title: Effect of curcumin on human colon cancer multidrug resistance in vitro and in vivo.
abstract: OBJECTIVE
  To determine whether curcumin reverses the multidrug resistance of human colon cancer cells in vitro and in vivo.
  
  
  METHODS
  In a vincristine-resistant cell line of human colon cancer, the cell viability of curcumin-treated cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Rhodamine123 efflux was evaluated to detect P-glycoprotein transporter activity, and expression of the multidrug resistance protein 1 and survivin genes was analyzed by reverse transcription polymerase chain reaction and western blotting. In addition, xenograft mouse tumors were grown and treated with curcumin. The morphology of the xenografts was investigated by hematoxylin-eosin staining. The in vivo expression of the multidrug resistance gene and P-glycoprotein and survivin genes and proteins was observed using reverse transcription-polymerase chain reaction and western blotting, respectively.
  
  
  RESULTS
  Curcumin was not obviously toxic to the vincristine-resistant human colon cancer cells at concentrations less than 25 μM, but the growth of cells was significantly inhibited. At concentrations greater than 25 μM, curcumin was toxic in a concentration-dependent manner. The sensitivity of cells to vincristine, cisplatin, fluorouracil, and hydroxycamptothecin was enhanced, intracellular Rhodamine123 accumulation was increased (p<0.05), and the expression of the multidrug resistance gene and P-glycoprotein were significantly suppressed (p<0.05). The combination of curcumin and vincristine significantly inhibited xenograft growth. The expression of the multidrug resistance protein 1 and survivin genes was significantly reduced in xenografts of curcumin-treated mice and mice treated with both curcumin and vincristine relative to control mice.
  
  
  CONCLUSIONS
  Curcumin has strong reversal effects on the multidrug resistance of human colon carcinoma in vitro and in vivo.
authors.affiliation: Chongqing Medical University, Department of Gastrointestinal Surgery, First Affiliated Hospital, Chongqing 400016, Chongqing, China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Lu
authors.forename: Yong
authors.initials: Y
authors.lastname: Qin
authors.forename: Chuang
authors.initials: C
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Zhong-Xue
authors.initials: ZX
authors.lastname: Fu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D003474:Curcumin / Q000494:pharmacology*; D018432:Drug Resistance, Multiple / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D003474:Curcumin