Colon Cancer Development In Rats Research Articles

Anticancer activity of zinc-tin oxide/dextran/geraniol nanocomposites against 1,2-dimethylhydrazine-induced colon cancer in rats: In vitro and In vivo study

BackgroundColorectal cancer (CRC) is the third most common cause of cancer-related mortality and the fourth most common cancer worldwide. Nanotechnology has experienced various developments, resulting in the emergence of novel cancer treatment methods. ObjectiveThe current work was planned to synthesize and characterize the zinc-tin-oxide/dextran/geraniol nanocomposites (ZSD-Ger-NCs) and evaluate their anticancer properties against colon cancer in vitro and in vivo studies. MethodologyThe ZSD-Ger-NCs were synthesized by the co-precipitation method and characterized using several techniques. The in vitro studies were conducted to evaluate the effect of ZSD-Ger-NCs on growth, apoptosis, and caspase activities in the HCT-116 cells. In vivo experiments were performed on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats. The effect of ZSD-Ger-NCs on body weight, and tumor volume was studied. The oxidative biomarker levels and myeloperoxidase (MPO) activity were analyzed using the corresponding kits. The colon tissues were subjected to histopathological analysis and immunohistochemical analysis. ResultsThe findings of various characterization methods revealed the generation of agglomerated ZSD-Ger-NCs with a well-defined shape and an average size of 197.40 nm. The ZSD-Ger-NCs treatment inhibited growth and promoted apoptosis in HCT-116 cells via augmenting caspase enzymes. In DMH-induced rats, the ZSD-Ger-NCs effectively increased body weight and reduced tumor volume. The ZSD-Ger-NCs treatment effectively mitigated the oxidative stress in the DMH-induced rats by augmenting the antioxidants. Histopathological findings proved that the ZSD-Ger-NCs reduced epithelial damage and dysplasia in the colon tissues. The expression of COX-2 was down-regulated by the ZSD-Ger-NCs treatment in DMH-induced rats. ConclusionThe findings of this work proved the anticancer properties of synthesized ZSD-Ger-NCs in inhibiting DMH-induced colon cancer development in rats. Therefore, it can be a talented anticancer candidate for treating colon cancer.

P0026 The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats

Background Curcuma purpurascens rhizome, a member of the Zingiberaceae family, is a popular spice in Indonesia and is traditionally used for assorted remedies. Dichloromethane extract of C. purpurascens rhizome (DECPR) has previously been shown to have apoptosis-inducing effect on colon cancer cells. Methods We examined the potential of DECPR to prevent colon cancer development in rats treated with azoxymethane (AOM, 15 ml/kg) by the incidence of aberrant crypt foci (ACF). Starting from the day immediately after AOM treatment, the rats were orally administered once a day for 2 months with 10% Tween-20 (5 ml/kg, cancer control), DECPR (250 mg/kg, low dose) and DECPR (500 mg/kg, high dose). Meanwhile, the control group was intra-peritoneally injected with fluorouracil (35 mg/kg) for 5 days consecutively. After euthanising the rats, the number of ACF was enumerated in colon tissues. Bax, Bcl-2, and PCNA protein levels were examined using immunohistochemical and western blot analyses. Antioxidant enzymatic activity was measured in colon tissue homogenates and associated with malondialdehyde level. Findings DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied with the reduced expression of PCNA. Up-regulation of Bax and down-regulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Interpretation DECPR significantly inhibits ACF formation in AOM-treated rats and may offer protection against colon cancer development.

The chemopreventive potential of Curcuma purpurascens rhizome in reducing azoxymethane-induced aberrant crypt foci in rats

Curcuma purpurascens BI. rhizome, a member of the Zingiberaceae family, is a popular spice in Indonesia that is traditionally used in assorted remedies. Dichloromethane extract of C. purpurascens BI. rhizome (DECPR) has previously been shown to have an apoptosis-inducing effect on colon cancer cells. In the present study, we examined the potential of DECPR to prevent colon cancer development in rats treated with azoxymethane (AOM) (15 mg/kg) by determining the percentage inhibition in incidence of aberrant crypt foci (ACF). Starting from the day immediately after AOM treatment, three groups of rats were orally administered once a day for 2 months either 10% Tween 20 (5 mL/kg, cancer control), DECPR (250 mg/kg, low dose), or DECPR (500 mg/kg, high dose). Meanwhile, the control group was intraperitoneally injected with 5-fluorouracil (35 mg/kg) for 5 consecutive days. After euthanizing the rats, the number of ACF was enumerated in colon tissues. Bax, Bcl-2, and proliferating cell nuclear antigen (PCNA) protein expressions were examined using immunohistochemical and Western blot analyses. Antioxidant enzymatic activity was measured in colon tissue homogenates and associated with malondialdehyde level. The percentage inhibition of ACF was 56.04% and 68.68% in the low- and high-dose DECPR-treated groups, respectively. The ACF inhibition in the treatment control group was 74.17%. Results revealed that DECPR exposure at both doses significantly decreased AOM-induced ACF formation, which was accompanied by reduced expression of PCNA. Upregulation of Bax and downregulation of Bcl-2 suggested the involvement of apoptosis in the chemopreventive effect of DECPR. In addition, the oxidative stress resulting from AOM treatment was significantly attenuated after administration of DECPR, which was shown by the elevated antioxidant enzymatic activity and reduced malondialdehyde level. Taken together, the present data clearly indicate that DECPR significantly inhibits ACF formation in AOM-treated rats and may offer protection against colon cancer development.

