| Schisandra chinensis(Turcz.)Baill.is the dried and mature fruit of Schisandrae chinensis of Magnoliaceae which is commonly known as " North Schisandra chinensis of China".As a traditional Chinese medicine,it possesses functions of astringeing lung,nourishing kidney,generating fluid and hidroschesis.Presently,the fruit of Schisandra chinensis as a medicinal part is often used in nutrition and functional food,while the stem of Schisandra chinensis as a non-medicinal part also contains a lot of active ingredients.Therefore,the development and utilization of the stem of Schisandra chinensis is of great significance to expand the medicinal resources of Schisandra chinensis.Lignans are the main chemical components in the stems of Schisandrae chinensis,which have various pharmacological effects such as liver protection,anti-tumor and diabetes treatment.Schisandrin B,a biphenylcyclooctene lignans with high content in Schisandrae chinensis,has a wide range of pharmacological activities,so it is often regarded as a research focus.Cisplatin is an anti-tumor drug widely used in clinical practice at present.It has a good effect on the treatment for multiple organ malignancies.However,as an anti-tumor drug,cisplatin may also produces some side effects in clinical usage like intestinal toxicity which is also one of the important factors affecting the quality of life of patients.Thus,searching for effective gastrointestinal protective protocol to reduce injury by cisplatin has also been a spot for its clinical application.Therefore,this study combined in vivo and in vitro test to demonstrate the improvement of Schisandra chinensis stem extract and the Schisandrin B in cisplatin induced intestinal injury respectively from inflammation,oxidative stress,apoptosis and intestinal barrier.Additionally,we also analyzed the regulation effect of Schisandrin B to cisplatin resulted intestinal flora disorder,which will lay a theory foundation for the development of chemotherapeutic intestinal protective clinical medicine.The main research contents are as follows:1.Comparison of main chemical components content in the stems and fruits of Schisandra chinensis on the basis of HPLCThe contents of lignans,such as Schisandrol A,Schisandrol B,Schisantherin A,Schisantherin B,Schisandrin A,Schisandrin B,Schisandrin C were 0.461%,0.346%,0.134%,0.067%,0.188%,0.305%,0.065% and 0.326%,0.235%,0.030%,0.034%,0.116%,0.214%,0.037% respectively determined by HPLC.Among them,main lignan content such as Schisandrol A,Schisandrin A,Schisandrin B were similar in the stems and fruit,so to some extent,stems can be used instead of the fruit.Moreover,comparison between monosaccharide components and polysaccharide content showed that both Schisandra fruit and stem contains mannose glucose,galactose and arabinose.Moreover,fruit parts also contained rhamnose and galacturonic acid monosaccharide components,and the crude polysaccharide content(11.5%)in fruit was significantly higher than stem(1.42%).Therefore,compared with other chemical components,the lignans in the stems are more prominent.These conclusions provide theory basis for further research.2.Protective effect of extracts from Schisandra chinensis stem in cisplatin induced intestinal damage miceThe effects of Schisandra chinensis fruit extract and Schisandra chinensis stem extract on intestinal damage mice induced by cisplatin were compared in vivo.The results showed that both Schisandra chinensis fruit extract and Schisandra chinensis stem extract had good intestinal protection effects at the dose of 300 mg/kg.Cisplatin induced oxidative stress intestinal damage can be reduced by increasing catalase(CAT)and glutathione peroxidase(GSH-Px)and decreasing malondialdehyde(MDA)levels.Meanwhile,tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)levels as well as NF-κB protein expression decreased to inhibit the cisplatin induced inflammatory injury.In addition,Schisandra chinensis fruit extract and Schisandra chinensis stem extract can also regulate the expression of PI3K/Akt signaling pathway and its downstream protein caspase 3 to inhibit apoptosis,decrease the level of diamine oxidase(DAO)and increase the expression of tight junction proteins(ZO-1)and occludin to enhance intestinal barrier function.Therefore,Schisandra chinensis stem extract also significantly alleviated cisplatin induced intestinal injury compared to schisandra chinensis fruit extract.3.Ameliorative effect of Schisandrin B on cisplatin induced IEC-6 cell injuryIn vitro model of cisplatin induced IEC-6 cell injury was established.The protective effect of Schisandrin B on cisplatin induced IEC-6 cell injury at doses of 2.5 μM,5 μM and 10 μM were screened from 7 lignin monomers by MTT assay.Schisandrin B can significantly reduce the consumption of superoxide dismutase(SOD)and CAT by cisplatin,and also decrease the level of MDA,indicating that Schisandrin B can effectively reduce the oxidative damage of IEC-6 cells induced by cisplatin.Besides,the ROS-mediated PI3K/Akt and caspase signaling pathways can also be regulated to alleviate cisplatin induced apoptosis.TUNEL and immunofluorescence staining also proved this theory.Western blot results further demonstrated that Schisandrin B decreased the expressions of NF-κB and TNF-α/IL-1β pathways and thus reduced the occurrence of inflammation.Wnt/β-catenin,as a functional signaling pathway driving intestinal self-recovery,is also regulated by Schisandrin B.The results above demonstrate that Schisandrin B can alleviate cisplatin induced IEC-6 cell damage by reducing oxidative stress,inflammation and apoptosis,and also plays an important role in maintaining intestinal integrity.4.Schisandrin B regulates ZO-1/occludin and Wnt/β-catenin signaling pathways to alleviate cisplatin induced intestinal injury in miceBased on the effect of Schisandrin B on cisplatin induced IEC-6 cell damage,the protective effect of Schisandrin B on intestinal tract and its molecular mechanism in vivo were further explored.The results showed that Schisandrin B could improve the intestinal mucosal barrier function by increasing the expression of ZO-1/occludin and regulating the Wnt/β-catenin signaling pathway,thereby further inhibiting the expression of NF-κB inflammatory pathway caused by intestinal barrier dysfunction,and also promoting the regeneration of intestinal stem cells.AB-PAS staining results showed that Schisandrin B could effectively improve the mucin secreting ability of small intestinal goblet cells and protect the intestinal tract from the invasion of external toxic factors.5.Regulation of Schisandrin B on cisplatin induced intestinal flora disturbance in miceThe intestinal flora of mice in each group was determined to investigate whether Schisandrin B had a regulatory effect on cisplatin induced intestinal flora disturbance.The results showed that Schisandrin B could significantly up-regulate the decrease in the abundance of Firmicutes and Bacteroidetes caused by cisplatin in mice.Moreover,the relative abundances of Lactobacillus and norank＿f＿＿Muribaculaceae were also inhibited significantly after cisplatin stimulation,but increased significantly after Schisandrin B treatment.In addition,as a genus associated with intestinal permeability,the up-regulation of Lactobacillus indirectly proved that Schisandrin B could decrease cisplatin induced the increased of intestinal permeability. |
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