Anticarcinogenic Effect of Raphanus Sativus on 1 , 2 Dimethylhydrazine ( DMH ) Induced Colon Cancer in Rats

Abstract

Background: Colon cancer is a major health problem worldwide and rated among as one of the top frequent cancers and is a major cause of morbidity and mortality. Treatment outcome is still not satisfactory and other treatment options are strongly needed. Carbohydrate protein interactions play a major role in numerous biological processes including cancer. However, the seeds of Raphanus sativus have never been tested for its anticancer effects on colon cancer. Therefore, this study aimed at elucidating the anti-carcinogenic effect of Raphanus sativus in combating chemically (DMH) induced colon cancer. Materials and methods: polysaccharides extract of Raphanus sativus (RS) was tested for its ability to reverse the carcinogenic effects of 1, 2 dimethylhydrazine (DMH) which is used for chemical induction of colon cancer in animal models. Rats were injected with DMH and the effects of RS extract either concomitant with or after the administration of DMH were evaluated. . We measured the serum Carcinoembryonic antigen and Carbohydrate antigen as a tumor markers, Glutathione reducatse and Glutathione S transferase as markers of antioxidant activity and liver functions. Results: RS significantly reduced Serum CEA (P<0.01) and CA19-9 (P<0.01) as an evidence of its anticarcinogenic effect in colon cancer. Moreover, RS was able to significantly increase activity of Glutathione reductase (p<0.01) and Glutathione- S- transferase (p<0.01) as a measure of antioxidant compared with DMH untreated group. Also RS was able to significantly increase activities of ALAT, ASAT and ALP (p<0.01). Chemical analysis of RS done by NMR and paper chromatography revealed that the polysaccharide in RS was -galactan and the type of bond that exists between sugar residues is 1, 3 and 1, 6 glucosidic linkages. Conclusions: This study shows that -galactan of Raphanus sativus has pronounced cytotoxic effects on colon cancer cell line. Moreover, it reduces serum tumor markers and enhancing antioxidant activity in the DMH injected animals. This polysaccharide might be a suitable candidate as a chemopreventive and as an adjuvant therapy for colon cancer.