ABSTRACT
Background and purpose:Recently, a large number of researches have shown that cruciferous plants have the chemopreventive effect on tumor. Mechanisms of antitumorigenesis were investigated on antioxidation, antimutation, immunity and inducing apoptosis, and so on. Mustard seeds (MS) are the seeds belong to the cruciferous plants. This study aimed to investigate antioxidation and immune deviation of MS on colorectal tumor in rats induced by 1, 2-dimethylhydrazine (DMH). Methods:A total of 48 male Wistar rats were randomly divided into four groups:DMH alone, DMH+5%MS, DMH+7.5%MS, and the untreated control group(Saline). Colorectal tumorigenesis was induced by intraperitoneal injecting 30 mg/kg DMH once a week for 20 weeks. At the end of 32 weeks, the rats were sacrificed, then colorectal tumor incidence was observed and histological type was determined by HE staining. A colorimetric assay was used to detect levels of the lipid peroxidation product malondialdehyde (MDA) and the activity of antioxidant enzymes in the serum of all rats. The levels of Th1 and Th2 cytokines were detected with Luminex200. Results: No tumorous lesion was found in the untreated control group. However, the total tumor incidence in DMH+5%MS group and DMH+7.5%MS group was signiifcantly decreased 33.3%and 58.3%respectively, compared with the DMH group’s (100%, P<0.05). As DMH induced colorectal tumorigenesis, MDA and Th2 cytokines in the serum were signiifcantly higher in the DMH group than those in the untreated control group (P<0.05), but the activities of antioxidant enzymes were signiifcantly lower (P<0.05). While the MS treatment, compared with the DMH group, signiifcantly suppressed the MDA level but enhanced the activities of antioxidant enzymes and levels of Th1 cytokines (P<0.05). Conclusion: MS significantly decrease prevalence rates of DMH-induced colorectal tumor in rats. The mechanism may be related with the antioxidation and immune balance deviation.
ABSTRACT
Background and purpose:Colorectal cancer is one of the most common cancers worldwide as well as a prevalent cause of morbidity and mortality in China.Mustard seed and its components have been reported to possess anticancer properties.The purpose of this study was to investigate the effect of a diet mixed with mustard seeds (MS)on the prevention of colorectal tumorigenesis in Kunming mice induced with azoxymethane.Methods:Sixweek-old female Kunming species mice of were randomly divided into 4 different groups:AOM alone,AOM+5%MS,AOM+10%MS,and the untreated control group.Colorectal tumorigenesis was subcutaneously induced by injecting 10 mg/kg of AOM once a week,for 3 weeks.Different doses of MS were administered in the diet during this study.Thirtytwo weeks after initiation,the mice were put down through cervical dislocation.The colon and recta of the mice were isolated and flushed with nonnal but ice-cold saline.The site,size,and number of colorectal tumors were recorded.The incidence of colorectal tumor in each group was determined.Results:No tumors were found in the control group.Compared to AOM-treated control group(86.7%),the occurrence of colorectal tumors was reduced to 60.0%when administered with a 5%diet of mustard seeds and to 41.7%(P＜0.05)with a diet of 10%mustard seeds.Tumor burden (tumors/mouse)was 2.2±1.2 in the AOM-treated control group whereas it was reduced to 1.1±1.1(P＜0.05)in the 5%diet of mustard seeds and 0.7±0.9(P＜0.05)in the 10%diet of mustard seeds.Conelusion:The results indicate that a diet of mustard seeds is able to inhibit the development of colorectal cancer in mice induced by AOM,suggesting possible future application of MS as a chemopreventive agent for colorectal cancer.