Gunasekera Richard S, Sewgobind Kiran, Desai Smruti, Dunn Larry, Black Homer S, McKeehan Wallace L, Patil Bhimanagouda
University of Houston-Victoria, Victoria, TX 77901, USA.
Nutr Cancer. 2007;58(2):171-7. doi: 10.1080/01635580701328339.
Consumption of lycopene, a carotenoid without provitamin A activity, has been associated with a lower risk of prostate and breast cancer. Lutein is another carotenoid that may be associated with a reduced risk of age-related macular degeneration, the leading cause of blindness in adults 65 years of age and older. Bioactive compounds such as lycopene and lutein, derived from natural plant sources, have been shown to act at low substrate levels through the action of intrinsic cytokines and growth factors and their receptors within tissues, particularly those of the fibroblast growth factor and transforming growth factor beta families. The effects of grapefruit-derived and commercial lycopene and lutein preparations on androgen independent cultured malignant type II tumor cells [Dunning R3327AT3 or AT3 cells (androgen-responsive, slow-growing tumor cells with well developed epithelium and stroma)] were compared to their benign parent type I tumor epithelial cells (DTE). Results demonstrated that both lycopene, in an alpha -cyclodextrin water soluble carrier, and lutein inhibited malignant AT3 cells in a concentration and time-dependent manner. No such effect was observed when benign DTE cells were examined, demonstrating selective inhibition of extremely malignant AT3 prostate cancer cells relative to their benign parent. Lutein demonstrated a similar but slightly diminished response as lycopene. When cells were treated with cocktails of lycopene and lutein, no synergistic or additive effect occurred. These studies are consistent with epidemiological studies that show inverse relationships of these carotenoids with prostate cancer.
番茄红素是一种不具有维生素A原活性的类胡萝卜素，摄入番茄红素与降低前列腺癌和乳腺癌风险有关。叶黄素是另一种类胡萝卜素，可能与降低年龄相关性黄斑变性风险有关，年龄相关性黄斑变性是65岁及以上成年人失明的主要原因。番茄红素和叶黄素等生物活性化合物源自天然植物来源，已证明它们在低底物水平下通过组织内固有细胞因子、生长因子及其受体（特别是成纤维细胞生长因子和转化生长因子β家族的受体）发挥作用。将葡萄柚来源的和市售的番茄红素及叶黄素制剂对雄激素非依赖性培养的恶性II型肿瘤细胞[邓宁R3327AT3或AT3细胞（雄激素反应性、生长缓慢、上皮和基质发育良好的肿瘤细胞）]的作用与其良性亲代I型肿瘤上皮细胞（DTE）进行比较。结果表明，以α-环糊精水溶性载体形式存在的番茄红素和叶黄素均以浓度和时间依赖性方式抑制恶性AT3细胞。检查良性DTE细胞时未观察到这种作用，这表明相对于其良性亲代，对极恶性的AT3前列腺癌细胞有选择性抑制作用。叶黄素表现出与番茄红素相似但略有减弱的反应。当用番茄红素和叶黄素混合物处理细胞时，未出现协同或相加作用。这些研究与显示这些类胡萝卜素与前列腺癌呈负相关的流行病学研究一致。
