Effect of dietary kelp on lipid peroxidation and glutathione peroxidase activity in livers of rats given breast carcinogen DMBA.
In our previous study of female rats, a diet containing 2% of powdered fronds of Laminaria religiosa (kelp) had a remarkable inhibitory effect on mammary tumorigenesis induced by orally given 7,12-dimethylbenz[a]anthracene (DMBA). In this study, the effect of the dietary kelp on lipid peroxidation and glutathione peroxidase (GSH-Px) activity in the liver was studied in the same experimental system. Two separate short- and long-term experiments were carried out on rats fed a diet with 2% kelp. DMBA (20 mg/kg body wt) was given to each animal 7 days after feeding began in short-term experiment and 27 days later in long-term experiment. Livers of all rats were obtained for quantitative determination and for histopathologic observation. Lipoperoxide in livers of the kelp-fed rats was of normal value, almost the same as that of untreated control rats; however, lipoperoxide in livers of control rats was significantly higher than in the other two groups in both experiments. A marked fatty change in livers of control rats was demonstrated in hepatic cells in peripheral zones of lobules in long-term experiment but not in short-term experiment. In long-term experiment, the amounts of GSH-Px and selenium in livers of kelp-fed rats were slightly less than those in untreated control rats but more than those in control rats. There was a more-intense positive reaction in the hepatic cells in the peripheral zones of the lobules in the kelp-fed and untreated rats and a less-intense positive reaction in control rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Maruyama
H
H
Department of Pathology, Kitasato University School of Hygienic Sciences, Kanagawa, Japan.
Watanabe
K
K
Yamamoto
I
I
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000008:administration & dosage / Q000633:toxicity*; D000284:Administration, Oral; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D004032:Diet; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism*; D007150:Immunohistochemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D008054:Lipid Peroxides / Q000378:metabolism; D008099:Liver / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000517:prevention & control; D051381:Rats; D011919:Rats, Inbred Strains; D012624:Seaweed / Q000502:physiology*; D012643:Selenium / Q000032:analysis / Q000378:metabolism; D013997:Time Factors
D000970:Antineoplastic Agents; D008054:Lipid Peroxides; D015127:9,10-Dimethyl-1,2-benzanthracene; D005979:Glutathione Peroxidase; D012643:Selenium