Crypt Multiplicity Research Articles

Effects of Scrophularia oxysepala Methanolic Extract on Early Stages of Dimethylhydrazine-Induced Colon Carcinoma in Rats: Apoptosis Pathway Approach.

Purpose: Colorectal cancer is one of the most prevalent cancers, worldwide. The present study aimed to examine the effects of Scrophularia oxysepala (SO) methanolic extract on 1,2-dimethylhydrazine (DMH) induced colon cancer model in the Wistar rats. Methods: The animals administered DMH (40 mg/kg/S.C.) biweekly for 2 weeks to induce aberrant crypt foci (ACF). Other groups of animals were given the SO extract (50, 100 and 200 mg/kg/orally once/day) either before or after the DMH treatments. In the end, all animals were killed and at necropsy, the colon samples examined. The ACF, aberrant crypt (AC), crypt multiplicity (CM), caspase 3 protein and apoptosis measurement were performed. Results: The SO extract significantly (P<0.001) decreased the number of AC, ACF, and CM in all pre- and post-treated groups and caused significant increases in caspase 3 and apoptosis as compared to the DMH group. However, post-treated animals showed significantly more effective than pre-treatment groups. Methanolic extract of SO showed a chemopreventive potential, by effectively reducing the number of AC, ACF, and CM and increasing caspase 3 protein and apoptosis. Conclusion: One of the possible mechanisms might be involved in the induction of apoptosis through the caspase 3 mediated pathway.

Promising Chemoprevention of Colonic Aberrant Crypt Foci by Portunus segnis Muscle and Shell Extracts in Azoxymethane-Induced Colorectal Cancer in Rats

This study subjected a rat model to the extracts of muscle and shell tissues from Portunus segnis to assess their therapeutic effects on the HT-29 colon cancer cells as well as on colonic Aberrant Crypt Foci (ACF) induced by Azoxymethane (AOM). The cell line was exposed to the extracts to compare the cytotoxicity of hexane, butanol, ethyl acetate, and water extract of muscle and ethanolic extract of the shell. Male rats (n=40) were assigned into control, positive, negative, and treatment groups. The animals were injected with AOM, except the control group, and then exposed to 250 and 500mg/kg of the crude extracts. Immunohistochemical localization of Bax and Bcl-2, as well as ACF and antioxidant enzymes, were evaluated in the rat colon. The butanolic muscle extract and ethanolic shell one demonstrated an IC50 of 9.02±0.19μg/ml and 20.23±0.27μg/ml towards the cell line, respectively. Dietary exposure inhibited the ACF formation and crypt multiplicity in the colon compared to the cancer control group. The activity of SOD and CAT increased, while that of MDA decreased. The expression of Bax and Bcl-2 increased and decreased, respectively. Taken together, the results show that both extractions were suggested to be suppressive to AOMinduced colon cancer.

Chemopreventive effect of Callistemon citrinus (Curtis) Skeels against colon cancer induced by 1,2-dimethylhydrazine in rats.

Callistemon citrinus (Curtis) Skeels is a shrub native of Australia. In spite of containing an important number of bioactive compounds (1,8-cineole, limonene and α-terpineol) recognized as a potential chemotherapeutic agents, it is only used as an ornamental plant in Mexico. This study investigated the chemopreventive effect of C. citrinus leaves extract on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats. Twenty-four rats were divided into 3 groups of eight rats. Group 1 served as negative control, groups 2 and 3 were given subcutaneous injections of DMH (65mg/kg b.w.) twice a week the first 2weeks, and then one the third week. In addition, group 3 was administrated with leaves extracts (250mg/kg b.w., orally daily) during the 22weeks of the experiment. Animals were killed and the presence of colon tumors and aberrant crypt foci (ACF) were scored for number and distribution pattern along the colon. The activity of two-phase II enzymes quinone reductase (QR) and glutathione S-transferase (GST) was determined in the liver and three segments of the colon: proximal, middle and distal. The results show that rats feed with C. citrinus leaves extract significantly reduced the size of tumors, the number of ACF and the crypt multiplicity. Additionally, C. citrinus leaves extract increased or maintained the activity of QR and GST in the different tissues as compared with DHM-treated group (p > 0.05). This study demonstrates that Callistemon citrinus extract could have a chemopreventive effect against colon carcinogenesis.

