title: [Effect of plant extracts on the in vitro dissolution of cystine stones: a study at the mesoscopic scale].
abstract: OBJECTIVE
  Assessing the efficacy to dissolve cystine stones in vitro of plant extracts used in traditional medicine to treat or prevent urolithiasis.
  
  
  METHODS
  Pure cystine stones were incubated during 8 weeks under magnetic stirring in the presence of four plant extracts or of NaCl 9 g/l solution used as control. Plants under examination were Arenaria ammophila (leaves and stems), Parietaria officinalis (leaves and flowers studied separately), Paronychia argentea (flowers). Each experiment was performed in triplicate. The mass loss of the stones and the pH of the solution were measured after each two weeks period. Possible changes in the cystine crystals at the stone surface were assessed at the mesoscopic scale using a scanning electron microscope.
  
  
  RESULTS
  None of the plant extracts has revealed a significant effect to dissolve cystine stones by comparison to the control during the time of the experiment. The best result was a mass loss of 99 mg at the end of experiment in the presence of A. ammophila vs. 43.7 mg for the NaCl solution (P=0.051). Considering the slopes of the dissolution, only that extract could have an actual efficacy on a more prolonged period.
  
  
  CONCLUSIONS
  Our study failed to demonstrate a significant effect of the tested plant extracts to dissolve cystine stones in vitro. However, the examination of the dissolution curves suggests that a more prolonged test period could allow an efficacy of some extracts, especially A. ammophila. Further studies are needed to verify such hypothesis. However, we cannot recommend the use of the tested plants to treat cystine stones in vivo.
authors.affiliation: Laboratoire de physique des solides, université Paris-XI, bâtiment 510, 91405 Orsay, France.
authors.forename: B
authors.initials: B
authors.lastname: Hannache
authors.forename: D
authors.initials: D
authors.lastname: Bazin
authors.forename: A
authors.initials: A
authors.lastname: Boutefnouchet
authors.forename: M
authors.initials: M
authors.lastname: Daudon
mesh_terms: D003553:Cystine; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D014545:Urinary Calculi / Q000188:drug therapy
chemical_list: D010936:Plant Extracts; D003553:Cystine