ω-3-Polyunsaturated Fatty Acids and Colon Cancer

C olorectal cancer is the third most common cancer in USA. American Cancer Society has estimated about 103,170 cases of colon and 40,290 cases of rectal cancer in 2012. Colorectal cancer deaths account for 9% of all cancer deaths; 51,690 deaths from colorectal cancer are estimated in 2012 [1]. Fatty acid composition of dietary fat is one of detrimental factors in colon cancer development. Studies have indicated that diets containing high level of ω-6-polyunsaturated fatty acids such as linoleic acid enhance whereas diets containing ω-3- polyunsaturated fatty acids such as eicosapentaenoic acid reduce chemically-induced colon cancer development in rodents [2,3]. Diets containing fish oil (source of ω-3-polyunsaturated fatty acid) decrease colon carcinogenesis [4]. The effects of dietary fish oil on eicosanoid metabolism have been implicated as a potential mechanism of colon cancer prevention. ω-3-Fattyacids present in fish oil inhibit oxidative metabolism of arachidonic acid by the cyclooxygenase (COX) pathway responsible for prostaglandin synthesis which act as a tumor promoter [5]. Dietary mustard oil, a rich source of α-linolenic acid, an ω-3fatty acid prevented colon cancer development in rats [6]. Dietary flaxseed oil, another very rich source of α-linolenic acid was effective in preventing colon cancer development in rats. Dietary flaxseed oil decreased the ratio of ω-6 to ω-3-fatty acids to optimal levels [7]. Dietary flaxseed meal, a rich source of α-linolenic acid, an ω-3-fatty acid and lignans also prevented colon cancer development in rats by increasing ω-3-fatty acids in serum and tissues, and decreasing expressions of COX-1 and COX-2 levels in tissues [8]. α-Linolenic acid and lignans (enterodiol and enterolactone derived from flaxseed) caused a decrease in cell proliferation and an increase in apoptosis in Caco-2, human colon cancer cells [9]. Dietary flaxseed also prevented intestinal tumor development in APC M in mice (a transgenic mice with mutation in APC gene causing development of spontaneous intestinal tumors) by increasing ω-3-fatty acids and lignans, and decreasing expressions of COX-1 and COX-2 levels [10]. Dietary canola oil, another source of α-linolenic acid was effective in preventing colon cancer development in rats by increasing ω-3-fatty acids in serum and tissues and decreasing the expression of COX-1 and COX-2 in tissues [11]. These studies have provided evidence indicating consumption of ω-3-fatty acids provides protection against colon cancer development in animal models and cell culture. Thus, dietary consumption of ω-3 fatty acid (fish, mustard, flax, canola) may provide protection in humans too. However, further studies in human volunteers are needed to establish the efficacy of ω-3-fatty acids for preventing colon cancer.

High Fat Mixed Lipid Diet Modifies Protective Effects of Exercise on 1,2 Dimethylhydrazine Induced Colon Cancer in Rats

The aim of the present study was to evaluate the effect of long-term swimming exercise in conjunction with a high fat mixed lipid (HFML) diet on colon cancer (CC) development and lipid peroxidation in the large bowel. We used forty male Wistar rats, which were randomly divided into one control group and four cancer groups: sedentary and swimming groups fed a standard diet (LFCO) and sedentary and swimming groups fed an HFML diet. Corticosterone was determined during the experiment. After 6 months of swimming, the rats were sacrificed and blood, heart, liver, muscle and large bowel were taken for determining the activity of serum enzymes, antioxidant capacity and CC development. The results demonstrate that exercise has a protective role in CC development. Attenuated development of CC and increased levels of malondialdehyde (MDA) in the large bowel of exercised rats show that one of the protective effects of exercise on developing CC is induction of oxidative stress. However, in terms of the combined effects of dietary fat and exercise, our results indicate that the protective role of exercise on CC development is significantly depressed by an HFML diet. An HFML diet significantly reduced the protective influence of exercise on colon carcinogenesis in rats and affected the degree of peroxidation in the large bowel during exercise, as well as concentrations of serum enzymes (LDH, α-HBDH, CK, ALT and AST). Our results indicate that an HFML diet, which reflects the composition of a Western style diet, is a significant modifier of the protective effects of exercise on CC development in rats.