Chemopreventive Effect of Allspice in Azoxymethane (AOM) Induced Fisher 344 Male Rats

Allspice contains phytochemicals which may have antioxidative and chemopreventive potential. The objective was to determine the effects of allspice on the AOM induced aberrant cryptic foci (ACF) in colon of Fisher 344 male rats. Rats were obtained from Harlan, IN, and raised in an environmentally controlled condition of 12 hours of light and dark cycles and at 50% relative humidity. Rats in experimental groups were fed with different concentrations of allspice (0.5%, 1% and 2%) in an AIN-93G based diet. Rats received AOM injections at 7 and 8 weeks of age at 16 mg/kg body weight. After 17 weeks, rats were asphyxiated with CO2, and liver, and colon samples were collected. Colons were stained with methylene blue to enumerate ACF and crypt multiplicity. Rats fed 0.5% allspice had the highest cecal pH (7.64) compared to control (6.88) (P ≤ 0.05). Rats in the treatment groups gained 225 g to 251 g over the 13-week period. A 29% reduction in total crypts was observed in rats fed 2% compared to 0.5% allspice. Highest number of crypts was seen in control group. Antioxidative enzyme activity was higher in rats fed allspice compared to the control group. Total tumors (0.25 - 2.5), tumor bearing rat ratio (1 - 2.5) and incidence rate (50% - 100%) in rats fed different concentrations of allspice were lower compared to rats in the control group (6.6%, 5.8%, and 100% respectively). Consumption of allspice in the diet reduced the number of ACF in Fisher 344 male rats. Allspice can be utilized in food formulations for its chemopreventive effects against colon cancer.

Evaluation of aqueous and hydro alcoholic extracts of Clerodendrum viscosum V. leaves &amp; Macrotyloma uniflorum L. seeds against DMH-induced colon cancer

Evaluation of anti-neoplastic activity of aqueous and hydro alcoholic extracts of Clerodendron viscosum V. leaves &amp; Macrotyloma uniflorum L. seeds against DMH-induced colon cancer is the objective of this study. Extracts were obtained using cold maceration process. Six groups of animals, each containing ten male albino wistar rats (80 – 100 g) were administered with respective treatment to evaluate the anti-neoplastic activity. On the last day of experimental period, fecal matter was collected and colons were removed. Fecal matter was homogenized, and subjected to the measurement of fecal pH and bacterial enzymes. Colons of five animals were subjected for the presence of MPLs, ACFs in each colon, and histopathology by using standard methodology. Colons of remaining five animals were subjected to homogenization to measure the bacterial enzymes such as β-Glucosidase, β-Glucuronidase, and mucinase. The extracts showed significant protective effect by showing significant decrease in the levels of fecal and colon β-glucosidase, β-glucuronidase, mucinase; reduction in total number of ACFs in each colon and crypt multiplicity. Although, all the plant extracts has shown protective effect against colon carcinogenesis, treatment with hydro alcoholic extracts has produced more pronounced effect as compared with aqueous extracts.

Chemoprevention by artesunate in a preclinical model of colorectal cancer involves down regulation of β-catenin, suppression of angiogenesis, cellular proliferation and induction of apoptosis

Use of anti-inflammatory drugs is well known to decrease the risk of colorectal cancer, one of the most common causes of cancer related mortality. In view of anti-inflammatory property of artesunate reported in various experimental models, the present study was carried out to evaluate its efficacy in rat model where colon carcinogenesis was induced by 1, 2 dimethylhydrazine (DMH). A time course study revealed that two injections of DMH given at an interval of one week resulted in appearance of multiple plaque lesions and aberrant crypt foci in the colon with a peak effect occurring at the end of 8 weeks. An efficacy study carried out with daily oral administration of artesunate (50 and 150 mg/kg) and aspirin (60 mg/kg) showed a marked reduction in pre-neoplastic changes with a significant decrease in the number of aberrant crypt foci, crypt multiplicity and restoration of histoarchitecture. Both the drugs down regulated β-catenin signaling, reduced the levels of angiogenic markers like VEGF, MMP-9 and inhibited cellular proliferation. The anti-cancer effect of these drugs was concomitant with the pro-apoptotic effect as revealed by increased DNA fragmentation, TUNEL positivity and Bax/Bcl2 immunoreactivity. This is the first study to evaluate the inhibitory effect of artesunate on pre-neoplastic changes in colon where its chemopreventive effect was found to be comparable to that of aspirin. Our study strengthens the previous findings and shows that it has a preventive and therapeutic potential in the treatment of colon cancer.

