DMH Administration Research Articles

Anonna crassiflora suppresses colonic carcinogenesis through its antioxidant effects, bioactive amines, and phenol content in rats

Marolo (Annona crassiflora) is an underutilized Brazilian Cerrado fruit with few reports in the literature about its bioactive compounds and functional properties. In this context, the chemoprevention against the carcinogen 1,2-dimethylhydrazine (DMH)-induced pre-neoplastic lesions in Wistar rat colon was investigated and correlated with marolo’s antioxidant activity and the contents of phenolic compounds and bioactive amines. Total phenolic compounds (TPC) and total flavonoids compounds (TFC) were determined in the marolo pulp extract by spectrophotometric and Ultra-Performance Liquid Chromatography and diode array detection (UPLC-DAD) analysis. Free bioactive amines were determined by High Performance Liquid Chromatography and fluorescence detection (HPLC-FLD) after post column derivatization with o-phthalaldehyde. In addition, the in vitro antioxidant activity was determined by DPPH, and ABTS. Wistar rats were treated orally with marolo pulp at 0.7, 1.4 and 2.8 g/kg body weight (bw)/day added to a standard ration. Four subcutaneous injections of DMH (40 mg/kg bw) were used to induce a pre-neoplastic lesion that was assessed by the aberrant crypt foci (ACF) assay. The marolo pulp (fresh weigh) showed high content of total phenolic compounds (9.16 mg GAE/g), with predominance of chlorogenic acid (1.86 µg/g) and epicatechin (0.99 µg/g), and total flavonoids (7.26 mg CE/g), ∼85 % of the TPC. The marolo pulp had significant contents of tyramine (31.97 mg/kg), putrescine (20.65 mg/kg), and spermidine (6.32 mg/kg). The marolo pulp inhibited (p < 0.05) pre-neoplastic lesions induced by DMH administration at the all concentrations tested. These findings indicate that marolo pulp has a colon carcinogenesis chemopreventive effect, which could be due to, at least in parts, its antioxidant action associated with its phenolics and flavonoids content as well of spermidine.

Effect of Ethanolic Extract of Tetrapleura Tetraptera on Some Antioxidant Enzymes in Rats Administered 1, 2-Dimethylhydrazine

This work was aimed at determining the antioxidant activity of an ethanol extract of Tetrapleura tetraptera fruits in rats administered DMH. Group 1 (positive control) contains rats without the administration of DMH, extract, or CMC. Group 2 (negative control) received DMH, 1 ml of 1% CMC, and no extract. Group 3 received a low dose of the ethanol extract of Tetrapleura tetraptera fruits (100mg/kg) and DMH. Group 4 received a high dose of the ethanol extract of Tetrapleura tetraptera (200mg/kg) and DMH. The DMH was administered once a week for four consecutive weeks, while the ethanol extract of Tetrapleura tetraptera was administered daily for four consecutive weeks. The result showed that there was a significant increase in the activities of SOD, CAT, and GST in rats administered an extract of Tetrapleura tetraptera fruits compared to the negative control group. In general, the introduction of Tetrapleura tetraptera to the rats caused an increase in the activity of the antioxidants compared to the negative control. The histopathological profile, however, showed that the DMH did not affect the liver, colon, and small intestine morphology. It could thus be concluded that the ethanol extract of Tetrapleura tetraptera fruit has potent antioxidant activity.

Panx1 knockout promotes preneoplastic aberrant crypt foci development in a chemically induced model of mouse colon carcinogenesis.

Colorectal cancer, which is the third leading cause of cancer-related deaths worldwide, is a multistep disease, featuring preneoplastic aberrant crypt foci (ACF) as the early morphological manifestation. The roles of hemichannel-forming transmembrane Pannexin 1 (Panx1) protein have not been investigated in the context of colon carcinogenesis yet, although it has contrasting roles in other cancer types. Thus, this study was conducted to examine the effects of Panx1 knockout (Panx1-/- ) on the early events of chemically induced colon carcinogenesis in mouse. Wild type (WT) and Panx1-/- female C57BL6J mice were submitted to a chemically induced model of colon carcinogenesis by receiving six intraperitoneal administrations of 1,2-dimethylhydrazine (DMH) carcinogen. Animals were euthanized 8 h (week 7) or 30 weeks (week 37) after the last DMH administration in order to evaluate sub-acute colon toxicity outcomes or the burden of ACF, respectively. At week 7, Panx1 genetic ablation increased DMH-induced genotoxicity in peripheral blood cells, malondialdehyde levels in the colon, and apoptosis (cleaved caspase-3) in colonic crypts. Of note, at week 37, Panx1-/- animals showed an increase in aberrant crypts (AC), ACF mean number, and ACF multiplicity (AC per ACF) by 56%, 57% and 20%, respectively. In essence, our findings indicate that Panx1 genetic ablation promotes preneoplastic ACF development during chemically induced mouse colon carcinogenesis, and a protective role of Panx1 is postulated.

