Yeh Shu-Lan, Wang Wei-Yu, Huang Chin-Hsiu, Hu Miao-Lin
Institute of Nutritional Science, Chung Shan Medical University, Taichung, Taiwan 402, ROC.
J Nutr Biochem. 2005 Dec;16(12):729-35. doi: 10.1016/j.jnutbio.2005.03.012. Epub 2005 Aug 11.
It has been suggested that beta-carotene itself is unstable under certain conditions and that a combination of antioxidants may prevent the pro-oxidative effects of beta-carotene. Thus, the present study aimed to investigate the interaction of beta-carotene with three flavonoids-naringin, rutin and quercetin-on DNA damage induced by ultraviolet A (UVA) in C3H10T1/2 cells, a mouse embryo fibroblast. The cells were preincubated with beta-carotene and/or flavonoid for 1 h followed by UVA irradiation, and DNA damage was measured using comet assay. We showed that beta-carotene at 20 microM enhanced DNA damage (by 35%; P<.05) induced by UVA (7.6 kJ/m2), whereas naringin, rutin and quercetin significantly decreased UVA-induced DNA damage. When each flavonoid was combined with beta-carotene during preincubation, UVA-induced cellular DNA damage was significantly suppressed and the effects were in the order of naringin > or = rutin > quercetin. The flavonoids decreased UVA-induced oxidation of preincorporated beta-carotene in the same order. Using electron spin resonance spectroscopy, we showed that the ability of these flavonoids to quench singlet oxygen was consistent with protection against DNA damage and beta-carotene oxidation. All three flavonoids had some absorption at the UVA range (320-380 nm), but the effects were opposite to those on DNA damage and beta-carotene oxidation. Taken together, this cell culture study demonstrates an interaction between flavonoids and beta-carotene in UVA-induced DNA damage, and the results suggest that a combination of beta-carotene with naringin, rutin or quercetin may increase the safety of beta-carotene.
有人提出，β-胡萝卜素本身在某些条件下不稳定，并且抗氧化剂的组合可能会阻止β-胡萝卜素的促氧化作用。因此，本研究旨在探讨β-胡萝卜素与三种黄酮类化合物（柚皮苷、芦丁和槲皮素）在小鼠胚胎成纤维细胞C3H10T1/2中对紫外线A（UVA）诱导的DNA损伤的相互作用。将细胞与β-胡萝卜素和/或黄酮类化合物预孵育1小时，然后进行UVA照射，并使用彗星试验测量DNA损伤。我们发现，20微摩尔的β-胡萝卜素会增强UVA（7.6千焦/平方米）诱导的DNA损伤（增加35%；P<0.05），而柚皮苷、芦丁和槲皮素则显著降低UVA诱导的DNA损伤。在预孵育期间，当每种黄酮类化合物与β-胡萝卜素联合使用时，UVA诱导的细胞DNA损伤被显著抑制，其效果顺序为柚皮苷≥芦丁>槲皮素。黄酮类化合物以相同顺序降低UVA诱导的预先掺入的β-胡萝卜素的氧化。使用电子自旋共振光谱，我们表明这些黄酮类化合物淬灭单线态氧的能力与对DNA损伤和β-胡萝卜素氧化的保护作用一致。所有三种黄酮类化合物在UVA范围（320 - 380纳米）都有一些吸收，但效果与对DNA损伤和β-胡萝卜素氧化的影响相反。综上所述，这项细胞培养研究证明了黄酮类化合物与β-胡萝卜素在UVA诱导的DNA损伤中的相互作用，结果表明β-胡萝卜素与柚皮苷、芦丁或槲皮素的组合可能会提高β-胡萝卜素的安全性。
