• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.850-855
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• 2007

Leptin is the adipocyte-specific product of the obese gene and plays a major role in food intake and energy metabolism. Leptin research was mainly focused on mammalian species, but understanding of leptin and its function in poultry is very poor. In this study, the duck leptin gene was amplified using the reverse transcription-polymerase chain reaction (RT-PCR) from duck liver RNA. The cDNA fragment was inserted into the pET-28a expression vector, and the resulting plasmid was expressed in Escherichia coli BL21 (DE3). Experimental mice were given an intraperitoneal injection of 10 mg/kg leptin dissolved in phosphate buffered saline (PBS), while the control mice were injected with PBS. The effect of leptin on food intake, body weight and fatty deposition in mice was detected. Sequence analysis revealed that duck leptin had a length of 438 nucleotides which encoded a peptide with 146 amino acid residues. The sequence shares highly homology to other animals. The coding sequence of duck leptin was 84 and 86% identical to human and pig leptin nucleotides sequence. Highest identity was with the rat coding sequence (95%). The identity of the amino acid sequence was 84, 82 and 96% respectively compared to that of the human, pig and rat. Results of SDS-PAGE analysis indicated that a fusion protein was specifically expressed in E. coli BL21 (DE3). The purified product was found to be biologically active during tests. Continuous administration of recombinant duck leptin inhibited food intake. Despite the decrease of food intake, leptin significantly induced body weight and fatty deposition. These changes were accompanied by a significant down-secretion of plasma glucose, cholesterol, triglyceride and insulin levels in mice. The observations provide evidence for an inhibitory effect of leptin in the regulation of food intake and for a potential role of duck leptin in the regulation of lipogenesis.

• The Korean Journal of Physiology and Pharmacology
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• 제24권2호
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• pp.149-156
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• 2020

Sodium 2-mercaptoethanesulfonate (mesna) is a protective agent that is widely used in medicine because of its antioxidant effects. Recently, reactive oxygen species (ROS) were shown to increase pigmentation. Thus, ROS scavengers and inhibitors of ROS production may suppress melanogenesis. Forkhead box-O3a (FoxO3a) is an antimelanogenic factor that mediates ROS-induced skin pigmentation. In this study, we aimed to investigate the whitening effect of mesna and the signaling mechanism mediating this effect. Human melanoma (MNT-1) cells were used in this study. mRNA and protein expression were measured by real-time quantitative PCR and Western blotting analysis to track changes in FoxO3a-related signals induced by mesna. An immunofluorescence assay was performed to determine the nuclear translocation of FoxO3a. When MNT-1 melanoma cells were treated with mesna, melanin production and secretion decreased. These effects were accompanied by increases in FoxO3a activation and nuclear translocation, resulting in downregulation of four master genes of melanogenesis: MITF, TYR, TRP1, and TRP2. We found that mesna, an antioxidant and radical scavenger, suppresses melanin production and may therefore be a useful agent for the clinical treatment of hyperpigmentation disorders.

• Journal of Korean Neurosurgical Society
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• 제59권3호
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• pp.259-268
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• 2016

Objective : Accumulation of advanced glycation end-products (AGE) and mitochondrial glycation is importantly implicated in the pathological changes of the brain associated with diabetic complications, Alzheimer disease, and aging. The present study was undertaken to determine whether sildenafil, a type 5 phosphodiesterase type (PDE-5) inhibitor, has beneficial effect on neuronal cells challenged with AGE-induced oxidative stress to preserve their mitochondrial functional integrity. Methods : HT-22 hippocampal neuronal cells were exposed to AGE and changes in the mitochondrial functional parameters were determined. Pretreatment of cells with sildenafil effectively ameliorated these AGE-induced deterioration of mitochondrial functional integrity. Results : AGE-treated cells lost their mitochondrial functional integrity which was estimated by their MTT reduction ability and intracellular ATP concentration. These cells exhibited stimulated generation of reactive oxygen species (ROS), disruption of mitochondrial membrane potential, induction of mitochondrial permeability transition, and release of the cytochrome C, activation of the caspase-3 accompanied by apoptosis. Western blot analyses and qRT-PCR demonstrated that sildenafil increased the expression level of the heme oxygenase-1 (HO-1). CoPP and bilirubin, an inducer of HO-1 and a metabolic product of HO-1, respectively, provided a similar protective effects. On the contrary, the HO-1 inhibitor ZnPP IX blocked the effect of sildenafil. Transfection with HO-1 siRNA significantly reduced the protective effect of sildenafil on the loss of MTT reduction ability and MPT induction in AGE-treated cells. Conclusion : Taken together, our results suggested that sildenafil provides beneficial effect to protect the HT-22 hippocampal neuronal cells against AGE-induced deterioration of mitochondrial integrity, and upregulation of HO-1 is involved in the underlying mechanism.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.352-373
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• 2003