Preventive Effects of Bovine Gallstone on Murine Colon Neoplasia: Room for Improvement?

Bovine gallstone (BGS) has been suggested to be used in the treatment of many diseases including neoplastic maladies in traditional medicine. Thus, this study aimed at evaluating the possible protective effects of BGS in mice colon tumor models. In the experiment, 8-week-old 30 male BALB/c mice weighing 25-30 g were randomly allocated into the control group (n=6), tumor group ((n=6; tumor induced by 1,2- dimethylhydrazine? [DMH]), BGS&amp;gt;DMH group (n=6; BGS given before DMH challenge), BGS//DMH group (n=6; simultaneous administration of BGS and DMH) and DMH&amp;gt;BGS group (n=6; tumor induced by DMH then BGS given). The colonic tumor was induced by weekly subcutaneous injection of DMH at a 20 mg/kg/mouse dose for consecutive 11 weeks. BGS preparations were given to mice cyclically. Atypical cryptic foci formation in the colon was examined by histopathological staining. The lowest rate of colon tumor was noted in BGS&amp;gt;DMH group where BGS was given prior to tumor challenge. In addition, simultaneous administration of DMH and BGS to mice inhibited tumor formation and development more significantly than those in other groups (except for BGS&amp;gt;DMH group). It was concluded that BGS significantly prevented colonic tumor formation if given to subjects before or during tumor challenge however, therapeutic capacity of BGS was not promising in this study. Keywords: Bovine, colon, gallstone, mouse, neoplasia.

Raptinal ameliorates 1,2-dimethylhydrazine-induced colon cancer through p53/Bcl2/Bax/caspase-3-mediated apoptotic events in vitro and in vivo.

Colon carcinoma stands as the most familiar malignancy throughout across the globe. Raptinal induce apoptosis through the alteration of cellular events. Thus, in the present investigation, the anticancer activity of raptinal counter to 1,2-dimethylhydrazine (DMH) persuaded colon carcinoma has been evaluated through both in vivo and in vitro systems. The pharmacophore analysis demonstrated the binding efficacy of raptinal with the apoptotic proteins. The chemotherapeutic activity of raptinal was examined through HT-29 human colorectal cancer (CRC) cell line as well as DMH persuaded CRC in the rat model. The cytotoxicity analysis, flow cytometry, and DAPI analysis have been carried out on HT-29 cell line through in vitro assessment. The colon carcinoma has been induced through DMH administration and subsequently Dextran sulfate sodium treatment in male Wistar rats. After 18 weeks of raptinal treatment, the colon tissues have been investigated for aberrant crypt foci (ACF) count, antioxidant status, histology, immunohistochemical assessment, and apoptotic analysis. The raptinal therapy on HT-29 cells demonstrated a substantial % of early apoptosis followed by G0 and G1 phase arrest, which subsequently led to apoptosis. Furthermore, it inhibits ACF development with improved colonic abrasions and structural integrity of colonic mucosa with increased levels of antioxidants, proapoptotic biomarkers including p53, caspase-3, Bax and downstream effects of Bcl-2, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 mutation. These findings indicate the raptinal effectively reduces colon cancer by inducing apoptosis through p53/Bcl2/Bax/caspase-3 pathway and suppressing IL-6, TNF-mediated chronic inflammation in the colon cancer microenvironment.

Ellagic acid modulates cisplatin toxicity in DMH induced colorectal cancer: Studies on membrane alterations

Systemic toxicity due to chemotherapy contributes to poor prognosis in patients receiving chemotherapy. The present study, therefore, explores the role of Ellagic acid, a phytochemical, in modulating cisplatin (CP) toxicity in dimethylhydrazine-induced colorectal cancer. Colons excised from DMH administered animals showed abnormal crypts and bulges over the mucosal surface. SEM revealed significant alterations and dysplastic lesions in DMH administered mice. Animals receiving combined treatment showed improvement in colonic epithelium with lesser irregularities. DMH and CP administration disturbed the membrane dynamics and integrity as observed with the fluorescent probes DPH and pyrene. However, EA co-supplementation with CP proved to be beneficial in normalizing the altered membrane. Ellagic acid co-supplementation along with CP; therefore, showed great promise and helped restore the membrane alterations in the colon caused due to CP-induced toxicity and DMH insult. These observations could pave way towards developing a combination therapy targeting colon carcinogenesis in future.

