title: In vitro enhancement of doxorubicin genotoxic activities and interference with cell cycle delay by Plumbago indica root ethanolic extract in human lymphocytes.
abstract: BACKGROUND
  Combinations of modern medicines with herbal medicines are being developedfor more effectiveness. Data on the safety and drug-herb interactions are needed to be clarified. Ethanolic extract of Plumbago indica root (EEPIR) is medicinally usedfor cancer treatment in Asian traditional medicine. However its mechanism of action is still inconclusive. Our previous study demonstrated that EEPIR was genotoxic and induced cell cycle delay in human lymphocytes in vitro.
  
  
  OBJECTIVE
  To investigate genotoxic potency and interference with cell cycle of EEPIR in combination with doxorubicin (DXR), a standard chemotherapeutic agent, in human lymphocytes by in vitro sister chromatid exchange (SCE) assay.
  
  
  METHODS
  Human lymphocytes were pretreated with EEPIR at 6.25-100 mcg/mlfollowed by DXR (0.1 mcg/ml). SCE levels and cell cycle kinetics were evaluated.
  
  
  RESULTS
  EEPIR pretreatments (6.5-50 mcg/ml) significantly enhanced genetic damage induced by DXR (p<0. 05). Delaying of the cell cycle was detected and related to EEPIR concentration. EEPIR at 100 mcg/ml, on the contrary, did not enhance DXR-induced genotoxicity but tended to lower genotoxicity compared to DXR treatment alone. It significantly delayed cell cycle the most (p<0.05).
  
  
  CONCLUSIONS
  EEPIR pretreatments at proper doses enhanced genotoxic damage induced by DXR in human lymphocytes. Delaying cell cycle by EEPIR could lower that potency. Usage of EEPIR, therefore, should be adjusted for safety. Combination of EEPIR with DXR might be usefulfor more efficient cancer treatment with less DXR toxicity. Further in vivo study is needed to support this in vitro evidence.
authors.forename: Treetip
authors.initials: T
authors.lastname: Ratanavalachai
authors.forename: Sumon
authors.initials: S
authors.lastname: Thitiorul
authors.forename: Sermkiat
authors.initials: S
authors.lastname: Tanuchit
authors.forename: Arunporn
authors.initials: A
authors.lastname: Itharat
authors.forename: Intouch
authors.initials: I
authors.lastname: Sakpakdeejaroen
mesh_terms: D002453:Cell Cycle / Q000187:drug effects*; D002478:Cells, Cultured; D004317:Doxorubicin / Q000633:toxicity*; D004357:Drug Synergism; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects*; D009152:Mutagenicity Tests; D010936:Plant Extracts / Q000633:toxicity*; D018517:Plant Roots / Q000737:chemistry; D029606:Plumbaginaceae / Q000737:chemistry*; D012854:Sister Chromatid Exchange / Q000187:drug effects*
chemical_list: D010936:Plant Extracts; D004317:Doxorubicin