Current Organizations / Institutes

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Previous Organizations / Institutes

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Gwi Yeong Jang has a total of 150 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Cynanchum wilfordii modulates inflammatory responses in LPS-stimulated RAW264.7 cells via the NF-κB and MAPK pathways

    by Yun-Jeong Ji, Min Hye Kang, Sin Hee Han, Young-Seob Lee, Myoung-Jin Kim, Jang Hoon Kim, Gwi Yeong Jang

    Cynanchum wilfordii is a widely used herb in Oriental medicine, known for its wide range of therapeutic applications. The present study was conducted with the aim of evaluating the effects of selected compounds isolated from C. wilfordii, including 4-hydroxyacetophenone (CW1), 2,4-dihydroxyacetophenone (CW2), wilfoside K1N (CW3), and cynandione A (CW4), on the inflammatory response induced by treatment of macrophages with LPS. The study focused on the analysis of the MAPK and NF-κB pathways. The results showed that treatment with CW1, CW2, CW3 and CW4 inhibited the expression of p-ERK, p-JNK, p-p38 and p-IkBa in LPS-induced macrophages, with CW4 exhibiting the greatest inhibitory effects. Furthermore, CW4 treatment showed the most significant inhibitory effect on p-IκB-α/IκB-α expression in the NF-κB pathway. In conclusion, the data demonstrate that CW4 exerts a robust inhibitory effect on macrophage inflammatory signalling pathways in the LPS-induced inflammatory response.


  • Open Access

    Roasted Astragalus membranaceus Inhibits Cognitive Decline in 5xFAD Mice by Activating the BDNF/CREB Pathway

    by Ji Hye Yoon, Jinyoung Maeng, Yujin Kim, Gidong Koo, Jeong Seok Shim, Sangeum Im, Subin Jung, Jihwan Shin, Gwi Yeong Jang, Sung-Su Kim, et al.

    Alzheimer's disease(AD) is a complex pathological process that incurs significant societal costs, yet effective treatments have not yet been developed. Novel compounds targeting β-amyloid, based on the amyloid cascade hypothesis, have failed to demonstrate clinical efficacy. Among natural products with diverse mechanisms, components contained in Astragali Radix (AR) have shown anti-dementia effects in various preclinical studies, including improved cognitive function, reduced β-amyloid levels, and decreased insulin resistance. This study administered a water-extracted roasted AR to 3-month-old female 5xFAD mice for 3 months, observing changes in cognitive behavior, blood glucose, and neural signaling. Roasted AR lowered glucose levels, improved working memory, fear avoidance memory, and spatial memory, and reduced anxiety behavior in 5xFAD mice. In the hippocampus, the protein expression of BDNF and p-CREB/CREB was increased, while p-JNK/JNK was decreased. The effects of roasted AR were similar to unroasted AR in 5xFAD mice, with some components being more abundant. Therefore, roasting AR enhances its taste and aroma, making it suitable for long-term consumption in the form of tea, which could be effective in preventing neurodegenerative diseases such as dementia.


  • Open Access

    Roasted Astragalus membranaceus Inhibits Aβ25–35-Induced Oxidative Stress in Neuronal Cells by Activating the Nrf2/HO-1 and AKT/CREB/BDNF Pathways

    by Yun-Jeong Ji, Min Hye Kang, Sin Hee Han, Geum-Soog Kim, Hyung Don Kim, Gwi Yeong Jang

