• Biomolecules & Therapeutics
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• 제27권3호
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• pp.327-335
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• 2019

As the elderly population is increasing, Alzheimer's disease (AD) has become a global issue and many clinical trials have been conducted to evaluate treatments for AD. As these clinical trials have been conducted and have failed, the development of new theraphies for AD with fewer adverse effects remains a challenge. In this study, we examined the effects of Theracurmin on cognitive decline using 5XFAD mice, an AD mouse model. Theracurmin is more bioavailable form of curcumin, generated with submicron colloidal dispersion. Mice were treated with Theracurmin (100, 300 and 1,000 mg/kg) for 12 weeks and were subjected to the novel object recognition test and the Barnes maze test. Theracurmin-treated mice showed significant amelioration in recognition and spatial memories compared those of the vehicle-treated controls. In addition, the antioxidant activities of Theracurmin were investigated by measuring the superoxide dismutase (SOD) activity, malondialdehyde (MDA) and glutathione (GSH) levels. The increased MDA level and decreased SOD and GSH levels in the vehicle-treated 5XFAD mice were significantly reversed by the administration of Theracurmin. Moreover, we observed that Theracurmin administration elevated the expression levels of synaptic components, including synaptophysin and post synaptic density protein 95, and decreased the expression levels of ionized calcium-binding adapter molecule 1 (Iba-1), a marker of activated microglia. These results suggest that Theracurmin ameliorates cognitive function by increasing the expression of synaptic components and by preventing neuronal cell damage from oxidative stress or from the activation of microglia. Thus, Theracurmin would be useful for treating the cognitive dysfunctions observed in AD.

• 한국응용과학기술학회지
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• 제36권1호
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• pp.208-216
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• 2019

본 연구는 박하 추출물을 통해 독성검사 및 항산화, 항염증과 같은 생리활성을 평가하고자 하였다. 박하 추출은 열수 및 80% 에탄올로 추출하였으며, RAW 264.7 세포를 통해 MTT를 통해 세포 생존율을 평가하였다. 또한, LPS로 유도한 RAW 264.7 세포를 통해 활성산소(ROS), 산화질소(NO), 류코트리엔 B4($LTB_4$), 항염 또는 염증성 사이토카인($IL-1{\beta}$, IL-6, $TNF-{\alpha}$, IL-10) 등을 ELISA 및 Luminex로 측정하였다. 그 결과, 박하 추출물은 열수 및 80% 에탄올 추출물에서 세포독성이 없었으며, 80% 에탄올 추출물의 $100{\mu}g/m{\ell}$ 농도에서 활성산소의 생성을 억제하였다. 또한, NO, LTB4, 염증 또는 항염증성 사이토카인의 생성을 모든 추출물에서 농도 의존적 효능을 나타냈다. 즉, 박하 추출물은 세포독성 없이 항산화 및 항염증 활성을 나타내는 생리학적 효능이 나타났다. 이와 같은 결과는 본 연구와 관련된 증상을 개선하기 위한 새로운 건강식품 및 치료제의 원료로 개발될 수 있다.

• Biomolecules & Therapeutics
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• 제31권1호
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• pp.97-107
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• 2023

Aristolochic acid (AA), extracted from Aristolochiaceae plants, plays an essential role in traditional herbal medicines and is used for different diseases. However, AA has been found to be nephrotoxic and is known to cause aristolochic acid nephropathy (AAN). AA-induced acute kidney injury (AKI) is a syndrome in AAN with a high morbidity that manifests mitochondrial damage as a key part of its pathological progression. Melatonin primarily serves as a mitochondria-targeted antioxidant. However, its mitochondrial protective role in AA-induced AKI is barely reported. In this study, mice were administrated 2.5 mg/kg AA to induce AKI. Melatonin reduced the increase in Upro and Scr and attenuated the necrosis and atrophy of renal proximal tubules in mice exposed to AA. Melatonin suppressed ROS generation, MDA levels and iNOS expression and increased SOD activities in vivo and in vitro. Intriguingly, the in vivo study revealed that melatonin decreased mitochondrial fragmentation in renal proximal tubular cells and increased ATP levels in kidney tissues in response to AA. In vitro, melatonin restored the mitochondrial membrane potential (MMP) in NRK-52E and HK-2 cells and led to an elevation in ATP levels. Confocal immunofluorescence data showed that puncta containing Mito-tracker and GFP-LC3A/B were reduced, thereby impeding the mitophagy of tubular epithelial cells. Furthermore, melatonin decreased LC3A/B-II expression and increased p62 expression. The apoptosis of tubular epithelial cells induced by AA was decreased. Therefore, our findings revealed that melatonin could prevent AA-induced AKI by attenuating mitochondrial damage, which may provide a potential therapeutic method for renal AA toxicity.

