title: Radiolysis and photolysis studies on active transient species of berberine.
abstract: In this paper, the photochemical and photobiological characters of the active radicals of berberine (BBR) was investigated for finding an efficient and safe photosensitizer with highly active transient products using in Photodynamic therapy (PDT) study. The active species of BBR was generated and identified by using pulse radiolysis method. In neutral aqueous solution, BBR react with hydrated electron and hydroxyl radical, forming the radical anion and neutral radical of BBR, and the related reaction rates were determined as 3.5×10(10) and 6.7×10(9) M(-1) s(-1), respectively. Further, the capability of BBR to photosensitize DNA cleavage was testified by laser flash photolysis (LFP) method, the results demonstrated that BBR neutral radical could react with guanine mononucleotide (K=1.9×10(9) M(-1) s(-1)) via electron transfer to give the guanine neutral radical. Additionally BBR selective cleavage single and double strand DNA at guanine moiety was observed. Finally, combining with the thermodynamic calculation, the possible photodamage mechanism of dGMP and DNA induced by BBR was clarified.
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Ling-Li
authors.initials: LL
authors.lastname: Cheng
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Wang
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Da-Hong
authors.initials: DH
authors.lastname: Huang
authors.affiliation: School of Life Science and Technology, Tongji University, Shanghai 200092, China.
authors.forename: Si-De
authors.initials: SD
authors.lastname: Yao
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
authors.forename: Guo-Ji
authors.initials: GJ
authors.lastname: Ding
authors.affiliation: School of Life Science and Technology, Tongji University, Shanghai 200092, China. Electronic address: wsl@mail.tongji.edu.cn.
authors.forename: Shi-Long
authors.initials: SL
authors.lastname: Wang
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China. Electronic address: zjiao@shu.edu.cn.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Jiao
mesh_terms: D065966:Absorption, Physicochemical; D000818:Animals; D000838:Anions; D001599:Berberine / Q000737:chemistry*; D002417:Cattle; D004247:DNA / Q000737:chemistry; D003848:Deoxyguanine Nucleotides / Q000737:chemistry; D010782:Photolysis; D017319:Photosensitizing Agents / Q000737:chemistry; D011675:Pulse Radiolysis; D012996:Solutions
chemical_list: D000838:Anions; D003848:Deoxyguanine Nucleotides; D017319:Photosensitizing Agents; D012996:Solutions; D001599:Berberine; C007257:2'-deoxyguanosine 5'-phosphate; D004247:DNA; C427203:calf thymus DNA
keywords: Berberine; DNA photodamage; Laser flash photolysis; Pulse radiolysis