    (1) Background: Astragalus membranaceus (AM) has antioxidant and anti-inflammatory effects, but its specific mechanism of action in the brain is still unclear. In this study, we developed a roasting process to maximize the cognitive improvement impact of AM. We focused on enhancing physiological activity to enhance the brain neuron protection effect and alleviate neuronal damage caused by neurodegenerative diseases. (2) Methods: AM was roasted at 260 °C for 20, 30, or 40 min, and the hot water extracts were tested on HT22 cells for ROS levels, apoptosis, and antioxidant protein expression. The effect on the BDNF-AKT-CREB pathway under stress was also analyzed. (3) Results: Roasted AM decreased ROS production and the expression of apoptosis-related factors while activating the expression of antioxidant proteins in HT22 cells treated with Aβ25–35. In particular, 30 min roasting (R-AM2) significantly reduced ROS production, inhibited cell death, and increased antioxidant protein expression. The Nrf2 pathway was activated Bax, and cleaved caspase-3 levels were reduced. BDNF and p-CREB expression were increased by 20% and 50–70%, respectively. In the MAPK pathway, p-ERK levels were increased by 30%, and p-P38 levels were increased by approximately 20%. (4) Conclusions: These findings suggest that roasted AM upregulates brain-derived neurotrophic factor (BDNF) in HT22 cells, providing neuroprotective effects by activating the AKT/CREB/BDNF pathway and inhibiting neuronal apoptosis. Therefore, roasted AM shows potential as a neuroprotective agent for preventing or treating neurodegenerative diseases, such as Alzheimer’s, linked to BDNF deficiency.


  • Open Access

    Platycodon grandiflorum exhibits anti-neuroinflammatory potential against beta-amyloid-induced toxicity in microglia cells

    by Yun-Jeong Ji, Min Hye Kang, Geum-Soog Kim, Hyung Don Kim, Gwi Yeong Jang

    Background/objectives: Platycodon grandiflorum (PG) is used in traditional oriental medicine to treat several ailments.Methods: The study investigated the anti-inflammatory and neuroprotective effects of PGW (P. grandiflorum) extract in Aβ25-35-induced inflammation in BV2 microglia cells.Result: PGW demonstrated significant inhibition of nitric oxide (NO) production, with reductions of 30.4, 36.7, and 61.2% at concentrations of 50, 100, and 200 μg/mL, respectively. Moreover, PGW effectively suppressed the production of pro-inflammatory cytokines IL-1β and IL-6 and exhibited significant inhibitory activity against TNF-α at 200 μg/mL. Furthermore, PGW treatment mitigated apoptosis in Aβ-induced BV2 cells by modulating the mitochondrial apoptosis pathway, regulating Bcl-2 family protein synthesis, and inhibiting caspase activation. Mechanistically, PGW attenuated the activation of the MAPK (JNK, ERK, p38) pathway induced by Aβ, showing a concentration-dependent decrease in phosphorylation levels of these proteins. Additionally, PGW inhibited the NF-κB pathway activation by reducing the phosphorylation levels of p65 and IκBα in a concentration-dependent manner.Conclusion: PGW demonstrated anti-inflammatory and neuroprotective effects in Aβ-induced neuronal cells, suggesting its potential as a therapeutic agent for neuroinflammatory associated with neurodegenerative diseases.


  • Open Access

    Heat Treatment Enhances the Neuroprotective Effects of Crude Ginseng Saponin by Increasing Minor Ginsenosides

    by Yun-Jeong Ji, Hyung Don Kim, Eun Suk Lee, Gwi Yeong Jang, Hyun-A Seong

    Ginsenoside is the primary active substance of ginseng and has many pharmacological effects, such as anti-cancer, immune, regulating sugar and lipid metabolism, and antioxidant effects. It also protects the nervous and cardiovascular systems. This study analyzes the effects of thermal processing on the bioactivities of crude ginseng saponin. Heat treatment increased the contents of minor ginsenosides in crude saponins, such as Rg3, and heat-treated crude ginseng saponin (HGS) had better neuroprotective effects than non-treated crude saponin (NGS). HGS reduced glutamate-induced apoptosis and reactive oxygen species generation in pheochromocytoma 12 (PC12) cells, significantly more than NGS. HGS protected PC12 cells against glutamate-induced oxidative stress by upregulating Nrf2-mediated antioxidant signaling and downregulating MAPK-mediated apoptotic signaling. HGS has the potential for the prevention and treatment of neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease.


