Division of Animal Biochemistry, National Dairy Research Institute, Karnal, 132001 Haryana, India.
Mol Biol Rep. 2011 Jun;38(5):3299-307. doi: 10.1007/s11033-010-0435-1. Epub 2010 Nov 19.
The present study investigated the effect of cow ghee (clarified butter fat) versus soybean oil on the expression of cyclins A and D1, and apoptosis regulating Bax, Bcl-2 and PKC-α genes in mammary gland of normal and 7,12-dimethylbenz(a)anthracene (DMBA) treated rats. Two groups of 21 days old female rats were fed for 44 weeks diet containing cow ghee or soybean oil (10%). The animals were given DMBA (30 mg/kg body weight) through oral intubation after 5 weeks feeding. Another two groups fed similarly but not given DMBA served as respective controls. In control groups, the expression of cyclin A was similar on both cow ghee and soybean oil, but that of cyclin D1 was more on soybean oil diet. However, in DMBA treated groups, the expression levels of cyclins A and D1 were significantly greater on soybean oil than on cow ghee. The expression levels of Bax, Bcl-2 and PKC-α were similar in two control groups. However, in tumor tissue expression levels of Bcl-2 and PKC-α were significantly lower in cow ghee fed rats than in soybean oil fed ones, but Bax was similarly expressed in both DMBA treated groups. The pro-apoptotic ratio Bax/Bcl-2 increased and the anti-apoptotic ratio PKC-α(Bcl-2/Bax) decreased in cow ghee group compared to soybean oil group in DMBA treated rats. Hence, the decreased expressions of cyclins A and D1, Bcl-2 and PKC-α mediate the mechanism by which cow ghee protects from mammary carcinogenesis.
本研究调查了奶牛黄油(澄清黄油脂肪)与大豆油对正常和 7,12-二甲基苯并蒽(DMBA)处理大鼠乳腺中环细胞 A 和 D1 的表达以及凋亡调节 Bax、Bcl-2 和 PKC-α基因的影响。两组 21 天大的雌性大鼠分别用含奶牛黄油或大豆油(10%)的饮食喂养 44 周。第 5 周喂养后,通过口服管饲向动物给予 DMBA(30 mg/kg 体重)。另外两组类似喂养但未给予 DMBA 作为各自的对照。在对照组中,奶牛黄油和大豆油对 cyclin A 的表达相似,但大豆油饮食中 cyclin D1 的表达更多。然而,在 DMBA 处理组中,大豆油饮食中 cyclins A 和 D1 的表达水平明显高于奶牛黄油。Bax、Bcl-2 和 PKC-α 的表达水平在两组对照中相似。然而,在肿瘤组织中,奶牛黄油喂养的大鼠的 Bcl-2 和 PKC-α 的表达水平明显低于大豆油喂养的大鼠,而 Bax 在两种 DMBA 处理组中的表达相似。与大豆油组相比,DMBA 处理的奶牛黄油组的促凋亡比值 Bax/Bcl-2 增加,而抗凋亡比值 PKC-α(Bcl-2/Bax)降低。因此,奶牛黄油对乳腺致癌作用的保护机制涉及 cyclins A 和 D1、Bcl-2 和 PKC-α 的表达降低。