• YAKHAK HOEJI
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• v.56 no.5
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• pp.299-303
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• 2012

Homosyringaldehyde was isolated and identified from the 80% methanol extract of roots of Cynanchum paniculatum. C. paniculatum has been widely used for the treatment of various diseases such as neurasthenia, insomnia, dysmenorrheal and toothache. This compound exerted significant neuroprotective activities against glutamate-induced neurotoxicity in hippocampal HT22 cell line by 37.53% (at the concentration of $100{\mu}M$). We investigated mode of action of this compound. Homosyringaldehyde ($100{\mu}M$) significantly decreased the ROS level and $Ca^{2+}$ concentration in the oxidative stress induced HT22 cells by oxidative glutamate toxicity. Thus, our results suggest that homosyringaldehyde significantly protect HT22 cells against glutamate-induced oxidative stress, via antioxidative activities. As the results, we suggest that homosyringaldehyde may be useful in the treatment of neurogenerative disorders.

• Journal of Ginseng Research
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• v.33 no.2
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• pp.111-114
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• 2009

The six phenolic-compound (ascorbic acid, maltol, esculetin,p-coumaric acid, cinnamic acid, and quercetin) contents of Panax ginseng c.A. Meyer were determined in this study. The results showed that the ascorbic acid, cinnamic acid, and esculetin contents of Panax ginseng C.A. Meyer are higher than those of the other ingredients. Among these compounds, ascorbic acid and cinnamic acid significantly inhibited LPS-induced nitric oxide production in the RAW 264.7 cells. Cinnamic acid also effectively inhibited the oxidative damages in the human neuroblastoma SH-SY5Y cells. Although this study examined the neuroprotective and anti-inflammatory activities using only one kind of cells, its results suggest that cinnarnic acid potently contributes to the neuroprotective and anti-inflammatory properties of Panax ginseng C.A. Meyer.

• Biomolecules & Therapeutics
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• v.29 no.6
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• pp.615-629
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• 2021

An active compound, triterpene saponin, astersaponin I (AKNS-2) was isolated from Aster koraiensis Nakai (AKNS) and the autophagy activation and neuroprotective effect was investigated on in vitro and in vivo Parkinson's disease (PD) models. The autophagy-regulating effect of AKNS-2 was monitored by analyzing the expression of autophagy-related protein markers in SH-SY5Y cells using Western blot and fluorescent protein quenching assays. The neuroprotection of AKNS-2 was tested by using a 1-methyl-4-phenyl-2,3-dihydropyridium ion (MPP⁺)-induced in vitro PD model in SH-SY5Y cells and an MPTP-induced in vivo PD model in mice. The compound-treated SH-SY5Y cells not only showed enhanced microtubule-associated protein 1A/1B-light chain 3-II (LC3-II) and decreased sequestosome 1 (p62) expression but also showed increased phosphorylated extracellular signal-regulated kinases (p-Erk), phosphorylated AMP-activated protein kinase (p-AMPK) and phosphorylated unc-51-like kinase (p-ULK) and decreased phosphorylated mammalian target of rapamycin (p-mTOR) expression. AKNS-2-activated autophagy could be inhibited by the Erk inhibitor U0126 and by AMPK siRNA. In the MPP⁺-induced in vitro PD model, AKNS-2 reversed the reduced cell viability and tyrosine hydroxylase (TH) levels and reduced the induced α-synuclein level. In an MPTP-induced in vivo PD model, AKNS-2 improved mice behavioral performance, and it restored dopamine synthesis and TH and α-synuclein expression in mouse brain tissues. Consistently, AKNS-2 also modulated the expressions of autophagy related markers in mouse brain tissue. Thus, AKNS-2 upregulates autophagy by activating the Erk/mTOR and AMPK/mTOR pathways. AKNS-2 exerts its neuroprotective effect through autophagy activation and may serve as a potential candidate for PD therapy.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.246-254
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• 2018