Precancerous ACF induction affects their regional distribution forsaking oxidative stress implication in 1,2-dimethylhydrazine-induced colon carcinogenesis model.

Colon cancer is thought to develop in a stepwise fashion. In this study, the relationship between aberrant crypt foci (ACF) regional distribution and oxidative stress evolution was studied in a murine model of initial colon carcinogenesis induced by dimethylhydrazine (DMH). Mice were given 2 weekly subcutaneous injections of DMH (20mg/kg) and killed at the 10th, 12th or 14th week. ACF was scored for number, distribution and crypt multiplicity after methylene-blue coloration and histologically analyzed afterwards. Oxidative stress evaluation was assessed through myeloperoxidase activity (MPO), nitric oxide (NO), L-ornithine and malondialdehyde (MDA) levels as well as antioxidant CAT, SOD and GSH. DMH treatment showed a shift from small to large ACF but also from distal to proximal colon between week 10 and 14 (p<0.05). This was further illustrated histologically with crypt disruption and mucin depletion. Oxidative stress imbalance was observed in all DMH-treated groups. All markers (MPO, MDA and NO) peaked at week 12 (p<0.01) and decreased at week 14 (p<0.05) while L-ornithine decreased through all protocol (p<0.01). Antioxidants decreased in all points (p<0.05) but only GSH increased at week 14 (p<0.05). This work provided insight to response-patterns of oxidative stress between distal and proximal colon, showing for the first time a decreasing implication during the development process and suggesting other inflammatory, immunologic or microbiota implication as factors to be considered during chemotherapy approaches.

Identification of High-Risk Aberrant Crypt Foci and Mucin-Depleted Foci in the Human Colon With Study of Colon Cancer Stem Cell Markers

BackgroundDuring colonoscopic screening, only macroscopic lesions will be identified, and these are usually the result of multiple genetic abnormalities. Magnification endoscopic detection of aberrant crypt foci (ACF), long before they acquire complex genetic abnormalities, is promising. However, the features of high-risk ACF-like lesions need to be identified. Materials and MethodsIn the present cross-sectional study, grossly visible normal mucosal flaps were shaved from 152 colectomies, including 96 colorectal cancer (CRC) cases and 56 controls (22 control specimens with disease with malignant potential and 34 without malignant potential). Methylene and Alcian blue stains were performed directly on the unfixed mucosal flaps to identify ACF and mucin-depleted foci (MDF). Detailed topographic analyses, with immunohistochemical staining for β-catenin and cancer stem cell (CSC) markers (CD44, CD24, and CD166) were performed. ResultsACF, MDF, and β-catenin–accumulated crypts were detected more in specimens with adjacent CRC. The left colon had ACF with a larger diameter and greater crypt multiplicity, density, and gyriform pit pattern and were considered the high-risk ACF group. MDF, more commonly associated with dysplasia, is also a marker of possible carcinogenesis. The CD44 CSC marker was significantly upregulated in ACF specimens compared with normal controls. Our 3-tier ACF-only pit pattern classification system showed better linearity with mucosal dysplasia than did the 6-tier Kudo classification. ConclusionHigh-risk ACF, when detected during chromoendoscopic screening, should be followed up. CSCs might play an important role in pathogenesis. Larger studies and genotypic risk stratification for definite identification of high-risk ACF are needed.

Early Life and Postnatal Western Diet Feeding and Susceptibility to Chemically Induced Colonic Aberrant Crypt Foci in Male Rats Offspring

ABSTRACTThe modifying effects of a Western diet (WD) during early life on the susceptibility to colon carcinogenesis induced by dimethylhydrazine (DMH) were examined in male rats as later adults. Three groups were studied: a lifetime control diet-fed group, a test group fed WD since pregnancy from dams until postnatal day (PND) 42, and a group fed WD at adulthood. At PND 70, all groups received the carcinogen DMH and were euthanized 10 wk later. Colonic aberrant crypt foci (ACF) were scored (number and crypt multiplicity) and the altered pattern of β-catenin expression was evaluated in the colonic lesions. ACF multiplicity (≥4 crypts) was significantly higher in the group fed WD at early life than in the group fed the control diet. ACF number, crypt multiplicity, and the number of high-grade dysplastic lesions were significantly higher in the group fed WD at adulthood than in the groupfed the control diet. The number of lesions with altered β-catenin expression was higher in the groups receiving WD at early life or at adulthood than in the lifetime control-diet-fed group. These findings indicate that WD exposure at early life increased the susceptibility to colon carcinogenesis at adulthood.

