• Journal of Life Science
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• v.25 no.6
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• pp.656-662
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• 2015

Natural products and natural product structures play a general and highly significant role in drug discovery and development process because it has various merits and potentials for new drug source that have extensive clinical experience, development time contraction, excellent stability and safety. In several neurological disorders, neuronal death and excessive activation of microglia (neuro-inflammation) are observed. A number of drug discovery-related neuronal cell death and neuro-inflammation was studied from natural products, respectively. However, until now, it has not been possible to study dual-protection molecules recorded in the Natural Product library. In the present study, using the natural product-derived library of the Institute for Korea Traditional Medical Industry, we investigated dual-protective molecules against glutamate (a classical excitatory neurotransmitter)-induced oxidative stress mediated neuronal cell death and LPS-induced excessive activated microglial cells (immune cells of the brain). Chrysophanol, extracted from Rheum palmatum, had dual-protective effects against both glutamate-induced neuronal cell death and LPS-induced NO production, triggering proinflammatory cytokines and microglia activation and resulting in neuroinflammation. Flow-cytometry analysis revealed that chrysophanol had a scavenger effect, scavenging glutamate- and LPS-induced reactive oxygen species (ROS) produced by neuronal and microglial cells, respectively. Based on the present study, chrysophanol may have an important protective role against neuronal cell death and neuroinflammation in the brain. The results may be helpful for studying drug development candidates for treating central nervous system disorders.

• Journal of Ginseng Research
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• v.44 no.5
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• pp.704-716
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• 2020

Background: Ginsenoside Rh2 (GRh2) is a characterized component in red ginseng widely used in Korea and China. GRh2 exhibits a wide range of pharmacological activities, such as anti-inflammatory, antioxidant, and anticancer properties. However, its effects on Toxoplasma gondii (T. gondii) infection have not been clarified yet. Methods: The effect of GRh2 against T. gondii was assessed under in vitro and in vivo experiments. The BV2 cells were infected with tachyzoites of T. gondii RH strain, and the effects of GRh2 were evaluated by MTT assay, morphological observations, immunofluorescence staining, a trypan blue exclusion assay, reverse transcription PCR, and Western blot analyses. The in vivo experiment was conducted with BALB/c mice inoculated with lethal amounts of tachyzoites with or without GRh2 treatment. Results and conclusion: The GRh2 treatment significantly inhibited the proliferation of T. gondii under in vitro and in vivo studies. Furthermore, GRh2 blocked the activation of microglia and specifically decreased the release of inflammatory mediators in response to T. gondii infection through TLR4/NF-κB signaling pathway. In mice, GRh2 conferred modest protection from a lethal dose of T. gondii. After the treatment, the proliferation of tachyzoites in the peritoneal cavity of infected mice markedly decreased. Moreover, GRh2 also significantly decreased the T. gondii burden in mouse brain tissues. These findings indicate that GRh2 exhibits an antieT. gondii effect and inhibits the microglial activation through TLR4/NF-κB signaling pathway, providing the basic pharmacological basis for the development of new drugs to treat toxoplasmic encephalitis.

• Journal of Life Science
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• v.26 no.6
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• pp.640-645
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• 2016

Microglial cells are immediately activated in the central nervous system in response to a variety of neuronal environmental changes, such as injuries or inflammation. In addition to the modulation of the intrinsic immune response, a key role of microglial cells is the phagocytosis of dying cells and cellular debris. In this study, the inhibitory effects of epigallocatechine-3-gallate (EGCG), a most abundant and active polyphenol component of green tea, on lipopolysaccharide (LPS)-induced microglial activation are determined. EGCG dose dependently suppressed LPS-induced nitric oxide production and the expression of inducible nitric oxide synthase (iNOS) in BV-2 microglial cells. EGCG are potent LPS-induced inhibitors of several pro-inflammatory cytokine expressions, such as TNF-α and IL-1β, in microglial cells. Furthermore, EGCG generally inhibits the induction of LPS-mediated microglial activation and potently inhibits the phagocytosis of LPS-stimulated BV2 microglia. Although the conditioned media from LPS-stimulated BV-2 cells caused the SN4741 cell death, that from the conditioned media of EGCG pretreated BV-2 cells did not diminish the viability of SN4741 cells. These results suggest EGCG, a green tea polyphenol, could be a promising available molecule for the modulation of harmful microglial activation.