• Nutrition Research and Practice
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• 제17권4호
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• pp.670-681
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• 2023

BACKGROUND/OBJECTIVES: Oxidative stress is caused by reactive oxygen species and free radicals that accelerate inflammatory responses and exacerbate fatigue. Tormentic acid (TA) has antioxidant and anti-inflammatory properties. Thus, the aim of present study is to determine the fatigue-regulatory effects of TA in H₂O₂-stimulated myoblast cell line, C2C12 cells and treadmill stress test (TST) and forced swimming test (FST) animal models. MATERIALS/METHODS: In the in vitro study, C2C12 cells were pretreated with TA before stimulation with H₂O₂. Then, malondialdehyde (MDA), lactate dehydrogenase (LDH), creatine kinase (CK) activity, tumor necrosis factor (TNF)-α, interleukin (IL)-6, superoxide dismutase (SOD), catalase (CAT), glycogen, and cell viability were analyzed. In the in vivo study, the ICR male mice were administered TA or distilled water orally daily for 28 days. FST and TST were then performed on the last day. In addition, biochemical analysis of the serum, muscle, and liver was performed. RESULTS: TA dose-dependently alleviated the levels of MDA, LDH, CK activity, TNF-α, and IL-6 in H₂O₂-stimulated C2C12 cells without affecting the cytotoxicity. TA increased the SOD and CAT activities and the glycogen levels in H₂O₂-stimulated C2C12 cells. In TST and FST animal models, TA decreased the FST immobility time significantly while increasing the TST exhaustion time without weight fluctuations. The in vivo studies showed that the levels of SOD, CAT, citrate synthase, glycogen, and free fatty acid were increased by TA administration, whereas TA significantly reduced the levels of glucose, MDA, LDH, lactate, CK, inflammatory cytokines, alanine transaminase, aspartate transaminase, blood urea nitrogen, and cortisol compared to the control group. CONCLUSIONS: TA improves fatigue by modulating oxidative stress and energy metabolism in C2C12 cells and animal models. Therefore, we suggest that TA can be a powerful substance in healthy functional foods and therapeutics to improve fatigue.

• Biomolecules & Therapeutics
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• 제32권1호
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• pp.84-93
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• 2024

Rosmarinic acid (RA) is a phenolic ester that protects human keratinocytes against oxidative damage induced by ultraviolet B (UVB) exposure, however, the mechanisms underlying its effects remain unclear. This study aimed to elucidate the cell signaling mechanisms that regulate the antioxidant activity of RA and confirm its cyto-protective role. To explore the signaling mechanisms, we used the human keratinocyte cell line HaCaT and SKH1 hairless mouse skin. RA enhanced glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS) expression in HaCaT cells in a dose- and time-dependent manner. Moreover, RA induced nuclear factor erythroid-2-related factor 2 (NRF2) nuclear translocation and activated the signaling kinases protein kinase B (AKT) and extracellular signal-regulated kinase (ERK). Treatment with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, the ERK inhibitor U0126, and small interfering RNA (siRNA) gene silencing suppressed RA-enhanced GCLC, GSS, and NRF2 expression, respectively. Cell viability tests showed that RA significantly prevented UVB-induced cell viability decrease, whereas the glutathione (GSH) inhibitors buthionine sulfoximine, LY294002, and U0126 significantly reduced this effect. Moreover, RA protected against DNA damage and protein carbonylation, lipid peroxidation, and apoptosis caused by UVB-induced oxidative stress in a concentration-dependent manner in SKH1 hairless mouse skin tissues. These results suggest that RA protects against UVB-induced oxidative damage by activating AKT and ERK signaling to regulate NRF2 signaling and enhance GSH biosynthesis. Thus, RA treatment may be a promising approach to protect the skin from UVB-induced oxidative damage.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.250-257
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• 2023