Chemopreventive Properties and Toxicity of Kelulut Honey in Sprague Dawley Rats Induced with Azoxymethane.

Ethnopharmacological Relevance. Colon cancer has been a major problem worldwide. Kelulut honey (KH) is produced by the stingless bees from Trigona species and has strong antioxidant activities that could be one of the potential chemopreventive agents from natural resources. Aim of This Study. This study investigated the chemopreventive properties and toxicity of KH in Sprague Dawley rats induced with azoxymethane (AOM). Material and Method. Twenty-four male Sprague Dawley rats aged 5 weeks were divided into 4 groups: (G1) untreated group not induced with AOM, (G2) untreated group induced with AOM, (G3) treated group induced with AOM, and (G4) treated group not induced with AOM. Injection of AOM (15 mg/kg) was via intraperitoneal route once a week for two subsequent weeks. The treatment groups were given oral administration of KH (1183 mg/kg body weight) twice daily for 8 weeks. Results. Treatment with KH significantly reduced the total number of aberrant crypt foci (ACF) and aberrant crypts (AC) and crypt multiplicity. KH was not toxic to the animals since the level of blood profile parameters, liver enzymes, and kidney functions was in normal range. Conclusions. The current finding shows that KH has chemopreventive properties in rats induced with colorectal cancer and also was found not toxic towards the animals.

Chemopreventive effect of myrtenal on bacterial enzyme activity and the development of 1,2-dimethyl hydrazine-induced aberrant crypt foci in Wistar Rats

Colon cancer remains as a serious health problem around the world despite advances in diagnosis and treatment. Dietary fibers are considered to reduce the risk of colon cancer as they are converted to short chain fatty acids by the presence of anaerobic bacteria in the intestine, but imbalanced diet and high fat consumption may promote tumor formation at different sites, including the large bowel via increased bacterial enzymes activity. The present study was conducted to characterize the inhibitory action of myrtenal on bacterial enzymes and aberrant crypt foci (ACF). Experimental colon carcinogenesis induced by 1,2-dimethylhydrazine is histologically, morphologically, and anatomically similar to human colonic epithelial neoplasm. Discrete microscopic mucosal lesions such as ACF and malignant tumors function as important biomarkers in the diagnosis of colon cancer. Methylene blue staining was carried out to visualize the impact of 1,2-dimethylhydrazine and myrtenal. Myrtenal-treated animals showed decreased levels of bacterial enzymes such as β-glucuronidase, β-glucosidase, and mucinase. Characteristic changes in the colon were noticed by inhibiting ACF formation in the colon. In conclusion, treatment with myrtenal provided altered pathophysiological condition in colon cancer-bearing animals with evidence of decreased crypt multiplicity and tumor progression.

Effect of Rumex Abyssinicus on preneoplastic lesions in dimethylhydrazine induced colon carcinogenesis in rats.

