Dahl T A, Bilski P, Reszka K J, Chignell C F
Department of Pharmacology & Experimental Therapeutics, School of Veterinary Medicine, Tufts University, Boston, MA 02111.
Photochem Photobiol. 1994 Mar;59(3):290-4. doi: 10.1111/j.1751-1097.1994.tb05036.x.
Curcumin, bis(4-hydroxy-3-methoxyphenyl)-1,6-diene-3,5-dione, is a yellow-orange dye derived from the rhizome of the plant Curcuma longa. Curcumin has demonstrated phototoxicity to several species of bacteria under aerobic conditions (Dahl, T. A., et al., 1989, Arch. Microbiol. 151 183), denoting photodynamic inactivation. We have now found that curcumin is also phototoxic to mammalian cells, using a rat basophilic leukemia cell model, and that this phototoxicity again requires the presence of oxygen. The spectral and photochemical properties of curcumin vary with environment, resulting in the potential for multiple or alternate pathways for the exertion of photodynamic effects. For example, curcumin photogenerates singlet oxygen and reduced forms of molecular oxygen under several conditions relevant to cellular environments. In addition, we detected carbon-centered radicals, which may lead to oxidation products (see accompanying paper). Such products may be important reactants in curcumin's phototoxicity since singlet oxygen and reduced oxygen species alone could not explain the biological results, such as the relatively long lifetime (t1/2 = 27 s) of the toxicant responsible for decreased cell viability.
姜黄素，即双（4-羟基-3-甲氧基苯基）-1,6-二烯-3,5-二酮，是一种从植物姜黄的根茎中提取的黄橙色染料。姜黄素已被证明在有氧条件下对多种细菌具有光毒性（达尔，T.A.等人，1989年，《微生物学档案》151卷，第183页），这表明存在光动力失活现象。我们现在发现，使用大鼠嗜碱性白血病细胞模型，姜黄素对哺乳动物细胞也具有光毒性，而且这种光毒性同样需要氧气的存在。姜黄素的光谱和光化学性质会随环境而变化，这导致其光动力效应可能通过多种或交替途径发挥作用。例如，在与细胞环境相关的几种条件下，姜黄素会光生成单线态氧和还原态的分子氧。此外，我们检测到了以碳为中心的自由基，这些自由基可能会导致氧化产物的产生（见随附论文）。这些产物可能是姜黄素光毒性中的重要反应物，因为仅单线态氧和还原态氧物种无法解释生物学结果，比如导致细胞活力下降的毒物具有相对较长的寿命（半衰期t1/2 = 27秒）。
