Amala Cancer Research Centre, Kerala, India.
Nutr Cancer. 2013;65(6):850-6. doi: 10.1080/01635581.2013.801501.
Anticarcinogenic activity of meso-zeaxanthin (MZ), a xanthophyll carotenoid with profound antioxidant activity, was evaluated against 3-methylcholanthrene (3-MC)-induced sarcoma in mice. Oral administration of MZ at different doses significantly increased tumor latency period. In 3-MC control group, animals started developing sarcoma on 6th week. However animals treated with 3-MC and MZ (50 and 250 mg/kg b.wt) started developing sarcoma only on 15th and 18th week, respectively. Survival of tumor-bearing mice was significantly increased by MZ treatment. Animals in 3-MC control group started dying due to tumor burden from 8th week. All animals treated with MZ (50 and 250 mg/kg b.wt) along with 3-MC were found to be alive even after 16 and 20 wk, respectively. Oral administration of MZ inhibited different CYP450 isoenzymes like CYP1A1 (PROD), CYP1A2 (MROD), and CYP2B1/2 (EROD), which are involved in carcinogen metabolism in a dose-dependent manner. Moreover, levels of phase II enzymes like UDP-glucuronyl transferase and glutathione-S-transferase, which are involved in detoxification of carcinogens, were significantly increased by MZ treatment. Results indicated that mode of action of MZ may be through inhibition of carcinogen activation coupled with enhancement of detoxification process. MZ may also inhibit promotion phases of carcinogenesis by its antioxidant activity.
具有强大抗氧化活性的类胡萝卜素中叶黄素（MZ）的抗癌活性，在小鼠中 3-甲基胆蒽（3-MC）诱导肉瘤模型中进行了评估。MZ 的不同剂量的口服给药显著增加了肿瘤潜伏期。在 3-MC 对照组中，动物在第 6 周开始出现肉瘤。然而，用 3-MC 和 MZ（50 和 250 mg/kg b.wt）处理的动物分别在第 15 周和第 18 周才开始出现肉瘤。MZ 处理显著增加了荷瘤小鼠的存活率。3-MC 对照组的动物从第 8 周开始因肿瘤负荷而死亡。用 MZ（50 和 250 mg/kg b.wt）与 3-MC 一起处理的所有动物，即使在 16 周和 20 周后，仍被发现存活。MZ 以剂量依赖的方式抑制了不同的 CYP450 同工酶，如 CYP1A1（PROD）、CYP1A2（MROD）和 CYP2B1/2（EROD），这些同工酶参与了致癌物的代谢。此外，参与致癌物解毒的 II 相酶，如 UDP-葡萄糖醛酸转移酶和谷胱甘肽-S-转移酶的水平，也被 MZ 处理显著增加。结果表明，MZ 的作用机制可能是通过抑制致癌物的激活，同时增强解毒过程。MZ 还可能通过其抗氧化活性抑制致癌作用的促进阶段。
