• Journal of Life Science
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• v.32 no.1
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• pp.51-55
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• 2022

Matrix metalloproteinase (MMP) enzymes are responsible for the degradation and formation of the extracellular matrix (ECM), and overproduction of MMPs is observed in several diseases, such as cancer and asthma, that progress with metastatic characteristics. Natural products, especially phytochemicals, have been an important source of MMP inhibitors with reduced side effects. Although the majority of phytochemicals inhibit the enzymatic activity of MMPs, some suppress MMP production. In this context, the current study evaluated the potential of Corydalis heterocarpa, a halophyte with reported bioactivities, to inhibit MMP expression in PMA-stimulated HT-1080 cells. A crude C. heterocarpa extract was shown to decrease the mRNA and protein expression of MMP-2 and MMP-9 while increasing the endogenous MMP inhibitors TIMP-1 and TIMP-2 which regulate MMP expression in healthy tissues. In addition, our results show that the inhibitory effects of C. heterocarpa might occur through suppression of the phosphorylation of MAPK signaling, the upstream activator of MMP overexpression. In conclusion, C. heterocarpa is a potential source of antimetastatic compounds that might serve as lead molecules to develop novel MMP inhibitors.

• Journal of the Korean Electrochemical Society
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• v.25 no.4
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• pp.184-190
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• 2022

Spinel LiMn₂O₄ (LMO) and layered LiNi_0.5Co_0.2Mn_0.3O₂ (NCM) are widely used as positive electrode materials for lithium-ion batteries. LMO and NCM positive electrode materials have a complementary properties. LMO has low cost and high safety and NCM materials show a relatively high specific capacity and better cycle life even at elevated temperature. Therefore, the LMO and NCM active materials are blended and used as a positive electrode in large-size batteries for electric vehicles (xEV). In this study, the cycle performance of a blended electrode prepared by simply mixing LMO and NCM and a bi-layer electrode in which two electrode layers aree sequentially coated are compared. The bi-layer electrode prepared by composing the same ratio of both active materials has similar capacity and cycle performance to the blend electrode. However, the LN electrode coated with LMO first and then NCM is the best in the full cell cycle performance at elevated temperature, and the NL electrode, in which NCM is first coated with LMO has a faster capacity degradation than the blended electrode because LMO is mainly located on the top of the electrode adjacent to electrolyte and graphite negative electrode. Also, the LSTA (linear sweep thermmametry) analysis results show that the LN bi-layer electrode in which the LMO is located inside the electrode has good thermal stability.

• Composites Research
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• v.36 no.1
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• pp.37-41
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• 2023

The treated water inside the ballast electrolytic cell creates a highly alkaline atmosphere due to hydroxide generated at the DSA(Dimension Stable Anode) electrode during electrolysis. In this study, a composite material that can replace the weakness of the PE-coated steel pipe used in the existing ballast pipe was prepared. The test samples are BRE(Basalt fiber reinforced epoxy), BRP(Basalt fiber reinforced unsaturated polyester), GRE(Glass fiber reinforced epoxy), and GRP(Glass fiber reinforced unsaturated polyester). And then it was immersed in NaOH for 720 hours. The friction test of each specimen was conducted. The Friction coefficient analysis according to material friction depth and interfacial adhesion behavior between resin and fiber were analyzed. As a result, the mechanism of interfacial separation between resin and fiber could be analyzed. In the case of the unsaturated polyester resin with low interfacial bonding strength the longer the immersion time in the alkaline solution, the faster the internal deterioration caused by the deterioration that started from the surface, resulting in a decrease in the friction coefficient. It is hoped that this study will help to understand the degradation behavior of composite materials immersed in various chemical solutions such as NaOH, acid, and sodium hypochlorite in the future.

