Effects on 7,12-dimethylbenz

Balasubramanian S, Govindasamy S. 1996. Inhibitory effect of dietary flavonol quercetin on 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis. Carcinogenesis 17(4) 877-879. 

Trust, K.A., A. Fairbrother, andM.J. Hooper. 1994. Effects of 7,12-dimethylbenz[a]anthracene on immune function and mixed-function oxygenase activity in the European starling. Environ, Toxicol. Chem. 13 821-830. 

Hawkins, W.E., W.W. Walker, J.S. Lytle, T.F. Lytle, and R.M. Overstreet. 1989. Carcinogenic effects of 7,12-dimethylbenz[a]anthracene on the guppy (Poecilia reticulata). Aquat. Toxicol. 15 63-82. 

Our laboratory has completed a series of studies designed to evaluate the simultaneous effects of dietary protein and fat on 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast cancer in rats. Sprague-Dawley female rats were assigned to nine diets in a 3 x 3 factorial arrangement with protein (casein) at 8, 16, and 32% of kcals and fat (corn oil) at 12, 24, and 48% of kcals. As fat content was increased, all nutrients other than carbohydrate were adjusted to remain constant with respect to calories. Forty rats were assigned to each diet for each of three experiments (Figure 1) to examine initiation, promotion, and the combined phases of chemically-induced carcinogenesis. 

In 1966-1967, we demonstrated that treatment of rats with certain polycyclic hydrocarbons or aromatic azo derivatives stimulated the in vitro and in vivo metabolism of 7,12-dimethylbenz[a]anthracene (9,10), which provided a mechanistic explanation for earlier research indicating an inhibitory effect of these compounds on 7,12-dimethylbenz[a]anthracene-induced mammary cancer and adrenal toxicity in rats (11-15). These early studies on mechanisms of inhibition of azo dye and polycyclic hydrocarbon carcinogenesis as well as subsequent studies suggested that induction of carcinogen detoxifying enzymes may be a useful strategy for cancer chemoprevention [reviewed in Refs. (16-18)]. 

Slaga TJ, Jecker L, Bracken WM, et al. 1979. The effects of weak or non-carcinogenic polycyclic hydrocarbons on 7,12- dimethylbenz(a)anthracene and benzo(a)pyrene skin tumor-initiation. Cancer Lett 7 51-59. 

Chen, Y. P., and C. A. Squier. 1990. Effect of nicotine on 7,12- dimethylbenz[a] anthracene carcinogenesis in hamster cheek pouch. J. Natl. Cancer Inst. 82(10) 861-64. 

Han, B.S., Fukamachi, K., Takasuka, N., Ohnishi, T., Maeda, M., Yamasaki, T., and Tsuda, H., Inhibitory effects of ITbeta-estradiol and 4-n-octylphenol on 7,12-dimethylbenz[a]anthracene-induced mammary tumor development in human c-Ha-ras proto-oncogene transgenic rats. Carcinogenesis, 23,1209-1215, 2002. 

Azuine, M.A., Amonkar, A.J., and Bhide, S.V., Chemopreventive efficacy of betel leaf extract and its constituents on 7,12-dimethylbenz(a)anthracene induced carcinogenesis and their effect on drug detoxification system in mouse skin, Indian J. Exp. Biol, 29, 346,1991. 

Carter, C. A., MithoUand, R.J., Shea, W., and Ip, MM. (1983) Effect of the Prostaglandin Synthetase Inhibitor Indomethacin on 7,12-Dimethylbenz(fl)Anthracene-Induced Mammary Tumorigenesis in Rats Fed Different Levels of Fat, Cancer Res. 43,3559-3562. 

Wang ZY, Huang M, Lou Y, Xie J, Reuhl K, Newmark H, Ho C, Yang C and Conney A. 1994. Inhibitory effects of black tea, green tea, decaffeinated black tea, and decaffeinated green tea on ultraviolet B light-induced skin carcinogenesis in 7,12-dimethylbenz[<3]anthracene-initiated SKH-1 mice. Cancer Res 54(13) 3428-3435. 

No effects on survival were observed in mice treated dermally with an unspecified volume of 5% phenol (3 times/week) or 10% phenol (2 times/week) in acetone for 12 months (Wynder and Hoffmann 1961). Pretreatment with a single dose of 7,12-dimethylbenz[a]anthracene (DMBA) followed by phenol resulted in increased skin tumors and decreased survival. 

Evarts RP, Brown CA Atta GJ The effects of hydroxylamine on the morphology of the rat mammary gland and on the induction of mammary tumors by 7,12-dimethylbenz( )anthracene. Exp Mol Pathol 30 337-348, 1979... 

Smooth muscle relaxant activity. Tine-ture of the gland, administered to rabbits, was active on the bladder and intestine " . Toxic effect. Gum, administered orally to adults, was active. A case of methemoglobinemia occurred in a 5-week-old male infant, after administration of asafetida preparation to alleviate colic. Treatment was with intravenous methylene blue and the infant recovered . Tumor-promoting activity. Water extract of the dried oleoresin, administered externally to mice at a dose of 200 pL/animal, was active vs 7,12-dimethylbenz[a]anthra-cene and croton oil treatment ". ... 

Anticarcinogenic Activity of CLA. Anticarcinogenic activity of synthetically prepared CLA was first tested in the two-stage mouse epidermal carcinogenesis model. In this study, 7 days, 3 days, and 5 min prior to 7,12-dimethylbenz[a]anthracene (DMBA) application, CLA was applied directly on the shaved backs of individual mice at doses of20,20, and 10 mg, respectively (7). Control mice were treated similarly with linoleic acid or acetone. All mice were given TPA to effect tumor promotion. It was found that CLA treated mice developed only about half as many papillomas and exhibited a lower tumor incidence than control mice. 

Cohen GM, Bracken WM, Iyer RP, et al. 1979. Anticarcinogenic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on benzo(a)pyrene and 7,12-dimethylbenz(a)anthracene tumor initiation and its relationship to DNA binding. Cancer Res 39 4027-4033. 

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