• Journal of Life Science
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• v.23 no.12
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• pp.1532-1540
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• 2013

T-box transcription factor 2 (Tbr2) is a member of the T-box family of transcription factors and it plays an important role in brain development, progenitor cell proliferation, and the modulation of differentiation and function in immune cells, such as CD8+ T cells and natural killer cells. This study aims to elucidate the involvement of Tbr2 in the pathophysiological events following pilocarpine-induced status epilepticus in mice. Status epilepticus resulted in prominent neuronal cell death in discrete brain regions, such as CA3, the hilus, and the piriform cortex. Interestingly, when the immunoreactivity of Tbr2 was examined two days after status epilepticus, it was transiently increased in CA3 and in the piriform cortex. Tbr2-positive cells in CA3 and the piriform cortex were double-labeled with CD11b, a marker of microglia and a subset of white blood cells, such as monocytes, CD8+ T cells, and natural killer cells. Moreover, the double-labeled cells with Tbr2 and CD11b showed amoeboid morphology, and this data indicates that Tbr2-expressing cells may be reactive microglia or infiltrating white blood cells. Furthermore, clustered Tbr2-positive cells were observed in the platelet endothelial cell adhesion molecule-1 (PECAM-1)-positive blood vessels near the CA3 area, which suggests that Tbr2-positive cells may be infiltrating the white blood cells. Based on this data, this study is the first to indicate the involvement of Tbr2 in neuropathophysiology in status epilepticus.

• Applied Microscopy
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• v.28 no.4
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• pp.425-434
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• 1998

This study was designed to investigate the microglial reactions to the neurodegenerative changes in the cat retina. All experiments were performed using adult cats of both sex, weighing $2,500g\sim3,500g$. 5,7-DHT $(100{\mu}g)$ dissolved in 0.1% ascorbic acid was injected into the vitreous body. All injections were performed in one-side eye; the other side served as the control, which was injected only with 0.1% ascorbic acid. Cats were sacrificed at 1, 3, 7, 14 and 21 days after intravitreal injection of 5,7-DHT For light microscopy, retinae were fixed with 4% paraformaldehyde and processed using NDPase histochemistry. Same retinae were fixed with 1% para(formaldehyde-2.5% glutaraldehyde and processed for electron microscopy. NDPase-positive microglial cells were mainly distributed in the inner plexiform layer of the retina, and characterized by a small somata with a few slender processes, which were also extended in the ganglion cell layer (GCL) and inner nuclear layer (INL). The intensity of the microglia stained for NDPase was abruptly increased at 7 day as compared with that of the control, and thereafter continuously sustained until 21 day, the last experimental group in this study. Under the electron microscopical observation, microglial cells in the control group exhibited elongate nucleus with perinuclear chromatin condensation, and the perikaryon was scanty. However, a few hypertrophic glial cells were frequently found at 3 days after the drug injection. By 7 day, most microglial cells directed toward the degenerated neurons in the GCL, and the number of microglial cells was slightly increased as compared with the former group. At the 14 day, most microglial cells wrapped the degenerated cells in the GCL, and a few cells showed phagocytotic features. By 21 day, most microglial cells were engaged in phagocytotic activity, and their cytoplasm was filled with the phagorytosed material. Based on the results, 5,7-DHT may act as a specific neurotoxin to the cat retina, and microglial reactions to the neuronal death are already induced in early experimental stage. These results indicate that the microglial cells in the cat retina show characteristic features as a protective effect of neural tissue.