• The Korea Journal of Herbology
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• v.24 no.3
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• pp.153-160
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• 2009

Objectives : The purpose of this study was to investigate the anti-inflammatory effects of extract from Trogopterorum Faeces (TF) on the RAW 264.7 cells. Methods : To prove the TF's anti-inflammatory effects, we investigated nitric oxide (NO) production and own cell viability. We examined the cytokine productions on lipopolysacchride (LPS)-induced RAW 264.7 cells and also cellular regulatory mechanisms. Results : TF does not have any cytotoxic effect. TF reduced LPS-induced NO production, interleukin (IL)-1b, IL-6, IL-10 and tumor necrosis factor-a (TNF-a) in RAW 264.7 cells. TF inhibited the activation of mitogen-activated protein kinases (MAPKs) such as p38, extracelluar signal-regulated kinase (ERK 1/2) and c-Jun NH2-terminal kinase (JNK) and also the degradation of inhibitory kappa B a (Ik-Ba) in the LPS-stimulated RAW 264.7 cells. TF reduced the serum levels of IL-1b, IL-6, TNF-a. The survival rate of LPS-induced endotoxin shock was increased by TF administration. Conclusions : TF down-regulated LPS-induced NO and cytokines production, which could provide a clinical basis for anti-inflammatory properties.

• Journal of Life Science
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• v.33 no.6
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• pp.523-529
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• 2023

Ubiquitination is a post-translational modification that is involved in the quality control of proteins and responsible for modulating a variety of cellular physiological processes. Protein ubiquitination and deubiquitination are reversible processes that regulate the stability of target substrates. The ubiquitin proteasome system (UPS) helps regulate tumor-promoting processes, such as DNA repair, cell cycle, apoptosis, metastasis, and angiogenesis. The UPS comprises a combination of ubiquitin, ubiquitin-activating enzymes (E1), ubiquitin-conjugating enzymes (E2), and ubiquitin-ligase enzymes (E3), which complete the degradation of target proteins. Ubiquitin-conjugating enzymes (UBE2s) play an inter-mediate role in the UPS process by moving activated ubiquitin to target proteins through E3 ligases. UBE2s consist of 40 members and are classified according to conserved catalytic ubiquitin-conjugating (UBC) domain-flanking extensions in humans. Since UBE2s have specificity to substrates like E3 ligase, the significance of UBE2 has been accentuated in tumorigenesis. The dysregulation of multiple E2 enzymes and their critical roles in modulating oncogenic signaling pathways have been reported in several types of cancer. The elevation of UBE2 expression is correlated with a worse prognosis in cancer patients. In this review, we summarize the basic functions and regulatory mechanisms of UBE2s and suggest the possibility of their use as therapeutic targets for cancer.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.2
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• pp.103-110
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• 2024

Lipid nanoparticles (LNPs) are a stable and an effective system that protects cell-impermeable biologically active compounds such as nucleic acids, proteins, and peptides against degradation caused by subtle environmental changes. This study focuses on developing LNPs encapsulating gallic acid (GA), an antioxidant, to effectively prolong the half-life of tetrahexyldecyl ascorbate (THDC), a oil-soluble vitamin C derivative. These LNPs were synthesized in small, uniform sizes at room temperature and pressure conditions using a microfluidics chip. Compared to liposomes manufactured under high pressure and high temperature conditions through conventional microfluidizers, LNPs manufactured through microfluidics chips had excellent dispersion and temperature stability, and improved skin absorption as well as improved oxidative stability of fat-soluble vitamin C derivatives. Future studies will focus on ex vivo and in vivo evaluations to study skin improvement to further validate these results.

• Journal of Life Science
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• v.34 no.7
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• pp.493-499
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• 2024

