Ray R S, Misra R B, Farooq M, Hans R K
Photobiology Laboratory, Industrial Toxicology Research Centre, Post Box No. 80, Mahatma Gandhi Marg, Lucknow- 226 001, India.
Toxicol In Vitro. 2002 Apr;16(2):123-7. doi: 10.1016/s0887-2333(01)00116-3.
Some of the commonly used antibiotics such as cephaloridine, cephalexin, cephradine, nystatin and nafcillin were tested for generation of singlet oxygen (1O(2)) under UV-B (290-320 nm) exposure and the order for 1O(2) generation was obtained: cephaloridine>cephalexin>nystatin>cephradine>nafcillin. In vitro study with deoxyguanosine (dGuo) showed that 1O(2) was responsible for drug-sensitized photodegradation of the guanine base of DNA and RNA. Sodium azide (NaN(3)) and 1,4-diazabicyclo [2.2.2] octane (DABCO) accorded significant inhibition (76-98%) in the production of (1)O(2) and photo-oxidation of dGuo. The combined effect of drug and UV-B irradiation is of paramount importance in view of cell-damaging reactions by 1O(2). Our findings are important because of increasing UV-B radiation on the earth's surface due to depletion of the stratospheric ozone layer. The selected drugs are used routinely for the treatment of various diseases and their combined action may cause undesirable phototoxic responses. Our study suggests that exposure to sunlight should be avoided after the intake of the photosensitive drugs.
对一些常用抗生素，如头孢噻啶、头孢氨苄、头孢拉定、制霉菌素和萘夫西林，进行了在UV-B（290 - 320纳米）照射下单线态氧（1O₂）生成情况的测试，并得出了1O₂生成顺序：头孢噻啶＞头孢氨苄＞制霉菌素＞头孢拉定＞萘夫西林。用脱氧鸟苷（dGuo）进行的体外研究表明，1O₂是导致DNA和RNA鸟嘌呤碱基药物敏化光降解的原因。叠氮化钠（NaN₃）和1,4 - 二氮杂双环[2.2.2]辛烷（DABCO）对1O₂的产生和dGuo的光氧化有显著抑制作用（76 - 98%）。鉴于1O₂会引发细胞损伤反应，药物与UV-B照射的联合作用至关重要。由于平流层臭氧层的消耗，地球表面UV-B辐射不断增加，我们的研究结果具有重要意义。所选药物常用于治疗各种疾病，它们的联合作用可能会引起不良的光毒性反应。我们的研究表明，服用光敏药物后应避免阳光照射。
