Neuroprotective effects of bornyl acetate on experimental autoimmune encephalomyelitis via anti-inflammatory effects and maintaining blood-brain-barrier integrity.

BACKGROUND: Bornyl acetate (BA), a chemical component of essential oil in the Pinus family, has yet to be actively studies in terms of its therapeutic effect on numerous diseases, including autoimmune diseases. PURPOSE: This study aimed to investigate the pharmacological effects and molecular mechanisms of BA on myelin oligodendrocyte glycoprotein (MOG35-55)-induced experimental autoimmune encephalomyelitis (EAE) mice in an animal model of multiple sclerosis (MS), a representative autoimmune disease in central nervous system. METHODS: BA (100, 200, or 400 mg/kg) was orally treated to EAE mice once daily for 30 days after immunization for the behavioral test and for the 16th-18th days for the histopathological and molecular analyses, from the onset stage (8th day) of EAE symptoms. RESULTS: BA mitigated behavioral dysfunction (motor disability) and demyelination in the spinal cord that were associated with the down-regulation of representative pro-inflammatory cytokines (interleukin (IL)-1 beta, IL-6, and tumor necrosis factor-alpha), enzymes (cyclooxygenase-2 and inducible nitric oxide synthase), and chemokines (monocyte chemotactic protein-1, macrophage inflammatory protein-1 alpha, and regulated on activation), and decreased infiltration of microglia (CD11b+/CD45+(low)) and macrophages (CD11b+/CD45+(high)). The anti-inflammatory effect of BA was related to the inhibition of mitogen-activated protein kinases and nuclear factor-kappa B pathways. BA also reduced the recruitment/infiltration rates of CD4+ T, Th1, and Th17 cells into the spinal cords of EAE mice, which was related to reduced blood-spinal cord barrier (BSCB) disruption. CONCLUSION: These findings strongly suggest that BA may alleviate EAE due to its anti-inflammatory and BSCB protective activities. This indicates that BA is a potential therapeutic agent for treating autoimmune demyelinating diseases including MS.

Daphne genkwa flower extract promotes the neuroprotective effects of microglia.

BACKGROUND: Microglia are innate immune cells in the central nervous system that play a crucial role in neuroprotection by releasing neurotrophic factors, removing pathogens through phagocytosis, and regulating brain homeostasis. The constituents extracted from the roots and stems of the Daphne genkwa plant have shown neuroprotective effects in an animal model of Parkinson's disease. However, the effect of Daphne genkwa plant extract on microglia has yet to be demonstrated. PURPOSE: To study the anti-inflammatory and neuroprotective effects of Daphne genkwa flower extract (GFE) in microglia and explore the underlying mechanisms. METHODS: In-vitro mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), inducible nitric oxide synthase, Arginase1, and brain derived neurotropic factor (BDNF) were analyzed by reverse transcription polymerase chain reaction in microglia cells. Nitric oxide (NO) and TNF-α protein were respectively analyzed by Griess reagent and Enzyme Linked Immunosorbent Assay. Immunoreactivity of Iba-1, Neu-N, and BDNF in mouse brain were analyzed by immunofluorescence staining. Phagocytosis capacity of microglia was examined using fluorescent zymosan-red particles. RESULTS: GFE significantly inhibited lipopolysaccharide (LPS)-induced neuroinflammation and promoted neuroprotection both in vitro and in vivo. First, GFE inhibited the LPS-induced inflammatory factors NO, iNOS, and TNF-α in microglial cell lines and primary glial cells, thus demonstrating anti-inflammatory effects. Arginase1 and BDNF mRNA levels were increased in primary glial cells treated with GFE. Phagocytosis was also increased in microglia treated with GFE, suggesting a neuroprotective effect of GFE. In vivo, neuroprotective and anti-neuroinflammatory effects of GFE were also found in the mouse brain, as oral administration of GFE significantly inhibited LPS-induced neuronal loss and inflammatory activation of microglia. CONCLUSION: GFE has anti-inflammatory effects and promotes microglial neuroprotective effects. GFE inhibited the pro-inflammatory mediators and enhanced neuroprotective microglia activity by increasing BDNF expression and phagocytosis. These novel findings of the GFE effect on microglia show an innovative approach that can potentially promote neuroprotection for the prevention of neurodegenerative diseases.

