• Journal of Ginseng Research
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• v.47 no.3
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• pp.420-428
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• 2023

Background: Ginsenoside F2 (GF2), a minor component of Panax ginseng, has been reported to possess a wide variety of pharmacological activities. However, its effects on glucose metabolism have not yet been reported. Here, we investigated the underlying signaling pathways involved in its effects on hepatic glucose. Methods: HepG2 cells were used to establish insulin-resistant (IR) model and treated with GF2. Cell viability and glucose uptake-related genes were also examined by real-time PCR and immunoblots. Results: Cell viability assays showed that GF2 up to 50 μM did not affect normal and IR-HepG2 cell viability. GF2 reduced oxidative stress by inhibiting phosphorylation of the mitogen-activated protein kinases (MAPK) signaling components such as c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 MAPK, and reducing the nuclear translocation of NF-κB. Furthermore, GF2 activated PI3K/AKT signaling, upregulated the levels of glucose transporter 2 (GLUT-2) and GLUT-4 in IR-HepG2 cells, and promoted glucose absorption. At the same time, GF2 reduced phosphoenolpyruvate carboxykinase and glucose-6-phosphatase expression as well as inhibiting gluconeogenesis. Conclusion: Overall, GF2 improved glucose metabolism disorders by reducing cellular oxidative stress in IR-HepG2 cells via MAPK signaling, participating in the PI3K/AKT/GSK-3β signaling pathway, promoting glycogen synthesis, and inhibiting gluconeogenesis.

• Journal of the Korean Society of Food Culture
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• v.38 no.3
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• pp.176-183
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• 2023

In this study, we investigated the effect of the extracts of Cyrtomium fortunei J.Sm. (CFJ) on lipopolysaccharide (LPS) induced inflammation in mouse BV-2 microglial cells. Nitric oxide (NO) production and cell viability were measured using the Griess reagent and the (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) (MTT) assay. Inflammatory cytokines were detected by quantitative polymerase chain reaction (qPCR) in BV-2 microglial cells with and without CFJ extracts. Subsequently, mitogen-activated protein kinases (MAPKs) and antioxidant markers were assessed by western blot analysis. It was found that the CFJ extract significantly decreased the production of pro-inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF]-α, and IL-1β) and NO in BV-2 microglial cells that were stimulated with LPS. In addition, the expression levels of the phosphorylation of the MAPK family (p38, c-Jun N-terminal kinases [JNK], and extracellular-signal regulated kinase [ERK]) were reduced by CFJ. Also, treatment with CFJ significantly increased the activities of superoxide dismutase type 1(SOD1) and Catalase in BV-2 microglial cells. Our results indicate that CFJ has a potent suppressive effect on the pro-inflammatory responses of activated BV-2 microglia. Therefore, CFJ has the potential to be an effective treatment for neurodegenerative diseases, as it can inhibit the production of inflammatory mediators in activated BV-2 microglial cells.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.56-56
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• 2023

The cone of Pinus rigida × Pinus taeda (PRT), a plant in the Pinaceae family, has long been used in traditional medicine to treat hemostasis, bruises, and burns. Previous research has shown that regulating oxidation-reduction reactions in reactive oxygen species can help inhibit melanogenesis, the process of melanin synthesis, which is a common target for addressing hyperpigmentation. Inhibiting tyrosinase is also known to be effective in this regard. Based on these findings, we conducted an investigation into the inhibitory effect of the ethyl acetate fraction of PRT (ERT) on melanogenesis in B16 F10 cells. We know that the expression levels of melanin biosynthesis-related proteins, including tyrosinase, TRP-1, and TRP-2, are regulated by MITF (microphthalmia-associated transcription factor) and cAMP, with cAMP affecting the activity of protein kinase A (PKA). PKA can reduce melanogenesis, and CREB reduces the phosphorylation of melanin-producing enzymes. In addition, the MAPK signaling pathway, composed of ERK, JNK, p38, and other factors, is also known to play a role in the inhibition of melanogenesis in melanocytes. Our immunoblotting results showed that ERT inhibited the expression of melanin production-related proteins (tyrosinase, TRP-1, TRP-2, and MITF) that were significantly increased by a-MSH treatment to promote melanin production. Furthermore, the phosphorylation levels of factors related to cAMP/PKA/CREB and MAPK signaling pathways were significantly reduced without affecting the total form. In conclusion, we believe that treatment with ERT can inhibit melanin synthesis by modulating the phosphorylation of cAMP/PKA/CREB and MAPK signaling pathways at the cellular level. These findings suggest the potential of ERT as a raw material for functional cosmetics and pharmaceuticals, thanks to its antioxidant activity and ability to inhibit melanogenesis. We thought that these findings of ERT as a natural plant resource will inspire further research and development in this area.

