Study On Anti-inflammatory Activity Of Flavonoids From Extracitons Of Ledum Palustre L.

Ledum plasture L.(Ericaceae), also named by Bai Shan Tai in China, is an evergreen shrub, which is widely distributed in the Great Khingan, Inner Mongolia and Changbai Mountains. Their extractive essential oil has been widely applied in many aspects of daily life, chemical industry and environment protecting, in addition, it was also reported that the extractions of its secondary metabolites are proved to be as effective as an antioxidant with anti-genetic-damage functionality. Our previous researches found that the methanol extract of Ledum plasture L. has an anti-inflammatory effect and is high in flavonoids content.Therefore, in this study, after the preparation of FEL (flavonoids from extractions of Ledum palustre L.), a specific color reaction technique of detecting flavonoids, including hydrochloric acid-magnesium powders, sodium borohydride, complexation with aluminum and lead salts, are carried out to indentify FEL. And then the UV-visible light scanning, high performance liquid chromatography investigation suggested that the myricein and quercetin were contained in the FEL by2hours hydrolyzing, while rutin can be found without hydrolysis. Finally, comparing Rutin as the control group, the total flavonoids in FEL were computed with the outcome equaled to (66.90±1.38)%.For the purpose of exploring the biological activities of FEL, an acute toxicity test to evaluate the security of FEL was firstly implemented in this study. And then the ICR mice were administered with FEL by the dosages on6.86g/kg,9.80g/kg,14.00g/kg and20.00g/kg respectively during a two-week observation period. The results showed that FEL has digestive and neuron system toxicities on mice and its LD50is17.61g/kg. According to the toxicity grading standards, FEL is on the non-toxic level, while overdose of FEL may cause some negative impact.In addition to our previous researches, further study on the anti-inflammatory effects of FEL was introduced to three individual inflammatory animal models. It has been indicated that FEL can significantly inhibit the potential increasing permeability on peritoneal vascular induced by acetic acid:100mg/kg FEL can reduce the exudation of Evan's blue by54.59%;200mg/kg FEL can relieve the degree of mice auricle edema induced by dimethylbenzene and the rate reached at30.27%. This indicated that FEL has a certain regulating effect on hemangiectasis and capillary permeability during the early period of inflammation. In carrageenan-induced air sacculitis model,100mg/kg FEL reduce NO content in serum and also reduce the total protein content from the lavage fluid of air sacculitis. In addition, high doses of FEL can significantly improve SOD activity and decrease MDA content in serum and liver. The results suggested that the FEL may play an anti-inflammatory effects by relieving the oxidative damage of cells in inflammation lesions.To sum up, the study suggested that the FEL has a good anti-inflammatory activity and enrich the medicinal value of Ledum plasture L. These results can be treated as a valuable research reference on Ledum plasture L. for its further development and utilization.