In Vivo Hypoglycemic Effects, Potential Mechanisms and LC-MS/MS Analysis of Dendropanax Trifidus Sap Extract.

Extracts of medicinal plants have been widely used to benefit human health. Dendropanax morbiferus (DM) has been well-studied for its anti-inflammatory and anti-oxidative effects, while Dendropanax trifidus (DT) is a lesser-known ecotype phylogenetically similar to DM, which has received significantly less attention. Studies thus far have primarily focused on leaf and bark extracts of DM, and not much is yet known about the properties of either DM or DT sap. Therefore, here we performed in vivo toxicity and efficacy studies, in order to assess the biological effects of DT sap. To establish a safe dosage range, single dose or two-week daily administrations of various concentrations were performed for ICR mice. Measurements of survival ratio, body/organ weight, blood chemistry, histochemistry and Western blots were performed. A concentration of ≤0.5 mg/g DT sap was found to be safe for long-term administration. Interestingly, DT sap significantly reduced blood glucose in female mice. In addition, increasing concentrations of DT sap decreased phosphorylated (p) insulin receptor substrate (IRS)-1(ser1101)/IRS-1 in liver tissues, while increasing pAMP-activated protein kinase (AMPK)/AMPK in both the liver and spleen. To analyze its components, liquid chromatography-tandem mass spectrometry of DT sap was performed in comparison with Acer saccharum (AS) sap. Components such as estradiol, trenbolone, farnesol, dienogest, 2-hydroxyestradiol and linoleic acid were found to be highly enriched in DT sap compared to AS sap. Our results indicate DT sap exhibits hypoglycemic effects, which may be due to the abundance of the bioactive components.

Astrocytic pyruvate dehydrogenase kinase-2 is involved in hypothalamic inflammation in mouse models of diabetes.

Hypothalamic inflammation plays an important role in disrupting feeding behavior and energy homeostasis as well as in the pathogenesis of obesity and diabetes. Here, we show that pyruvate dehydrogenase kinase (PDK)-2 plays a role in hypothalamic inflammation and its sequelae in mouse models of diabetes. Cell type-specific genetic ablation and pharmacological inhibition of PDK2 in hypothalamic astrocytes suggest that hypothalamic astrocytes are involved in the diabetic phenotype. We also show that the PDK2-lactic acid axis plays a regulatory role in the observed metabolic imbalance and hypothalamic inflammation in mouse primary astrocyte and organotypic cultures, through the AMPK signaling pathway and neuropeptidergic circuitry governing feeding behavior. Our findings reveal that PDK2 ablation or inhibition in mouse astrocytes attenuates diabetes-induced hypothalamic inflammation and subsequent alterations in feeding behavior.

Neuroprotective and Anti-Neuroinflammatory Effects of a Poisonous Plant Croton Tiglium Linn. Extract.

Neuroinflammation is involved in various neurological diseases. Activated microglia secrete many pro-inflammatory factors and induce neuronal cell death. Thus, the inhibition of excessive proinflammatory activity of microglia leads to a therapeutic effect that alleviates the progression of neuronal degeneration. In this study, we investigated the effect of Croton tiglium(C. tiglium) Linn. extract (CTE) on the production of pro- and anti-inflammatory mediators in microglia and astrocytes via RT-PCR, Western blot, and nitric oxide assay. Neurotoxicity was measured by cell viability assay and GFP image analysis. Phagocytosis of microglia was measured using fluorescent zymosan particles. CTE significantly inhibited the production of neurotoxic inflammatory factors, including nitric oxide and tumor necrosis factor-α. In addition, CTE increased the production of the neurotrophic factor, brain-derived neurotrophic factor, and the M2 phenotype of microglia. The culture medium retained after CTE treatment increased the survival of neurons, thereby indicating the neuroprotective effect of CTE. Our findings indicated that CTE inhibited pro-inflammatory response and increased the neuroprotective ability of microglia. In conclusion, although CTE is known to be a poisonous plant and listed on the FDA poisonous plant database, it can be used as a medicine if the amount is properly controlled. Our results suggested the potential benefits of CTE as a therapeutic agent for different neurodegenerative disorders involving neuroinflammation.