BackgroundCancer as a multistage process can be reversed or blocked by using chemopreventive agents. Colon cancer chemoprevention has been widely investigated using cyclooxygenase inhibitors and many other chemicals of synthetic or natural origin. This particular study was carried out to assess the colon cancer chemopreventive effect of hydro-methanol extract of Rumex abyssinicus rhizome on rats.MethodColon cancer chemopreventive potential of hydro-methanol extract of Rumex abyssinicus rhizome was determined based on the number and multiplicity of aberrant crypt foci (ACF). Fifteen DMH (1, 2-dimethylhydrazine) treated and five untreated Wistar female rats were used. DMH was administered subcutaneously 30 mg/kg, after its pH was adjusted to 6.5–7. Treatment groups started receiving extract after six weeks of weekly DMH injections. The rats were divided in to four groups: Group 1 received only oral normal saline, Group 2 received DMH and normal saline, Group 3 and 4 received DMH plus 250 mg/kg and 500 mg/kg extract, respectively. Specific phytoconstituents of the plant, which were reviewed from original articles, were virtually evaluated for cyclooxygenase-2 (COX-2) inhibition. The binding energies and interactions of the phytochemicals from Rumex abyssinicus against COX-2 were determined by Autodock4.2.ResultsThere was a statistically significant reduction (p-value < 0.05) in the number of aberrant crypt (AC) and aberrant crypt foci (ACF) at both administered doses. However, significant association (p-value > 0.05) was not observed in reducing crypt multiplicity. The docking process resulted in estimated binding energies [−6.83 kcal/mol to −7.9 kcal/mol] which are closer to the positive controls or Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) [−4.55 kcal/mol to −10.84 kcal/mol]. The phytochemical-COX-2 interaction indicated the involvement of key amino acid residues in inhibition of cyclooxygenase like ARG120, TYR355, TYR385, SER530 and GLY526.ConclusionsRumex abyssinicus had demonstrated a chemopreventive potential at post-initiation stage. As the virtual screening data suggested, COX-2 inhibition by the anthraquinones in the extract could be one mechanism for the observed chemopreventive effect.

Oral concentrated grape juice suppresses expression of NF-kappa B, TNF-α and iNOS in experimentally induced colorectal carcinogenesis in Wistar rats.

The aim of this study was to evaluate the effects of grape juice on colon carcinogenesis induced by azoxymethane (AOM) and expression of NF-kB, iNOS and TNF- α. Forty male Wistar rats were divided into 7 groups: G1, control; G2, 15 mg/kg AOM; G3, 1% grape juice 2 weeks before AOM; G4, 2% grape juice 2 weeks before AOM; G5, 1% grape juice 4 weeks after AOM; G6, 2% grape juice 4 weeks after AOM; G7, 2% grape juice without AOM. Histological changes and aberrant crypt foci (ACF) were studied, while RNA expression of NF- kB, TNF- and iNOS was evaluated by qPCR. The number of ACF was higher in G2, and G4 presented a smaller number of crypts per focus than G5 (p=0.009) and G6. Small ACF (1-3) were more frequent in G4 compared to G2, G5 and G6 (p=0.009, p=0.009 and p=0.041, respectively). RNA expression of NF-kB was lower in G3 and G4 compared to G2 (p=0.004 and p=0.002, respectively). A positive correlation was observed between TNF- α and NF-kB gene expression (p=0.002). In conclusion, the administration of 2% grape juice before AOM reduced the crypt multiplicity, attenuating carcinogenesis. Lower expression of NF-kB was observed in animals exposed to grape juice for a longer period of time, regardless of concentration.

Apoptosis Induction in Colon Cancer Cell Lines and Alteration of Aberrant Crypt Foci in Rat Colon by Purple Rice (Oryza sativa L. var. glutinosa) Extracts

Crude ethanol extracts (CEE) of purple rice was fractionated to obtain hexane soluble (HSF) and ethyl acetate soluble fractions (EASF). Total antioxidant capacity was higher in CEE than the HSF and EASF. However, HSF exhibited strong antiproliferation and apoptosis induction against colon cancer cell lines, both p53 wild-type (RKO) and mutant (SW620) strains. Then, the CEE was used to determine the effects on the progression of aberrant crypt foci (ACF), a preneoplastic lesion seen in colon carcinogenesis in rats. Male Wistar rats were subcutaneously injected of 40 mg/kg body weight dimethylhydrazin (DMH) once weekly for 2 wk. After 2 wk, rats were orally administered ethanol extract at 100 and 1000 mg/kg body weight, for 4 wk. Rats fed with only the high dose of CEE had significantly decreased numbers of ACF per rat (45.56%) and crypt multiplicity (AC/focus) (16.67%) compared to rats that received DMH alone. The result also demonstrated that CEE induced apoptosis in colonic epithelium cells of rat received colon carcinogen as detected the increasing of caspase-3 activity. This finding could be concluded that purple rice extracts inhibited aberrant colonic epithelial cell progression via apoptosis induction.

