title: In vitro and in vivo safety of aqueous extracts of Graptopetalum paraguayense E. Walther.
abstract: BACKGROUND
  Graptopetalum paraguayense E. Walther, a widely consumed vegetable in Taiwan, has many biological effects and has been used in folk medicine to alleviate hepatic disorders, exert diuretic effects, and relieve pain and infections. However, little data exist regarding its safety.
  
  
  METHODS
  Two genotoxicity assays were performed: chromosomal aberration of Chinese hamster ovary (CHO-K1 cells) (in vitro) and micronucleus assay in mice (in vivo). Acute oral toxicity and 28-day repeated feeding toxicity tests were performed by oral gavage in Sprague-Dawley (SD) rats.
  
  
  RESULTS
  GWE did not increase micronucleus ratios in vivo, and by chromosome aberration assay, GWE was safe up to 1.2mg/ml with regard to clastogenicity. Chromatid breakage was observed at high concentrations (2.5 and 5.0mg/ml) of GWE. GWE had no acute lethal effect at the maximum dose (5g/kg bw) in rats. In the 28-day study, there were no adverse effects on body weight, feed consumption, hematology, blood biochemical parameters, organ weight, or pathology.
  
  
  CONCLUSIONS
  The acute toxicity study showed that the LD(50) of GWE was greater than the tested dose (up to 1g/kg bw) in SD rats. In the subacute toxicity study, the no observed adverse effect level (NOAEL) of GWE in rats was 1g/kg bw. The in vivo study of mammalian erythrocyte micronuclei confirmed the Ames test results, demonstrating that GWE has no mutagenicity. High doses of GWE require further examination due to its clastogenic potential.
authors.affiliation: Department of Food and Nutrition, Providence University, 200 Chungchi Road, Shalu, Taichung 433, Taiwan, ROC.
authors.forename: Yun-Chin
authors.initials: YC
authors.lastname: Chung
authors.forename: Su-Tze
authors.initials: ST
authors.lastname: Chou
authors.forename: Jyun-Kai
authors.initials: JK
authors.lastname: Jhan
authors.forename: Junn-Wang
authors.initials: JW
authors.lastname: Liao
authors.forename: Shu-Ju
authors.initials: SJ
authors.lastname: Chen
mesh_terms: D000818:Animals; D002460:Cell Line; D002842:Chromatids / Q000187:drug effects; D003257:Consumer Product Safety; D029627:Crassulaceae / Q000009:adverse effects; D006224:Cricetinae; D004912:Erythrocytes / Q000187:drug effects*; D005260:Female; D007928:Lethal Dose 50; D008297:Male; D008519:Medicine, Traditional; D051379:Mice; D008813:Mice, Inbred ICR; D048629:Micronuclei, Chromosome-Defective; D019055:No-Observed-Adverse-Effect Level; D010053:Ovary / Q000187:drug effects*; D010936:Plant Extracts / Q000009:adverse effects / Q000494:pharmacology*; D018515:Plant Leaves; D017207:Rats, Sprague-Dawley; D013624:Taiwan; D018675:Toxicity Tests
chemical_list: D010936:Plant Extracts