Gomisin N attenuated cerebral ischemia-reperfusion injury through inhibition of autophagy by activating the PI3K/AKT/mTOR pathway.

BACKGROUND: Ischemic stroke is a major global cause of mortality and permanent disability.  Studies have shown that autophagy is essential to maintain cell homeostasis and inevitably lead to neuronal damage after cerebral ischemia. Gomisin N (GN), lignin isolated from Schisandra chinensis, possesses multiple pharmacological activities. However, there is no research on the potential of GN for neuroprotection in ischemic stroke. PURPOSE: The current work aimed to explore the potential therapeutic possibilities of GN on ischemic stroke and investigate the underlying molecular mechanisms. STUDY DESIGN: The neuroprotective effects of GN on PC12 cells induced by oxygen glucose deprivation/reoxygenation (OGD/R) and mice with middle cerebral artery occlusion/reperfusion (MCAO/R) injury were investigated. METHODS: On day 3 after ischemia, the infarct volume and neurological function were assessed. The level of autophagy was measured in vivo and in vitro using Transmission electron microscopy (TEM) and Monodansylcadaverine (MDC) staining. The interaction between GN and PI3K/AKT/mTOR pathway was investigated by molecular docking. Additionally, the expressions of critical proteins in the PI3K/AKT/mTOR signaling pathway and autophagy markers were determined by western blotting. RESULTS: In compared to the Model group, GN might considerably improve the neurological and locomotor function following a stroke, as well as lower the volume of the cerebral infarct volume and the number of autophagosomes. GN therapy may suppress autophagy by activating the PI3K/Akt/mTOR signaling pathway in the penumbra. In vitro, MDC and TEM results showed that GN treatment obviously suppressed autophagy. Meanwhile, GN downregulated LC3II/LC3I expression ratio while upregulated the p62 expression level. In further studies, GN dramatically boosted the expression ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR proteins in PC12 cells following OGD/R damage. However, the PI3K inhibitor (LY294002) reversed the increase of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR expression ratio induced by GN administration. Also, LY294002 significantly partially attenuated GN induced reduction of autophagy and increase of cell viability compared with GN treatment alone. CONCLUSIONS: Here, we first demonstrate the neuroprotective effects of GN on MCAO mice and OGD/R induced PC12 cells injury. A possible mechanism by which GN prevents ischemic stroke is proposed: GN could restrain autophagy by stimulating the PI3K/AKT/mTOR signaling pathways. More effects and mechanisms of GN on the rehabilitation of ischemic stroke are worthy to be explored in the future.

Erythrocyte Membrane-Enveloped Salvianolic Acid B Nanoparticles Attenuate Cerebral Ischemia-Reperfusion Injury.

Purpose: Ischemic stroke is the second leading cause of death and the third leading cause of disability worldwide. Salvianolic acid B (SAB), a water-soluble phenolic acid derived from the traditional Chinese medicine Salvia miltiorrhiza, exerted protective effects on cerebral ischemia-reperfusion injury. However, the efficacy of SAB is seriously hindered by poor blood brain barrier (BBB) permeability and short biological half-life in plasma. Brain targeted biomimetic nanoparticle delivery systems offer much promise in overcoming these limitations. Methods: A brain targeted biomimetic nanomedicine (RR@SABNPs) was developed, which comprised of SAB loaded bovine serum albumin nanoparticles and functionalized red blood cell membrane (RBCM) with Arg-Gly-Asp (RGD). The characterization parameters, including particle size, zeta potential, morphology, Encapsulation Efficiency (EE), Drug Loading (DL), release behavior, stability, and biocompatibility, were investigated. Moreover, the middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was used to assess the therapeutic efficacy of RR@SABNPs on ischemic stroke. Finally, the reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were detected by DHE and JC­1 staining in oxygen-glucose deprivation/reperfusion (OGD/R) and H2O2 injured PC12 cells. Results: RR@SABNPs exhibited spheric morphology with core-shell structures and good stability and biocompatibility. Meanwhile, RR@SABNPs can significantly prolong SAB circulation time by overcoming the reticuloendothelial system (RES) and actively targeting ischemic BBB. Moreover, RR@SABNPs had comprehensive protective effects on MCAO/R model mice, manifested as a reduced infarct volume and improved neurological and sensorimotor functions, and significantly scavenged excess ROS and maintained MMP. Conclusion: The designed brain targeted biomimetic nanomedicine RR@SABNPs can significantly prolong the half-time of SAB, deliver SAB into the ischemic brain and exhibit good therapeutic effects on MCAO/R model mice.

