title: Berberine potentizes apoptosis induced by X-rays irradiation probably through modulation of gap junctions.
abstract: BACKGROUND
  Clinical combination of some traditional Chinese medical herbs, including berberine, with irradiation is demonstrated to improve efficacy of tumor radiotherapy, yet the mechanisms for such effect remain largely unknown. The present study investigated the effect of berberine on apoptosis induced by X-rays irradiation and the relation between this effect and gap junction intercellular communication (GJIC).
  
  
  METHODS
  The role of gap junctions in the modulation of X-rays irradiation-induced apoptosis was explored by manipulation of connexin (Cx) expression, and gap junction function, using oleamide, a GJIC inhibitor, and berberine.
  
  
  RESULTS
  In transfected HeLa cells, Cx32 expression increased apoptosis induced by X-rays irradiation, while inhibition of gap junction by oleamide reduced the irradiation responses, indicating the dependence of X-rays irradiation-induced apoptosis on GJIC. Berberine, at the concentrations without cytotoxicity, enhanced apoptosis induced by irradiation only in the presence of functional gap junctions.
  
  
  CONCLUSIONS
  These results suggest that berberine potentizes cell apoptosis induced by X-rays irradiation, probably through enhancement of gap junction activity.
authors.affiliation: Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.forename: Dong-dong
authors.initials: DD
authors.lastname: Yuan
authors.forename: Xiao-ting
authors.initials: XT
authors.lastname: Hong
authors.forename: Liang
authors.initials: L
authors.lastname: Tao
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001599:Berberine / Q000494:pharmacology*; D017629:Gap Junctions / Q000187:drug effects* / Q000378:metabolism* / Q000528:radiation effects; D006367:HeLa Cells; D006801:Humans; D009829:Oleic Acids / Q000494:pharmacology; D014965:X-Rays
chemical_list: D009829:Oleic Acids; D001599:Berberine; C029407:oleylamide