Contains at least 3% tannins, consisting of ellagitannins and proanthocyanidins (approximately 8:2). The most significant ellagitannins include castalagin, roburins A–E, vescalin, vescalagin; for proanthocyanidins, B-type dimers are present. The drug also contains triterpenes such as friedelin, friedelinol, and 3-friedelanol.
Because of its astringent effect, it is used to alleviate symptoms of hemorrhoids, as an anti-diarrheal for mild diarrhea, and for mild inflammations of the oral cavity and skin.
This is the cut, dried bark of young branches with a smooth, light gray to greenish outer surface and a slightly longitudinally striated, light brown to pinkish inner surface. The fracture is splintery and coarsely fibrous.
The drug is listed in the pharmacopoeia.
In pulverized drug under the microscope we can see:
Flat cork cells with brownish to reddish contents
Parenchyma with clusters of calcium oxalate druses, usually arranged in vertical rows
Phloem fibers accompanied by chambered fibers with oxalate crystals
Clusters of sclereids with or without tannin (orange interior)