Diosgenin Ameliorates Non-alcoholic Fatty Liver Disease by Modulating the Gut Microbiota and Related Lipid/Amino Acid Metabolism in High Fat Diet-Fed Rats.

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disease closely associated with dietary habits. Diosgenin is abundant in yam, a common food and traditional Chinese medicine. The molecular mechanism of diosgenin on NAFLD has been preliminarily explored. However, the effect of diosgenin on metabolism and gut microbiota in NAFLD has not been reported. This study confirmed that diosgenin could suppress excessive weight gain, reduce serum levels of total cholesterol and triglycerides, and decrease liver fat accumulation in high-fat diet-induced NAFLD rats. Moreover, fecal metabolomics analysis suggested diosgenin improved abnormal lipid and amino acid metabolism. Bile acids, including lithocholic acid and ursodeoxycholic acid 3-sulfate that function as excretion, absorption, and transport of fats, were remarkably regulated by diosgenin. Aromatic amino acid and lysine metabolism was regulated by diosgenin as well. 16S rRNA gene sequencing analysis demonstrated that diosgenin restored gut microbiota disorder, especially Globicatella, Phascolarctobacterium, Pseudochrobactrum, and uncultured_bacterium_f_Prevotellaceae at the genus level. Additionally, these regulated bacterial genera showed significant correlations with lipid and amino acid metabolism-related biomarkers. This study further confirmed the significant effect of diosgenin on NAFLD, and provided a new perspective for the mechanism.

Network Pharmacological Study on Mechanism of the Therapeutic Effect of Modified Duhuo Jisheng Decoction in Osteoporosis.

Background: Modified Duhuo Jisheng Decoction (MDHJSD) is a traditional Chinese medicine prescription for the treatment of osteoporosis (OP), but its mechanism of action has not yet been clarified. This study aims to explore the mechanism of MDHJSD in OP through a combination of network pharmacology analysis and experimental verification. Methods: The active ingredients and corresponding targets of MDHJSD were acquired from the Traditional Chinese Medicine System Pharmacology (TCMSP) database. OP-related targets were acquired from databases, including Genecards, OMIM, Drugbank, CTD, and PGKB. The key compounds, core targets, major biological processes, and signaling pathways of MDHJSD that improve OP were identified by constructing and analysing the relevant networks. The binding affinities between key compounds and core targets were verified using AutoDock Vina software. A rat model of ovariectomized OP was used for the experimental verification. Results: A total of 100 chemical constituents, 277 targets, and 4734 OP-related targets of MDHJSD were obtained. Subsequently, five core components and eight core targets were identified in the analysis. Pathway enrichment analysis revealed that overlapping targets were significantly enriched in the tumour necrosis factor-alpha (TNF-α) signaling pathway, an inflammation signaling pathway, which contained six of the eight core targets, including TNF-α, interleukin 6 (IL-6), transcription factor AP-1, mitogen-activated protein kinase 3, RAC-alpha serine/threonine-protein kinase, and caspase-3 (CASP3). Molecular docking analysis revealed close binding of the six core targets of the TNF signaling pathway to the core components. The results of experimental study show that MDHJSD can protect bone loss, inhibit the inflammatory response, and downregulate the expression levels of TNF-α, IL-6, and CASP3 in ovariectomized rats. Conclusion: The mechanism of MDHJSD in the treatment of OP may be related to the regulation of the inflammatory response in the bone tissue.