Antimicrobial peptides are antimicrobial substances inherent in animals and plants, with strong antibacterial activity even in small amounts and with various other functions such as antiviral and antioxidant actions. Plants can be grown with just water and sunlight, allowing for their mass production at low costs. However, transforming a chloroplast into one that produces antimicrobial peptides, rather than growing plants, increases the amount of protein expression and minimizes contamination of the ecosystem because gene transfer by pollen does not occur. In that context, using transgenic plant chloroplasts to produce recombinant proteins increases protein degradation and reduces the solubility of proteins. To solve this problem, we fused SUMO, a fusion protein, with a recombinant protein. We also used a 6xHis tag to purify the fusion protein. The antimicrobial peptide stomoxyn is an antibacterial substance found in stable flies. Stomoxyn has an α-helix structure and is amphiphilic, which allows it to dissolve bacterial cell membranes. In this study, we constructed a transformation vector to express stomoxyn in both plant chloroplasts and Escherichia coli and used this vector to confirm the expression of stomoxyn in E. coli. The expression of the protein was then confirmed in E. coli using a transformation vector. The expressed stomoxyn was purified by nickel column and SUMOase treatment, and its antibacterial activity was confirmed using an agar diffusion assay. The EGFP gene was used to ensure that the transformed vector was inserted into the chloroplast.

• Animal Bioscience
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• v.37 no.1
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• pp.95-104
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• 2024

Objective: In the present study, we aimed to investigate the effects of enzymolysis fermentation of Chinese herbal medicines (CHMs) on egg production performance, egg quality, lipid metabolism, serum reproductive hormone levels, and the mRNA expression of the ovarian hormone receptor of laying hens in the late-laying stage. Methods: A total of 360 Hy-Line Brown laying hens (age, 390 days) were randomly categorized into four groups. Hens in the control (C) group were fed a basic diet devoid of CHMs, the crushed CHM (CT), fermented CHM (FC), and enzymatically fermented CHM (EFT) groups received diets containing 2% crushed CHM, 2% fermented CHM, and 2% enzymatically fermented CHM, respectively. Results: Compared with crushed CHM, the acid detergent fiber, total flavonoids, and total saponins contents of fermented CHM showed improvement (p<0.05); furthermore, the neutral and acid detergent fiber, total flavonoids, and total saponins contents of enzymatically fermented CHM improved (p<0.05). At 5 to 8 weeks, hens in the FC and EFT groups showed increased laying rates, haugh unit, albumin height, yolk color, shell thickness, and shell strength compared with those in the C group (p<0.05). Compared with the FC group, the laying rate, albumin height, and Shell thickness in the EFT group was increased (p<0.05). Compared with the C, CT, and FC groups, the EFT group showed reduced serum total cholesterol and increased serum luteinizing hormone levels and mRNA expressions of follicle stimulating hormone receptor and luteinizing hormone receptor (p<0.05). Conclusion: These results indicated that the ETF group improved the laying rate and egg quality and regulated the lipid metabolism in aged hens. The mechanism underlying this effect was likely related to cell wall degradation of CHM and increased serum levels of luteinizing hormone and mRNA expression of the ovarian hormone receptor.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.1
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• pp.67-75
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• 2024

Skin aging progresses due to external factors such as ultraviolet rays and infections. These factors cause skin fibroblasts to secrete proteolytic enzymes, matrix metalloproteinases (MMPs). MMPs induce the degradation of collagen located in the extracellular matrix, directly influencing aging. The stems of Akebia quinata Decaisne have been reported to have antioxidant and anti-inflammatory effects. However, the anti-aging effect of Akebia quinata Decaisne stem ethanol extract (AQSEE) is not known. Therefore, we studied the TNF-α-induced MMP-1 inhibitory effect in human fibroblasts. When the cell viability of AQSEE was confirmed through MTT asaay, it showed no toxicity up to 400 ㎍/mL. The inhibition of MMP-1 mRNA and protein secretion was confirmed through RT-qPCR and ELISA, and results showed a significant decrease at concentrations of 100, 200, 400 ㎍/mL. We also confirmed by Western blotting that phosphorylation of MAPKs signaling pathway and transcription factors was reduced. As a result, phosphorylation of p38, c-Jun, p65 was significantly decreased at all concentrations. DPPH and ABTS assays were performed to confirm the radical scavenging ability of AQSEE, and the results showed a significant decrease at all concentrations. The results of this study confirmed the MMP-1 inhibitory effect and radical scavenging ability, which suggests that it can be used as an anti-aging substance.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.457-474
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• 2003

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.