Review on “Long-Dan”, one of the traditional Chinese medicinal herbs recorded in Chinese pharmacopoeia

“Long-Dan” is an important traditional Chinese medicinal (TCM) herb used widely for the treatment of inflammation, hepatitis, rheumatism, cholecystitis, and tuberculosis. In the Chinese Pharmacopoeia, the roots and rhizomes of four species from the genus Gentiana (Gentianaceae) are recorded as the original materials of “Long-Dan”, called Gentianae Radix et Rhizoma. The species included G. manshurica, G. scabra, G. triflora and G. rigescens, which are distributed in different areas of China. Though iridoid and secoiridoid glucosides were reported as the main constituents in “Long-Dan”, these four different species also resulted in different minor components, which may related to their pharmacological activities. Herein, we summarized the herbal textual study, distribution, chemical constituents, biological investigation and quality control of the recorded “Long-Dan” origins in Chinese Pharmacopoeia during the period 1960 to 2011.