Hesperetin alleviates DMH induced toxicity via suppressing oxidative stress and inflammation in the colon of Wistar rats.

1,2-Dimethylhydrazine (DMH), a colon-specific environmental toxicant is one among the carcinogen responsible for the cause of colon cancer. The present study was designed to evaluate the protective effect of Hesperetin (HST) against colon toxicity induced by DMH in Wistar rats. HST, a flavonoid widely found in citrus fruits possesses several biological activities including anti-microbial, anti-oxidant properties among others. A single dose of DMH (40 mg/kg body weight) was administered subcutaneously on 1st day for induction of colon toxicity followed by oral treatment with HST at a dose of 20 mg/kg bodyweight for 14 consecutive days. DMH administration leads to excessive ROS generation, resulting in an imbalance in redox homeostasis and causing membrane lipid peroxidation, which is also partly due to the decrease in the level of tissue antioxidant machinery. Our result showed HST significantly ameliorates DMH-induced lipid peroxidation and also substantially increases the activity/level of various anti-oxidant proteins (GR, GPx, GST, GSH, and SOD). HST was also found to reduce the expression of inflammatory proteins (TNF-α, IL-6, i-NOS, COX-2, NF-kB-p65), goblet cell disintegration as well as mucin depletion (sulfo and sialomucin) in the colon that was found to be elevated upon administration of DMH. Our histological results further provide confirmation of the protective role of HST against DMH-induced pathological alterations. The results of the present study demonstrate supplementation of HST is beneficial in ameliorating DMH-induced toxicity by suppressing oxidative stress, inflammation, goblet cell disintegration as well mucin depletion in the colon of Wistar rats.

Harmol alleviates dimethylhydrazine induced colon cancer by downregulating Bcl2/IL-6/TNF-α expression in association with p53 mediated apoptosis

Objectives: Colorectal cancer is the world’s third most prevalent cancer. Herbal drugs are increasingly being used to treat a variety of disorders, including cancer, due to the severe adverse effects. Harmol, natural molecule containing β-carboline alkaloids, has aroused the interest of researchers due to its diverse biological functions, including anticancer properties. Methods: In this study, the chemotherapeutic effects of harmol have been investigated on HT-29 colon cancer cell line and a rat model of colon cancer. In the in vitro study the cytotoxicity assay, DAPI analysis and the flow cytometric analysis was performed to assess the anticancer efficacy of harmol in HT-29 cell. The colorectal cancer was developed in male Wistar rats through the administration of DMH followed by treatment with DSS. The rats were treated with harmol (100, 200 and 400 mg/kg) for 18 weeks. At the end of therapy, the colon tissues were assessed for ACF, in vivo antioxidant activity, histopathology, immunohistochemistry, immunofluorescence analysis and apoptosis assay. Results: The in vitro data suggested that the harmol therapy would significantly increase the percentage of early apoptosis in HT-29 cells through halting of G0/G1 phase. Furthermore, inhibition of ACF development with improved colonic abrasion and morphological features in colonic mucosal region were noted. Harmol treatment also increased the levels of antioxidants and p53 and downregulated Bcl2, IL-6 and TNF-α expression. Conclusion: These outcomes signify that harmol successfully recover colorectal carcinoma by reprogramming the p53, Bcl2, IL-6 and TNF-α pathway in rats.

Survival effect of probiotics in a rat model of colorectal cancer treated with capecitabine.

