title: The toxicity of Callilepis laureola, a South African traditional herbal medicine.
abstract: OBJECTIVE
  To review the literature on the toxicity of Callilepis laureola, and to assess the cytotoxicity of C. laureola in human hepatoblastoma Hep G2 cells in vitro.
  
  
  METHODS
  Cells were incubated for up to 48 h in the presence of increasing concentrations of an aqueous extract of C. laureola (0.3-13.3 mg/mL). Cytotoxicity was quantitated spectrophotometrically by the metabolism of the tetrazolium dye MTT. Cytoviability of the control cells was considered to be 100%.
  
  
  RESULTS
  C. laureola produced cytotoxicity in a concentration-dependent manner. Cytotoxicity was significant at all concentrations tested (0.3-2.5 mg/mL, p < 0.05 vs. controls and 3.3-13.3 mg/mL, p < 0.0001 vs. controls). After 6 h, 100% toxicity was observed at a concentration of 6.7 mg/mL.
  
  
  CONCLUSIONS
  C. laureola causes significant cytotoxicity in Hep G2 cells in vitro. These findings are in accordance with the observed hepatotoxicity in clinical cases of C. laureola poisoning.
authors.affiliation: Division of Clinical Pharmacology, E240, Sunnybrook and Women's College Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Popat
authors.forename: N H
authors.initials: NH
authors.lastname: Shear
authors.forename: I
authors.initials: I
authors.lastname: Malkiewicz
authors.forename: M J
authors.initials: MJ
authors.lastname: Stewart
authors.forename: V
authors.initials: V
authors.lastname: Steenkamp
authors.forename: S
authors.initials: S
authors.lastname: Thomson
authors.forename: M G
authors.initials: MG
authors.lastname: Neuman
mesh_terms: D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D006801:Humans; D016488:Medicine, African Traditional; D010936:Plant Extracts / Q000506:poisoning*; D010946:Plants, Medicinal
chemical_list: D010936:Plant Extracts