title: Experimental evidence for alleviating nociceptive hypersensitivity by single application of capsaicin.
abstract: The single application of high-concentration of capsaicin has been used as an analgesic therapy of persistent pain. However, its effectiveness and underlying mechanisms remain to be further evaluated with experimental approaches. The present study provided evidence showing that the single application of capsaicin dose-dependently alleviated nociceptive hypersensitivity, and reduced the action potential firing in small-diameter neurons of the dorsal root ganglia (DRG) in rats and mice. Pre-treatment with capsaicin reduced formalin-induced acute nocifensive behavior after a brief hyperalgesia in rats and mice. The inhibitory effects of capsaicin were calcium-dependent, and mediated by the capsaicin receptor (transient receptor potential vanilloid type-1). We further found that capsaicin exerted inhibitory effects on the persistent nociceptive hypersensitivity induced by peripheral inflammation and nerve injury. Thus, these results support the long-lasting and inhibitory effects of topical capsaicin on persistent pain, and the clinic use of capsaicin as a pain therapy.
authors.affiliation: Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031, China. xlma@ion.ac.cn.
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Ma
authors.affiliation: Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031, China. fxzhang@ucalgary.ca.
authors.forename: Fang-Xiong
authors.initials: FX
authors.lastname: Zhang
authors.affiliation: Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031, China. dfei2014@ion.ac.cn.
authors.forename: Fei
authors.initials: F
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China. baolan@sibcb.ac.cn.|School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China. baolan@sibcb.ac.cn.
authors.forename: Lan
authors.initials: L
authors.lastname: Bao
authors.affiliation: Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai, 200031, China. xu.zhang@ion.ac.cn.|School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China. xu.zhang@ion.ac.cn.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000982:Antipruritics / Q000008:administration & dosage / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology*; D005727:Ganglia, Spinal / Q000187:drug effects*; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009474:Neurons / Q000187:drug effects; D010146:Pain / Q000188:drug therapy*
chemical_list: D000982:Antipruritics; D002211:Capsaicin; D002118:Calcium