title: Cytotoxicity of three South African medicinal plants using the Chang liver cell line.
abstract: BACKGROUND
  Arctotis arctotoides, Gasteria bicolor and Pittosporum viridiflorum are commonly used in the Eastern Cape, South Africa by traditional healers for the treatment of opportunistic fungal infections in HIV/AIDS patients. Unfortunately, there is a dearth of published data regarding the toxicity of the selected plants, despite the fact that experimental screening of toxicity is crucial to guarantee the safety of the users.
  
  
  METHODS
  Therefore, it was decided to evaluate the cytotoxicity of the hexane and acetone extracts of the medicinal plants against the Chang Liver cell line using the in vitro MTT assay. Different concentrations of the extracts were added into 24-hour cultured cells and incubated for 72 hours under specific condition (37 °C, 5% CO2). Cell survival was evaluated using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay.
  
  
  RESULTS
  Depending on the dosage and duration of treatment, the cytotoxic effects of Gasteria bicolor and Pittosporum viridiflorum were considered relatively weak (but not entirely absent) and less of a toxicity risk. Arctotis arctotoides extracts were the most toxic both in terms of IC50 values as well as the steeper slope of the dose response curve. The IC50 values for the acetone and hexane extracts of this plant were 17.4 and 12.4 µg/ml respectively.
  
  
  CONCLUSIONS
  These relatively low values raise concern for potential hepatotoxic effects and deserve further investigation or at least a warning to potential users.
authors.affiliation: Department of Botany, Faculty of Science and Agriculture, University of Fort Hare, South Africa; E-Mail: wilfredotang5@yahoo.com.
authors.forename: Wilfred Mbeng
authors.initials: WM
authors.lastname: Otang
authors.affiliation: Department of Botany, Faculty of Science and Agriculture, University of Fort Hare, South Africa; E-Mail: wilfredotang5@yahoo.com.
authors.forename: Donald Scott
authors.initials: DS
authors.lastname: Grierson
authors.affiliation: Department of Biochemistry and Microbiology, Faculty of Science and Agriculture, University of Fort Hare, P/Bag X1314, Alice 5700, South Africa, E-Mail: RNdip@ufh.ac.za ; Department of Biochemistry and Microbiology, Faculty of Science, University of Buea, Cameroon.
authors.forename: Roland Ndip
authors.initials: RN
authors.lastname: Ndip
mesh_terms: D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008099:Liver / Q000187:drug effects; D010936:Plant Extracts / Q000633:toxicity*; D010946:Plants, Medicinal / Q000737:chemistry*; D013019:South Africa
chemical_list: D010936:Plant Extracts
keywords: Chang liver cell line; Cytotoxicity; medicinal plants; opportunistic fungal infections