lrisin is an endogenous secreted muscle factor, Which not only plays a certain clinical application value in a variety of metabolic diseases, cardiovascular and cerebrovascular diseases, neurological diseases, tumors and other diseases, but also affects the occurrence and development of organ ischemia/reperfusion injury. ln this paper, the role and mechanism of irisin in organ ischemia/reperfusion injury Were summarized, aiming to provide neW ideas for prevention and treatment of organ ischemia/reperfusion injury.

Short-chain fatty acids (SCFAs) are organic acids with no more than 6 carbon atoms produced during the anaerobic fermentation of dietary fiber in the intestinal tract, which can regulate intestinal flora, repair intestinal mucosal barrier, and reduce intestinal injury.Ischemia-reperfusion injury (IRI) is the main cause of various diseases, and the pathological mechanisms involved are intricate, among which inflammation, oxidative stress, apoptosis and autophagy are the most common. According to current studies, SCFAs can affect the occurrence and development of IRI in various organs by regulating different cell signal transduction. In this paper, the role and mechanism of SCFAs in alleviating tissue and organ ischemia-reperfusion injury were preliminarily summarized, providing theoretical reference for clinical prevention and treatment of IRI.

AIM: To explore schisandrin B (Sch B) pretreatment reduces intestinal ischemia reperfusion injury (IIRI) through inhibiting apoptosis by activation of Nrf2/HO-1 signing pathway in mice by network pharmacology and in vivo experiment. METHODS: (1) The targets of Sch B and IIRI were searched from online databases, Drawing Venn diagram to obtain the common target of them. Cytoscape software was imported to construct the protein-protein interaction (PPI) network to establish the "Drugs-Disease-core target gene" network. The mechanism of Sch B against IIRI was predicted through GO and KEGG enrichment analysis. (2) Thirty-six C57BL/6J mice were randomly divided into six groups (n = 6). The model of IIRI was established in four groups except the sham operation group. Three of the groups were pretreated with Sch B, Nrf2 inhibitor ML385, and Sch B + ML385, respectively. After the experiment, intestinal tissue samples were taken for HE staining, Chiu ' s score, apoptosis staining, immunohistochemistry (IHC), and immunoblotting (Western blot). RESULTS: A total of 412 Sch B related tar- gets, 2 166 IIRI related targets and 153 common targets were screened out through network pharmacology. There were 88 "Sch B-IIRI-core target gene" included NFE2L2 (Nrf2), HMOX1 (HO-1), BCL2, CASP3 (caspase 3), and so on. KEGG enrichment analysis screened 163 related pathways, apoptosis pathway ranked high showing that the pathway may play a key role in the treatment of IIRI by Sch B. The animal experiment had shown that Sch B reduced the Chiu's score and apoptotic while upregulating Nrf2, HO-1, Bcl-2 protein expression levels and Bcl-2/Bax, downregulating Bax, and cleaved caspase-3 expression levels, thereby reducing IIRI in mice, and that Nrf2 inhibitor ML385 reversed this process (P < 0.05). CONCLUSION: This study reveals that Sch B has the characteristics of multi-target and multi-pathway in the reduction of IIRI, and Sch B can reduce IIRI through inhibiting apoptosis by activation of Nrf2/ HO-1 pathway.