title: Investigation on the toxic potential of Tribulus terrestris in vitro.
abstract: BACKGROUND
  Tribulus terrestris L. (Zygophyllaceae) has been commonly used to energize, vitalize, and improve sexual function and physical performance in men.
  
  
  OBJECTIVE
  This study investigates the potential cytotoxic and genotoxic, and endocrine disrupting activities of T. terrestris in vitro.
  
  
  METHODS
  The whole T. terrestris plant was extracted with water, methanol, and chloroform. The genotoxic potential of T. terrestris extracts at 3-2400 µg/mL was assessed by Comet assay in a rat kidney cell line (NRK-52E) and by Ames assay in Salmonella typhimurium TA98 and TA100 strains. Endocrine disrupting effects of the extracts at concentrations of 0.22-25 000 µg/mL were assessed by YES/YAS assay in Saccharomyces cerevisiae. Cytotoxic activity of the extracts was determined by the MTT test in NRK-52E cells. The different exposure times were used for four tests (3-48 h).
  
  
  RESULTS
  The methanol extract of T. terrestris IC50 value was 160 µg/mL. The other extracts did not show cytotoxic effects. In the Comet and Ames genotoxicity assays, none of the extracts possessed genotoxic activities at concentrations of 0-2400 µg/mL. Only the water extract of T. terrestris induced frame shift mutations after metabolic activation. The water extract also showed estrogenic activity by YES/YAS assay in S. cerevisiae at concentrations ≥27 µg/mL (≥2.6-fold), while the other T. terrestris extracts had anti-estrogenic properties.
  
  
  CONCLUSIONS
  Tribulus terrestris had estrogenic and genotoxic activities. The study was useful in determining its toxicological effects and the precautions regarding consumption.
authors.affiliation: Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Istanbul University , Istanbul , Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Abudayyak
authors.forename: A T
authors.initials: AT
authors.lastname: Jannuzzi
authors.forename: G
authors.initials: G
authors.lastname: Özhan
authors.forename: B
authors.initials: B
authors.lastname: Alpertunga
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000302:isolation & purification / Q000633:toxicity*; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009153:Mutagens / Q000302:isolation & purification / Q000633:toxicity*; D010936:Plant Extracts / Q000302:isolation & purification / Q000633:toxicity*; D051381:Rats; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D014162:Transfection; D032444:Tribulus / Q000737:chemistry / Q000633:toxicity*
chemical_list: D052244:Endocrine Disruptors; D047628:Estrogen Receptor alpha; D009153:Mutagens; D010936:Plant Extracts; D011944:Receptors, Androgen
keywords: Cytotoxicity; endocrine disturbing; genotoxicity