Mammary cell cultures, inhibition

In addition to their possible prooxidant activity (see above) polyphenols and flavonoids may influence cancer cells via their antioxidant properties. Recently, Jang et al. [219] studied cancer chemopreventive activity of resveratrol, a natural polyphenolic compound derived from grapes (Chapter 29). These authors showed that resveratrol inhibited the development of preneoplastic lesions in carcinogen-treated mouse mammary glands in culture and inhibited tumorigenesis in a mouse skin cancer model. Flavonoids silymarin and silibinin also exhibited antitumor-promoting effects at the stage I tumor promotion in mouse skin [220] and manifested antiproliferative effects in rat prostate cancer cells [221]. 

Cytotoxic activity. Ethanol (90%) extract of the dried plant, in cell culture administered at a concentration 0.25 mg/mL, was active on human lymphocytes. The extract was active on Veto cells, effective dose (EDjo 0.15 mg/mL Chinese hamster ovary (CHO) cells, EDjq 0.575 mg/mL and Dalton s lymphoma, EDjo 0.6 mg/mL "" ". Water extract of the dried gum, in cell culture at a concentration of 500 pg/mL, produced weak activity on CA-mammary-microalveolar cells "° L Digestive enzyme inhibition. Asafoetida, administered orally to rats at a dose of 2500 mg% for 8 weeks, decreased the levels of... 

Studies of Medina and Oborn (75) examined the growth potential of normal, preneoplastic and neoplastic mammary cells grown in primary monolayer cell cultures and on three established mammary cell lines. Selenium, present as sodium selenite in erum-free medium inhibited alj mammary cell cultures at 1 X 10 M. 

Selenium, at 5 X10 M, stimulated the growth of primary cell cultures of normal mammary cells and C4 preneoplastic cells and the established cell line YN-4 but not the growth of D2 preneoplastic cells and tumors in primary cell cultures and of established cell lines CL-S1 and Waz-2t. The differential response of cells from preneoplastic outgrowth lines C4 and D2 and of D2 primary tumors in vitro correlated with the sensitivity of these same cell populations to selenium mediated inhibition of growth and tumorigenesis in vivo. Selenium had little effect on 3 or 4 preneoplastic mammary outgrowth lines. Recent studies by Poirier et al., (70) have shown that... 

Calcidiol la-hydroxylase is not restricted to the kidney, but is also found in placenta, bone cells (in culture), mammary glands, and keratinocytes. The placental enzyme makes a significant contribution to fetal calcitriol, but it is not clear whether the calcidiol 1-hydroxylase activity of other tissues is physiologically significant or not. Acutely nephrectomized animals given a single dose of calcidiol do not form any detectable calcitriol, but there is some formation of calcitriol in anephric patients, which increases on the administration of cholecalciferol or calcidiol. However, thus extrarenal synthesis is not adequate to meet requirements, so that osteomalacia develops in renal failure (Section 3.4.1). The enzyme is inhibited, or possibly repressed, by strontium ions this is the basis of strontium-induced vitamin D-resistant rickets, which responds to the administration of calcitriol or la-hydroxycalciol, but not calciferol or calcidiol (Omdahl and DeLuca, 1971). 

Cytotoxidty inhibition - in vitro (Cell culture) at 8.0 pM vs. CA-mammary-MCF-7. Taxol cytotoxicity inhibition. 

Various studies have shown the toxicity of various free monosaccharides towards mammalian cells. L-Fucose was found to inhibit the growth of some cells in culture, but only at high doses,292 and to inhibit the growth of implanted, mammary tumors in rats.293 In an examination of the effect of 93 carbohydrates on cell proliferation,294 D-fucose was one of the 42 that were toxic or growth-inhibitory, but the effect of L-fucose was not reported. The inhibitory effect of L-fucose in implanted, mammary tumors293 was considered to be accompanied by its incorporation into serum glycoproteins, and this would offer a possible explanation for some of its biological properties. 

Chen ZH, Hurh YJ, Na HK, Kim JH, Chun YJ, Kim DH, Kang KS, Cho MH, Surh Y-J. 2004. Resveratrol inhibits TCDD-induced expression of CYP1A1 and CYP1B1 and catechol estrogen-mediated oxidative DNA damage in cultured human mammary epithelial cells. Carcinogenesis 25 2005-2013. 

The assays based on tumor initiation events include the inhibition of DMBA-induced mutagenicity with Salmonella typhimurium strain of bacteria and the induction of quinone reductase in cultivated HeLa cells. The compounds that are inhibitors of DMBA-induced mutagenicity bioassays with Salmonella typhimurium also inhibit preneoplastic lesion formation in mammary organ culture. The induction of quinone-reductase in HeLa cells may indicate cancer chemoprevention activity [29]. 

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