Phytochemical Analysis Of Extractions From Ledum Palustre L. And Their Anti-inflammatory, Analgesic Activities

Ledum palustre L.vat.plustre(Ericaceae),known locally as Baishan Cha(in Chinese language:tea of Changbai) is widespread in the forests of Changbai Mountain and Great Khingan area of northeast China,and its decocta is effective to alleviate symptoms of tussis and asthma,while its essential oil is used to treat gastric ulcer and irregular menstruation in the local pharmacopoeia.In this study,we analysed the phytochemical constituents of Ledum palustre L.var. palustre by solvent polarity.According to a spectrograph results,it totally contains 119.0±13.7 g flavonoids per kilogram raw materials.High Performance Liquid Chromatography investigation showed that at least four flavonoids contain in the methanol extraction of leaves:rutin,myricetin,quercetin and kaempferol.Through a meticulous Gas Chromatography-Mass Spectrometry investigation of essential oil of Ledum palustre L.var.palustre,extracted by wet distillation,we confirmed 55 constituents by searching NIST2002 MS librabry,while in that of its variety Ledum palustre L.var.dilatatum Wahl.,we determined 49 constituents.The major constituents of essential oil from Ledum palustre L.var.palustre are:p-Cymene (26.54%),8-Hydroxy-p-cymene(3.41%),Cyclohexanol,1-ethenyl-(3.14%),et al., while that from Ledum palustre L.var.dilatatum are:p-Cymene(23.97%), 4-Terpineol(7.28%),Cyclohexanol,1-ethenyl-(2.42%),beta-Terpinene(1.50%), (+)-4-Carene(1.43%),et al..All the constituents can be classified by their chemical properties into 7 catagories:hydrocarbons,alcohols,esters,aldehydes,phenols,epoxy compounds,and peroxides;and be classified by their main carbon skeletons into 5 catagories.The constituents and contents of essential oil show varieties due to the differences in growing environments,climates,plucking timings and extracting methods of plants.However,the main carbon skeletons are constant.Since the essential oils from Ledum palustre L.are valuable pharmaceutically and commercially,and flavonoids of Ledum palustre L.have potential anti-inflammatory and analgesic activities,we set up an extracting flow of both natural products in one system.The flow is conjuncted by 3 major processes:wet distillation of essetial oil, extraction of raw flavonoids by hot ethanol,and purification of the flavonoids by macroporous resin chromatography.We have also investigated the analgesic effect of the essential oil,methanol extract and aqueous extract of Ledum palustre L.palustre by using model of acetic acid-induced writhing response and anti-inflammatory effect of these three extracts by using model of lambda-carrageenan-induced paw adema in mice.In the analgesic test, methanol extract(10.0 and 1.0 mg/kg) and aqueous extract(10.0 mg/kg) decreased the acetic acid-induced writhing response.In anti-inflammatory test,methanol extract (10.0 and 1.0 mg/kg) and aqueous extract(10.0 mg/kg) decreased the paw edema at the second,third,fourth,fifth,and sixth hour after lambda-carrageenan administration. High performance liquid chromatography result suggested that the analgesic and anti-inflammatory effects of methanol extract might be related to its flavonoid components.