Conjugated linoleic acid isomers and mammary cancer prevention
Conjugated linoleic acid isomers and mammary cancer prevention
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DOI：
10.1207/s15327914nc431_6
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发表时间：
2002-01-01
影响因子：
2.9
通讯作者：
Saebo, A
中科院分区：
文献类型：
--
作者：
Ip, C;Dong, Y;Saebo, A
越来越多的证据表明，共轭亚油酸 (CLA) 的各个异构体可能具有独特的生物或生化作用。本研究的主要目的是确定 9,11-CLA 和 10,12-CLA 的抗癌活性是否存在差异。这是通过评估大鼠乳腺癌前病变和癌的减少来实现的，这些大鼠接受单剂量甲基亚硝基脲治疗，并在饮食中给予 0.5% 的任一高度纯化的 CLA 异构体。我们的结果表明，两种异构体的抗癌功效非常相似。施用致癌物后 6 周，癌前病变总数减少了 33-36%。 24 周时，乳腺癌总数减少了 35-40%。分析乳腺脂肪垫中每种 CLA 异构体及其各自代谢物的浓度。 10,12-CLA的组织水平远低于9,11-CLA。两组之间每种异构体的代谢物库非常相似，仅占总共轭二烯脂肪酸的一小部分。饲喂 9,11-CLA 导致其他不饱和脂肪酸的变化最小。相比之下，添加 10,12-CLA 会产生更广泛的扰动。检测到 16:1 和 16:2 的比例虽小但显着增加；与此同时，20:2、20:3、20:4、22:4 和 22:6 的比例也有所下降。上述观察结果表明，10,12-CLA 在干扰亚油酸和亚麻酸的伸长和去饱和方面可能比 9,11-CLA 更有效。总之，我们的研究表明，在 0.5% 剂量水平下，9,11-CLA 和 10,12-CLA 的抗癌活性非常相似，尽管 10,12-CLA 在乳腺组织中的积累远低于 9,11-CLA。其他不饱和脂肪酸在 10,12-CLA 作用中的这些令人困惑的变化需要澄清。
There is increasing evidence that individual isomers of conjugated linoleic acid (CLA) may have unique biological or biochemical effects. A primary objective of this study was to determine whether there might be differences in the anticancer activity of 9,11-CLA and 10,12-CLA. This was achieved by evaluating the reduction in premalignant lesions and carcinomas in the mammary gland of rats that had been treated with a single dose of methylnitrosourea and given 0.5% of either highly purified CLA isomer in the diet. Our results showed that the anticancer efficacies of the two isomers were very similar. At 6 wk after carcinogen administration, the total number of premalignant lesions was reduced by 33-36%. At 24 wk, the total number of mammary carcinomas was reduced by 35-40%. The concentration of each CLA isomer and its respective metabolites was analyzed in the mammary fat pad. Tissue level of 10,12-CLA was much lower than that of 9,11-CLA. The pool of metabolites from each isomer was very similar between the two groups and represented only a small fraction of total conjugated diene fatty acids. Feeding of 9,11-CLA resulted in minimal changes in other unsaturated fatty acids. In contrast, fee-ding of 10,12-CLA produced a wider spectrum of perturbations. Small but significant increases in 16:1 and 16:2 were detected; these were accompanied by decreases in 20:2, 20:3, 20:4, 22:4, and 22:6. The above observation suggests that 10,12-CLA might be more potent than 9,11-CLA in interfering with elongation and desaturation of linoleic and linolenic acids. In summary, our study showed that, at the 0.5% dose level, the anticancer activity of 9,11-CLA and 10,12-CLA was very similar, even though accumulation of 10,12-CLA in the mammary tissue was considerably less than that of 9,11-CLA. These confounding changes of the other unsaturated fatty acids in contributing to the effect of 10,12-CLA need to be clarified.