Enzyme fermentation is a type of food processing technique generally used to improve the biological activities of food and herbal medicines. In this study, a Syzygii Flos (clove) extract was fermented using laccase derived from Trametes versicolor (LTV). The fermented clove extract showed greater neuroprotective effects against glutamate toxicity on HT22 than the non-fermented extract did. HPLC analysis revealed that the eugenol (1) and dehydrodieugenol (2) contents had decreased and increased, respectively, after fermentation. The content of 2 peaked at 1 h after fermentation to $103.50{\pm}8.20mg/g_{ex}$ (not detected at zero time), while that of 1 decreased to $79.54{\pm}4.77mg/g_{ex}$ ($185.41{\pm}10.16mg/g_{ex}$ at zero time). Compound 2 demonstrated promising HT22 neuroprotective properties with inhibition of $Ca^{2+}$ influx, the overproduction of intracellular reactive oxygen species, and lipid peroxidation. In addition, LTV showed the best fermentation efficacy compared with laccases derived from Pleurotus ostreatus and Rhus vernicifera.

• Korean Journal of Pharmacognosy
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• v.47 no.3
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• pp.211-216
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• 2016

In the course of our continuing search for biologically active components from Korean medicinal plants, we isolated the main compound, luteolin 5-glucoside from aqueous fraction of Ajuga spectabilis. The structure was elucidated by the basis of $^1H$ and $^{13}C$ NMR and TOF ESI-MS data. Quantitative analysis of luteolin 5-glucoside was carried out on a XBridge C18 column ($S-5{\mu}m$, $4.6{\times}250mm$) with gradient elution composed of acetonitrile:water. The results exhibit that the average content of main compound in A. spectabilis were 0.048%. Oxidative stress plays a major role Alzheimer's disease (AD) and other neurodogenerative disease. AD is major health problem and there is currently no clinically accepted treatment to cure or stop its progression. Pretreatment with luteolin 5-glucoside markedly attenuated $H_2O_2$-induced cell viability loss in a dose-dependent manner. Luteolin 5-glucoside also inhibited the formation of intracellular reactive oxygen species in SH-SY5Y. The results suggest that luteolin 5-glucoside from A. spectabilis has protective effects against oxidative stress-induced cytotoxicity, which might be a potential therapeutic compound for treating and/or preventing neurodegenerative disease implicated with oxidative stress.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.105-112
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• 2021

Excessive accumulation of the amyloid beta (Aβ) peptide has been implicated in the pathogenesis of Alzheimer's disease (AD). Paeonia lactiflora (PL) has been used in treatments of several conditions such as inflammation, arthritis, and cognitive impairment. The purpose of this study was to investigate the neuroprotective effect and mechanisms of PL and its active compound, paeoniflorin (PF), on Aβ_25-35-induced neurotoxicity in SH-SY5Y cells. We evaluated cell viability, lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) production. Furthermore, underlying mechanism of PL and PF on the regulation of amyloidogenic pathway was analyzed by Western blotting. In our results, Aβ_25-35-induced neuronal cell loss was observed, whereas treatment with PL (10, 50, and 100 ㎍/mL) and PF (1, 5, and 10 ㎍/mL) significantly elevated the cell viability, and decreased LDH release and ROS production. In addition, exposure of SH-SY5Y cells to Aβ_25-35 significantly increased the protein levels of amyloid precursor protein (APP)-C-terminal fragment β, β-site APP-cleaving enzyme, and presenilin-1 and -2. However, treatment with PL and PF inhibited the amyloidogenic pathway via the down-regulation of those protein expressions. Taken together, our results indicate that PL, and its active compound PF, could protect SH-SY5Y cells against Aβ_25-35-induced cell neurotoxicity by attenuating LDH release and ROS production, and these effects may be attributed to regulation of amyloidogenic pathway-related protein expression. In conclusion, PL and PF could be a potential to prevent neurodegenerative disorders such as AD.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.804-809
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• 2005