• Molecules and Cells
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• v.46 no.10
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• pp.627-636
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• 2023

Periodontal disease is a chronic inflammatory disease that leads to the gradual destruction of the supporting structures of the teeth including gums, periodontal ligaments, alveolar bone, and root cementum. Recently, interests in alleviating symptoms of periodontitis (PD) using natural compounds is increasing. Avenanthramide-C (Avn-C) is a polyphenol found only in oats. It is known to exhibit various biological properties. To date, the effect of Avn-C on PD pathogenesis has not been confirmed. Therefore, this study aimed to verify the protective effects of Avn-C on periodontal inflammation and subsequent alveolar bone erosion in vitro and in vivo. Upregulated expression of catabolic factors, such as matrix metalloproteinase 1 (MMP1), MMP3, interleukin (IL)-6, IL-8, and COX2 induced by lipopolysaccharide and proinflammatory cytokines, IL-1β, and tumor necrosis factor α (TNF-α), was dramatically decreased by Avn-C treatment in human gingival fibroblasts and periodontal ligament cells. Moreover, alveolar bone erosion in the ligature-induced PD mouse model was ameliorated by intra-gingival injection of Avn-C. Molecular mechanism studies revealed that the inhibitory effects of Avn-C on the upregulation of catabolic factors were mediated via ERK (extracellular signal-regulated kinase) and NF-κB pathway that was activated by IL-1β or p38 MAPK and JNK signaling that was activated by TNF-α, respectively. Based on this study, we recommend that Avn-C may be a new natural compound that can be applied to PD treatment.

• Biomolecules & Therapeutics
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• v.32 no.2
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• pp.249-260
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• 2024

New supplements with preventive effects against skin photodamage are receiving increasing attention. This study evaluated the anti-photoaging effects of salmon nasal cartilage proteoglycan (SPG), acting as a functional material for skin health. We administered SPG to in vitro and in vivo models exposed to ultraviolet B (UVB) radiation and assessed its moisturizing and anti-wrinkle effects on dorsal mouse skin and keratinocytes and dermal fibroblasts cell lines. These results showed that SPG restored the levels of filaggrin, involucrin, and AQP3 in the epidermis of UVB-irradiated dorsal skin and keratinocytes, thereby enhancing the keratinization process and water flow. Additionally, SPG treatment increased the levels of hyaluronan and skin ceramide, the major components of intercellular lipids in the epidermis. Furthermore, SPG treatment significantly increased the levels of collagen and procollagen type 1 by down-regulating matrix metalloproteinase 1, which play a crucial role in skin fibroblasts, in both in vitro and in vivo models. In addition, SPG strongly inhibited mitogen-activated protein kinase (MAPKs) signaling, the including extracellular signal-regulated kinase, c-Jun N-terminal kinase (JNK), and p38. These findings suggest that dietary SPG may be an attractive functional food for preventing UVB-induced photoaging. And this SPG product may provide its best benefit when treating several signs of skin photoaging.

• Biomolecules & Therapeutics
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• v.32 no.2
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• pp.224-230
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• 2024

Pinitol (3-O-Methyl-D-chiro-inositol) has been reported to possess insulin-like effects and is known as one of the anti-diabetic agents to improve muscle, liver, and endothelial cells. However, the beneficial effects of pinitol on the skin are not well known. Here, we investigated whether pinitol had effects on human dermal fibroblasts (HDFs), and human dermal equivalents (HDEs) irradiated with ultraviolet A (UVA), which causes various damages including photodamage in the skin. We observed that pinitol enhanced wound healing in UVA-damaged HDFs. We also found that pinitol significantly antagonized the UVA-induced up-regulation of matrix metalloproteinase 1 (MMP1), and the UVA-induced down-regulation of collagen type I and tissue inhibitor of metalloproteinases 1 (TIMP1) in HDEs. Electron microscopy analysis also revealed that pinitol remarkably increased the number of collagen fibrils with regular banding patterns in the dermis of UVA-irradiated human skin equivalents. Pinitol significantly reversed the UVA-induced phosphorylation levels of ERK and JNK but not p38, suggesting that this regulation may be the mechanism underlying the pinitol-mediated effects on UVA-irradiated HDEs. We also observed that pinitol specifically increased Smad3 phosphorylation, which is representative of the TGF-β signaling pathway for collagen synthesis. These data suggest that pinitol exerts several beneficial effects on UVA-induced damaged skin and can be used as a therapeutic agent to improve skin-related diseases.

• IMMUNE NETWORK
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• v.23 no.4
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• pp.34.1-34.15
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• 2023

Lung cancer, particularly non-small cell lung cancer (NSCLC) which contributes more than 80% to totally lung cancer cases, remains the leading cause of cancer death and the 5-year survival is less than 20%. Continuous understanding on the mechanisms underlying the pathogenesis of this disease and identification of biomarkers for therapeutic application and response to treatment will help to improve patient survival. Here we found that a molecule known as DUSP10 (also known as MAPK phosphatase 5) is oncogenic in NSCLC. Overexpression of DUSP10 in NSCLC cells resulted in reduced activation of ERK and JNK, but increased activation of p38, which was associated with increased cellular growth and migration. When inoculated in immunodeficient mice, the DUSP10-overexpression NSCLC cells formed larger tumors compared to control cells. The increased growth of DUSP10-overexpression NSCLC cells was associated with increased expression of tumor-promoting cytokines including IL-6 and TGFβ. Importantly, higher DUSP10 expression was associated with poorer prognosis of NSCLC patients. Therefore, DUSP10 could severe as a biomarker for NSCLC prognosis and could be a target for development of therapeutic method for lung cancer treatment.

