| abstract |
Fractions extracted from the rhyzomes or leaves of various ferns, in particular Dryopteris crassirhizoma, Polypodium vulgare, Linn, Polypodium leucotomos, Phelbodium Decumanun J. Smith, Polypodium decumanun, Cyathea taiwaniana, or rhyzomes of Polypodium aureum Linn or Polypodium triseriales, are effective in treatment of psoriasis. The fraction is extracted in a polar solvent by partitioning an extract between a polar solvent and a non-polar solvent e.g. water and n-hexane. Further purification of the fraction may occur e.g. by passing through an interchange column, neutralising with calcium hydroxide and recrystallising. |