RESUMEN
Cervus elaphus sibericus (CES), commonly known as deer antler, has been used as a medicinal herb because of its various pharmacological activities, including its anti-infective, anti-arthritic, anti-allergic, and anti-oxidative properties. However, the precise mechanisms by which CES functions as a potent anti-oxidative agent remain unknown; particularly, the effects of CES on cortical neurons and its neurobiological mechanism have not been examined. We used primary cortical neurons from the embryonic rat cerebral cortex and hydrogen peroxide to induce oxidative stress and damage in neurons. After post-treatment of CES at three concentrations (10, 50, and 200 µg/mL), the influence of CES on the neurobiological mechanism was assessed by immunocytochemistry, flow cytometry, and real-time PCR. CES effectively prevented neuronal death caused by hydrogen peroxide-induced damage by regulating oxidative signaling. In addition, CES significantly induced the expression of brain-derived neurotrophic factor and neurotrophin nerve growth factor, as well as regeneration-associated genes. We also observed newly processing elongated axons after CES treatment under oxidative conditions. In addition, filopodia tips generally do not form a retraction bulb, called swollen endings. Thus, CES shows therapeutic potential for treating neurological diseases by stimulating neuron repair and regeneration.
RESUMEN
PURPOSE: Lycopus lucidus Turcz (LLT) is a potent traditional medicinal herb that exerts therapeutic effects, regulating inflammatory disorders. However, the precise mechanisms by which LLT plays a potent role as an anti-inflammatory agent are still unknown, and in particular, the effects of LLT on cortical neurons and related mechanisms of neuroinflammation have not been studied. The NLRP3 inflammasome pathway is one of the most well known as an important driver of inflammation. We therefore hypothesized that LLT, as an effective anti-inflammatory agent, might have neurotherapeutic potential by inhibiting the NLRP3 inflammasome pathway in cortical neurons. MATERIALS AND METHODS: Primary cortical neurons were isolated from the embryonic rat cerebral cortex, and H2O2 was used to stimulate neuron damage in vitro. After treatment with LLT at three concentrations (10, 25, and 50 µg/mL), the expression of iNOS, NLRP3, ASC, caspase-1, IL-1ß, IL-18, IL-6, and IL-10 was determined by immunocytochemistry, qPCR, and ELISA. Neuron apoptosis was also evaluated using Annexin V-FITC/PI double staining FACS analysis. Neural regeneration-related factors (BDNF, NGF, synaptophysin, NT3, AKT, and mTOR) were analyzed by immunocytochemistry and qPCR. RESULTS: LLT effectively protected cultured rat cortical neurons from H2O2-induced neuronal injury by significantly inhibiting NLRP3 inflammasome activation. In addition, it significantly reduced caspase-1 activation, which is induced by inflammasome formation and regulated the secretion of IL-1ß/IL-18. We demonstrated that LLT enhances axonal elongation and synaptic connectivity upon H2O2-induced neuronal injury in rat primary cortical neurons. CONCLUSION: It was first demonstrated in vitro that LLT suppresses NLRP3 inflammasome activation, attenuates inflammation and apoptosis, and consequently promotes neuroprotection and the stimulation of neuron repair, suggesting that it is a promising therapeutic for neurological diseases.
RESUMEN
Inula britannica var. chinensis (IBC) has been used as a traditional medicinal herb to treat inflammatory diseases. Although its anti-inflammatory and anti-oxidative effects have been reported, whether IBC exerts neuroprotective effects and the related mechanisms in cortical neurons remain unknown. In this study, we investigated the effects of different concentrations of IBC extract (5, 10, and 20 µg/mL) on cortical neurons using a hydrogen peroxide (H2O2)-induced injury model. Our results demonstrate that IBC can effectively enhance neuronal viability under in vitro-modeled reaction oxygen species (ROS)-generating conditions by inhibiting mitochondrial ROS production and increasing adenosine triphosphate level in H2O2-treated neurons. Additionally, we confirmed that neuronal death was attenuated by improving the mitochondrial membrane potential status and regulating the expression of cytochrome c, a protein related to cell death. Furthermore, IBC increased the expression of brain-derived neurotrophic factor and nerve growth factor. Furthermore, IBC inhibited the loss and induced the production of synaptophysin, a major synaptic vesicle protein. This study is the first to demonstrate that IBC exerts its neuroprotective effect by reducing mitochondria-associated oxidative stress and improving mitochondrial dysfunction.
RESUMEN
Axonal regeneration after spinal cord injury (SCI) is difficult to achieve, and no fundamental treatment can be applied in clinical settings. DNA methylation has been suggested to play a role in regeneration capacity and neuronal growth after SCI by controlling the expression of regeneration-associated genes (RAGs). The aim of this study was to examine changes in neuronal DNA methylation status after SCI and to determine whether modulation of DNA methylation with ascorbic acid can enhance neuronal regeneration or functional restoration after SCI. Changes in epigenetic marks (5-hydroxymethylcytosine (5hmC) and 5-methylcytosine (5mC)); the expression of Ten-eleven translocation (Tet) family genes; and the expression of genes related to inflammation, regeneration, and degeneration in the brain motor cortex were determined following SCI. The 5hmC level within the brain was increased after SCI, especially in the acute and subacute stages, and the mRNA levels of Tet gene family members (Tet1, Tet2, and Tet3) were also increased. Administration of ascorbic acid (100 mg/kg) to SCI rats enhanced 5hmC levels; increased the expression of the Tet1, Tet2, and Tet3 genes within the brain motor cortex; promoted axonal sprouting within the lesion cavity of the spinal cord; and enhanced recovery of locomotor function until 12 weeks. In conclusion, we found that epigenetic status in the brain motor cortex is changed after SCI and that epigenetic modulation using ascorbic acid may contribute to functional recovery after SCI.