enzymes in acetaminophen-induced hepatotoxicity [20]. The probiotic L rhamnosus GG showed its potential in modulating BBM-associated disaccharidases and i-ALP in the inflamed intestine caused by Giardia intestinalis [21]. In addition, Ochratoxin A–mediated toxicity could also be ameliorated by the intervention of Lactobacillus reuteri CRL 1098 and Lactobacillus acidophilus CRL [22]. Moreover, it was found that probiotics can also replenish the altered microbial load and contribute to maintenance of structural integrity and hence can be used for the establishment of the intestinal barrier [23]. Previous studies demonstrated that probiotics can efficiently protect the intestine from chemical intoxication by reducing the oxidative stress and also by secreting different antioxidants. In our earlier study with Pediococcus pentosaceus strain GS4, it was observed that GS4 efficiently produced antioxidants and conjugated linoleic acid; a health beneficial metabolites by biohydrogenation and also able to survive in simulated gastrointestinal fluids [24], [25], [26], [27]. Therefore, we were interested to test the hypothesis of whether this probiotic strain GS4 might also have the ability to mitigate the toxic effects of a chemical carcinogen with the modulation of the gut microbiota. To test our hypothesis, we first evaluated the protective efficacy of probiotic GS4 at the structural level through histologic analysis of the liver and kidney, whereas liver functionality was determined biochemically. In order to demonstrate the shielding effect of the probiotic on the intestinal structural integrity, the biomarkers related to intestinal structure and function were also studied. This study also aimed to ascertain the precise role of probiotic GS4 in the alleviation of induced toxicity through replenishing the microbial load in the gastrointestinal tract disrupted by chemical carcinogens.
Section snippets
Chemicals and media
Azoxymethane was purchased from Sigma-Aldrich Fine Chemicals (St Louis, MO, USA). Media and all other chemicals of analytical grade were procured from HiMedia, Mumbai, India.
Probiotic GS4 growth conditions and dose preparation
The P. pentosaceus strain GS4 (GenBank ID: HMO44322) was grown on De-Man Rogosa Sharpe (MRS) broth/agar and was incubated at 37°C following the standard microbiological procedures. The probiotic dose was prepared by following the previously described method with modification [28]. Overnight culture was diluted to obtain OD
P. pentosaceus strain GS4 reduced toxicity caused by AOM intoxication
Initially, the protective efficacies exhibited by GS4 were evaluated at the structural level by histopathologic studies of the liver and kidney. That AOM induction caused severe toxicity in AOM-induced mice (G2) at the structural level, which was evident from the periportal infiltration of lymphocytes, defused granularity in hepatocytes and the Kupffer cells hyperplasia in the liver (Fig. 2A) and the degenerative changes in tubular epithelial cells in the kidney (Fig. 2B). In support of the
Discussion
A mice model was used to gain insights into the toxicity imposed by AOM induction and to highlight the shielding effects produced by the oral administration of probiotic P. pentosaceus strain GS4 for the first time. The current study was focused on the effect of probiotic therapy, on the organs of the host exposed to the toxic chemical AOM at the structural and functional levels. The results of this study indicated the protective efficacy of GS4 rendered to the liver and kidney both at the
Conflicts of interest
None.
Acknowledgment
The authors would like to express gratitude to the management of VIT University for financial support from the Vice Chancellor's fund (RGEMS-2014). V.D. would like to acknowledge Council of Scientific & Industrial Research (CSIR) for providing senior research fellowship. The authors also thank S. Vijayalakshmi, Associate Professor in English, School of Sciences and Languages, VIT University, for her contribution in grammar and English correction.
References (44)
- et al.
Attenuation of histopathological alterations of colon, liver and lung by dietary fibre of barley Rihane in azoxymethane-treated rats
Food Chem
(2014) - et al.
Neurobiological characterization of an azoxymethane mouse model of acute liver failure
Neurochem Int
(2006) - et al.
Expression of G protein a subunits in normal rat colon and in azoxymethane-induced colonic neoplasms
Gastroenterology
(1998) - et al.
Probiotic supplementation reduces a biomarker for increased risk of liver cancer in young men from Southern China
Am J Clin Nutr
(2006) - et al.
Probiotic Enterococcus lactis IITRHR1 protects against acetaminophen-induced hepatotoxicity
Nutrition
(2012) - et al.
Lactobacillus reuteri CRL 1098 and Lactobacillus acidophilus CRL 1014 differently reduce in vitro immunotoxic effect induced by Ochratoxin A
Food Chem Toxicol
(2012) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding
Anal Biochem
(1976)Method for assay of intestinal disaccharides
Anal Biochem
(1964)- et al.
Protective effects of probiotic Lactobacillus casei Zhang against endotoxin- and d-galactosamine-induced liver injury in rats via anti-oxidative and anti-inflammatory capacities
Int Immunopharmacol
(2013) - et al.
Intestinal beneficial effects of kefir-supplemented diet in rats
Nutr Res
(2007)
Probiotic food supplement reduces stress-induced gastrointestinal symptoms in volunteers: a double-blind, placebo-controlled, randomized trial
Nutr Res
Effects of the consumption of Bifidobacterium lactis HN019 (DR10™) and galacto-oligosaccharides on the microflora of the gastrointestinal tract in human subjects
Nutr Res
Colorectal cancer epidemiology: incidence, mortality, survival, and risk factors
Clin Colon Rectal Surg
Colon cancer: a civilization disorder
Dig Dis
Colorectal cancer and inflammatory bowel disease: epidemiology, risk factors, mechanisms of carcinogenesis and prevention strategies
Anticancer Res
Diet and colorectal cancer: current evidence for etiology and prevention
Nutr Hosp
Surgical resection of hepatic metastases from colorectal cancer: a systematic review of published studies
Br J Cancer
MACC1, a newly identified key regulator of HGF-MET signaling, predicts colon cancer metastasis
Nat Med
Chemopreventive efficacy of sulindac sulfone against colon cancer depends on time of administration during carcinogenic process
Cancer Res
Lactobacillus supplementation for diarrhoea related to chemotherapy of colorectal cancer: a randomised study
Br J Cancer
Cancer and the gut microbiota: an unexpected link
Sci Transl Med
Secondary effects induced by the colon carcinogen azoxymethane in BDIX rats
APMIS
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2017, Asian Pacific Journal of Tropical BiomedicineCitation Excerpt :P. pentosaceus GS4 has bio-hydrogenation property which can produce conjugated linoleic acid [21]. Furthermore, it plays an important role in the mitigation of induced toxicity in liver, kidney and intestine as safe and nontoxic probiotic [22], and it is good to control the induced colon carcinogenesis in mice which caused apoptosis [5]. Recent study on viability of P. pentosaceus GS4 in simulated gastric condition showed maximum survivability and resistance to processing stress, and further viability and stability may be achieved in presence of protective agents such as lactose, ascorbic acid and inulin [23].
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2016, Journal of Functional FoodsCitation Excerpt :A previous study demonstrated that VSL#3 could mitigate colorectal cancer via the gut modulation for the production and the local delivery of CLA (Bassaganya-Riera et al., 2012a). It is important to note that the probiotic GS4 could modify the gut microflora (Dubey et al., 2015); therefore, it is apparent from these results that CLA-producing bacterial load increased after GS4 intervention, elevating its conjugation ability. Moreover, the fact that quantity of LA (substrate) (~20 mg) is enough for gut microflora to produce CLA (Edionwe & Kies, 2001) further explains the anti-proliferative and pro-apoptotic efficacy of probiotic GS4.