title: Synergistic Effect of Curcumin in Combination with Anticancer Agents in Human Retinoblastoma Cancer Cell Lines.
abstract: OBJECTIVE
  Curcumin (diferuloylmethane), a phenolic compound obtained from the rhizome of the herb Curcuma longa, is known to have anti-proliferative and anti-tumor properties. In this study, we evaluated the cytotoxic effect of curcumin alone and in combination with individual drugs like carboplatin, etoposide, or vincristine in a human retinoblastoma (RB) cancer cell line.
  
  
  METHODS
  A drug-drug interaction was analyzed using the median effect/isobologram method and combination index values were used to characterize the interaction as synergistic or additive. We also performed the apoptosis and cell-cycle kinetics study with single drugs in combination with curcumin in a human RB cell lines (Y79 and Weri-Rb1).
  
  
  RESULTS
  Curcumin caused concentration-dependent decrease in cell proliferation, cell kinetics, and also induced apoptosis in both the RB cell lines. When combination of curcumin with individual drugs like carboplatin or etoposide or vincristine was treated on to RB cells, both cell viability and cell cycling were reduced and increased apoptosis was noted, in comparison with single drug treatment. These effects were significant in both the cell lines, indicating the ability of curcumin to increase the sensitivity of RB cells to chemotherapy drugs.
  
  
  CONCLUSIONS
  Our in vitro findings showed that the combination of curcumin with single drug treatment showed marked synergistic inhibitory effect against RB cell lines. These results suggest that curcumin can be used as a modulator which may have a potential therapeutic value for the treatment of RB cancer patients.
authors.affiliation: a L&T Department of Ocular Pathology , Vision Research Foundation , Sankara Nethralaya, Nungambakkam , Chennai , Tamil Nadu , India and.|b Birla Institute of Technology & Science (BITS) Scholar , Pilani , Rajasthan , India.
authors.forename: Seethalakshmi
authors.initials: S
authors.lastname: Sreenivasan
authors.affiliation: a L&T Department of Ocular Pathology , Vision Research Foundation , Sankara Nethralaya, Nungambakkam , Chennai , Tamil Nadu , India and.
authors.forename: Subramanian
authors.initials: S
authors.lastname: Krishnakumar
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D016190:Carboplatin / Q000008:administration & dosage; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D003474:Curcumin / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005047:Etoposide / Q000008:administration & dosage; D006801:Humans; D019572:Retinal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D012175:Retinoblastoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D017304:Annexin A5; D014750:Vincristine; D005047:Etoposide; D016190:Carboplatin; D053148:Caspase 3; D003474:Curcumin
keywords: Additive; chemotherapy drugs; combination index; curcumin; isobologram; retinoblastoma; synergistic