Studies of chemoprevention in rats with colorectal cancer caused by 1, 2-dimethylhydrazine

Purpose：We examined the inhibitory effects of arabinoxylane and fumagillol as chemopreventive drugs on colorectal carcinogenesis initiated by 1，2-dimethylhydrazine(DMH)in Wistar rats.Materials and Methods：Female Wistar rats were obtained at five weeks of age from Japan SLC Inc..After a minimum quarantine period of one week，DMH was administered to the rats as a carcinogen and simultaneously they received arabinoxylane or fumagillol as chemopreventive drugs.Subcutaneous injection of 20毫克/公斤DMH was done once a week from the age of 6weeks to 16weeks.After the injection ofDMH，rats receiving only tap water with a control diet were designated as group1(non-treated group)。Rats injected with DMH who at the same time received arabinoxylane 50 mg/kg orally in their drinking water were designated as group2.Those receiving a subcutaneous injection offumagillol lOmg/kg or 30 mg/kg twice a week from the age of 6weeks to 36weeks were designated as groups3and4，respectively.The...More se three groups were the treated groups。At21weeks，about half of the rats in the four groups were sacrificed and the numbers of lesions with the atypical crypt foci(ACF)of premalignant lesions observed in the total colorectum were counted.At36weeks，the remaining rats in the four groups were sacrificed，the numbers of lesions with colorectal cancers and polyps were counted，and the survival rates of the rats in the four groups were calculated。Results：L，The incidences of ACF in groups2and4were significantly lower than the incidence in group1(p&lt；0.05)。There was no difference in the incidences ofACF between group1 and group3.JLThe incidences of colorectal cancers and polyps decreased in groups2，3-and4compared with that in group1，but there were no statistically significant differences among the four groups，i The survival rates at 36weeks were100per cent in group2，80per cent in group3，62per cent in group4，and 32per cent in group1.There was a significant differe100 per cent in group2，80 per cent in group3，62per cent in group4，and 32per cent in group1.There was a significroup1&lt()。Conclusion：Administration of arabinoxylane significantly decreased the incidences of ACF and was survived the all of the rats until the end of this experiment.The results suggest that arabinoxylane might be a candidate for chemoprevention strategy for colorectal cancer in humans。Less：Less

Purpose : We examined the inhibitory effects of arabinoxylane and fumagillol as chemopreventive drugs on colorectal carcinogenesis initiated by 1, 2-dimethylhydrazine (DMH) in Wistar rats. Materials and Methods : Female Wistar rats were obtained at five weeks of age from Japan SLC Inc.. After a minimum quarantine period of one week, DMH was administered to the rats as a carcinogen and simultaneously they received arabinoxylane or fumagillol as chemopreventive drugs. Subcutaneous injection of 20 mg/kg DMH was done once a week from the age of 6 weeks to 16 weeks. After the injection ofDMH, rats receiving only tap water with a control diet were designated as group 1 (non-treated group). Rats injected with DMH who at the same time received arabinoxylane 50mg/kg orally in their drinking water were designated as group 2.Those receiving a subcutaneous injection offumagillol lOmg/kg or 30mg/kg twice a week from the age of 6 weeks to 36 weeks were designated as groups 3 and 4, respectively. The … More se three groups were the treated groups. At 21 weeks, about half of the rats in the four groups were sacrificed and the numbers of lesions with the atypical crypt foci (ACF) of premalignant lesions observed in the total colorectum were counted. At 36 weeks, the remaining rats in the four groups were sacrificed, the numbers of lesions with colorectal cancers and polyps were counted, and the survival rates of the rats in the four groups were calculated. Results : L, The incidences of ACF in groups 2 and 4 were significantly lower than the incidence in group 1 (p<0.05). There was no difference in the incidences ofACF between group 1 and group 3.JLThe incidences of colorectal cancers and polyps decreased in groups 2, 3ーand 4 compared with that in group 1, but there were no statistically significant differences among the four groups, i The survival rates at 36 weeks were 100 per cent in group 2, 80 per cent in group 3, 62 per cent in group 4, and 32 per cent in group 1.There was a significant difference between group 1 and group 2 (p<0.()5). Conclusion : Administration of arabinoxylane significantly decreased the incidences of ACF and was survived the all of the rats until the end of this experiment. The results suggest that arabinoxylane might be a candidate for chemoprevention strategy for colorectal cancer in humans. Less