Department of Forensic Science, School of Bioengineering and Biosciences, Lovely Professional University, Punjab, India; Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow, India.
Photobiology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research, Post. Box 80, M.G. Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow, India.
Regul Toxicol Pharmacol. 2018 Jun;95:298-306. doi: 10.1016/j.yrtph.2018.04.003. Epub 2018 Apr 4.
Benzophenone-2 (BP2), a common ingredient of sunscreens formulation is widely used as UV filter. We have assessed the photogenotoxic and photocytotoxic potential of BP2. Photostability test showed that BP2 is unstable under UV exposure. Cell proliferation assay revealed that viability of HaCaT cells significantly reduced under UVA, UVB and sunlight exposure. DCF fluorescence intensity proved intracellular ROS generation capacity of BP2 under sunlight, UVA and UVB irradiation. Photodynamic degradation of guanine base of DNA is promoted by BP2 under UV treatment. Genotoxicity assessed by comet assay, showed that photosensitized BP2 enhanced DNA damage, which is measured in term of % tail DNA and olive tail moment. Genotoxic potential of BP2 was further validated with photomicronuclei assay. Photogenotoxicity of BP2 was lastly confirmed by formation of CPDs (Cyclo butane pyrimidine dimmers). DNA damage induced by BP2 was irreversible and extended incubation periods (6-12 h) not favored the recovery from damaged DNA. JC 1 staining showed significant reduction in mitochondrial membrane potential. Membrane integrity compromisation of HaCaT cells was established by AO (Acridine orange), EtBr (Ethidium bromide) staining and confirmed with sub G1 population of cell cycle. Thus, results suggest that BP2 should be avoided in topical application for safe sunscreen practices.
二苯甲酮-2（BP2）是防晒霜配方中的常见成分，被广泛用作紫外线滤光剂。我们评估了 BP2 的光遗传毒性和光细胞毒性。光稳定性测试表明，BP2 在紫外线照射下不稳定。细胞增殖试验表明，HaCaT 细胞在 UVA、UVB 和阳光照射下的活力明显降低。DCF 荧光强度证明了 BP2 在阳光、UVA 和 UVB 照射下产生细胞内 ROS 的能力。BP2 在紫外线处理下促进了 DNA 鸟嘌呤碱基的光动力降解。彗星试验评估的遗传毒性表明，光敏化的 BP2 增强了 DNA 损伤，这可以通过尾 DNA 的百分比和橄榄尾矩来衡量。光微核试验进一步验证了 BP2 的遗传毒性潜力。最后通过 CPDs（环丁烷嘧啶二聚体）的形成证实了 BP2 的光遗传毒性。BP2 诱导的 DNA 损伤是不可逆的，延长孵育时间（6-12 小时）不利于受损 DNA 的恢复。JC-1 染色显示线粒体膜电位显著降低。AO（吖啶橙）、EtBr（溴化乙锭）染色证实了 HaCaT 细胞的膜完整性受损，并通过细胞周期的亚 G1 群体得到证实。因此，结果表明 BP2 应避免在局部应用中，以安全的防晒措施。
