• Journal of Life Science
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• v.33 no.3
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• pp.277-286
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• 2023

Sarcopenia is the age-related loss of muscle mass and function. It is a natural part of aging and can lead to decreased mobility and increased frailty. The ubiquitin-proteasome pathway, which is involved in muscle protein degradation, is closely linked to sarcopenia. Germinated Rhynchosia nulubilis hydrolysate (GRH) has been reported to have anti-inflammatory and antioxidant properties, but there have been no reports on its inhibitory effect on muscle reduction. However, no study has yet explored the relationship between GRH and muscle loss inhibition. In this study, we evaluated the effects of GRH on muscle atrophy inhibitory activity in dexamethasone (Dexa)-induced muscle atrophy C2C12 myotubes and mouse models. Moreover, we identified a molecular pathway underlying the effects of GRH on skeletal muscle. May Grunwald-Giemsa staining showed that the length and area of myotubes increased in the groups treated with GRH. In addition, the GRH-treated group significantly reduced the expression of muscle ring finger protein 1 and muscular atrophy F-box (MAFbx) in the Dexa-induced muscular atrophy C2C12 model. GRH also improved muscle strength in C57BL/6 mice with Dexa-induced muscle atrophy, resulting in prolonged running exhaustive time and increased grip strength. We found that muscle strengthening by GRH was correlated with a decreased expression of the MAFbx gene in mouse muscle tissue. In conclusion, GRH can attenuate Dexa-induced muscle atrophy by inhibiting the ubiquitin-proteasome pathway via downregulation of the MAFbx gene expression.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1635-1647
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• 2023

Muscle atrophy, which is defined as a decrease in muscle mass and strength, is caused by an imbalance between the anabolism and catabolism of muscle proteins. Thus, modulating the homeostasis between muscle protein synthesis and degradation represents an efficient treatment approach for this condition. In the present study, the protective effects against muscle atrophy of ethanol extracts of Morus alba L. (MA) and Angelica keiskei Koidz. (AK) leaves and their mixtures (MIX) were evaluated in vitro and in vivo. Our results showed that MIX increased 5-aminoimidazole-4-carboxamide ribonucleotide-induced C2C12 myotube thinning, and enhanced soleus and gastrocnemius muscle thickness compared to each extract alone in dexamethasone-induced muscle atrophy Sprague Dawley rats. In addition, although MA and AK substantially improved grip strength and histological changes for dexamethasone-induced muscle atrophy in vivo, the efficacy was superior in the MIX-treated group. Moreover, MIX further increased the expression levels of myogenic factors (MyoD and myogenin) and decreased the expression levels of E3 ubiquitin ligases (atrogin-1 and muscle-specific RING finger protein-1) in vitro and in vivo compared to the MA- and AK-alone treatment groups. Furthermore, MIX increased the levels of phosphorylated phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), and mammalian target of rapamycin (mTOR) that were reduced by dexamethasone, and downregulated the expression of forkhead box O3 (FoxO3a) induced by dexamethasone. These results suggest that MIX has a protective effect against muscle atrophy by enhancing muscle protein anabolism through the activation of the PI3K/Akt/mTOR signaling pathway and attenuating catabolism through the inhibition of FoxO3a.

• Journal of Life Science
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• v.29 no.10
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• pp.1071-1079
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• 2019

In this study, we investigated the antioxidant and anti-aging activities of Schisandra chinensis seed fractions by adding them to UVB-irradiated HaCaT cells and analyzing the suppression of matrix metalloproteinases (MMPs). An electron-donating assay, ABTS radical scavenging assay, and hydrogen peroxide scavenging assay showed that the ethyl acetate fraction of S. chinensis seed (SCEAf) has scavenging activities. A collagenase inhibition activity assay showed that SCEAf had inhibitory effects of over 92.3% at $500{\mu}g/ml$ concentration. An MTT assay was performed to determine the cytotoxicity of SCEAf in HaCaT cells and the results showed that SCEAf increased cellular viability in a concentration-dependent manner. In addition, SCEAf was found to increase the viability of cells irradiatged by UVB $50mJ/cm^2$. To examine the anti-aging effects of SCEAf on HaCaT cells irradiated with UVB $50mJ/cm^2$, the expression of MMP-1 and -3 was analyzed by Western blotting and reverse-transcription polymerase chain reaction. The results showed that MMP-1 and -3 proteins and mRNA levels were downregulated in a concentration-dependent manner in response to SCEAf. These results suggest that SCEAf can prevent aging and alleviate aging symptoms by inhibiting collagenase activity in skin keratinocytes damaged by UVB. Therefore, S. chinensis seeds may have the potential for use as functional ingredients with anti-aging effects in the cosmetic and food industries.