Effect of processing on folic acid fortified Baladi bread and its possible effect on the prevention of colon cancer

This paper studied the possible effect of folic acid in fortified Baladi bread on the prevention of colon cancer development in rats. Wheat flour samples (82% extraction rate) and soy bean flour were analyzed to determine their folic acid contents using the High Performance Liquid Chromatography (HPLC). Unfortified and folic acid fortified Baladi breads were prepared. Samples from each step of bread preparation were analyzed for folic acid concentration. Protein, fat, ash, fibers and carbohydrates percentages were also determined. Rats were divided into five groups, four of them were injected subcutaneously with dimethylhydrazine (DMH). After 15 weeks, the rats were sacrificed for pathological examination. Results showed that the folic acid content in wheat flour (82% extraction rate) was found to be highly significantly lower than that in soybean flour. After baking, folic acid content in all breads was found to decrease significantly. The highest protein and fat contents were found in soybean flour fortified Baladi bread. The colons of rats of groups 3 (fed 5% soy flour fortified Baladi bread) and 5 (fed Baladi bread fortified with 5% soy flour + 8 mg folic acid/kg wheat flour) were the mostly affected by DMH injection as premalignant changes were observed.

Suppression of azoxymethane-induced colon cancer development in rats by dietary resistant starch

Resistant starch is a complex carbohydrate that reaches the colon where it can be fermented by the colonic microflora resulting in production of short chain fatty acids (SCFA), in particular butyrate. RS effects on colorectal tumourigenesis are contrasting and protection remains controversial. Butyrate has an important role as the preferred metabolic fuel and regulator of colonocyte proliferation, differentiation and apoptosis and may play a role in cancer prevention. Thus variation in butyrate production from different substrates might explain the variation in effect of RS. This study evaluated the hypothesis that feeding dietary resistant starch (as high amylose maize starch) would protect against azoxymethane (AOM)-colon carcinogenesis and favourably influence the colonic luminal environment. Male Sprague-Dawley rats (n = 90 were provided one of three diets: Control (without added dietary fibre or RS), 10% HAS (contained 100 g/kg raw high amylose maize starch) or 20% HAS (contained 200 g/kg high amylose maize starch). Rats were fed their experimental diets for 4 weeks after which they were injected with AOM (15 mg/kg) during the fifth and six week. Colons were resected (25 weeks post second injection) for evaluation of tumour formation, apoptosis, proliferating cell nuclear antigen (PCNA) labelling index and short chain fatty acid levels. Feeding resistant starch significantly reduced the incidence (P

Biphasic Effect of Falcarinol on CaCo-2 Cell Proliferation, DNA Damage, and Apoptosis

The polyacetylene falcarinol, isolated from carrots, has been shown to be protective against chemically induced colon cancer development in rats, but the mechanisms are not fully understood. In this study CaCo-2 cells were exposed to falcarinol (0.5-100 microM) and the effects on proliferation, DNA damage, and apoptosis investigated. Low-dose falcarinol exposure (0.5-10 microM) decreased expression of the apoptosis indicator caspase-3 concomitantly with decreased basal DNA strand breakage. Cell proliferation was increased (1-10 microM), whereas cellular attachment was unaffected by <10 microM falcarinol. At concentrations above 20 microM falcarinol, proliferation of CaCo-2 cells decreased and the number of cells expressing active caspase-3 increased simultaneously with increased cell detachment. Furthermore, DNA single-strand breakage was significantly increased at concentrations above 10 microM falcarinol. Thus, the effects of falcarinol on CaCo-2 cells appear to be biphasic, inducing pro-proliferative and apoptotic characteristics at low and high concentrations of falcarinol, respectively.

Suppression of azoxymethane‐induced colon cancer development in rats by a cyclooxygenase‐1 selective inhibitor, mofezolac

We demonstrated recently that mofezolac, a cyclooxygenase-1 (COX-1) selective inhibitor, suppresses the development of azoxymethane (AOM)-induced colonic aberrant crypt foci in F344 rats and intestinal polyps in APC1309 mice. In the present study, we therefore investigated the effects of mofezolac on colon cancer development. Male F344 rats were injected subcutaneously with 15 mg/kg body weight of AOM in the back twice at 7-day intervals from 5 weeks of age, and fed a diet containing 600 or 1200 ppm mofezolac for 32 weeks, starting 1 day before the first dosing of AOM. Treatment with 1200 ppm mofezolac significantly reduced the incidence, multiplicity and volume of colon carcinomas to 79%, 2.15 +/- 1.65 and 7.5 +/- 11.8 mm3, respectively, compared with 94%, 3.19 +/- 1.87 and 23.7 +/- 31.2 mm3 in the AOM treatment alone. Administration of 600 ppm mofezolac showed only a slight reduction. No side effects were observed in any of the groups. These results confirm that COX-1, as well as COX-2, contributes to colon carcinogenesis and that mofezolac may be a good chemopreventive agent for human colon cancer.

