Gentianae radix

Abstract

Gentian root (Gentianae radix) consists of the dried rhizomes and roots of Gentiana lutea L. (Gentianaceae). It occurs as single or branched subcylindrical pieces of various lengths and usually 10-40 mm in thickness. The smooth, transversely cut surface shows a bark, occupying about one-third of the radius, separated by the well-marked cambium from an indistinctly radiate and parenchymatous xylem. Powdered gentian roots show specific diagnostic characters, namely fragments of the subero-phellodermic layer, cortical and ligneous parenchymatous cells, and lignified vessels. The raw material contains gentiopicroside (also known as gentiopicrin), swertiamarin and sweroside, and a very small amount of amarogentin, which causes the bitter taste. Also present are xanthones (gentisin, isogentisin, gentioside), phytosterols, phenolic acid, trisaccharides (gentianose), polysaccharides (pectin), and essential oil. The bitterness of the raw material stimulates secretions in the gastrointestinal tract, especially of gastric juice. Traditionally, Gentianae radix is used to increase the appetite during recovery from acute atonic dyspepsia. Its antihepatotoxic, adaptogenic, and anti-inflammatory activities are also postulated from many experiments. Possible effects on the central nervous system of Gentianae radix have been investigated such as antidepressant and analgesic activities in mice. Extract of G. lutea showed radioprotective activity, probably due to its antioxidant activity.