Glutamate는 포유류의 중추신경계에 분포하는 흥분성 신경전달물질로, 기억, 인지, 그리고 학습 등에 있어서 중요한 역할을 한다. 하지만 고농도의 Glutamate는 신경세포에 독성을 유발하여 신경세포사멸을 유도함으로써 알츠하이머병, 파킨슨병, 뇌졸중 등의 신경퇴행성질환을 일으키는 것으로 알려져 있다. 본 연구에서 아열대 천연물의 항산화 활성과 신경보호 효과를 분석하였다. 11종의 아열대 추출물 중에서 Salacca wallichiana 추출물 (SE)의 라디칼 소거활성이 뛰어난 것으로 나타났다. 그리고 SE의 신경보호 효과를 조사한 결과 glutamate로 유도되는 cell death로부터 신경세포를 보호하였다. 또한 glutamate로 유도되는 apoptosis로부터 HT22 세포를 보호하는 효과는 Annexin V와 PI로 염색한 후 flow cytometry를 통해 분석되었다. 추가적으로 H₂DCFDA 염색을 이용하여 SE가 glutamate로 유도되는 세포 내 활성 산소 종 (ROS)을 억제한다는 것을 확인했다. SE의 신경보호 효과는 oxidative stress로 유발되는 Mitogen-activated protein kinase (MAPK) signaling pathway를 억제함으로써 신경세포를 보호하는 것으로 나타났다. 결과적으로 SE가 신경퇴행성질환을 예방하기 위한 치료제 개발에 기여할 수 있음을 나타낸다.

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.368-378
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• 2024

Cordycepin, a valuable bioactive component isolated from Cordyceps militaris, has been reported to possess anti-cancer potential and the property to enhance the effects of chemotherapeutic agents in various types of cancers. However, the ability of cordycepin to chemosensitize cholangiocarcinoma (CCA) cells to gemcitabine has not yet been evaluated. The current study was performed to evaluate the above, and the mechanisms associated with it. The study analyzed the effects of cordycepin in combination with gemcitabine on the cancer stem-like properties of the CCA SNU478 cell line, including its anti-apoptotic, migratory, and antioxidant effects. In addition, the combination of cordycepin and gemcitabine was evaluated in the CCA xenograft model. The cordycepin treatment significantly decreased SNU478 cell viability and, in combination with gemcitabine, additively reduced cell viability. The cordycepin and gemcitabine co-treatment significantly increased the Annexin V+ population and downregulated B-cell lymphoma 2 (Bcl-2) expression, suggesting that the decreased cell viability in the cordycepin+gemcitabine group may result from an increase in apoptotic death. In addition, the cordycepin and gemcitabine co-treatment significantly reduced the migratory ability of SNU478 cells in the wound healing and trans-well migration assays. It was observed that the cordycepin and gemcitabine cotreatment reduced the CD44^highCD133^high population in SNU478 cells and the expression level of sex determining region Y-box 2 (Sox-2), indicating the downregulation of the cancer stem-like population. Cordycepin also enhanced oxidative damage mediated by gemcitabine in MitoSOX staining associated with the upregulated Kelch like ECH Associated Protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) expression ratio. In the SNU478 xenograft model, co-administration of cordycepin and gemcitabine additively delayed tumor growth. These results indicate that cordycepin potentiates the chemotherapeutic property of gemcitabine against CCA, which results from the downregulation of its cancer-stem-like properties. Hence, the combination therapy of cordycepin and gemcitabine may be a promising therapeutic strategy in the treatment of CCA.

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.329-340
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• 2024

Mangiferin is a kind of natural xanthone glycosides and is known to have various pharmacological activities. However, since the beneficial efficacy of this compound has not been reported in retinal pigment epithelial (RPE) cells, this study aimed to evaluate whether mangiferin could protect human RPE ARPE-19 cells from oxidative injury mimicked by hydrogen peroxide (H₂O₂). The results showed that mangiferin attenuated H₂O₂-induced cell viability reduction and DNA damage, while inhibiting reactive oxygen species (ROS) production and preserving diminished glutathione (GSH). Mangiferin also antagonized H₂O₂-induced inhibition of the expression and activity of antioxidant enzymes such as manganese superoxide dismutase and GSH peroxidase, which was associated with inhibition of mitochondrial ROS production. In addition, mangiferin protected ARPE-19 cells from H₂O₂-induced apoptosis by increasing the Bcl-2/Bax ratio, decreasing caspase-3 activation, and blocking poly(ADP-ribose) polymerase cleavage. Moreover, mangiferin suppressed the release of cytochrome c into the cytosol, which was achieved by interfering with mitochondrial membrane disruption. Furthermore, mangiferin increased the expression and activity of heme oxygenase-1 (HO-1) and nuclear factor-erythroid-2 related factor 2 (Nrf2). However, the inhibition of ROS production, cytoprotective and anti-apoptotic effects of mangiferin were significantly attenuated by the HO-1 inhibitor, indicating that mangiferin promoted Nrf2-mediated HO-1 activity to prevent ARPE-19 cells from oxidative injury. The results of this study suggest that mangiferin, as an Nrf2 activator, has potent ROS scavenging activity and may have the potential to protect oxidative stress-mediated ocular diseases.