Suppression of azoxymethane‐induced colon cancer development in rats by a prostaglandin E receptor EP1‐selective antagonist

Prostaglandin E(2) is involved in colon carcinogenesis through its binding to the PGE(2) receptor subtypes EP(1), EP(2), EP(3) and EP(4). We have demonstrated that administration of ONO-8711, an EP(1)-selective antagonist, suppresses development of AOM-induced ACF in C57BL/6 mice and F344 rats. ONO-8711 also reduced the numbers of intestinal polyps in Min mice. In the present study, we investigated the long-term effects of ONO-8711 on colon cancer development in rats treated with AOM. Male F344 rats were injected subcutaneously with AOM (15 mg/kg body weight) once a week for the first 2 weeks to develop colon cancer. Administration of 400 or 800 p.p.m. ONO-8711 in their diets for 32 weeks reduced the incidence, multiplicity and volume of colon carcinomas. The incidence of colon adenocarcinomas in AOM-treated rats was 97, 83 and 76% (P < 0.05) in the 0, 400 and 800 p.p.m. of ONO-8711 groups, respectively. The multiplicity of adenocarcinomas was also decreased significantly, being 3.31 +/- 0.33, 2.34 +/- 0.27 (P < 0.05) and 2.06 +/- 0.34 (P < 0.01) with 0, 400 and 800 p.p.m. of ONO-8711, respectively. Moreover, treatment with 800 p.p.m. ONO-8711 reduced the mean volume of adenocarcinomas to 49% (P < 0.05) of the value for the AOM treatment alone. Furthermore, the BrdU labeling index was decreased significantly in colon cancer cells by 800 p.p.m. ONO-8711. These results confirm that EP(1) is involved in colon carcinogenesis and that EP(1)-selective antagonists might be promising candidates for colon cancer chemopreventive agents.

Butyrate enemas in experimental colitis and protection against large bowel cancer in a rat model

BACKGROUND & AIMS: Butyrate is effective in experimental colitis by increasing transglutaminase activity. Because ulcerative colitis increases the risk of colonic neoplasia, the aim of this study was to investigate whether butyrate treatment reduces mucosal sensitivity to colon cancer development in rats with experimental colitis. METHODS: Colon cancer was induced by azoxymethane injections in 10 rats with trinitrobenzensulfonic acid-induced colitis and 10 rats without colitis. Three additional groups of rats with colitis were treated with butyrate, mesalamine, and saline enemas, respectively, twice daily for 8 weeks; 1 week after colitis induction, tumors were induced. Biopsy specimens for assessment of proliferation pattern and transglutaminase activity were obtained during the latent period of cancer development. Characteristics of tumors were recorded 27 weeks after the first exposure to azoxymethane. RESULTS: Experimental colitis enhanced carcinogenesis; butyrate therapy reduced both incidence and size of tumors and also affected colonic proliferation pattern. Transglutaminase levels were restored by butyrate treatment in rats with colitis. CONCLUSIONS: The protective effect of butyrate against large bowel cancer in experimental colitis suggests its usefulness in long-term therapy to decrease disease relapses and to reduce colon cancer risk in ulcerative colitis. (Gastroenterology 1996 Jun;110(6):1727-34)

Inhibition of initiation and promotion by N-methylnitrosourea-induced colon carcinogenesis in rats by non-steroid anti-inflammatory agent indomethacin.

The non-steroid anti-inflammatory drug indomethacin, a prostaglandin synthesis inhibitor, may play a role to prevent the chemically induced colon cancer development in rats. CD-Fischer rats were given 3 intrarectal doses of 4 mg N-methyl-N-nitrosourea in week 1 as an initiation procedure to induce colon cancer. The experimental groups received a 0.001% water solution of indomethacin freely as drinking water at various times either during the initiation stage or the subsequent promotion stage. At autopsy in week 31, the treatment reduced the colon cancer development in the group of rats treated for week 1 (initiation stage), and for week 2-30 (early and late promotion stages) and for week 11-30 (late promotion stage), compared with untreated controls. However, removal of the treatment after effective treatment in promotion stage permitted the cancer development, and it suggests that the initiated cells are surviving during the treatment in promotion stage. It is concluded that indomethacin may inhibit methylnitrosourea-induced initiation and regulate promotion in colon carcinogenesis, presumably correlated with an inhibition of prostaglandin synthesis in the colon by indomethacin.