• Journal of Nutrition and Health
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• v.50 no.1
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• pp.25-31
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• 2017

Purpose: Neuroinflammation is mediated by activation of microglia implicated in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Inhibition of neuroinflammation may be an effective solution to treat these brain disorders. Petalonia binghamiae is known as a traditional food, based on multiple biological activities such as anti-oxidant and anti-obesity. In present study, the anti-neuroinflammatory potential of Petalonia binghamiae was investigated in LPS-stimulated BV2 microglial cells. Methods: Cell viability was measured by MTT assay. Production of nitric oxide (NO) was examined using Griess reagent. Expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was detected by Western blot analysis. Activation of nuclear factor ${\kappa}B$ ($NF-{\kappa}B$) signaling was examined by nuclear translocation of $NF-{\kappa}B$ p65 subunit and phosphorylation of $I{\kappa}B$. Results: Extract of Petalonia binghamiae significantly inhibited LPS-stimulated NO production and iNOS/COX-2 protein expression in a dose-dependent manner without cytotoxicity. Pretreatment with Petalonia binghamiae suppressed LPS-induced $NF-{\kappa}B$ p65 nuclear translocation and phosphorylation of $I{\kappa}B$. Co-treatment with Petalonia binghamiae and pyrrolidine duthiocarbamate (PDTC), an $NF-{\kappa}B$ inhibitor, reduced LPS-stimulated NO release compared to that in PB-treated or PDTC-treated cells. Conclusion: The present results indicate that extract of Petalonia binghamiae exerts anti-neuroinflammation activities, partly through inhibition of $NF-{\kappa}B$ signaling. These findings suggest that Petalonia binghamiae might have therapeutic potential in relation to neuroinflammation and neurodegenerative diseases.

• Journal of Life Science
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• v.29 no.11
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• pp.1258-1266
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• 2019

Yangkyuksanhwa-Tang (YKSH), consisting of nine different herbs, is commonly used in Soyangin-type individuals with stroke, based on the Sasang Constitution Theory in Korea. However, no evidence has yet confirmed a beneficial effect of YKSH in ischemic stroke treatment. In this study, we investigated the effects of YKSH on ischemic brain injury in a mouse model of cerebral ischemia. Focal cerebral ischemia in mice was induced by photothrombosis, and behavioral recovery was evaluated. Infarct volume, inflammation, and newly generated cells were evaluated by histology and immunochemistry. YKSH treatment resulted in a significant recovery from the motor impairments induced by focal cerebral ischemia, as determined with wire grip and rotarod tests. YKSH treatment also decreased the infarct volume and the number of cells positive for tumor necrosis factor-${\alpha}$ and myeloperoxidase when compared with a vehicle-treated control group. By contrast, YKSH treatment considerably increased the number of cells positive for glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1, as well as the number of cells doubly positive for Ki67/doublecortin when compared with the vehicle-treated group. These results suggest that YKSH treatment attenuated the infarct size by anti-inflammatory action, astrocyte and microglia activation, and neuronal proliferation, thereby facilitating neurofunctional recovery from a cerebral ischemic assault. YKSH could therefore be a potential treatment for neurofunctional restoration of the injured brains of patients with stroke.

• Biomolecules & Therapeutics
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• v.27 no.3
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• pp.327-335
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• 2019

As the elderly population is increasing, Alzheimer's disease (AD) has become a global issue and many clinical trials have been conducted to evaluate treatments for AD. As these clinical trials have been conducted and have failed, the development of new theraphies for AD with fewer adverse effects remains a challenge. In this study, we examined the effects of Theracurmin on cognitive decline using 5XFAD mice, an AD mouse model. Theracurmin is more bioavailable form of curcumin, generated with submicron colloidal dispersion. Mice were treated with Theracurmin (100, 300 and 1,000 mg/kg) for 12 weeks and were subjected to the novel object recognition test and the Barnes maze test. Theracurmin-treated mice showed significant amelioration in recognition and spatial memories compared those of the vehicle-treated controls. In addition, the antioxidant activities of Theracurmin were investigated by measuring the superoxide dismutase (SOD) activity, malondialdehyde (MDA) and glutathione (GSH) levels. The increased MDA level and decreased SOD and GSH levels in the vehicle-treated 5XFAD mice were significantly reversed by the administration of Theracurmin. Moreover, we observed that Theracurmin administration elevated the expression levels of synaptic components, including synaptophysin and post synaptic density protein 95, and decreased the expression levels of ionized calcium-binding adapter molecule 1 (Iba-1), a marker of activated microglia. These results suggest that Theracurmin ameliorates cognitive function by increasing the expression of synaptic components and by preventing neuronal cell damage from oxidative stress or from the activation of microglia. Thus, Theracurmin would be useful for treating the cognitive dysfunctions observed in AD.