BACKGROUNDProbiotics are used to manage a number of gastrointestinal disorders due to their beneficial properties. Clinical reports showed that probiotics also improve the life quality of patients with colorectal cancer (CRC) subjected to oncologic treatment. In a CRC animal model, probiotics supplementation has the potential to decrease the formation of aberrant crypts and ameliorate tumor malignancy, enhancing the antitumor effect of 5-fluorouracil (5-FU) chemotherapy. Based on these data, we hypothesize that the administration of probiotics impact positively in the overall survival and life quality of rats with CRC under the treatment of capecitabine, which is the pro drug of 5-FU. AIMTo evaluate the probiotics effects in a rat CRC model treated with capecitabine and followed until the end of life.METHODS1,2-Dimethylhidrazine dihydrochloride (1,2-DMH) was employed as carcinogen inductor of CRC. Fifty male Wistar-Lewis rats were randomly assigned to one of five following groups: Control (n = 5), Control + probiotics (Control-P group, n = 5), 1,2-DMH alone (DMH group, n = 10), 1,2-DMH + capecitabine (DMH-C group, n = 10), 1,2-DMH + probiotics (DMH-P group, n = 10) and 1,2-DMH + capecitabine + probiotics (DMH-C-P group, n = 10). All parametric data were expressed as the mean ± SD. The statistical significance of differences was analyzed using one-way ANOVA. Data were analyzed with InfoStat software. The results were considered statistically significant at P < 0.05. Overall survival was evaluated with the Kaplan-Meier estimator with the log-rank test.RESULTSThe data of mean overall survival for DMH, DMH-P, DMH-C, DMH-C-P, Control and Control-P groups were 250 d [95% confidence interval (CI): 242.5-253.1], 268 d (95%CI: 246.3-271.4), 380 d (95%CI: 337.8-421.9), 480 d (95%CI: 436.9-530.7), 588 d (95%CI: 565.8-609.3) and 590 d (95%CI: 564.3-612.9), respectively, with a significant difference between DMH-C and DMH-C-P groups (P = 0.001). Comparing all groups by Kaplan-Meier estimator, we found a significantly different in the overall survival of DMH and DMH-P groups respect to DMH-C (P = 0.001) and DMH-C-P (P = 0.001) groups; interestingly, there were no meaningful differences between Control, Control-P and DMH-C-P groups (P = 0.012). The tendency of change in body weight gain of the rats at 90 d of finishing DMH administration was similar in Control group compared with DMH-C and DMH-C-P groups; however, and of relevance, DMH-C-P group has experienced a higher body weight gain at the end of animal’s life than DMH-C group (P = 0.001). In DMH-C-P group we found a positive effect of probiotics in clinical manifestations since diarrhea, constipation and blood stool were absenting. Also, the tumor burden was lower in DMH-C-P than DMH-C, DMH-P or DMH groups (1.25 vs 1.81 vs 3.9 vs 4.8 cm2, respectively). DMH-C and DMH-C-P groups showed only mucinous carcinoma type while in other DMH groups the tumor types were variable. However, mucinous carcinoma from DMH-C-P group showed invasion until muscularis propria layer. Interestingly, metastatic lymph node was observed in DMH, DMH-C and DMH-P groups but not in DMH-C-P. All animals in Control group died from natural causes without objective injuries. All animals of DMH and DMH-P groups died from tumor complications (i.e., obstruction or intestinal perforation); however, this cause was seen only in 44.5% of DMH-C and DMH-C-P groupsCONCLUSIONProbiotics administration improves life quality of rats with CRC under capecitabine treatment and also has a positive effect in the overall survival of these animals treated with this drug.

Effect of Kefir, Yacon (Smallanthus sonchifolius) and the Association Between Yacon and Kefir on Intestinal Physiology in Rats With Colon Cancer

Abstract Objectives To evaluate the effect of consumption of yacon flour, kefir and the association between them on colon cancer induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats, SCFA production, fecal pH and intestinal permeability. Methods The study was conducted with 60 adult Wistar rats divided into 5 groups. For 5 weeks, groups T, Y, K and YK received 1,2-dimethylhydrazine (DMH) to induce colon cancer. After 5 weeks of DMH administration, animals in groups C and T received the standard diet, group Y received a diet with yacon flour with 5% FOS, group K received 1mL /day of kefir and the YK group received a diet with yacon and kefir, for 15 weeks. After euthanasia, intestinal lesions, intraluminal pH, short-chain fatty acids (SCFA) and intestinal permeability were analyzed. Results An increase in macroscopic lesions was observed in groups K (58%) and YK (42%) and a reduction of 5% in group Y, compared to group T. In addition, an increase in neoplastic changes was observed in all groups compared to group T: Y (33%), K (67%) and YK (78%). There was no significant difference in the concentrations of acetate and proprionate, pH, lactulose and mannitol between groups, and butyrate was not found in the samples. Conclusions The consumption of yacon flour, kefir and their association did not influence intestinal physiology and promoted the worsening of the development of colon carcinogenesis in rats. Funding Sources FAPES - Fundação de Amparo à Pesquisa e Inovação do Espírito Santo CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico

