morin and Sepsis

Sepsis-associated encephalopathy (SAE) often leads to cognitive impairments in the rest life of septic survivors. The potential pathological changes of SAE are complicated and have not been fully understood. Morin, a flavone compound exhibiting neuroprotective activity and anti-inflammation effect, was employed to treat with CLP-induced septic mice in our study. The data from a novel object recognition test and tail suspension test indicated that morin treatment reversed cognitive dysfunction and relieved depressive-like behaviors in septic mice. Morin down-regulated the expressions of IL-6, MCP-1, TNF-α and IL-10 in serum and diminished microglia activation in septic mice. Additionally, Western blot results showed that morin reduced the phosphokinase GSK3β activity and elevated the phosphatase PP2A activity, which led to lower tau phosphorylation. Morin reduced Aβ deposition and protected the synapse integrity, which might be the possible mechanism of protecting cognitive functions in septic mice. In conclusion, we identified that morin exerted anti-inflammation and anti-neurodegeneration effects in septic mice, and prevented further cognitive impairments.

Topics: Animals; Antioxidants; Cognitive Dysfunction; Disease Models, Animal; Flavonoids; Inflammation Mediators; Male; Mice; Mice, Inbred BALB C; Neuroprotective Agents; Sepsis; Sepsis-Associated Encephalopathy

Morin is a flavonoid isolated from certain fruits and Chinese herbs and is known to possess various medicinal properties. In this study, we investigated the anti-inflammatory effects of morin on lipopolysaccharide (LPS)-induced microglial activation, both in vitro and in vivo. We found that morin inhibited inducible nitric oxide synthase (iNOS) and pro-inflammatory cytokines in LPS-stimulated BV2 microglial cells. Furthermore, morin suppressed the microglial activation and cytokine expression in the brains of LPS-stimulated mice. Subsequent mechanistic studies revealed that morin inhibited the action of LPS-activated mitogen-activated protein kinases (MAPKs), protein kinase B (Akt) phosphorylation, nuclear factor-κB (NF-κB), and activating protein-1 (AP-1). Further, the phosphorylation and DNA binding activity of cAMP responsive element binding protein (CREB) was enhanced by morin. Moreover, morin suppressed the LPS-induced expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits, while it increased heme oxygenase-1 (HO-1) expression and nuclear factor erythroid 2-related factor 2 (Nrf2) activation. Therefore, our data suggest that morin exerts anti-inflammatory effects in LPS-stimulated microglia by downregulating MAPK and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways while upregulating protein kinase A (PKA)/CREB and Nrf2/HO-1 signaling pathways.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cyclic AMP-Dependent Protein Kinases; Cytokines; Flavonoids; Heme Oxygenase-1; Inflammation; Lipopolysaccharides; Membrane Proteins; Mice, Inbred ICR; Microglia; Mitogen-Activated Protein Kinases; Neuroprotective Agents; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Sepsis; Signal Transduction