NANOPARTICLES AND COLORECTAL CANCER: CAN THE USE OF METAL NANOPARTICLE COMPOSITIONS AFFECT OXIDATIVE STRESS MARKERS AND COLON HISTOLOGICAL CHANGES UNDER DMH-INDUCED CARCINOGENESIS.

Colorectal cancer (CRC) - a significant global health challenge. Exploring biological markers of oxidative stress is crucial, as they can play an essential role in initiating the transition from an organ's "healthy state" to a "malignant injury." There is substantial promise in investigating the level of 8-isoprostane (8-isoPGF2α) as a novel and dependable marker of oxidative stress. This paper presents that 8-isoprostane levels have been linked to the development of severe structural changes in the colon wall, accompanied by endogenic intoxication syndrome. The obtained results prove the strong connection between oxidative stress and carcinogenesis progression. Our research further illustrates the favorable and potentially beneficial impact of the Au/Ag/Fe NPs composition, which can find utility in a diverse range of contemporary applications.

Long-term 1,2-dimethylhydrazine triggers pathological remodeling of colon mucosa through repression of sestrin2, nuclear factor (erythroid-derived 2)-like 2, and sirtuin4 stimulating mitochondrial stress and metabolic reprogramming.

1,2-Dimethylhydrazine (DMH) is a plant toxicant that enters the food web through the diet. It is biotransformed into azoxymethane, a colon carcinogen, during the first hepatic passage. In mice, this study assessed the role of glutamate dehydrogenase (GDH), a key glutaminolysis enzyme in DMH-induced colorectal cancer (CRC). Colon samples were taken from mice given 6 or 15 weekly doses of 20 mg/kg DMH and serially sacrificed. Repeated DMH doses induced early aberrant crypt foci that evolved into irreversible adenocarcinomas over 24 weeks, along with an increase in GDH and lactate dehydrogenase activities (+ 122%, + 238%, P < 0.001), indicating a switch to aerobic glycolysis and glutaminolysis. Transcriptional downregulation of the endogenous GDH inhibitor, sirtuin4, and two redox regulators, mitochondrial sestrin2 and nuclear factor (erythroid derivative 2)-like 2 (- 26% and - 22%, P < 0, 05; and - 30%, P < 0.01), exacerbated mitochondrial stress by boosting mitochondrial superoxide dismutase activity (+ 240% (P < 0.001) while depressing catalase activity and GSH levels (- 57% and - 60%, P < 0.001). In vitro, allosteric GDH inhibition by 50 µM epigallocatechin gallate decreased human carcinoma (HCT-116) cells' viability, clonogenicity, and migration (- 43% and - 57%, P < 0.001, 41%, P < 0.05), while stimulating ROS release (+ 57%, P < 0.001). Dimethylfumarate (DMF), a linear electrophile and mitochondrial fumarate analog, rebalanced ROS levels (- 34%, P < 0.05) and improved GDH activity, cell viability, and tumorogenic capacity (+ 20%, 20%, P < 0.001; and 33%, P < 0.05). Thus, the pathological remodeling of colon mucosa is supported by metabolic reprogramming bypassing uncoupled mitochondria. DMF highlights the critical role of electrophile response elements in modulating redox mithormesis and redox homeostasis during CRC.

Effect of Diacerein on HOTAIR/IL-6/STAT3, Wnt/ß-Catenin and TLR-4/NF-κB/TNF-α axes in colon carcinogenesis.

Colorectal cancer (CRC) is a common malignancy with high mortality and poor prognosis. Diacerein (DIA) is an anti-inflammatory used for treatment of osteoarthritis. We delineated some underlying molecular mechanisms of DIA's anti-carcinogenic effect in CRC using in vivo and in vitro models. Human Caco-2 cells were treated with DIA followed by MTT and Annexin V assays and CRC was experimentally induced using 1,2-dimethylhydrazine. DIA (50 mg/kg/day, orally) was administrated for 8 weeks. The MTT assay confirmed cytotoxic effect of DIA in vitro and Annexin V confirmed its apoptotic effect. DIA resulted in regression of tumour lesions with reduced colonic TLR4, NF-κB and TNF-α protein levels and down-regulated VEGF expression, confirming anti-angiogenic impact. DIA triggered caspase-3 expression and regulated Wnt/ß-Catenin pathway, by apparently interrupting the IL-6/STAT3/ lncRNA HOTAIR axis. In conclusion, DIA disrupted IL-6/STAT3/ lncRNA HOTAIR axis which could offer an effective therapeutic strategy for the management of CRC.

Quercetin attenuated oxidative DNA damage through NRF2 signaling pathway in rats with DMH induced colon carcinogenesis.