• Molecules and Cells
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• v.40 no.7
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• pp.457-465
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• 2017

Streptozotocin (STZ)-induced murine models of type 1 diabetes have been used to examine ER stress during pancreatic ${\beta}$-cell apoptosis, as this ER stress plays important roles in the pathogenesis and development of the disease. However, the mechanisms linking type 1 diabetes to the ER stress-modulating anti-diabetic signaling pathway remain to be addressed, though it was recently established that ERK5 (Extracellular-signal-regulated kinase 5) contributes to the pathogeneses of diabetic complications. This study was undertaken to explore the mechanism whereby ERK5 inhibition instigates pancreatic ${\beta}$-cell apoptosis via an ER stress-dependent signaling pathway. STZ-induced diabetic WT and CHOP deficient mice were i.p. injected every 2 days for 6 days under BIX02189 (a specific ERK5 inhibitor) treatment in order to evaluate the role of ERK5. Hyperglycemia was exacerbated by co-treating C57BL/6J mice with STZ and BIX02189 as compared with mice administered with STZ alone. In addition, immunoblotting data revealed that ERK5 inhibition activated the unfolded protein response pathway accompanying apoptotic events, such as, PARP-1 and caspase-3 cleavage. Interestingly, ERK5 inhibition-induced exacerbation of pancreatic ${\beta}$-cell apoptosis was inhibited in CHOP deficient mice. Moreover, transduction of adenovirus encoding an active mutant form of $MEK5{\alpha}$, an upstream kinase of ERK5, inhibited STZ-induced unfolded protein responses and ${\beta}$-cell apoptosis. These results suggest that ERK5 protects against STZ-induced pancreatic ${\beta}$-cell apoptosis and hyperglycemia by interrupting the ER stress-mediated apoptotic pathway.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.797-806
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• 2018

This study attempted to investigate the effects of Paeonia Lactiflora Pallas (P. lactiflora) on the inhibition of oxygen free radical, anti-inflammation and MMP-1 inhibitory activity and examine its possibility as a functional cosmetic material. For test methods, the inhibition of oxygen free radical after measuring reactive oxygen species (ROS) in the cell, cytotoxicity assessment and anti-inflammation were measured, and MMP-1 inhibitory effects in the HDF cell were measured. According to the test, the inhibition of ROS was confirmed in RAW 264.7 and HDF cells. In terms of cytotoxicity assessment, 90% or higher cell viability was detected at $5/10{\mu}g/mL$ Paeonia Lactiflora Pallas extract while it was 80% or higher at other concentration levels in both RAW 264.7 and HDF cells. In addition, NO production was inhibited in the RAW 264.7 cell while MMP-1 was significantly inhibited in the HDF cell. The above results reveal a possibility of Paeonia Lactiflora Pallas extract as a functional cosmetic material after confirming the inhibition of ROS synthesis in the cell, antioxidant and anti-inflammatory effects by inhibiting NO synthesis, low toxicity on skin cells and anti-aging effect through MMP-1 inhibition.

• Current Optics and Photonics
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• v.6 no.3
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• pp.227-235
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• 2022

To investigate the aging-related physiological functions of organic light-emitting diodes (OLEDs), we examined mRNA expression changes in aging-related genes due to oxidative stress inhibition by 630-nm red light OLEDs. As a result of irradiating 630-nm OLED with an intensity of 5 mW/cm² for 15 min, the viability of dermal fibroblasts significantly increased by 1.3-fold. In addition, reactive oxygen species generated by H₂O₂ were significantly reduced about 4.9-fold by irradiation with 630-nm OLED. Quantitative reverse-transcription polymerase chain reaction results showed that 630-nm OLEDs altered aging-related gene mRNA expression levels through antioxidant activity. The mRNA expression levels of matrix metalloproteinase1 (MMP1) and MMP9 decreased significantly, by about 2.2- and 2.5-fold, compared to the control group, whereas those of collagen, type I, and alpha 1 increased significantly, by 4.9-fold. The mRNA expression levels of cancer suppression genes p16 and p53 in dermal fibroblasts were also significantly reduced by 630-nm OLED irradiation, by about 1.4- and three-fold, respectively, compared to the control. Overall, it was confirmed that 630-nm OLED irradiation lowered the level of ROS formation induced by H₂O₂ in dermal fibroblasts, and that this antioxidant effect could regulate the mRNA expression levels of aging- and tumor suppression-related genes. This study shows a link between 630-nm OLED irradiation and anti-aging physiological functions such as antioxidant function, and suggests the potential of OLEDs as a useful light source for skin care.

• Food Science and Preservation
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• v.24 no.8
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• pp.1129-1137
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• 2017

