Institute of Photonics and Phototechnology, Northwest University, Xi'an 710069, China.
Acta Biochim Biophys Sin (Shanghai). 2009 Dec;41(12):1033-43. doi: 10.1093/abbs/gmp099.
Mangostin (MAG), a kind of xanthone widely used in diet and medicine, has antioxidant, anti-inflammatory, antimicrobial, and anticancer activities. On account of its antioxidant activity, MAG might protect cancer cells from free radical damage in photodynamic therapy (PDT) during which reactive oxygen species production was stimulated leading to irreversible tumor cell injury. In this study, the antioxidant activity of MAG was investigated and the influence of MAG on K562 cells in 5-aminolevulinic acid (ALA)-based PDT is demonstrated. The results showed that MAG could scavenge hydroxyl radical, superoxide anion, and hydrogen peroxide and inhibit the formation of malondialdehyde (MDA), but increase the amounts of singlet oxygen in cell-free systems. MAG inhibits cell proliferation and enhances cell apoptosis, lipid peroxidation, and DNA damage in ALA-PDT on K562 cells. NaN3, a singlet oxygen quencher, suppresses the MAG-induced cell apoptosis, lipid peroxidation, and DNA damage. In conclusion, MAG enhances the PDT-induced cytotoxicity in K562 cells and singlet oxygen was involved in this process. These results implied that the effect of antioxidants on PDT might be determined by its sensitization ability to singlet oxygen.
山竹素（MAG）是一种广泛应用于饮食和医学的酮类化合物，具有抗氧化、抗炎、抗菌和抗癌活性。由于其抗氧化活性，MAG 可能会在光动力疗法（PDT）中保护癌细胞免受自由基损伤，在 PDT 中，活性氧的产生被刺激，导致肿瘤细胞不可逆损伤。在这项研究中，研究了 MAG 的抗氧化活性，并证明了 MAG 对基于 5-氨基酮戊酸（ALA）的 PDT 中 K562 细胞的影响。结果表明，MAG 可以清除羟自由基、超氧阴离子和过氧化氢，并抑制丙二醛（MDA）的形成，但会增加细胞体系中单线态氧的含量。MAG 抑制 K562 细胞中 ALA-PDT 中的细胞增殖并增强细胞凋亡、脂质过氧化和 DNA 损伤。NaN3 是单线态氧猝灭剂，可抑制 MAG 诱导的细胞凋亡、脂质过氧化和 DNA 损伤。总之，MAG 增强了 K562 细胞中 PDT 诱导的细胞毒性，而单线态氧参与了这一过程。这些结果表明，抗氧化剂对 PDT 的影响可能取决于其对单线态氧的敏化能力。