Attenuation of histopathological alterations of colon, liver and lung by dietary fibre of barley Rihane in azoxymethane-treated rats

This study was carried out to determine the effect of dietary fibre (DF) of barley Rihane (BR) in the attenuation of colon, liver and lung histopathology alterations induced by azoxymethane (AOM) in rats. Rats were fed a control (C) or experimental diet containing 30% of BR. The intended rats for cancer treatment received two successive subcutaneous injections of azoxymethane (AOM) at 20mg/kg body weight. The colons were analyzed for crypt multiplicity after 12weeks of treatment. A histological study of the colon, liver and lungs was determined. The results showed that the BR diet significantly reduced the number of aberrant crypt per focus and altered their distribution. In addition, DF of BR increased significantly the mucus secretion compared to control group. The use of the AOM as colon specific carcinogen substance altered the liver and lung architectures, whereas the presence of DF of BR could be a protective factor for these organs.

Flaxseed (Linum usitatissimum L.) and Its Total Non-digestible Fraction Influence the Expression of Genes Involved in Azoxymethane-induced Colon Cancer in Rats

The influence of flaxseed (Linum usitatissimum L.) and its total non-digestible fraction (TNDF) on the expression of genes involved in azoxymethane (AOM)-induced colon cancer in Sprague Dawley rats was analyzed. The dose used in the animal model was two tablespoons of flaxseed per day, which is the dose recommended for humans. Flaxseed significantly decreased the crypt multiplicity (10.50 ± 3.5) compared with the AOM treatment (34.00 ± 11.0), which suggests that flaxseed exhibits a preventive effect against colon cancer. Both treatments (flaxseed and TNDF) influence the overexpression of genes involved in cell cycle arrest and mitochondrial apoptosis: p53, p21, bcl-2, bax and caspase-3. Flaxseed induced the expression of p53 and p21, whereas TNDF triggered the p21-independent expression of p53. This finding suggests that both of these treatments induced cell cycle arrest. In addition, TNDF induced mitochondrial apoptosis because the TNDF + AOM group exhibited the expression of caspase-3, decreased bcl-2 expression and increased bax expression. These results suggest that the expression of the analyzed genes is associated with the presence of dietary antioxidants linked to the cell wall of flaxseed.

Sericin consumption suppresses development and progression of colon tumorigenesis in 1,2-dimethylhydrazine-treated rats

Colon cancer is one of the most common cancers in many regions of the world and is prevented by dietary interventions. This study aimed to examine the chemopreventive effect of silk protein, sericin, against 1,2-dimethylhydrazineinduced colon tumorigenesis in rats in comparison with control casein diet. The result showed that 5 out of 14 of casein fed rats developed colon tumors, whereas only 1 from 14 sericin fed rats exhibited tumors. Consumption of sericin prior to or during carcinogen exposure reduced the number of aberrant crypt foci. In addition to crypt number, crypt multiplicity was less progressive in sericin fed group. The sericin diet also exhibited anti-oxidant activity as evidenced by reduced lipid peroxidation in the colons. This finding suggests that consumption of sericin may reduce the progression of colon tumor development possibly by suppressing the initiation and promotion stages of colon tumorigenesis.

P-0188 Chemopreventive Potential of 22β-hydroxyoleanonic Acid in experimental Colon Cancer model: Expression of Transcription Factors

ABSTRACT Introduction Triterpenoids have shown tremendous potential to be developed as chemopreventive agent against number of cancers. 22β-Hydroxyoleanonic acid is a semisynthetic triterpenoid, which has been synthesized from pentacyclic triterpenoid Lantadene A. We have determined the chemopreventive effect of 22β-hydroxyoleanonic acid in colon cancer, using in vitro and in vivo models. Methods The 22β-hydroxyoleanonic acid was synthesized from pentacyclic triterpenoid Lantadene A. This synthesis is a part of our Lantadene A pharmacophore optimization programme. The structure of 22β-hydroxyoleanonic acid was identified by spectral and elemental analysis. The ability to induce apoptosis was determined by its in vitro antiradical activity, cytotoxic studies using human colon adenocarcinoma and normal monkey kidney cell lines, and the expression of β-catenin and proliferating cell nuclear antigen (PCNA) in human colon cancer cell lines (COLO 320 DM). The chemopreventive potential of 22β-hydroxyoleanonic acid in colon carcinogenesis was assessed by injecting 1,2-dimethylhydrazine (DMH, 20 mg/kg b.w.) into male Wistar rats and supplementing this with 22β-hydroxyoleanonic acid throughout the experimental period of 20 weeks at 5, 10, and 20 mg/kg b.w. Further, effect of 22β-hydroxyoleanonic acid on various transcription factors was studied by ELISA and immunohistochemical localization Results 22β-Hydroxyoleanonic acid induced significant dose-dependent growth inhibition of COLO 320 DM cells (IC50 32.2 µM), induced apoptosis by scavenging reactive oxygen species, and suppressed the expression of β-catenin and PCNA antigens in human colon cancer cells. 22β-Hydroxyoleanonic acid supplementation reduced the number of aberrant crypt and crypt multiplicity in DMH-initiated rats in a dose-dependent manner with no toxic effects. Significant increase in the protein levels of c-jun, p65, and p53 by ELISA were observed in DMH treated mice tumors whereas less expression was observed in 22β-hydroxyoleanonic acid treated tumors. Further, immunohistochemical localization of transcription factors was studied which also showed less localization of c-jun, p65, and p53 in 22β-hydroxyoleanonic acid treated tumors as compared to localization in DMH treated tumors. Conclusion The study showed that 22β-hydroxyoleanonic acid showed potential chemopreventive activity and may be linked to the deregulation of above molecular targets which warrants further studies.

