title: Enhanced radiation damage in irradiated and non-irradiated bystander regions by co-exposure to myosmine.
abstract: It is important to evaluate the health effects of radiation concurrent exposure to chemicals in our daily life. Myosmine, an alkaloid in tobacco plants and various edibles and staple foods, has been considered as a co-genotoxic agent in vitro. In the present study, the damage induced by radiation concurrent exposure to myosmine was assessed in human primary cell line AG1522. Myosmine at 5 or 10 mM for 3 h treatment induced a significantly dose-dependent increase in micronucleus (MN) frequencies, but not for 1 mM. However, 1 mM myosmine distinctly enhanced MN frequencies in both irradiated and non-irradiated bystander regions after different doses (0.2, 1 and 10 cGy) of alpha-particle irradiation. Treatment with c-PTIO, a nitric oxide (NO) scavenger, the induced fractions of MN frequencies were dramatically inhibited both in 1 cGy alpha-particle irradiated and non-irradiated bystander regions with or without myosmine treatment. Moreover, 1mM myosmine treatment distinctly enhanced gamma-H2AX foci formation in both 1 cGy alpha-particle irradiated and non-irradiated bystander regions. These data indicated that myosmine effectively enhanced the low dose alpha-particle-induced DNA damage in both irradiated and non-irradiated bystander regions and nitric oxide played a very important role in such process.
authors.affiliation: Key Laboratory of Ion Beam Bioengineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China.
authors.forename: Erkang
authors.initials: E
authors.lastname: Jiang
authors.forename: Lingyan
authors.initials: L
authors.lastname: Zhu
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhao
authors.forename: Guoping
authors.initials: G
authors.lastname: Zhao
authors.forename: Linzhi
authors.initials: L
authors.lastname: Bao
authors.forename: Shaopeng
authors.initials: S
authors.lastname: Chen
authors.forename: Gen
authors.initials: G
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: An
authors.initials: A
authors.lastname: Xu
authors.forename: Lijun
authors.initials: L
authors.lastname: Wu
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000512:Alpha Particles; D002460:Cell Line; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000187:drug effects* / Q000528:radiation effects*; D016166:Free Radical Scavengers; D006657:Histones / Q000378:metabolism; D006801:Humans; D007120:Immunochemistry / Q000379:methods; D015162:Micronucleus Tests / Q000379:methods; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D016166:Free Radical Scavengers; C468783:H2AX protein, human; D006657:Histones; D009569:Nitric Oxide; C002398:myosmine