  • Open Access

    Memory-Improving Activity of the Flower Extract from Chrysanthemum boreale (Makino) Maskino in Scopolamine-Treated Rodents

    by Seungeun Lee, Gwiyeong Jang, Jiwook Jung, Saetbyeol Park, Jeonghoon Lee, Yunji Lee, Jihye Lee, Yunjeong Ji, Jehun Choi, Geumsoog Kim

    One of the factors related to the pathogenesis of Alzheimer’s disease, a disease characterized by gradual cognitive and memory impairment, is an inflammatory process induced by the amyloid-β-mediated activation of microglia. In the present study, an extract of the Chrysanthemum boreale (Makino) Makino (CB) flower, which has inhibitory effects on inflammation and the production of phosphorylated tau in cells, was investigated for its ameliorative effect on memory dysfunction in scopolamine-treated Alzheimer’s disease models. The CB-extract-diet-administered groups, which were treated chronically with scopolamine (intraperitoneal), showed increased spontaneous alterations (12.5–15.5% increase) in the Y-maze test and latency to escape (3.7–6.7-fold increase) in the passive avoidance test, compared to the negative control (NC) group. Rats administered the CB extract also showed a higher tendency (66–86% increase) of hippocampal brain-derived neurotrophic factor expression than NC rats. Moreover, the ratio of phosphorylated extracellular signal-regulated kinase/extracellular signal-regulated kinase in the CB-extract-administered group was lower (48.0–52.2%) than that (100%) in the NC group. In the Morris water maze test conducted on the fifth day, the free-swimming times of the CB-extract-administered mice that were also treated with scopolamine for a short time (5 d) increased (51.7–56.1%) significantly compared to those of the NC mice. Finally, high-performance liquid chromatography analysis confirmed that isochlorogenic acid A, linarin, and chlorogenic acid are the major phenolic components of the CB extract. These results suggest that the extract of CB flowers might be useful as a functional material with memory-enhancing effects.


  • Open Access

    Anti-Obesity Activity in 3T3-L1 Cells of Cornus officinalis Fruits Harvested at Different Times

    by Eun Suk Lee, Su Ji Choi, Hyung Don Kim, Min Hye Kang, Yun-Jeong Ji, Geum-Soog Kim, Gwi Yeong Jang

    Obesity, a metabolic disease linked to several other diseases, is emerging as a global problem. We determined the harvest time that maximized the anti-obesity effect by evaluating the inhibition of lipid accumulation in 3T3-L1 cells treated with fruits of Cornus officinalis. FS1 (pericarp + seeds, harvested 15 September) showed excellent anti-obesity activity (Oil Red O; 26.12 ± 1.37% vs. MDI) and inhibited the expression of PPAR-γ (0.05 ± 0.01 ford vs. MDI), C/EBPα (0.03 ± 0.02 ford vs. MDI), and C/EBPβ (0.33 ± 0.07 ford vs. MDI) at 200 μg/mL. The antioxidant activity of FS1 was also the most effective. In addition, FS1 contained higher levels of active ingredients than samples harvested in other periods. Especially, content of loganin, verbenalin, and sweroside was high. In terms of anti-obesity activity and functional components, immature COF (FS1) was the best, and these results indicate that it is necessary to adjust the harvest time, when used as an anti-obesity agent.


  • Open Access

    Sasa borealis Ethanol Extract Protects PC12 Neuronal Cells against Oxidative Stress

    by Min Hye Kang, Yun-Jeong Ji, Yu Mi Han, Gwi Yeong Jang, Dong Hwi Kim, Jeong Hoon Lee, Geum-Soog Kim, Su Ji Choi, Hyung Don Kim

    The overproduction of reactive oxygen species (ROS) can cause oxidative stress to biomolecules such as nucleic acids, proteins, and lipids, leading to neurodegenerative disorders. Sasa borealis (SB) has antioxidant, anti-inflammatory, antidiabetic, and anti-obesity effects. We evaluated the neuroprotective activity of SB on hydrogen peroxide (H2O2)-induced oxidative stress. We investigated the antioxidant and neuroprotective effects of SB water extract (SBW) and SB ethanol extract (SBE) by measuring the radical scavenging activities and intracellular ROS production. SBE, which had a high level of isoorientin, had higher antioxidative activities than SBW in 2,2′-azino-bis-(3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt (ABTS+) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. It also reduced ROS generation in pheochromocytoma 12 (PC12) cells more significantly than SBW. It increased the translation of heme oxygenase-1 (HO-1), superoxide dismutase 2 (SOD2), catalase (CAT), and glutathione peroxidase (GPx) with a corresponding increase in the translation of NF-E2-related factor-2 (Nrf-2). In conclusion, SBE with high levels of phenolic compounds such as isoorientin shows promise for preventing neurodegenerative diseases.