• The Korea Journal of Herbology
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• v.38 no.1
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• pp.11-19
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• 2023

Objectives : Neuroinflammation is a common pathological mechanism of neurodegenerative diseases, and the development of therapeutic agents is urgently needed. Red ginseng has been known to be good for the immune stimulation in Eastern Asia. Although the immuno-stimulatory activity of red ginseng are already known, the neuro-protective effects of cultivated red ginseng with fermented complex mushroom-cereal mycelium (RGFM) have not been conducted. Thus, in this study, we tried to investigate the anti-neuroinflammatory effect of RGFM water extract on lipopolysaccharide (LPS) stimulated BV2 cells. Methods : BV2 cells were pretreated with RGFM 1 h prior to LPS exposure. To determine the neuro-protective effects of RGFM water extract, we measured the expression of inflammatory mediators including inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and nitric oxide (NO) and pro-inflammatory cytokines such as interleukin (IL)-1𝛽, IL-6 and tumor necrosis factor (TNF)-𝛼 in LPS-stimulated BV2 cells. In addition, to find out the regulatory mechanism of RGFM water extract, we assessed the protein levels of mitogen-activated protein kinases (MAPKs) and inhibitory 𝜅B𝛼 (I𝜅B𝛼) by western blotting. Results : In our study, treatment of RGFM reduced the mRNA expression of iNOS and COX-2 and suppressed NO production in LPS-stimulated BV2 cells. Additionally, the secretion of IL-1𝛽 and TNF-𝛼 but not IL-6 was significantly inhibited by RGFM. Furthermore, RGFM water extract inhibited the phosphorylation of c-Jun N-terminal kinase (JNK). Conclusions : Taken together, these findings suggest that RGFM water extract has a protective effect on neuroinflammation through inhibition of JNK.

• The Korea Journal of Herbology
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• v.29 no.3
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• pp.27-33
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• 2014

Objectives : The aim of this study was to investigate the protective effect of extract of Thuja orientalis leaves (TOFE) against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity by inhibition of inflammation in in vitro and in vivo models of Parkinson's disease (PD). Methods : We evaluated the effect of TOFE against lipopolysaccharide (LPS)/1-methyl-4-phenylpyridinium ($MPP^+$) toxicity using nitric oxide (NO) assay, inducible NO synthase and cyclooxygenase 2 western blot, tyrosine hydroxylase and microglia activation immunohistochemistry (IHC) in BV2 cell, primary rat mesencephalic neurons, or C57BL/6 mice. We also evaluated the effect of TOFE in mice PD model induced by MPTP. C57BL/6 mice were treated with TOFE 50 mg/kg for 5 days and were injected intraperitoneally with four administrations of MPTP on the last day. We conducted behavioral tests and IHC analysis to see how TOFE affect MPTP-induced neuronal loss of dopaminergic neurons in substantia nigra pars compacta (SNpc) and striatum (ST) of mice. To assess the anti-inflammation effects, we carried out glial fibrillary acidic protein and macrophage-1 antigen integrin alpha M in IHC in SNpc and ST of mice. Results : In an in vitro system, TOFE decreasesd NO generations in BV2 cells. TOFE protected dopaminergic cells against LPS or $MPP^+$-induced toxicity in primary mesencephalic dopaminergic neurons. In vivo system, TOFE at 50 mg/kg treated group showed improved motor deteriorations than the MPTP only treated group and TOFE significantly protected striatal dopaminergic damage from MPTP-induced neurotoxicity in mice. Moreover, TOFE inhibited activation of astrocyte and microglia in SNpc and ST of the mice. Conclusions : We concluded that TOFE showed anti-parkinsonian effect by protection of dopaminergic neurons against MPTP toxicity through anti-inflammatory actions.