Effect of magnesium hydroxide on 1,2-dimethylhydrazine-induced intestinal carcinogenesis in rats.

Abstract

Modifying effect of magnesium hydroxide on 1, 2-dimethylhydrazine (DMH)-induced intestinal carcinogenesis was examined in a rat model using 1, 2-dimethylhydrazine (DMH). Although the incidence or multiplicity of the small intestinal tumors of rats of Groups 2-5 which were s.c. injected DMH (20mg/kg, body weight) once 2 weeks for 10 times at the commencement of experiment and were given magnesium hydroxide (250 or 500 or 1000 or 2000ppm in diet) throughout the experiment, were not different from those of Group 1 exposed to DMH alone (Group 1), the incidence or multiplicity of the large intestinal tumors of the groups given the carcinogen and magnesium hydroxide were rather lower or smaller than that of the group given the carcinogen alone. Significant differences were obtained with the mutiplicity between Group 2 or 4 or 5 and Group 1 (P<0.02 or P<0.02 or P<0.05). These results appear to indicate an inhibitory effect of magnesium hydroxide on DMH induced large bowel carcinogenesis and are in agreement with those of our previous study in rats using methylazoxymethanol acetate. The agent could be a promising chemopreventive agent for large bowel carcinogenesis in humans together with other trace elements such as selenium or calcium.