  • Open Access

    Crude Saponin from Platycodon grandiflorum Attenuates Aβ-Induced Neurotoxicity via Antioxidant, Anti-Inflammatory and Anti-Apoptotic Signaling Pathways

    by Yun-Jeong Ji, Sujin Kim, Jwa-Jin Kim, Gwi Yeong Jang, Minho Moon, Hyung Don Kim

    Although Platycodon grandiflorum saponins exhibit many beneficial biological effects in various diseases and conditions, how they protect nerve cells against neurodegenerative diseases and Alzheimer’s disease (AD) pathology is unknown. We investigated whether P. grandiflorum crude saponin (PGS) protects neurons from neurodegeneration caused by amyloid beta (Aβ)-induced oxidative stress. Hippocampal neuron HT-22 cells were used in the in vitro experiment, and AD mice (5XFAD mice) were used as the in vivo model. Intracellular reactive oxygen species (ROS) was stained with DCF-DA and assessed using fluorescence microscopy. To elucidate the mechanism underlying neuroprotection, intracellular protein levels were assessed by western blotting. In 5XFAD mice, an animal model of AD, nerve damage recovery due to the induction of Aβ toxicity was evaluated by histological analysis. PGS attenuates Aβ-induced neurotoxicity by inhibiting Aβ-induced reactive oxygen species (ROS) production and apoptosis in HT-22 cells. Furthermore, PGS upregulated Nrf2-mediated antioxidant signaling and downregulated NF-κB-mediated inflammatory signaling. Additionally, PGS inhibited apoptosis by regulating the expression of apoptosis-associated proteins. In addition, PGS ameliorated Aβ-mediated pathologies, leading to AD-associated cognitive decline. Conclusions: Taken together, these findings suggest that PGS inhibits Aβ accumulation in the subiculum and cerebral cortex and attenuates Aβ toxicity-induced nerve damage in vitro and in vivo. Therefore, PGS is a resource for developing AD therapeutics.


  • Open Access

    Antioxidant and Anti-Melanogenic Activities of Heat-Treated Licorice (Wongam, Glycyrrhiza glabra × G. uralensis) Extract

    by Min Hye Kang, Gwi Yeong Jang, Yun-Jeong Ji, Jeong Hoon Lee, Su Ji Choi, Tae Kyung Hyun, Hyung Don Kim

    Melanin is a brown or black pigment that protects skin from ultraviolet radiation and reactive oxygen species (ROS). However, overproduction of melanin is associated with lentigines, melasma, freckles and skin cancer. Licorice has shown antioxidant, anti-tumor, anti-platelet, anti-inflammatory and immunomodulatory activities and is used as a natural treatment for skin whitening. We aimed to confirm the potential of Wongam, a new cultivar of licorice developed by the Rural Development Administration (RDA), as a whitening agent in cosmetics. In addition, we verified the effect of heat treatment on the bioactivity of licorice by comparing antioxidant and anti-melanogenic activities of licorice extract before and after heating (130 °C). The heat-treated licorice extract (WH-130) showed higher radical-scavenging activities in the ABTS+ (2,2′-azino-bis-(3-ethylbenzothiazolin-6-sulfonic acid) diammonium salt) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays. In addition, WH-130 inhibited melanogenesis more effectively due to downregulation of tyrosinase in B16F10 melanoma cells than non-heated licorice extract. Moreover, heat treatment increased total phenolic content. In particular, isoliquiritigenin, an antioxidant and anti-melanogenic compound of licorice, was produced by heat treatment. In conclusion, WH-130, with increased levels of bioactive phenolics such as isoliquiritigenin, has potential for development into a novel skin whitening material with applications in cosmetics.