title: Xanthosoma sagittifolium and Laportea aestuans: species used to prevent osteoporosis in Brazilian traditional medicine.
abstract: BACKGROUND
  Xanthosoma sagittifolium Schott. (Araceae) and Laportea aestuans (L.) Chew (Urticaceae) are two medicinal species used as food and to prevent and treat bone diseases, such as osteoporosis, in traditional Brazilian medicine.
  
  
  OBJECTIVE
  To investigate the free calcium concentration and further support the traditional use of these species as medicine.
  
  
  METHODS
  L. aestuans and X. sagittifolium leaves were dehydrated and cooked to evaluate the presence of free calcium. The total oxalate content was determined by heat digestion in H(2)SO(4), oxalate precipitation with CaCl(2) and permanganate titration.
  
  
  RESULTS
  The calcium content found in L. aestuans was quite significant (638.00 mg/100 g), whereas the fresh and cooked leaves of X. sagittifolium demonstrated a low content of calcium, at 273.17 and 369.81 mg/100 g, respectively.
  
  
  CONCLUSIONS
  The use of this species for the prevention and treatment of bone diseases is in agreement with the results of the free calcium (Ca(++)) analyses. Our data show that each species may be used as a health supplement in poor communities, provided that studies validate their safe use.
authors.affiliation: Department of Botany, Federal University of Pernambuco, Recife, PE, Brazil. afmoliveira@gmail.com
authors.forename: Gisele Lopes
authors.initials: GL
authors.lastname: de Oliveira
authors.forename: Laise de
authors.initials: Ld
authors.lastname: Holanda Cavalcanti Andrade
authors.forename: Antonio Fernando
authors.initials: AF
authors.lastname: Morais de Oliveira
mesh_terms: D001938:Brazil / Q000208:ethnology; D002118:Calcium / Q000627:therapeutic use; D008519:Medicine, Traditional / Q000379:methods*; D010024:Osteoporosis / Q000208:ethnology / Q000517:prevention & control*; D010936:Plant Extracts / Q000302:isolation & purification / Q000627:therapeutic use; D018515:Plant Leaves / Q000737:chemistry*; D013045:Species Specificity; D027003:Urticaceae; D031063:Xanthosoma
chemical_list: D010936:Plant Extracts; D002118:Calcium