Styrax camporum, a typical species of the Brazilian cerrado, attenuates DNA damage, preneoplastic lesions and oxidative stress in experimental rat colon carcinogenesis

ABSTRACT Styrax camporum Pohl, a typical species from the Brazilian cerrado, commonly known as “benjoeiro”, is used to treat gastroduodenal diseases. In previous studies carried out by our research group, hydroalcoholic extract of S. camporum stems (SCHE) exhibited antigenotoxic and antiproliferative effects. For a comparative analysis of the chemopreventive effect of SCHE, the aim of this study was to investigate the influence of SCHE against carcinogen 1,2-dimethylhydrazine (DMH)-induced DNA damage and pre-neoplastic lesions in Wistar rat colon. Animals were treated orally with SCHE at 250, 500 or 1000 mg/kg body weight in conjunction with a subcutaneous injection of DMH. DNA damage was assessed using the comet assay while tpre-neoplastic lesions by aberrant crypt foci (ACF) assay. The following hepatic oxidative stress markers were determined including activities of catalase (CAT) and glutathione S-transferase (GST) as well as levels of reduced glutathione (GSH) and malondialdehyde (MDA). Treatment with SCHE was not genotoxic or carcinogenic at the highest dose tested (1000 mg/kg b.w.). The extract effectively inhibited DNA damage and pre-neoplastic lesions induced by DMH administration at all concentrations tested. Measurement of CAT, and GST activities and levels of GSH showed that SCHE did not reduce oxidative processes. In contrast, treatment with SCHE (1000 mg/kg b.w.) decreased liver MDA levels. Taken together, these findings suggested the chemopreventive effect attributed to SCHE in colon carcinogenesis, may be related to its capacity to inhibit DNA damage as well as an antioxidant action associated with its chemical constituents egonol and homoegonol.

Refinement of Animal Model of Colorectal Carcinogenesis through the Definition of Novel Humane Endpoints.

Simple SummaryEnsuring animal welfare is essential in protocols using laboratory animals. Applying a score sheet with 14 biological parameters, we assessed the welfare of 29 male Wistar rats used as models of colorectal carcinogenesis (CRC). We found a uniformity of characteristics preceding the premature animals’ death, including an increase of 10% in body weight, swollen abdomen, diarrhea, and priapism. In addition, we observed that surface abdominal temperature was higher in animals with CRC. We considered that the parameters already described in other cancer models are insufficient and considered assessing the abdominal temperature, priapism, and sudden increase in the body weight in the model of CRC.This study aimed to define appropriate humane endpoints (HEs) for an animal model of colorectal carcinogenesis (CRC). Twenty-nine male Wistar rats were divided into two control groups (CTRL1 and CTRL2) injected with ethylenediamine tetraacetic acid (EDTA)–saline solutions and two induced groups (CRC1 and CRC2) injected with 1,2-dimethylhydrazine (DMH) for seven weeks. A score sheet with 14 biological parameters was used to assess animal welfare. Groups CRC1 and CTRL1 and groups CRC2 and CTRL2 were euthanized 11 and 17 weeks after the first DMH administration, respectively. Five animals from the induced groups died unexpectedly during the protocol (survival rates of 75.0% and 66.7% for groups CRC1 and CRC2, respectively). The final mean body weight (BW) was smaller in the CRC groups when compared with that in the CTRL groups. A uniformity of characteristics preceding the premature animals’ death was observed, namely an increase of 10% in mean BW, swollen abdomen, diarrhea, and priapism. The surface abdominal temperature of group CRC2 was significantly higher, when compared with that of group CTRL2. The parameters already described in other cancer models proved to be insufficient. For the CRC model, we considered assessing the abdominal temperature, priapism, and sudden increase in the BW.

Methanolic Extract of Muntingia Calabura L. Mitigates 1,2-Dimethyl Hydrazine Induced Colon Carcinogenesis in Wistar Rats

Objective The present study aimed to evaluate the efficacy of methanolic extract of Muntingia calabura L. leaves (MEMC) in ameliorating oxidative stress and inflammation associated with 1,2-dimethyl hydrazine (DMH) induced colon cancer. Methods The antioxidant enzymes, oxidative stress markers, liver and renal toxicity markers were evaluated. Histopathological examination of colon tissues was carried out with the aid of alcian blue stain and Hematoxylin and Eosin stain. Results MEMC supplementation at doses of 100 and 200 mg/kg body weight of rats causes the antioxidant enzymic levels to retain near to its normal range. Meanwhile the oxidative stress markers, which showed an elevation from its normal level upon DMH administration, gets significantly reduced on MEMC treatment. Histopathological observation also revealed that the severity of colorectal cancer was reduced by the supplementation of MEMC. Conclusion The findings from the present study showed that MEMC can exert a potential role to ameliorate the oxidative stress and inflammation associated with colorectal cancer.