Rhamnose-rich (RROP-s) and fucose-rich (FROP-s) oligo-and polysaccharides were prepared and extensively characterised by physical and chemical procedures [1,2] and compared to L-fucose. Their biological properties were then studied on human skin fibroblast cell cultures, human skin explant cultures and on hairless rat skin, using a variety of cell-biological, biochemical and computerised morphometrical procedures. Among the most important properties we could establish, the following are of particular interest for the tretment and prevention of age-dependent modifications of human skin (loss of skin-tissue, cells and matrix, wrinkle formation and others) : stimulation of cell proliferation (by $^3$[H]-thymidine incorporation and the MTT test), scavenging of reactive oxygen species (ROS) using several different procedures, and protease (MMP-2 and MMP-9) down-regulation. A topical preparation, using RROP-s and FROP-s, and/or L-fucose, was shown to increase cell proliferation, dermal matrix synthesis, efficient scavenging of ROS-s and to increase also the thickness of dermal tissue when applied for 4 weeks on hairless rat skin, accompanied by the densification of collagen bundles as well as by an increase of elastin synthesis. Using fluorescent labeled FROPs, it could be shown that these oligosaccharides react with cell-membrane receptors and especially with the elastin-laminin-receptor and the fucose-mannose receptor, but they penetrate also in the cell nucleus, suggesting the possibility of a direct action on the regulation of gene expression. When applied to the human skin of a team of voluntary women encompassing all age-groups, the efficiency of FROP-containing preparation could be confirmed using indentometry and computerised evaluation of skin micro-relief, as well as evaluation of periorbital wrinkles. It appears therefore that these preparations correspond to all the requirements of active anti-aging principles.

• Macromolecular Research
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• 제17권12호
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• pp.1015-1020
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• 2009

The role of the water structure present in hydrogels from nutlets of three species of salvias, S. miltiorrhiza (SM), S. sclarea (SS) and S. viridis (SV), was analyzed by differential scanning calorimetry (DSC). The sharp endothermic peaks that appeared at $5.9^{\circ}C$ (SM), $2.8^{\circ}C$ DC (SS) and $1.8^{\circ}C$ (SV) in each 1.0% hydrogel of 10.4-15.8% were not affected by addition of 0.1 M urea and alkali-metal salts. The order-disorder portions in the network were slightly affected by the distribution of freezable and non-freezable water in the hydrogel networks. The SV hydrogel was further used to investigate the effects of additives (0.1-8.0 M urea and 0.1-5.0 M NaCl) on its melting behavior. At 0.5-4.0 M urea and 1.0-3.0 M NaCl, two endothermic peaks appeared, corresponding to unbound (high temperature) and bound (low temperature) water in the gel networks, and eventually merged into one endothermic peak at 5.0-8.0 M urea and 4.0-4.5 M NaCl. After this merger, the endothermic peak shifted to 3.7, 4.0 and $5.6^{\circ}C$ at 5.0, 6.0 and 8.0 M urea, respectively. In the case of NaCl, a combination of peaks that occurred at 4.0-4.5 M were accompanied by a shift to lower temperature (-14.4 and $15.3^{\circ}C$) and the endothermic peak finally disappeared at 5.0 M NaCl due to the strong binding of water in the gel networks.

• KSBB Journal
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• 제28권5호
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• pp.303-309
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• 2013

The extract from Lysimachia foenum-graecum (LFE) has been known to possess various instructive characters including anti-oxidant, anti-obesity, fungicidal activities. However, the accurate mechanism of those effects of LFE is not well known. In that respect, we evaluated the apoptotic effect and anti-cancer efficacy of extracts of LFE in MCF-7 breast cancer cells. In this study, we hypothesized that LFE may exert cancer cell apoptosis through regulating p53 and mitochondria-mediated apoptotic proteins. And this substance can generate ROS to cause free radical-induced apoptosis. Accordingly, the generation of ROS by LFE triggers the activation of p53 which are accompanied by pro-apoptotic protein activation and suppression of pro-survival proteins. We determined with MTT assay, flow cytometry for detection of intracellular ROS and Annexin V-PI staining, Western blotting. Consequently, our researches demonstrated that the treatment of LFE to breast cancer cells resulted in an activation of p53, Puma, Bax, cleaved-PARP and an inhibition of Bcl-2 expressions.

• Molecules and Cells
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• 제37권2호
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• pp.109-117
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• 2014

Microbiota in the niches of the rhizosphere zones can affect plant growth and responses to environmental stress conditions via mutualistic interactions with host plants. Specifically, some beneficial bacteria, collectively referred to as Plant Growth Promoting Rhizobacteria (PGPRs), increase plant biomass and innate immunity potential. Here, we report that Enterobacter sp. EJ01, a bacterium isolated from sea china pink (Dianthus japonicus thunb) in reclaimed land of Gyehwa-do in Korea, improved the vegetative growth and alleviated salt stress in tomato and Arabidopsis. EJ01 was capable of producing 1-aminocy-clopropane-1-carboxylate (ACC) deaminase and also exhibited indole-3-acetic acid (IAA) production. The isolate EJ01 conferred increases in fresh weight, dry weight, and plant height of tomato and Arabidopsis under both normal and high salinity conditions. At the molecular level, short-term treatment with EJ01 increased the expression of salt stress responsive genes such as DREB2b, RD29A, RD29B, and RAB18 in Arabidopsis. The expression of proline biosynthetic genes (i.e. P5CS1 and P5CS2) and of genes related to priming processes (i.e. MPK3 and MPK6) were also up-regulated. In addition, reactive oxygen species scavenging activities were enhanced in tomatoes treated with EJ01 in stressed conditions. GFP-tagged EJ01 displayed colonization in the rhizosphere and endosphere in the roots of Arabidopsis. In conclusion, the newly isolated Enterobacter sp. EJ01 is a likely PGPR and alleviates salt stress in host plants through multiple mechanisms, including the rapid up-regulation of conserved plant salt stress responsive signaling pathways.