Accumulating recent studies have demonstrated the preventive and therapeutic effects of polyphonic compounds such as quercetin in colorectal cancer. Therefore, we aimed to evaluate the underlying mechanisms for positive effects of quercetin in rats with 1,2-dimethylhydrazine (DMH)- induced colorectal cancer. For this purpose, male Wistar rats were classified as 6 groups, including group 1 without any intervention, group 2 as quercetin received rats (50 mg/kg), groups 3 as DMH received rats (20 mg/kg) group 4-6 DMH and quercetin received rats. DNA damage, DNA repair, the expression levels and activities of enzymic antioxidants, non-enzymic antioxidants, and NRF2/Keap1 signaling were evaluated in colon tissues of all groups. Our results showed significant suppression of DNA damage and induction of DNA repair in DMH + Quercetin groups, particularly in entire-period in comparison to other groups (p < .05). The expression levels and activities of enzymic and non-enzymic antioxidants were increased in DMH + Quercetin groups (p < .05). Lipid and protein peroxidation were significantly suppressed in DMH + Quercetin groups (p < .05). In addition, quercetin also modulated NRF2/Keap1 signaling and its targets, detoxifying enzymes in DMH + Quercetin groups. Our finding demonstrated that quercetin supplementation effectively reversed DMH-mediated oxidative stress and DNA damage through targeting NRF2/Keap1 signaling pathway.

Induction of Colon Cancer in Mice with 1,2-Dimethylhydrazine.

In this protocol, colon cancer is induced in mice through a series of injections with 1,2-dimethylhydrazine. Mice will develop primarily colon tumors starting at about 3 mo after the first injection. Tumors in the lung, uterus, and small intestine may also be seen, as well as lymphomas.

Effects of Lactobacillus salivarius Ren on cancer prevention and intestinal microbiota in 1, 2-dimethylhydrazine-induced rat model.

Probiotics have been suggested as a prophylactic measure in colon cancer. The aim of this study was to investigate the impact of Lactobacillus salivarius Ren (Ren) in modulating colonic microbiota structure and colon cancer incidence in a rat model after injection with 1,2-dimethyl hydrazine (DMH). The results indicated that oral administration of Ren could effectively suppress DMH-induced colonic carcinogenesis. A significant decrease in cancer incidence (87.5% to 25%) was detected in rats fed with a dose of 5 × 10(10) CFU/kg bodyweight per day. Using denaturing gradient gel electrophoresis and Real-time PCR combined with multivariate statistical methods, we demonstrated that injection with DMH significantly altered the rat gut microbiota, while Ren counteracted these DMH-induced adverse effects and promoted reversion of the gut microbiota close to the healthy state. Tvalue biplots followed by band sequencing identified 21 bacterial strains as critical variables affected by DMH and Ren. Injection of DMH significantly increased the amount of Ruminococcus species (sp.) and Clostridiales bacteria, as well as decreasing the Prevotella sp. Administration of Ren reduced the amount of Ruminococcus sp., Clostridiales bacteria, and Bacteroides dorei, and increased the amount of Prevotella. Real-time PCR results were consistent with the results derived by t-value biplots. These findings suggested that Ren is a potential agent for colon cancer prevention. In conclusion, the results in the present study suggest a potential therapeutic approach based on the modulation of intestinal microflora by probiotics may be beneficial in the prevention of colorectal carcinogenesis.

ß-sitosterol prevents lipid peroxidation and improves antioxidant status and histoarchitecture in rats with 1,2-dimethylhydrazine-induced colon cancer.

Oxidative stress has become widely viewed as an underlying condition in diseases such as ischemia/reperfusion disorders, central nervous system disorders, cardiovascular disease, cancer, diabetes, etc. The role that antioxidants play in the process of carcinogenesis has recently gained considerable attention. ß-Sitosterol, a naturally occurring sterol molecule, is a relatively mild to moderate antioxidant and exerts beneficial effects in vitro by decreasing the level of reactive oxygen species. The present study evaluated the antioxidant potential of ß-sitosterol in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis. The enzymatic and nonenzymatic antioxidants and lipid peroxides in colonic and hepatic tissues were evaluated. Generation of reactive oxygen species, beyond the body's endogenous antioxidant capacity, causes a severe imbalance of cellular antioxidant defense mechanisms. Elevated levels of liver lipid peroxides by DMH induction were effectively decreased by ß-sitosterol supplementation. ß-Sitosterol also exhibited a protective action against DMH-induced depletion of antioxidants such as catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, and reduced glutathione in colonic and hepatic tissues of experimental animals. Supplementation with ß-sitosterol restored the levels of nonenzymatic antioxidants (vitamin C, vitamin E, and glutathione). Histopathological alterations in DMH-induced animals were restored to near normal in rats treated with ß-sitosterol. Thus, ß-sitosterol by virtue of its antioxidant potential may be used as an effective agent to reduce DMH-induced oxidative stress in Wistar rats and may be an effective chemopreventive drug for colon carcinogenesis.

Effects of a vegetables-fruit mixture on liver and colonic 1,2-dimethylhydrazine-metabolizing enzyme activities in rats fed low- or high-fat diets.

The effects of a vegetables-fruit mixture (19.5% w/w) were studied on hepatic (h) and colonic (c) 1,2-dimethylhydrazine (DMH)-metabolizing enzyme activities (ethoxy- and pentoxyresorufine-O-deethylation, NDMA-demethylase, glutathione-S-transferase, UDP-glucuronyltransferase) in rats fed low- or high-fat diets (20 or 40 energy%). A vegetables-fruit mixture added to the diets resulted in altered enzyme activities in animals either treated or not treated with DMH. Remarkably, the vegetables-fruit mixture given to DMH-treated rats decreased glutathione-S-transferase (h) and increased NDMA-demethylase activities (c), whereas the mixture given to controls increased glutathione-S-transferase (h) and decreased NDMA-demethylase activities (c). The high-fat diets only modulated enzyme activities in animals not treated with DMH.