• IMMUNE NETWORK
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• v.20 no.3
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• pp.25.1-25.13
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• 2020

Acinetobacter baumannii is known for its multidrug antibiotic resistance. New approaches to treating drug-resistant bacterial infections are urgently required. Cathelicidin-related antimicrobial peptide (CRAMP) is a murine antimicrobial peptide that exerts diverse immune functions, including both direct bacterial cell killing and immunomodulatory effects. In this study, we sought to identify the role of CRAMP in the host immune response to multidrug-resistant Acinetobacter baumannii. Wild-type (WT) and CRAMP knockout mice were infected intranasally with the bacteria. CRAMP^-/- mice exhibited increased bacterial colony-forming units (CFUs) in bronchoalveolar lavage (BAL) fluid after A. baumannii infection compared to WT mice. The loss of CRAMP expression resulted in a significant decrease in the recruitment of immune cells, primarily neutrophils. The levels of IL-6 and CXCL1 were lower, whereas the levels of IL-10 were significantly higher in the BAL fluid of CRAMP^-/- mice compared to WT mice 1 day after infection. In an in vitro assay using thioglycollate-induced peritoneal neutrophils, the ability of bacterial phagocytosis and killing was impaired in CRAMP^-/- neutrophils compared to the WT cells. CRAMP was also essential for the production of cytokines and chemokines in response to A. baumannii in neutrophils. In addition, the A. baumannii-induced inhibitor of κB-α degradation and phosphorylation of p38 MAPK were impaired in CRAMP^-/- neutrophils, whereas ERK and JNK phosphorylation was upregulated. Our results indicate that CRAMP plays an important role in the host defense against pulmonary infection with A. baumannii by promoting the antibacterial activity of neutrophils and regulating the innate immune responses.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.699-709
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• 2024

Oxya chinensis sinuosa (OC) is a well-known edible insect. Several researches on the health benefits of OC consumption have been performed to date; however, their effect on eye health remains largely unknown. This study aimed to assess the protective effects of OC extracts on the oxidative stress on the retinal pigment epithelium (RPE) cells. Oxidative damage has been identified as one of the key regulatory factors in agerelated macular degeneration. H₂O₂-induced reactive oxygen species (ROS) production, a well-known oxidative stress factor, can cause cell death in retinal pigment epithelia cells. In this study, we found that three OC extracts effectively prevented H₂O₂-induced ROS production and subsequent death of ARPE-19 cells in a dose-dependent manner. In addition, the OC extracts inhibited the phosphorylation of mitogen-activated protein kinases including p38, JNK, and ERK. The OC extracts restored IκBα degradation induced by H₂O₂, indicating that OC extracts suppressed the activation of nuclear factorκB. Furthermore, the three OC extracts were shown to have antioxidant effects by upregulating the intracellular expression of key antioxidant proteins such as SOD, NQO, and HO-1. Here we demonstrated the antioxidant and anti-apoptotic effects of the OC extracts on ARPE-19, indicating their potential role in improving eye health. These results suggest that three OC extracts plays a critical role in oxidative stress-induced cell death protects in ARPE-19 cells.

• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.949-957
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• 2024

There has been a growing interest in skin beauty and antimelanogenic products. Melanogenesis is the process of melanin synthesis whereby melanocytes are activated by UV light or hormone stimulation to produce melanin. Melanogenesis is mediated by several enzymes, such as tyrosinase (TYR), microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TRP-1), and TRP-2. In this study, we investigated the effect of Tuber himalayense extract on melanin synthesis in α-melanocyte-stimulating hormone (α-MSH)-treated B16F10 melanoma cells. We confirmed that T. himalayense extract was not toxic to α-MSH-treated B16F10 melanoma cells and exhibited a significant inhibitory effect on melanin synthesis at concentrations of 25, 50, and 100 ㎍/ml. Additionally, the T. himalayense extract inhibited melanin, TRP-1, TRP-2, tyrosinase, and MITF, which are enzymes involved in melanin synthesis, in a concentration-dependent manner. Furthermore, T. himalayense extract inhibited the mitogen-activated protein kinase (MAPK) pathways, such as extracellular signal-regulated kinase-1/2 (ERK), c-Jun N-terminal kinase (JNK), and p38. Therefore, we hypothesized that various components of T. himalayense extract affect multiple factors involved in melanogenesis in B16F10 cells. Our results indicate that T. himalayense extract could potentially be used as a new material for preparing whitening cosmetics.