Study On High Voltage Pulsed Electric Field Extraction Technology And Pharmacological Activity Of Lignans From The Stems Of Schisandra Chinensis

The Schisandra chinensis is the dried ripe fruit of Magnoliaceae plant Schisandra chinensis(Turcz.)Baill.Studies showed that S.chinensis contains lignans,terpenoids,polysaccharides and other chemical constituents,in which lignan components with basic skeleton of biphenyl cyclooctadiene are the main active ingredient.As we know,S.chinensis is a perennial vine.In order to increase the yield and quality of the fruits,about 30-40% stems of S.chinensis were pruned every year.In China,the utilization of the stems is limited.In addition to use as mountain pepper,it is rarely used and is considered as the waste of during the procession of the S.?chinensis.The stems and fruit of S.chinensis both contain lignans,but too much oil in the fruit makes it difficult to extract lignans,the stems of S.chinensis could be used to replace the fruit for industrial production of lignans,which could expand the medicinal resources of S.chinensis.Thus,in this thesis,the extraction process of the stems of S.chinensis and pharmacological effect and molecular mechanism of extract of the stems of S.chinensis in acetaminophen(APAP)-induced liver injury and high-fat diet(HFD)-induced obesity in mice were further studied,which was meaningfulfor the development of S.chinensis as health products and clinical therapeutic drugs.High-voltage pulsed electric field(PEF)was used to study the extraction process of lignans in the stems of S.chinensis.The ratio of material to liquid,the electric field intensity and pulse number as the dependent variable,and Schisandrol A,Schisandrol B,Deoxyschisandrin,Schisandrin B yield of four lignans content were the investigation index.Four kinds of lignans in the stems of S.chinensis on high voltage pulsed electric field rapid extraction process were optimized by 3 factor 3 level response surface methology(RSM)on the basis of single factor experiment results.The results showed that the yield is 2.28% with the optimum extraction conditions of 80% ethanol extraction solution,25 kV/cm electric field strength,8 pulse number,and 1:30 g/mL solid-liquid ratio.The extraction process is fast,economical,time-saving,and suitable for process production.As previous studies reported,the stems of S.chinensis containing lignans,polysaccharide,etc.,with hepatoprotective,anti-cancer,anti-obesity and other activities.To expand the medicinal parts of S.chinensis,it is necessary to conduct in-depth research on the chemical constituents and pharmacological activities of S.chinensis.These works could provide necessary theoretical references for future industrial development of S.chinensis.APAP is a common antipyretic and analgesic.It is safe at a therapeutic dose,but APAP overdoses cause severe liver damage and liver failure.The present study was designed to evaluate protective activity of an ethanol extract of the stems of Schisandra chinensis(SCE)and its possible molecular mechanisms on APAP-induced hepatotoxicity in a mouse model.The results showed that SCE pretreatment for 7 consecutive days significantly ameliorated liver dysfunction and oxidative stress,was evidenced by significant decreases in aspartate transaminase(AST),alanine aminotransferase(ALT),malondialdehyde(MDA)content and elevations in reduced glutathione(GSH)and superoxide dismutase(SOD)levels.As the same time,SCE inhibited the final product of lipid peroxidation the production of 4-hydroxynonenal(4-HNE),and reduce the final nitration product the levels of 3-nitrotyrosine(3-NT).Furthermore,SCE management also significantly decreased the proteins expression levels of pro-apoptotic Bax,and Cleaved Caspase-3 by APAP.Pretreatment with SCE reduced the overexpression of nitric oxide synthase(iNOS)and cyclooxygenase-2(COX-2).In summary,the findings from the present work clearly demonstrated that SCE exerted significant alleviation in APAP-induced oxidative stress,inflammation and apoptosis.In addition,about the liver injury protective activity and renal protection activity of the lignans have been reported.But the lignans of S.chinensis whether improve high fat diet induced fat accumulation of pharmacological effects is not clear.We further explore the effect of extract from the stems of Schisandra chinensis(SCE)on HFD induced obesity in mice.The model of HFD induced obese model of C57BL/6J mice for 8 weeks was established.The contents of serum aspartate aminotransferase(AST),alanine aminotransferase(ALT),triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein cholesterol(LDL-C),high density lipoprotein cholesterol(HDL-C)and hepatic triglyceride(TG),total cholesterol(T-CHO),glutathione(GSH)and malondialdehyde(MDA)was measured.The pathological changes with H&E staining and oil red O was observed for investigating the effect of SCE in the obese mice.In addition,the assay of CYP2E1,4-HNE using immunofluorescence staining and the expression of iNOS and COX-2 protein with western blot analyzing was measured to explore the effect of SCE on lipid peroxidation and inflammatory response.Compared with the HFD group,low and high dose groups of SCE significantly reduced the serum AST,ALT,TG,T-CHO,LDL-C and hepatic TG,TC and MDA levels,elevated the serum HDL-C and hepatic GSH levels and improved liver tissue steatosis,inflammatory infiltration and accumulation of lipid droplets,oxidative stress and inflammatory response.In summary,SCE may improve lipid metabolism in HFD induced obese mice by inhibiting oxidative stress and inflammatory response.In summary,this study shows that: PEF extraction lignans of the stems from S.chinensis is fast,economic,time-saving,suitable for the production process;SCE has a protective effect on acute liver injury induced by APAP and its mechanism by improving oxidative stress,reduce inflammation and anti-apoptosis.SCE has protective effect on HFD induced obese mice,SCE may through the lipid metabolism inhibition of oxidative stress and inflammation in obese mice induced by improved HFD,it provides a theoretical reference for the development of lipid lowering,and provides a theoretical basis for further research and clinical research of SCE,thereby expanding the medicinal resources of S.chinensis.