Organic UV filters inhibit multixenobiotic resistance (MXR) activity in Tetrahymena thermophila: investigations by the Rhodamine 123 accumulation assay and molecular docking

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• 作者：Li Gao ; Tao Yuan ; Peng Cheng ; Chuanqi Zhou ; Junjie Ao ; Wenhua Wang…
• 刊名：Ecotoxicology
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：25
• 期：7
• 页码：1318-1326
• 全文大小：978 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment
  Environment
  Monitoring, Environmental Analysis and Environmental Ecotoxicology
  Ecology
  Environmental Management
  
• 出版者：Springer Netherlands
• ISSN：1573-3017
• 卷排序：25

文摘

Multixenobiotic resistance (MXR) transporters, which belong to ATP-binding cassette (ABC) family proteins, are present in living organisms as a first line of defense system against xenobiotics and environmental contaminants. The effects of six organic UV filters (4-methyl -benzylidene camphor, 4-MBC; benzophenone-3, BP-3; butyl methoxydibenzoyl-methane, BM-DBM; ethylhexyl methoxy cinnamate, EHMC; octocrylene, OC and homosalate, HMS) on multixenobiotic resistance (MXR) in Tetrahymena thermophila were investigated in this study. It was found that 4-MBC, BP-3 and BM-DBM could significantly inhibit activity of the MXR system, causing concentration dependent accumulation of rhodamine 123; while EHMC, OC and HMS had weak MXR inhibition. The IC₅₀ (50 % inhibition concentration) values of 4-MBC, BP-3 and BM-DBM were 23.54, 40.59 and 26.37 μM, respectively, with inhibitory potentials of 23.1, 13.4 and 20.6 % relative to verapamil (VER, a model inhibitor of P-glycoprotein). Our results firstly provide the evidence for UV filters inhibition effect on MXR in aquatic organisms. In addition, it was revealed by molecular docking analysis that the selected six UV filters can occupy the same binding site on T. thermophila P-gp as VER does; and form H-bonds with residues Ser 328 and/or Asn 281. This study raises the awareness of aquatic ecological risk from the organic UV filters exposure, as they would be involved in potentiating toxic effects by chemosensitizing.KeywordsUV filterMultixenobiotic resistanceTetrahymena thermophilaP-glycoproteinMolecular docking