lignans and Brain-Injuries--Traumatic

Traumatic brain injury (TBI) leads to neuronal damage and neurological dysfunction. The aim of our study was to investigate the antioxidative effect of honokiol on TBI in rats with biochemical, histopathological and immunohistochemical methods.. Sprague-Dawley rats were subjected to TBI with a weight-drop device using 300 g/1 m weight/height impact. Forty-five rats were divided into three groups as control group, TBI group and TBI + honokiol group (5 mg/kg/day, i.p.). Honokiol (5 mg/kg) dissolved in dimethyl sulfoxide (DMSO) was intraperitoneally administered to rats for 7 days after the trauma. At the end of experiment, blood samples were taken from the animals and analysed with various biochemical markers.. Histopathological examination of the trauma group revealed some degenerated pyramidal cells, dilatation and congestion in blood vessels, hyperplasia in endothelial cells, inflammatory cell infiltration around the vein and disruptions in glial extensions. In TBI + honokiol group, pyramidal neurons showed a decrease in degeneration, slight dilatation in blood vessels, improvement of endothelial cells towards the lumen, and reduction of inflammatory cells in the vessel. In TBI + honokiol group, vascular endothelial growth factor expression was positive in the endothelial and few inflammatory cells of the mildly dilated blood vessels. In the blood brain barrier deteriorated after trauma, it was observed that the glial foot processes were positive expression and extended to the endothelial cells in the TBI + honokiol group.. Glial fibrillary acidic protein expression showed a positive reaction in these processes. Considering the important role of antioxidants and inflammatory responses in cerebral damage induced by traumatic head injury, honokiol is thought to be important in decreasing lipid peroxidation, protecting the membrane structure of blood brain barrier, degeneration of neurons and glial cells.

Topics: Animals; Biphenyl Compounds; Blood-Brain Barrier; Brain Injuries, Traumatic; Disease Models, Animal; Glial Fibrillary Acidic Protein; Glutathione Peroxidase; Immunohistochemistry; Lignans; Male; Malondialdehyde; Permeability; Peroxidase; Rats, Sprague-Dawley; Vascular Endothelial Growth Factor A

Topics: Animals; Apoptosis; Aquaporin 4; Blood-Brain Barrier; Brain Edema; Brain Injuries, Traumatic; Capillary Permeability; Caspase 3; Cell Line; Dioxoles; Disease Models, Animal; Endothelial Cells; Extracellular Signal-Regulated MAP Kinases; Lignans; Male; Mice, Inbred C57BL; Neuroprotective Agents; Occludin; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Time Factors; Zonula Occludens-1 Protein

Mechanical trauma injury is a severe insult to neural cells. Subsequent secondary injury involves the release of inflammatory factors that have dramatic consequences for undamaged cells, leading to normal cell death after the initial injury. The present study investigated the capacity for arctigenin (ARC) to prevent secondary effects and evaluated the mechanism underlying the action of microRNA (miRNA)-199a and miRNA-16 in a mechanical trauma injury (MTI) model using SH-SY5Y cells in vitro. SH-SY5Y cells are often applied to in vitro models of neuronal function and differentiation. Recently, miRNAs have been demonstrated to play a crucial role in NF-κB and cholinergic signaling, which can regulate inflammation. The cell model was established by scratch-induced injury of human SH-SY5Y cells, which mimics the characteristics of MTI. A cell counting kit-8 (CCK-8), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and immunocytochemistry were used to measure cell viability. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the inflammatory cytokine and cholinesterase (CHE) content. The lactate dehydrogenase (LDH) content was measured to assess the degree of cell injury. The mRNA levels were measured by RT-PCR to analyze ARC's mechanism of action. miRNA inhibitors and mimics were used to inhibit and strengthen the expression of miRNAs. Protein expression was detected by western blotting analysis. ARC treatment reduced the TNF-α and IL-6 levels as well as the number of TUNEL+ apoptotic SH-SY5Y cells surrounding the scratch and increased the IL-10 level compared to the controls. ARC attenuated the increase of the cell damage degree and LDH content induced by scratching, indicating increased cell survival. Mechanistic studies showed that ARC upregulated the miRNA-16 and miRNA-199a levels to reduce upstream protein (IKKα and IKKβ) expression and inhibit NF-κB signaling pathway activity; moreover, the increased miRNA-199a suppresses cholinesterases to increase cholinergic signaling, resulting in decreased expression of proinflammatory cytokines. ARC treatment confers protection for SH-SY5Y cells through positive regulation of miRNA expression, thereby reducing the inflammatory response. In turn, these effects accelerate injury repair in the scratch-induced injury model. These results might provide insights into the pharmacological role of ARC in anti-inflammation and neuroprotection in neural cells.

Topics: Anti-Inflammatory Agents; Apoptosis; Brain Injuries, Traumatic; Cell Line, Tumor; Furans; Humans; Lignans; MicroRNAs; Neurons; Neuroprotective Agents; NF-kappa B