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.349-360
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• 2024

Oxidative stress contributes to the onset of chronic diseases in various organs, including muscles. Morroniside, a type of iridoid glycoside contained in Cornus officinalis, is reported to have advantages as a natural compound that prevents various diseases. However, the question of whether this phytochemical exerts any inhibitory effect against oxidative stress in muscle cells has not been well reported. Therefore, the current study aimed to evaluate whether morroniside can protect against oxidative damage induced by hydrogen peroxide (H₂O₂) in murine C2C12 myoblasts. Our results demonstrate that morroniside pretreatment was able to inhibit cytotoxicity while suppressing H₂O₂-induced DNA damage and apoptosis. Morroniside also significantly improved the antioxidant capacity in H₂O₂-challenged C2C12 cells by blocking the production of cellular reactive oxygen species and mitochondrial superoxide and increasing glutathione production. In addition, H₂O₂-induced mitochondrial damage and endoplasmic reticulum (ER) stress were effectively attenuated by morroniside pretreatment, inhibiting cytoplasmic leakage of cytochrome c and expression of ER stress-related proteins. Furthermore, morroniside neutralized H₂O₂-mediated calcium (Ca²⁺) overload in mitochondria and mitigated the expression of calpains, cytosolic Ca²⁺-dependent proteases. Collectively, these findings demonstrate that morroniside protected against mitochondrial impairment and Ca²⁺-mediated ER stress by minimizing oxidative stress, thereby inhibiting H₂O₂-induced cytotoxicity in C2C12 myoblasts.

• 한국식품저장유통학회지
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• 제20권4호
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• pp.583-591
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• 2013

본 연구에서는 밤나무 과실의 속껍질인 율피를 이용하여 알레르기성 피부질환 기능성 원료로 사용 가능성을 조사하였다. 율피 열수추출물과 율피 발효추출물의 총 폴리페놀 함량은 1 mg/mL에서 각각 $73.85{\pm}1.78$, $81.32{\pm}1.73{\mu}g/mL$였으며, 동일한 농도에서 총 플라보노이드 함량은 $18.72{\pm}0.20$, $14.70{\pm}0.21{\mu}g/mL$로 나타났다. 항산화 활성으로 율피 열수 추출물과 율피 발효추출물의 전자공여능은 1 mg/mL에서 각각 $73.74{\pm}1.18$, $67.17{\pm}1.87%$로 나타났으며, superoxide anion radical 소거능은 동일한 농도에서 각각 $91.58{\pm}2.51$, $100.15{\pm}4.30%$로 두 그룹 간 항산화 활성은 큰 차이를 보이지 않았다. HS68 세포를 대상으로 율피 열수추출물과 율피 발효추출물에 대한 세포 독성을 조사 한 결과, 율피 발효추출물에서 율피 추출물과 비교 시 세포 생존율이 1.33배 증가하였다. 또한 LPS로 유도된 RAW264.7 대식세포에서 0.05 mg/mL 율피 열수추출물과 율피 발효추출물 처리에 의한 NO생산량은 각각 $36.27{\pm}4.52$, $29.56{\pm}4.91{\mu}M$로 율피 발효 추출물 처리군에서 항염증 활성이 유의적으로 높았다. 아토피 유발 NC/Nga 마우스 모델에서 율피 열수추출물 및 율피 발효추출물을 도포하여 육안 상 관찰한 피부 병변은 율피 열수추출물 처리군에서 대조군과 비교해 피부 형태학적으로 일부 호전되는 경향을 보였으나, 율피 발효추출물 처리군은 멜라닌 함량과 피부 홍반의 감소 등 뚜렷한 개선효과를 보였으며 정상군과 유사한 피부 형태를 나타내었다. 또한 피부에 존재하는 염증성 사이토카인인 IL-$1{\beta}$와 TNF-${\alpha}$의 발현이 율피 열수추출물과 비교 시 율피 발효추출물에서는 각각 13.68, 3.63% 억제되었다. 이는 in vitro 실험과 유사하게 염증과 관련된 유전자의 발현을 저해함으로써 율피 발효추출물이 염증억제 효과는 물론 항아토피 효능을 나타내는 것으로 여겨진다. 따라서 율피 열수추출물 뿐만 아니라 율피 발효추출물 역시 아토피 피부질환을 개선하는데 유용한 물질로 활용될 수 있는 효과적인 조성물이라 사료된다.