title: In vivo and in vitro hemostatic activity of Chromolaena odorata leaf extract.
abstract: BACKGROUND
  Chromolaena odorata (L.) R.M.King & H.Rob. (Asteraceae) or Siam weed has long been used to stop bleeding in Thailand and many countries. Only the aqueous leaf extract was investigated in in vivo and there have been conflicting results of in vitro hemostatic mechanisms of this plant.
  
  
  OBJECTIVE
  The most appropriate C. odorata leaf extract that promoted the highest hemostatic activity and the hemostatic mechanisms of these plant extracts will be investigated.
  
  
  METHODS
  The lyophilized aqueous leaf extract and alcoholic (50, 70, and 95% ethanol) extracts from the fresh and dried leaves were investigated both in vivo and in vitro. The bleeding time in male Wistar rats was measured to investigate the hemostatic effect. The hemostatic mechanisms were tested using in vitro platelet aggregation and blood coagulation tests in sheep plasma.
  
  
  RESULTS
  All extracts displayed significantly reducing bleeding time (<2.5 min) in rats but did not induce platelet aggregation or blood clotting in the in vitro study. The in vitro blood clotting times of all extracts were >0.6 min. Ethanol extract (70%) from the dried leaves proved to be the extract producing the highest hemostatic activity in vivo with the bleeding time of 1.85 min.
  
  
  CONCLUSIONS
  The in vivo study with rats confirmed the significant ability of this plant extract to stop bleeding. However, the sufficient amount of calcium and active compounds which are aggregating and clotting agents to enhance blood coagulation and platelet aggregation in in vitro tests should be further studied.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudthaya Road, Ratchathevi, Bangkok, Thailand.
authors.forename: Hataichanok
authors.initials: H
authors.lastname: Pandith
authors.forename: Suchitra
authors.initials: S
authors.lastname: Thongpraditchote
authors.forename: Yuvadee
authors.initials: Y
authors.lastname: Wongkrajang
authors.forename: Wandee
authors.initials: W
authors.lastname: Gritsanapan
mesh_terms: D000287:Administration, Topical; D000818:Animals; D001760:Bleeding Time; D001777:Blood Coagulation / Q000187:drug effects; D036604:Chromolaena / Q000737:chemistry*; D020834:Ethnopharmacology; D006470:Hemorrhage / Q000188:drug therapy*; D006490:Hemostatics / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D010314:Partial Thromboplastin Time; D010936:Plant Extracts / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves / Q000737:chemistry*; D010974:Platelet Aggregation / Q000187:drug effects; D011517:Prothrombin Time; D051381:Rats; D017208:Rats, Wistar; D034561:Sheep, Domestic; D012867:Skin / Q000098:blood supply / Q000187:drug effects / Q000293:injuries; D040521:Subcutaneous Tissue / Q000098:blood supply / Q000187:drug effects / Q000293:injuries; D013785:Thailand
chemical_list: D006490:Hemostatics; D010936:Plant Extracts