Combination of quercetin and exercise training attenuates depression in rats with 1,2-dimethylhydrazine-induced colorectal cancer: Possible involvement of inflammation and BDNF signalling.

What is the central question of this study? What are the alleviative effects of the combination of exercise training and quercetin supplementation on colorectal cancer-related depression in rats with 1,2-dimethylhydrazine-induced colorectal cancer and what is the corresponding signalling pathway? What is the main finding and its importance? We showed that the combination of exercise training and quercetin supplementation resulted in a significant decrease in tumour incidence and improvement in depressive-like behaviours through modulation of the BDNF/TrKβ/β-catenin axis in the prefrontal cortex. In addition to physical problems, depression is considered to be one of the most important challenges for patients with various types of cancers, particularly colorectal cancer. Inflammation and upregulation of brain neurotrophic factors are two major links between cancer and depression. In this study, we aimed to evaluate the alleviative effects of quercetin and exercise training on depressive-like behaviours in rats with 1,2-dimethylhydrazine (DMH)-induced colorectal cancer and to investigate the underlying mechanisms. Animals were assigned into the following five groups: (i) control group; (ii) DMH (20mgkg-1 s.c., once a week for 10weeks); (iii) DMH for 10weeks, followed by quercetin (50mgkg-1 p.o., once per week) for 12weeks; (iv) DMH for 10weeks, followed by exercise training for 12weeks; and (v) DMH for 10weeks, followed by quercetin and exercise training for 12weeks. The DMH-treated rats showed an increase in depressive-like behaviours in both open field and forced swimming tests. Histopathological examination revealed neural damage and reduced Nissl bodies in the prefrontal cortex. In addition, administration of DMH increased inflammatory cytokines in the serum, prefrontal cortex and tumour tissues and decreased the expression levels of brain-derived neurotrophic factor (BDNF), tyrosine kinase β receptor (TrKβ) and β-catenin in the cortex. In contrast, treatment with quercetin and exercise training effectively alleviated all the above-mentioned DMH-associated behavioural, biochemical and histopathological alterations without changing its anti-tumour activity. Taken together, our results show that the combination of quercetin and exercise training exerts potent anti-tumour and anti-depressive effects through suppression of inflammation and upregulation of the BDNF/TrKβ/β-catenin axis in the prefrontal cortex.

Early molecular events associated with liver and colon sub-acute responses to 1,2-dimethylhydrazine: Potential implications on preneoplastic and neoplastic lesion development

This study unveiled the early cellular and molecular events induced by 1,2-dimethylhydrazine (DMH) in the colon and liver and their implications on pre- and neoplastic lesion burden in a late timepoint. Male Wistar rats received four DMH injections (40 mg/kg body weight) for 2 weeks and were sacrificed 24 h (short-term study) or 22 (medium-term study) weeks after the last DMH administration. In the short-term study, DMH led to increased leukocyte (comet assay) and colon (H2AX) genotoxicity, enhanced proliferation (Ki-67) and apoptosis (caspase-3) indexes in both liver and colon. Furthermore, the expression of mRNA (Cat, Gsta1, Gsta2, Gpx1, Gstm1, Sod1, Sod2 and Sod3) and the activity of antioxidant agents were diminished in the colon and liver of DMH-induced rats, eliciting an environment of oxidative stress featuring elevated lipid hydroperoxide levels. Apoptosis effectors were upregulated in the liver (Bax, Casp3 and Fas), and developmental genes were downregulated in both colon and liver (Foxa1, Foxa2, Smad2 and Smad4). In the medium-term study, DMH led to a high number of preneoplastic colonic aberrant crypt foci and tumors (adenomas and invasive adenocarcinomas) but few preneoplastic hepatic glutathione S-transferase (GST-P)-positive foci. Our novel gene expression data highlights overlooked mechanisms in the liver (main metabolizing organ) and colon (main target organ) on toxicity and carcinogenesis induced by repeated doses of DMH, as both organs should be considered in further interventions on the initiation stage of colon carcinogenesis.

