Characterisation of an extract from the leaves of Cissampelos sympodials Eichl. on the spontaneous tone of isolated trachea

G Thomas, F Burns, Susan Pyne, Nigel Pyne

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An aqueous fraction of the ethanol extract of the leaves (AFL) of Cissampelos sympodialis Eichl. (Menispermaceae) was shown to relax the spontaneous tone of guinea-pig tracheal smooth muscle rings with an IC50 of 20.5 μg/mL. The AFL inhibited cyclic nucleotide phosphodiesterase activity in isolated smooth muscle homogenates and stimulated an increase in intracellular cAMP synthesis in intact cultured smooth muscle cells. A complete inhibition of phosphodiesterase activity in isolated homogenates was almost achieved. These studies indicate that the AFL contains a substance which is a non-selective, but highly potent inhibitor of phosphodiesterase activity. This probably accounts for its effect on the spontaneous tone of guinea-pig tracheal smooth muscle.
Original languageEnglish
Pages (from-to)496-499
Number of pages4
JournalPhytotherapy Research
Publication statusPublished - 1997


  • phosphodiesterases
  • cAMP
  • cGMP
  • cissampelos sympodialis Eichl

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