Red Strain Oryza Sativa-Unpolished Thai Rice Prevents Oxidative Stress and Colorectal Aberrant Crypt Foci Formation in Rats

Oxidative stress has been proposed to be involved in colorectal cancer development. Many dark pigments of plants have potent oxidative stress preventive properties. In this study, unpolished Thai rice was assessed for antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. Red strain unpolished Thai rice was also administered to rats exposed to azoxymethane (AOM) for induction of aberrant crypt foci (ACF). Serum malondialdehyde (MDA) and ferric reducing antioxidant power (FRAP) were investigated for cellular oxidative stress and serum antioxidants, respectively. Red pigment unpolished Thai rice demonstrated high antioxidant activity and was found to significantly and dose dependently decrease the total density and crypt multiplicity of ACF. Consumption of Thai rice further resulted in high serum antioxidant activity and low MDA cellular oxidative stress. Interestingly, the density of ACF was strongly related to MDA at r=0.964, while it was inversely related with FRAP antioxidants (r=-0.915, p<0.001). The results of this study suggest that the consumption of red strain of unpolished Thai rice may exert potentially beneficial effects on colorectal cancer through decrease in the level of oxidative stress.

The modulatory influence of p-methoxycinnamic acid, an active rice bran phenolic acid, against 1,2-dimethylhydrazine-induced lipid peroxidation, antioxidant status and aberrant crypt foci in rat colon carcinogenesis

We investigated the chemopreventive effect of p-methoxycinnamic acid (p-MCA), an active phenolic acid of rice bran, turmeric, and Kaemperfia galanga against 1,2-dimethylhydrazine-induced rat colon carcinogenesis. Male albino Wistar rats were randomly divided into six groups. Group 1 consisted of control rats that received a modified pellet diet and 0.1% carboxymethyl cellulose. The rats in Group 2 received a modified pellet diet supplemented with p-MCA [80mg/kg body weight (b.wt.) post-orally (p.o.)] everyday. The rats in Groups 3–6 received 1,2-dimethylhydrazine (DMH) (20mg/kgb.wt.) via subcutaneous injections once a week for the first 4weeks; additionally, the rats in Groups 4, 5 and 6 received p-MCA at doses of 20, 40 and 80mg/kgb.wt./day p.o., respectively, everyday for 16weeks. The rats were sacrificed at the end of the experimental period of 16weeks. The DMH-treated rats exhibited an increased incidence of aberrant crypt foci (ACF) development; an increased crypt multiplicity; decreased concentrations of tissue lipid peroxidation markers such as thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and lipid hydroperoxides (LOOH); decreased levels of tissue enzymic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR); and decreased levels of non-enzymic antioxidants such as reduced glutathione (GSH) and vitamins C, E and A in the colon. Supplementation with p-MCA significantly reversed these changes and significantly inhibited the formation of ACF and its multiplicity. Thus, our findings demonstrate that p-MCA exerts a strong chemopreventive activity against 1,2-dimethylhydrazine-induced colon carcinogenesis by virtue of its ability to prevent the alterations in DMH-induced circulatory and tissue oxidative stress and preneoplastic changes. p-MCA was more effective when administered at a dose of 40mg/kgb.wt. than at the other two doses tested.