UHPLC–Q/Orbitrap/MS/MS fingerprinting and antitumoral effects of Prosopis strombulifera (LAM.) BENTH. queous extract on allograft colorectal and melanoma cancer models

The aqueous extract of the Argentinean native plant, Prosopis strombulifera (PsAE), presents cytotoxicity against human cancer cell lines by inducing cytostasis, necrosis and apoptosis; with diminution of clonogenic survival; without genotoxic effects nor oral animal toxicity. Until now, the chemical extract composition and its in vivo antitumoral properties remain unknown; these studies are the aim of the current work. The PsAE was characterized by chemical fingerprinting and the metabolome was identified by tandem UHPLC-PDA-HESI-Q-orbitrap® mass spectrometry. Colorectal tumors were induced by DMH administration and melanomas resulted from B16-F0 S.C. cells injection; then, animals were treated orally with PsEA. To correlate in vivo results with in vitro cytotoxicity, B16-F0 cell were cultured to determine: cell proliferation and viability by dye exclusion assays, MTT and CFSE dilution; cell cycle distribution by flow cytometry; and immunoblotting of p21cip1, PCNA, cleaved caspase 3, cleaved PARP and TUBA1A. Based on UHPLC-OT-MS and PDA analysis, twenty-six compounds were identified, including: 5 simple organic acids, 4 phenolic acids, 4 procyanidins, 11 flavonoids, and 2 oxylipins. On C57BL6 mice, PsAE significantly increases the median survival on colorectal cancer and reduces the final volume and weight of melanomas. Over cultured cells, the treatment induce over-expression of p21, cytostasis by G2/M cell cycle arrest and apoptosis; while, on in vivo melanomas, treatment up-regulates p21 and slightly decreases PCNA. In conclusion, PsAE is composed by phenolic compounds which demonstrate cytotoxic and antitumoral properties when is orally administrated. Presented results support future research of PsAE as a potential phytomedicine for cancer treatment.

Gallic acid prevents 1, 2-Dimethylhydrazine induced colon inflammation, toxicity, mucin depletion, and goblet cell disintegration.

1,2-Dimethylhydrazine (DMH), an environmental toxicant specifically targets the colon. The present study was aimed to evaluate the efficacy of gallic acid (GA) against colon toxicity induced by DMH in Wistar rats. GA, a phenolic acid has numerous beneficial properties, which include antiviral, antifungal and antioxidant properties which help cells to overcome oxidative stress and balance the redox homeostasis. GA was administered orally at two doses (25 and 50 mg/kg body weight) once daily for 14 days and a single dose (40 mg/kg body weight) of DMH was administered subcutaneously on 14th day. Animals were sacrificed on the 15th day and we could find that GA at both the doses significantly ameliorates DMH-induced increased toxicity markers and also substantially increases the glutathione content level and activities of detoxifying enzymes. It also ameliorates the expression of proliferation, inflammation, apoptosis, goblet cell disintegration, and mucin depletion in the colon that was elevated upon administration of DMH. Histological alterations provide further confirmation of the protective role of GA against DMH-induced colon toxicity. The results of this study clearly indicate supplementation of GA is beneficial in ameliorating DMH-induced oxidative stress, inflammation, proliferation, apoptosis, mucin depletion, and goblet cell disintegration in colon of Wistar rats.

Transcutaneous Vagus Nerve Stimulation Regulates the Cholinergic Anti-inflammatory Pathway to Counteract 1, 2-Dimethylhydrazine Induced Colon Carcinogenesis in Albino wistar Rats.

