Effect of vitamin D-3 on carcinogen-modified liver enzymes and tumour incidence in experimental rat mammary carcinogenesis

The anticarcinogenic effect of vitamin DJ in relation to biochemical and mo rphological markers in 7,12-dimethylbenz(alpha)anthracene (DMBA)-induced ma mmary carcinogenesis was investigated in two different sets of experiments. For each set, female Sprague-Dawley rats were divided into four groups, to allow comparison among treated and non-treated groups. At 50 days of age, animals of group B and C were given DMBA injection (0.5 mg/100 g body weigh t) through the tail vein, and normal control (group A) animals received the oil emulsion vehicle alone. Vitamin D-3 at the dose of 0.3 mu g/0.1ml prop ylene glycol was given orally twice a week, in carcinogen as well as non-ca rcinogen treated animals (group C and c), until the termination of the expe riments (22-24 weeks for biochemical markers, and 35 weeks for morphology). At approximately 22-24 weeks, when marked lobular hyperplasia in DMBA cont rol groups were confirmed through histology, the biochemical markers were m odulated towards normal value for vitamin DJ in the treatment group, in com parison to the disturbed values caused by carcinogen administration in grou p B animals. Again, vitamin DJ supplementation was effective in reducing th e tumour incidence (70% in comparison to 90% in group B). The results thus clearly concluded the antineoplastic potential of vitamin D3, and the exist ing correlation between biological and biochemical markers. (C) 1999 Lippin cott Williams & Wilkins.