• 대한한의학회지
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• 제25권3호
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• pp.191-202
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• 2004

Objectives : This study was designed to elucidate the synergistic cytotoxic mechanisms of the co-treatment of Gagamjengac-tang (GGJAT) and As₂O₃ in human lung cancer cell line, H-157. Methods : The combination of GGJAT and As₂O₃ synergistically augmented the cytotoxicity of GGJAT and As₂O₃ in H­157 cells. The cytotoxicity by the combination of these two drugs was revealed as apoptosis which was characterized by chromatin condensation and fragmentation in DAPI staining. Results : Antioxidant NAC completely blocked the apoptotic death of H-157 cells by GGJAT and As₂O₃. The apoptotic cytotoxicity of GGJAT and As₂O₃ was accompanied by the induction of DR4 and DR5 in RT-PCR. In addition, antioxidant enzymes such as SOD1, GSH synthetase and GSH reductase were also increased in H-157 cells treated with GGJAT and As₂O₃. However, of note, p53, Fas, FasL and TRAIL were not detected in H-157 cells treated with GGJAT and As₂O₃ by RT-PCR. Conclusions : These results suggest that the synergistic cytotoxicity of the co-treatment of H-457 cells treated with GGJAT and As₂O₃ may cause induction of death receptors DR4 and DR5 as well as reactive oxygen species.

• Biomolecules & Therapeutics
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• 제21권4호
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• pp.270-276
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• 2013

Fucoxanthin is an important carotenoid derived from edible brown seaweeds and is used in indigenous herbal medicines. The aim of the present study was to examine the cytoprotective effects of fucoxanthin against hydrogen peroxide-induced cell damage. Fucoxanthin decreased the level of intracellular reactive oxygen species, as assessed by fluorescence spectrometry performed after staining cultured human HaCaT keratinocytes with 2',7'-dichlorodihydrofluorescein diacetate. In addition, electron spin resonance spectrometry showed that fucoxanthin scavenged hydroxyl radical generated by the Fenton reaction in a cell-free system. Fucoxanthin also inhibited comet tail formation and phospho-histone H2A.X expression, suggesting that it prevents hydrogen peroxide-induced cellular DNA damage. Furthermore, the compound reduced the number of apoptotic bodies stained with Hoechst 33342, indicating that it protected keratinocytes against hydrogen peroxide-induced apoptotic cell death. Finally, fucoxanthin prevented the loss of mitochondrial membrane potential. These protective actions were accompanied by the down-regulation of apoptosis-promoting mediators (i.e., B-cell lymphoma-2-associated ${\times}$ protein, caspase-9, and caspase-3) and the up-regulation of an apoptosis inhibitor (B-cell lymphoma-2). Taken together, the results of this study suggest that fucoxanthin defends keratinocytes against oxidative damage by scavenging ROS and inhibiting apoptosis.

• 생약학회지
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• 제49권3호
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• pp.231-239
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• 2018

Parkinson's disease (PD), one of common neurodegenerative diseases, is caused by the death of dopaminergic neurons in the substantia nigra pars compacta. The loss of dopaminergic neurons in PD is associated with oxidative stress and mitochondrial dysfunction. Hyperoside (quercetin 3-O-${\beta}$-D-galactopyranoside) was reported to have protective properties against oxidative stress by reducing intracellular reactive oxygen species (ROS) and increasing antioxidant enzyme activity. In this study, we examined the neuroprotective effect of hyperoside against 1-methyl-4-phenyl pyridinium ($MPP^+$)-induced cell model of PD and the underlying molecular mechanisms. Hyperoside significantly decreased $MPP^+$-induced cell death, accompanied by a reduction in poly ADP-ribose polymerase (PARP) cleavage. Furthermore, it attenuated $MPP^+$-induced intracellular ROS and disruption of mitochondrial membrane potential (MMP), with the reduction of Bax/Bcl-2 ratio. Moreover, hyperoside significantly increased the phosphorylation of Akt, but it has no effects on $GSK3{\beta}$ and MAPKs. Pharmacological inhibitor of PI3K/Akt abolished the cytoprotective effects of hyperoside against $MPP^+$. Taken together, these results demonstrate that hyperoside significantly attenuates $MPP^+$-induced neurotoxicity through PI3K/Akt signaling pathways in SH-SY5Y cells. Our findings suggest that hyperoside might be one of the potential candidates for the treatment of PD.