title: Antimalarial activity of plumbagin in vitro and in animal models.
abstract: BACKGROUND
  Plumbagin is the major active constituent in several plants including Plumbago indica Linn. (root). This compound has been shown to exhibit a wide spectrum of biological and pharmacological activities. The present study aimed to evaluate the in vitro and in vivo antimalarial activity of plumbagin including its acute and subacute toxicity in mice.
  
  
  METHODS
  In vitro antimalarial activity of plumbagin against K1 and 3D7 Plasmodium falciparum clones were assessed using SYBR Green I based assay. In vivo antimalarial activity was investigated in Plasmodium berghei-infected mouse model (a 4-day suppressive test).
  
  
  RESULTS
  Plumbagin exhibited promising antimalarial activity with in vitro IC50 (concentration that inhibits parasite growth to 50%) against 3D7 chloroquine-sensitive P. falciparum and K1 chloroquine-resistant P. falciparum clones of 580 (270-640) and 370 (270-490) nM, respectively. Toxicity testing indicated relatively low toxicity at the dose levels up to 100 (single oral dose) and 25 (daily doses for 14 days) mg/kg body weight for acute and subacute toxicity, respectively. Chloroquine exhibited the most potent antimalarial activity in mice infected with P. berghei ANKA strain with respect to its activity on the reduction of parasitaemia on day 4 and the prolongation of survival time.
  
  
  CONCLUSIONS
  Plumbagin at the dose of 25 mg/kg body weight given for 4 days was safe and produced weak antimalarial activity. Chemical derivatization of the parent compound or preparation of modified formulation is required to improve its systemic bioavailability.
authors.forename: Wiriyaporn
authors.initials: W
authors.lastname: Sumsakul
authors.forename: Tullayakorn
authors.initials: T
authors.lastname: Plengsuriyakarn
authors.forename: Wanna
authors.initials: W
authors.lastname: Chaijaroenkul
authors.forename: Vithoon
authors.initials: V
authors.lastname: Viyanant
authors.forename: Juntra
authors.initials: J
authors.lastname: Karbwang
authors.affiliation: Chulabhorn International College of Medicine, Thammasat University (Rangsit Campus), Pathumtani 12121, Thailand. kesaratmu@yahoo.com.
authors.forename: Kesara
authors.initials: K
authors.lastname: Na-Bangchang
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D001682:Biological Availability; D001835:Body Weight / Q000187:drug effects; D002738:Chloroquine / Q000494:pharmacology; D004195:Disease Models, Animal; D005260:Female; D066298:In Vitro Techniques; D008288:Malaria / Q000188:drug therapy / Q000469:parasitology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009285:Naphthoquinones / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity; D010962:Plasmodium berghei / Q000187:drug effects*; D010963:Plasmodium falciparum / Q000187:drug effects*; D018675:Toxicity Tests
chemical_list: D000962:Antimalarials; D009285:Naphthoquinones; D002738:Chloroquine; C014758:plumbagin