Topic
7,12-Dimethylbenz[a]anthracene
About: 7,12-Dimethylbenz[a]anthracene is a research topic. Over the lifetime, 1717 publications have been published within this topic receiving 40892 citations.
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TL;DR: It is reported that lycopene counteracts the hepatic response to DMBA by altering the expression of Bax, Bcl-2, caspases, and oxidative stress biomarkers in animal model.
Abstract: Context: Lycopene is a carotenoid found in tomato, watermelon, pink grapefruit, and guava in high concentration. Dietary intake of lycopene has been proposed to inversely correlate with the risk of cancer. It has also been reported to provide protection against cellular damage caused by reactive oxygen species, which makes it worthwhile to study the effect of lycopene on liver damage in rat model.Objective: In this study, we report the effect of lycopene on 7,12-dimethylbenz[a]-anthracene (DMBA)-induced expression of Bax, Bcl-2, caspases, and oxidative stres biomarkers in the liver.Materials and methods: Lycopene was administered orally at 20 mg/kg body weight for 20 weeks followed by the intraperitoneal injection of DMBA (50 mg/kg body weight) on day 1 and day 30 of the experiment. Control rats received vehicle (olive oil) or DMBA alone. Rats were sacrificed after completion of the treatment.Results: We observed that the levels of Bax, caspase-3, and caspase-9 decreased to 44, 67, and 43%, respectively, ...
24 citations
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TL;DR: The data illustrate, for the first time, the ability of the mammary tissue to metabolize 7,12-dimethylbenz(a)anthracene.
Abstract: The metabolism of 7,12-dimethylbenz(a)anthracene to hydroxymethyl derivatives differs in hepatic and mammary tissue homogenates. Countercurrent distribution and carrier recrystallization have been shown to be effective additional tools in the identification of 7-hydroxymethyl-12-methylbenz(a)anthracene, 12-hydroxymethyl-7-methylbenz(a)anthracene, and 7,12-dihydroxymethylbenz(a)anthracene. In the hepatic tissue, 7,12-dimethylbenz(a)anthracene is transformed into all three of these metabolites whereas the mammary gland formed only the monohydroxy compounds. Pretreatment of rats with 3-methylcholanthrene induces a marked increase in 7,12-dimethylbenz(a)anthracene-metabolizing enzymes in the liver causing further conversion of the 7-hydroxymethyl-12-methylbenz(a)anthracene, 12-hydroxymethyl-7-methylbenz(a)anthracene, and 7,12-dihydroxy-7,12-dimethylbenz(a)anthracene to more polar components. In contrast, mammary gland caused a diminution but still detectable level of the carcinogenic 7-hydroxymethyl-12-methylbenz(a)anthracene and a noticeable increase in the conversion to 12-hydroxymethyl-7-methylbenz(a)anthracene. The data illustrate, for the first time, the ability of the mammary tissue to metabolize 7,12-dimethylbenz(a)anthracene.
24 citations
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TL;DR: Investigation of whether curcumin inhibits 7,12-dimethylbenz[a]anthracene (DMBA)-induced, MPA-accelerated tumors in Sprague-Dawley rats suggested that cur cumin be tested as a dietary chemopreventive agent in women already exposed to MPA, in an effort to decrease or delay the risk of breast cancer associated with combined HT.
Abstract: Objective
Combined hormone replacement therapy (HRT) containing estrogen and progestin (medroxyprogesterone acetate [MPA]) leads to increased risk of breast cancer in postmenopausal women, compared with HRT regimens containing estrogen alone, or placebo. We previously reported that, in animal models, progestins can accelerate the development of mammary tumors by increasing VEGF levels. We furthermore showed that curcumin, an Indian spice derived from the turmeric root, specifically inhibits MPA-induced VEGF secretion from breast cancer cells in vitro. In the present study, we investigated whether curcumin inhibits DMBA-induced, MPA-accelerated tumors in Sprague-Dawley rats.
24 citations
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TL;DR: Morphometric analysis of this animal model further defines the dynamic changes in the mouse ovary in response to DMBA as a dose-dependent decrease in ovarian volume and number of corpora lutea in each ovary.
24 citations
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TL;DR: Of all skin carcinomas diagnosed histologically in DMBA/TPA-exposed mice, less than one-third had been identified clinically while the mice were alive, and most of the carcinomas arose within papillomas.
Abstract: Groups of female SENCAR or BALB/c mice were initiated once intraperitoneally with 300 micrograms/mouse of 7,12-dimethylbenz(a)anthracene (DMBA) or 20 mg/mouse of urethane at 7 weeks of age. Beginning one week later, mice received topically applied acetone or 12-O-tetradecanoylphorbol-13-acetate (TPA), once weekly, at 2.5 micrograms/mouse for weeks 1 through 6 and 1.25 micrograms/mouse for weeks 7 through 52. The skin lesions were evaluated clinically. A complete necropsy was performed on all mice at week 52. SENCAR mice exposed to DMBA/TPA and urethane/TPA had more skin tumors than SENCAR mice exposed to DMBA or urethane alone and more than BALB/c mice in any treatment group. Of all skin carcinomas diagnosed histologically in DMBA/TPA-exposed mice, less than one-third had been identified clinically while the mice were alive. Most of the carcinomas arose within papillomas. BALB/c mice developed more vascular and uterine tumors than did SENCAR mice injected with DMBA and more lung and vascular tumors than did SENCAR mice injected with urethane. TPA exposure after treatment with either initiator had no significant effect on internal tumor development in either SENCAR or BALB/c mice.
23 citations