The fringe tree, Chionanthus retusus (Oleaceae) has been used as a natural remedy that helps a paralytic stroke, dementia, phlegm and malaria. This study was conducted to investigate the antioxidant and anti-aging activities of water extracts obtained from the flesh of C. retusus by reflux extraction at room temperature and $80^{\circ}C$, and pressure heating extraction at $110^{\circ}C$, for an increment of their practical use. The highest extraction yield from the flesh of C. retusus was 67.94% extract by pressure heating extraction at $110^{\circ}C$. The content of total polyphenol compounds was the highest by 72.71 mg/g in $80^{\circ}C$ extract by reflux extraction. The highest content of total flavonoid compounds was 7.60 mg/g at $110^{\circ}C$ extract. The results of soluble protein and reducing sugar contents showed the highest content of 4.93 mg/g and 46.77 mg/g in $110^{\circ}C$ extract, respectively. In the analysis of DPPH radical scavenging activity, all extracts showed an excellent effect of 92% in 1.0 mg/mL concentration. The highest effect of ABTS radical scavenging activity was 88.67% at $110^{\circ}C$ extraction in 1.0 mg/mL concentration. Nitrite scavenging ability was the highest as 66.16% at $110^{\circ}C$ extract at pH 1.2 and 1.0 mg/mL concentration. The results of SOD-like activity and xanthine oxidase inhibition activities showed the highest effect of 14.95% and 59.45% at $110^{\circ}C$ extract in 1.0 mg/mL, respectively. Tyrosinase inhibition activity for whitening effect was the highest of 35.31% at $85^{\circ}C$ in 1.0 mg/mL. In the analysis of anti-aging effect, collagenase and elastase inhibition activity showed the highest effects of 37.78% at $110^{\circ}C$ and 20.39% at $80^{\circ}C$, respectively. All results of antioxidant activities and anti-aging effects increased along with the concentration increases. These results indicated that the extracts extracted from the flesh of C. retusus at $80^{\circ}C$ and $110^{\circ}C$ have a large amount of useful ingredients, an excellent antioxidant activity, like as DPPH and ABTS radical scavenging activity, and anti-aging effects to develop functional products than those of $25^{\circ}C$.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.1
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• pp.69-79
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• 2020

Aging is one of the risk factors for the development of cardiovascular diseases. During the progression of cellular senescence, cells enter a state of irreversible growth arrest and display resistance to apoptosis. As a flavonoid, quercetin induces apoptosis in various cells. Accordingly, we investigated the relationship between quercetin-induced apoptosis and the inhibition of cellular senescence, and determined the mechanism of oxidative stress-induced vascular smooth muscle cell (VSMC) senescence. In cultured VSMCs, hydrogen peroxide (H₂O₂) dose-dependently induced senescence, which was associated with increased numbers of senescence-associated β-galactosidase-positive cells, decreased expression of SMP30, and activation of p53-p21 and p16 pathways. Along with senescence, expression of the anti-apoptotic protein Bcl-2 was observed to increase and the levels of proteins related to the apoptosis pathway were observed to decrease. Quercetin induced apoptosis through the activation of AMP-activated protein kinase. This action led to the alleviation of oxidative stress-induced VSMC senescence. Furthermore, the inhibition of AMPK activation with compound C and siRNA inhibited apoptosis and aggravated VSMC senescence by reversing p53-p21 and p16 pathways. These results suggest that senescent VSMCs are resistant to apoptosis and quercetin-induced apoptosis attenuated the oxidative stress-induced senescence through activation of AMPK. Therefore, induction of apoptosis by polyphenols such as quercetin may be worthy of attention for its anti-aging effects.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.653-659
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• 2018

In this study, we investigated the antioxidant activities and anti-aging efficacy in terms of suppression of matrix metalloproteinases (MMPs) in UVB-irradiated HaCaT cells by adding the ethanol extracts of Josaengheogchal (JE) and Shintoheug rice (SRE). In the electron-donating ability and ABTS radical-scavenging assays, we observed that both JE and SRE had scavenging activities and in a collagenase inhibition assay, both extracts showed inhibition effects of over 73% at $1,000{\mu}g/mL$ concentration. The expression of MMP-1 and -3, when the extracts were treated with UVB $50mJ/cm^2$, irradiated human HaCaT keratinocytes, was analyzed by western blotting and reverse-transcription polymerase chain reaction (RT-PCR). The results showed that MMP-1 and -3 proteins and mRNAs were downregulated in a concentration-dependent manner in response to both extracts. Therefore, we expect that these compounds have a potential for the use as functional ingredients with anti-aging effects in the cosmetic and food industries.

• Food Science and Preservation
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• v.19 no.4
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• pp.463-469
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• 2012

In this study, the anti-oxidant and anti-elastase activities of four abalone viscera extracts were investigated to screen the most promising extract. This extract was further studied in terms of its anti-skin-aging properties. In the DPPH-scavenging assay, the Tris-HCl extract showed a $58.60{\pm}0.88%$ radical-scavenging activity, which was followed closely by the ethanol extract that had a $55.40{\pm}0.62%$ scavenging activity. In the anti-elastase assay, however, the ethanol extract showed the significantly highest elastase inhibition activity. Furthermore, none of the extracts had a harmful effect on the human dermal fibroblast, as revealed in the MTT assay. In the cell study, the effect of the ethanol extract at various concentrations on the human dermal fibroblast was investigated. At the 10 ${\mu}g/mL$ concentration, the ethanol extract boosted the pro-collagen type I synthesis to $705.30{\pm}3.06$ ng/mL and reduced the MMP-1 to $54.30{\pm}0.80$ ng/mL, which was considered the optimum concentration. This is the first study that focused on the anti-oxidant and anti-skin-aging effects of abalone viscera extract. Its results may provide fundamental data for further study.