The present work was undertaken to study the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on 1, 2-dimethyhydrazine (DMH) induced colon cancer and role of the cholinergic anti-inflammatory pathways (CAP) in the same. Groups of rats were randomly divided into ten groups (n = 8). DMH administration was very well apparent for autonomic dysfunction as observed through distorted hemodynamic (electrocardiogram and heart rate variability), increased aberrant crypt foci and flat neoplastic lesions (methylene blue staining, scanning electron microscopy and Hematoxylin and eosin staining). DMH administration was also recorded for per-oxidative damage. taVNS application restored the autonomic function, cellular morphology and curtailed the oxidative damage. DMH application conspicuously inhibited the mitochondrial apoptosis which was restored back after taVNS application, when scrutinized through immunoblotting and quantitative real time polymerase chain reaction studies. taVNS application up-regulated the CAP as perceived through increased expression for α7 nicotinic acetylcholine receptor(α7nAchR) and decreased expression for nuclear factor kappa-ligand-chain-enhancer of activated B cells (NFκBp65), tissue necrosis factor-α and high mobility group box-1 at protein and mRNA levels. All in all, taVNS up-surged the CAP to counteract DMH induced colon carcinogenesis. Among all the stimulation parameters used, taVNS 3 (pulse width-1 ms, frequency-6 Hz, voltage-6 v, duration-240 min) was observed to be the most effective. Since only chemotherapy and surgery are available options for management of CRC, which are troublesome and painful, there is currently no non-invasive method available for management of CRC. Results of the current study affirmed the effectiveness of taVNS against DMH induced colon cancer. The present study established taVNS as a novel and non-invasive approach toward the management of CRC.

Combination Therapy with Quercetin and 5-Fluorouracil Ameliorates 1,2-Dimethylhydrazine Induced Carcinogenesis in the Colon of Wistar Rats.

Background: Colorectal carcinoma (CRC) is a common cause of cancer-related death worldwide. 5-fluorouracil (5-FU), a first-line chemotherapeutic drug in CRC, has several side effects limiting its therapeutic outcomes. Quercetin (QU) is a dietary bioflavonoid with antioxidant and cytotoxic prooxidant properties. Here, we hypothesize that combination treatment with QU and 5-FU can modulate 1,2-dimethylhydrazine (DMH) induced histological and biochemical changes in the colon of Wistar rats. Methods: A Wistar rats CRC model was established and the animals were randomly divided into five groups. Rats in group A received a suspending vehicle. Group B rats received DMH twice a week subcutaneously for 4 weeks. Animals in the other groups (C, D and E) received the same treatment of DMH, along with QU or 5-FU (individually) or combined QU+5-FU treatment. Results: The DMH-treated rats developed adverse histological alterations (aberrant crypt foci, ACF) and biochemical changes (elevated serum CA19-9; reduced tissue levels of enzymatic antioxidants; elevated CDH12 protein expression and decreased SOX7 mRNA levels). Treatment of DMH-treated animals with QU+5-FU (but not with QU or 5-FU, individually) significantly reversed these changes (i.e., suppressed the formation of ACF; decreased the CA19-9 levels; reduced CDH12 protein expression and increased SOX7 mRNA expression). Conclusions: Conclusively, to the best of our knowledge, our study was the first to evaluate the effects of QU+5-FU treatment on the histological and molecular changes following DMH administration in a rat colon model. Our data suggest that combination therapy with QU+5-FU has therapeutic benefits in colon cancer induced by DMH, with potential for translation to spontaneous disease.

Protective Effect of Lactobacillus casei on DMH-Induced Colon Carcinogenesis in Mice.

The administration of probiotics is a promising approach to reduce the prevalence of colon cancer, a multifactorial disease, with hereditary factors, as well as environmental lifestyle-related risk factors. Biogenic polyamines, putrescine, spermidine, and spermine are small cationic molecules with great roles in cell proliferation and differentiation as well as regulation of gene expression. Ornithine decarboxylase is the first rate-limiting enzyme for polyamine synthesis, and upregulation of ornithine decarboxylase activity and polyamine metabolism has been associated with abnormal cell proliferation. This paper is focused on studying the protective role of Lactobacillus casei ATCC 393 in a chemically induced mouse model of colon carcinogenesis, directing our attention on aberrant crypt foci as preneoplastic markers, and on polyamine metabolism as a possible key player in carcinogenesis. BALB/c mice were administered 1,2-dimethylhydrazine dihydrochloride (DMH) to induce colon cancer (20mg/kg body weight, subcutaneous, twice a week for 24weeks). L. casei ATCC 393 was given orally (106CFU, twice a week), 2weeks before DMH administration. Hematoxylin and eosin staining, high-performance liquid chromatography, and Western blotting were used to evaluate aberrant crypt foci, urinary polyamines, and ornithine decarboxylase expression in the colon. The experimental data showed that the preventive administration of L. casei ATCC 393 may delay the onset of cancer as it significantly reduced the number of DMH-induced aberrant crypt foci, the levels of putrescine, and the expression of ornithine decarboxylase. Hence, this probiotic strain has a prospective role in protection against colon carcinogenesis, and its antimutagenic activity may be associated with the maintenance of polyamine metabolism.