In general, oxidative stress resulting from an imbalance between prooxidant and
antioxidant systems plays an important role in the pathogenesis of
cancer.
Morin (3,5,7,2',4'-pentahydroxyflavone), a member of the flavanol group, has been shown to possess chemopreventive potential against hepatocellular and
colon cancer in experimental animals. Given the demonstrated importance of
morin, aim of the present study was to evaluate the effect of
morin on antiproliferative and
anticarcinogenic effect against DMBA-induced experimental mammary
carcinogenesis.
Oral administration of 7,12-dimethylbenz(a)-anthracene (25 mg/kg
body weight) to rats resulted in significant reduction of
body weight, enzymic
antioxidants (
superoxide dismutase,
catalase,
glutathione peroxidase, and
glutathione reductase), and nonenzymic
antioxidants (
reduced glutathione,
vitamin C, and
vitamin E). The levels of lipid peroxidation markers (
thiobarbituric acid reactive substances and hydroperoxides) and
tumor markers such as CA 15-3, AFP and CEA in serum were increased significantly in
cancer-induced animals as compared to control rats. Oral supplementation of
morin at a dose of 50 mg/kg
body weight significantly improved the
body weight, enzymic, and nonenzymic
antioxidants and considerably decreased the lipid peroxidation marker and
tumor markers levels. Histological observations also correlated with the biochemical parameters.
Tumor bearing animals showed marked increase in
proliferating cell nuclear antigen-positive cells and also the number of AgNOR/nuclei compared with control rats while this expression levels were significantly reduced upon
morin treatment. Thus, this study reveals the possible beneficial effect of
morin as chemopreventive agent against the oxidative stress induced during mammary
carcinogenesis.