Effective Components. Northeast The Guanzhong Anti H1n1 Subtype Swine Influenza Virus Research

Dongbeiguanzhong, a perennial evergreen herb recorded in the "Shen Nong's Herbal", is dry roots and petioles of Dryopteris (Dryopteris crassirhizoma Nakai). It distributes widely in China especially in Heilongjiang province. Dongbeiguanzhong has become the focus of research at home and abroad, because of its low toxicity and important role in improving uterine smooth muscle and in anti-tumor.In recent years, detailed studies of the morphology, reproductive methods, identification, and pharmacological activity about Dongbeiguanzhong have been reported. But there are few studies of its anti-viral activity and no report on its activity components of the anti-H1N1 subtype swine influenza virus. In order to determine its anti-H1N1 subtype swine influenza activity, 30% and 60% ethanol extracts from Dongbeiguangzhong at safe concentration screened in MDCK cells by MTT method were studied. At the safe concentration, the protection rates of different components for MDCK cell pathologically changed by H1N1 subtype swine influenza virus were determined by cytopathic effect inhibition method, which reflects its anti viral activity in vitro. The results showed that the anti H1N1 subtype swine influenza activity of 60% ethanol fraction which shown related to the concentration was significant while that of the 30% ethanol fraction non significant. Therefore, 60% ethanol component was determined as the main active site of anti H1N1 subtype swine influenza virus.The 60% extract components of Dongbeiguanzhong were isolated by the silica gel column, ODS column, HPLC and so on. Structures of five compounds had been determined by ¹H-NMR, ¹³C-NMR spectroscopy and other methods. They are epicatechin,(Z)-3,5,5-trimethyl-4-(3(3,4,5-trihydroxy-6-(hydroxymethyl)-tetrahydro-2H-pyran-2-yloxy) butylidene ) cyclohex-2-enone,β-rhamno, p-Cumaric acid and catechin.Anti H1N1 subtype swine influenza activity in vitro of picatechin with maximum content in the five compounds was conducted by cytopathic effect inhibition method and MTT colorimetric method. The results showed that epicatechin had significant anti H1N1 subtype swine influenza activity while its protection rate for MDCK cells pathologically induced by H1N1 subtype swine influenza virus as high as 52%. By anti-H1N1 subtype swine influenza active ingredients'screening, active chemical components'isolating and identification, and determination of the activity of mono chemical epicatechin, the anti-viral activity of traditional Chinese medicine Dongbeiguanzhong was further revealed, which provided some important scientific evidence for the research and development of new anti-viral drugs.