Rhubarb (Rheum spp) are herbaceous perennials that are members of the Polygonaceae family. The leaves are best avoided as they are considered to be toxic due to the relatively high levels of oxalic acid.
The part of the plant traditionally used for medicinal purposes is the rhizome or root and to a lesser extent the petioles. Rhubarb is astringent and has both cathartic and laxative properties. It is thus used as a traditional treatment for constipation. In Chinese medicine it is used to treat a number of conditions such as jaundice, abdominal pain, skin afflictions and disruptions in the menstrual cycle. The compounds believed to be responsible for the laxative properties are the anthraquinones chrysophanic acid (chrysophanol) (1), emodin (2), aloe-emodin (3), rhein (4), physicon (5) and their glycosides. The plant is also known to contain stilbenoids such as rhaponticin (6), volatile oil, phenolic acids and flavonoids.
The current official herbal drug preparation containing rhubarb is Compound Rhubarb Tincture BP which is prepared from coarsely powdered dried underground parts of Rheum palmatum L. or R. officinale Baillon or of hybrids of these two species or a mixture.
Ransom Naturals produces herbal drug preparations containing Rhubarb which is RH/20 – Compound Rhubarb Tincture BP.