Rhamnus purshiana/frangula Common name: Cascara sagrada, Buckthorn
Parts used: Bark, collected in the spring and early summer when it is easily peeled from the wood. The bark is stored for at least one year (up to 3) in order to allow for the consitituents that would otherwise cause griping to decompose. The collected bark is dried in the shade.
Constituents: Anthroquinone glycosides (up to 10%), emodin glycosides, dianthrones, free aglycones.
Medicinal actions: Laxative, bowel tonic, bitter
Medicinal use: Rhamnus is indicated in chronic constipation. It is a gentle, tonifying laxative and is therefore indicated in the elderly and pediatric populations.
Pharmacy: Powdered bark: 1 – 2.5g/dose. Liquid extract: 2-5 ml/dose. Decoction of root: 1-2 tsp/cup/dose. Tincture (1:5), 0.5-1ml/dose.
Toxicity: Fresh Rhamnus purshiana bark is emetic and cathartic.