Research On The Extraction Of Bistort Chemical Constituents And The Antioxidative Effects Of Its Active Ingredient

Research Background and ObjectivesPolygonum bistorta L.is one of common traditional Chinese medicines.It has such functions as clearing heat,relieving convulsion,dispelling dampness,reducing swelling and easing pain.It is often used for treating various diseases such as stomatitis,pharyngitis,hepatitis,enteritis,dysentery,carbuncle,fever,fright convulsion,tetanus,dysentery with bloody stools,snakebites,and diarrhea due to damp-heat.In recent years,there have been many researches on Bistort and its extracts.Studies have shown that bistort n-butanol extract has functions such as analgesia,inhibition of the central system.Moreover,Bistort and its extracts were found to exert as a cardiovascular protective molecular,as its extracts could protect from cardiac hypertrophy of rats caused by isoprenaline,protect from myocardial ischemia reperfusion injury,resistant to experimental arrhythmia,inhibition of the autorhythmicity.In order to further study and develop bistort,we further isolated its chemical components.In this experiment,we mainly focused on the separation and purification and structural identification of bistort ethyl acetate extract,further explored the antioxidant mechanism of the active ingredient of bistort(ethyl acetate extract),and made a preliminary discussion on its antitumor effect.Methods1.Extraction,separation and identification of bistort ethyl acetylacetate500g Polygonum bistorta L was extracted with 60% aqueous ethanol(3000 mL)for 2h by reflux extraction method.The extracting solution was recycled until it had no smell of alcohol,then was extracted with water saturated ethyl acetate and n-butyl alcohol to obtain ethyl acetate extract,n-butanol extract and water-soluble extract;ethyl acetate extract was separated by silica gel column chromatography and experienced gradient elution with methylene chloride-methanol mixture(100:1-1:100).Finally,its structure was elucidated on the basis of physical properties and spectral analysis.2.Antioxygenation of Polygonum Bistorla L.ethyl acetylacetate extract.50 rats were randomly divided into normal saline solution group,solvent control group(10%DMSO),VE group(50.0mg/kg)and extract groups of 0.5,1.0 and 2.0mg/kg bistort ethyl acetate.Each group received intragastric administration for 15 consecutive days.On Day 16,all the rats were intraperitoneally injected with 10% chloral hydrate(350mg/kg,ip).The heart blood was collected to separate the serum.The activities of superoxide dismutase(SOD),lactic dehydrogenase(LDH)and creatine kinase(CK),content of malondialdehyde(MDA),and activity and total antioxidant capacity(TAOC)of glutathione peroxidase(GSH-PX)in serum were detected respectively.Results1.11 compounds were separated from Polygonum Bistorla L: β-sitosterol,Dihydromyricetin,Quercetin,Kaempferol,Epicatechin,Chlorogenic acid,Melim,Gallic acid,6-hydroxy-1,2,3,4-tetrahydronaphthalene-1-carboxylic acid,Protocatechuic acid and Ellagic acid,respectively.Dihydromyricetin,Kaempferol,6-hydroxy-1,2,3,4-tetrahydronaphthalene-1-carboxylic acid were first isolated from Polygonum Bistorla L.6-hydroxy-1,2,3,4-tetrahydronaphthalene-1-Carboxylic acid were first isolated from Polygonum.2.Antioxygenation of Polygonum Bistorla L.ethyl acetylacetate extract.Compared with the solvent control group1.0mg/kg,2.0mg/kg of bistort ethyl acetate extracts significantly improved SOD activity in serum of rats and also significantly decreased MDA content.0.5mg/kg,1.0mg/kg,2.0mg/kg of bistort ethyl acetate extracts significantly improved GSH-PX activity and TAOC in serum of rats and also significantly decreased LDH activity,CK activity(P<0.05 or P<0.01).The results suggested that bistort ethyl acetate extract had a remarkable antioxidant effect.Conclusions1.Compound 2,4 and 9 were first separated from Polygonum bistorta L,and compound 9 was extracted from Polygonum for the first time.2.Significant antioxidation was observed in bistort ethyl acetylacetate extract,which might be related to the mechanism by which bistort extract enhanced the activities of SOD and GSH-PX,increased TAOC,inhibited the activities of LDH and CK,and decreased MDA content.