title: Effects of 4-methylbenzylidene camphor (4-MBC) on neuronal and muscular development in zebrafish (Danio rerio) embryos.
abstract: The negative effects of overexposure to ultraviolet (UV) radiation in humans, including sunburn and light-induced cellular injury, are of increasing public concern. 4-Methylbenzylidene camphor (4-MBC), an organic chemical UV filter, is an active ingredient in sunscreen products. To date, little information is available about its neurotoxicity during early vertebrate development. Zebrafish embryos were exposed to various concentrations of 4-MBC in embryo medium for 3 days. In this study, a high concentration of 4-MBC, which is not being expected at the current environmental concentrations in the environment, was used for the purpose of phenotypic screening. Embryos exposed to 15 μM of 4-MBC displayed abnormal axial curvature and exhibited impaired motility. Exposure effects were found to be greatest during the segmentation period, when somite formation and innervation occur. Immunostaining of the muscle and axon markers F59, znp1, and zn5 revealed that 4-MBC exposure leads to a disorganized pattern of slow muscle fibers and axon pathfinding errors during the innervation of both primary and secondary motor neurons. Our results also showed reduction in AChE activity upon 4-MBC exposure both in vivo in the embryos (15 μM) and in vitro in mammalian Neuro-2A cells (0.1 μM), providing a possible mechanism for 4-MBC-induced muscular and neuronal defects. Taken together, our results have shown that 4-MBC is a teratogen and influences muscular and neuronal development, which may result in developmental defects.
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.|Department of Mechanical and Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Vincent Wai Tsun
authors.initials: VW
authors.lastname: Li
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.|Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Mei Po Mirabelle
authors.initials: MP
authors.lastname: Tsui
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.|Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Xueping
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Michelle Nga Yu
authors.initials: MN
authors.lastname: Hui
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.|Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Jin
authors.affiliation: Department of Mechanical and Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Raymond H W
authors.initials: RH
authors.lastname: Lam
authors.affiliation: School of Environmental and Life Sciences, The University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia.
authors.forename: Richard Man Kit
authors.initials: RM
authors.lastname: Yu
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.|Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Margaret B
authors.initials: MB
authors.lastname: Murphy
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.|Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Jinping
authors.initials: J
authors.lastname: Cheng
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.|Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
authors.forename: Paul Kwan Sing
authors.initials: PK
authors.lastname: Lam
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China. bhcheng@cityu.edu.hk.|Department of Biomedical Science, City University of Hong Kong, 83 Tat Chee Avenue SAR, Hong Kong, China. bhcheng@cityu.edu.hk.
authors.forename: Shuk Han
authors.initials: SH
authors.lastname: Cheng
mesh_terms: D000818:Animals; D002164:Camphor / Q000031:analogs & derivatives* / Q000633:toxicity; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D024510:Muscle Development / Q000187:drug effects*; D009420:Nervous System / Q000187:drug effects* / Q000254:growth & development; D013473:Sunscreening Agents / Q000633:toxicity*; D014466:Ultraviolet Rays; D015027:Zebrafish / Q000196:embryology*
chemical_list: D013473:Sunscreening Agents; D002164:Camphor; C038939:enzacamene
keywords: 4-Methylbenzylidene camphor; Acetylcholinesterase; Neuron; Somite; Toxicity; Zebrafish embryos