title: In vitro cytotoxic and pro-apoptotic effects of water extracts of Tulbaghia violacea leaves and bulbs.
abstract: BACKGROUND
  Infusions of Tulbaghia violacea (wild garlic) in water are used in traditional medicine in Southern Africa to treat numerous diseases, including cancer. Several studies have previously demonstrated the cytotoxic activities of extracts of T. violacea in cultured cancer cells. Their findings support the potential anti-cancer properties of this plant. However, these studies made use of organic solvent extraction methods, while the traditional use of the plant involves the preparation of infusions in water.
  
  
  METHODS
  In the current study, we investigated the potential anti-cancer properties of infusions of T. violacea. We also performed a comparative study investigating the cytotoxic activities of T. violacea bulbs and leaves. A panel of four cancer cell lines (HepG2, MCF7, H157, and HT29) and one non-cancerous cell line (KMST6) was treated with the two extracts and the effects of the extracts on the growth of the cells were evaluated. We also investigated whether the growth inhibitory effects were associated with the induction of apoptosis and whether the mechanism of cell death is the result of oxidative stress and the activation of caspase-3.
  
  
  RESULTS
  We found that extracts of the leaves and not the bulbs have growth inhibitory effects and that this is the result of the induction of apoptosis, which is associated with the production of Reactive Oxygen Species (ROS) and the activation of caspase-3. The leaf extract demonstrated variable selective toxicity towards the cancer lines. Although the extract also induced cell death in the non-cancerous cell line (KMST6), we found that the levels of toxicity were lower in this cell line.
  
  
  CONCLUSIONS
  this study confirms that infusions of T. violacea have potential anti-cancer activity and that this bioactivity is contained in the leaf extract. This study lends support to claims that this plant can be used to treat cancer.
authors: Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa.
authors: G M
authors: GM
authors: Saibu
authors: Tshwane University of Technology, Faculty of Science, Department of Pharmaceutical Science, Building 4, Arcadia Campus, Pretoria 001, South Africa.
authors: D R
authors: DR
authors: Katerere
authors: Agricultural Research Council, Private Bag X05, Onderstepoort, Pretoria 0110, South Africa.
authors: D J G
authors: DJ
authors: Rees
authors: Department of Biotechnology, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa. Electronic address: memeyer@uwc.ac.za.
authors: M
authors: M
authors: Meyer
mesh_terms: D000490:Allium; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D012997:Solvents; D014867:Water; D053148:Caspase 3
keywords: Apoptosis; Cancer; Caspase-3; Infusions; Reactive Oxygen Species; Tulbaghia violacea