The EtOAc-soluble fraction from a methanolic extract of Hovenia dulcis Thunb. exhibited neuroprotective activity against glutamate-induced neurotoxicity in mouse hippocampal HT22 cells. The neuroprotective activity-guided isolation resulted in 8 phenolic compounds (1-8), such as vanillic acid (1), ferulic acid (2), 3,5-dihydroxystilbene (3), (+)-aromadendrin (4), methyl vanillate (5), (-)-catechin (6), 2,3,4-trihydrobenzoic acid (7), and (+)-afzelechin (8). Among these, compounds 6 and 8 had a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells. Furthermore, compound 6 had a DPPH free radical scavenging effect with an $IC_{50}$ value of $57.7{\mu}M$, and a superoxide anion radical scavenging effect with an $IC_{50}$ value of $8.0{\mu}M$. Both compounds 6 and 8 had ABTS cation radical scavenging effects with $IC_{50}$ values of $7.8{\mu}M\;and\;23.7${\mu}M$, respectively. These results suggest that compounds 6 and 8 could be neuroprotectants owing to their free radical scavenging activities.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.178-184
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• 2019

Parkinson's disease is a neurodegenerative disease characterized by the progressive loss of dopaminergic neurons within the substantia nigra pars compacta. In the present study, we investigated whether ${\beta}-Lapachone$ (${\beta}-LAP$), a natural naphthoquinone compound isolated from the lapacho tree (Tabebuia avellanedae), elicits neuroprotective effects in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. ${\beta}-LAP$ reduced the tyrosine hydroxylase (TH)-immunoreactive fiber loss induced by MPTP in the dorsolateral striatum, and alleviated motor dysfunction as determined by the rotarod test. In addition, ${\beta}-LAP$ protected against MPTP-induced loss of TH positive neurons, and upregulated B-cell lymphoma 2 protein (Bcl-2) expression in the substantia nigra. Based on previous reports on the neuroprotective role of nuclear factor-E2-related factor-2 (Nrf2) in neurodegenerative diseases, we investigated whether ${\beta}-LAP$ induces upregulation of the Nrf2-hemeoxygenae-1 (HO-1) signaling pathway molecules in MPTP-injected mouse brains. Western blot and immunohistochemical analyses indicated that ${\beta}-LAP$ increased HO-1 expression in glial fibrillary acidic protein-positive astrocytes. Moreover, ${\beta}-LAP$ increased the nuclear translocation and DNA binding activity of Nrf2, and the phosphorylation of upstream adenosine monophosphate-activated protein kinase (AMPK). ${\beta}-LAP$ also increased the localization of p-AMPK and Nrf2 in astrocytes. Collectively, our data suggest that ${\beta}-LAP$ exerts neuroprotective effect in MPTP-injected mice by upregulating the p-AMPK/Nrf2/HO-1 signaling pathways in astrocytes.

• Natural Product Sciences
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• v.12 no.3
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• pp.134-137
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• 2006

Four lignan compounds including gomisin J (1), schizandrin (2), gomisin A (3), and angeloyl gomisin H (4) have been isolated from the MeOH extract of Schizandra chinensis fruits. The evaluation for protective effect of compounds 1-4 against tert-butyl hydroperoxide (t-BHP)-induced cytotoxicity in hippocampal HT22 cell line was conducted. Compound 1 showed significant protective effect with an $EC_{50}$ value of $43.3{\pm}2.3\;{\mu}M$, whereas compounds 2-4 were inactive. Trolox, one of the well-known antioxidant, used as a positive control, and also showed protective effect with an $EC_{50}$ value of $213.8{\pm}8.4\;{\mu}M$. These results suggest that compound 1 may possess the neuroprotective activity against oxidant-induced cellular injuries.

• Natural Product Sciences
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• v.13 no.2
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• pp.101-104
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• 2007

Four isoflavones including tectorigenin (1), irisflorentin (2), irigenin (3), and tectoridin (4) have been isolated from the 70% EtOH extract of Belamcanda chinensis rhizome. The evaluation for protective effect of compounds 1-4 against glutamate-induced cytotoxicity in hippocampal HT22 cell line was conducted. Compound 1 showed significant protective effect with an EC$_{50}$ value of 67.25 ${\pm}$ 1.2 ${\mu}$M, whereas compounds 2-4 were inactive. These results suggest that compound 1 may possess the neuroprotective activity against oxidative cellular injures.