Potent anti-inflammatory and analgesic steroidal alkaloids from Veratrum taliense

"Pimacao" (the roots and rhizomes of Veratrum taliense Loes.) has been used as traditional folk medicine in Yunnan province (PR China) for the treatment of pain, swelling, and inflammation. It is the main component of the renowned traditional Chinese medicine, "Yunnan Baiyao". Previous investigations and clinical research have shown significant analgesic activity of Pimacao. The aim of the present study was to find out the compounds responsible for anti-inflammatory and analgesic activity present in V. taliense. The total alkaloids were the subject of phytochemical investigation and the compounds were isolated by multiple step chromatography. Their structures were elucidated on the basis of comprehensive spectroscopic data. Anti-inflammatory activity was evaluated using carrageenan induced paw oedema and analgesic activity was assessed using acetic acid-induced writhing in mice. Three new steroidal alkaloids, veratralines A–C (1–3), together with five known analogs, were isolated from the roots and rhizomes of V. taliense. All the compounds had the analgesic activity and significantly decreased the number of writhes caused by acetic acid much better than Dolantin. All the alkaloids except 8, possessed anti-inflammatory activity, in which 3, 5, and 7 significantly inhibited the paw oedema caused by carrageenan compared with Indomethacin. This is the first report of jervine-type alkaloids responsible for the anti-inflammatory and analgesic properties of Pimacao. We provide scientific evidence to support that the roots and rhizomes of V. taliense are useful in traditional Chinese medicine for the treatment of pain and inflammation.