Hyoung Joon Park

National Institute of Animal Science, Sŏul, Seoul, South Korea

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Publications (10)15.45 Total impact

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    ABSTRACT: The aim of the study was to investigate the anti-obesity effect of Coprinus comatus (CC) in high-fat diet-fed Zucker rat (fa/fa). Obesity was induced by feeding on high-fat diet (HFD) containing 60% kcal fat for 10 weeks, in which CC extracts were administrated through the gastrointestinal tract at a concentration of 200 mg/kg BW/day for 10 weeks. The total polyphenol and flavonoid contents of CC extracts were found to be of catechin equivalent/g, and of quercetin equivalent/g extract, respectively. The DPPH, ABTS, and hydroxyl radical scavenging activities of CC extracts were 15.34 %, 17.25%, and 16.18%, respectively. In animal study, CC administration significantly reduced the body weight, while there were no significant differences in the daily food intake between the HFD-fed Zucker rats and HFD plus CC-fed rats. CC treatment decreased epididymal and perirenal fat weights in HFD-fed Zucker rats. Significant decreases in the levels of triglyceride and total cholesterol in the serum and liver were observed in the CC-treated group compared with HFD-fed Zucker rats. Serum HDL-cholesterol levels in the CC-treated group were increased compared with the HFD-fed groups. Serum AST and ALT activities in the CC group were significantly lower than those of the HFD-fed group. Taken together, these data demonstrated that CC has potential in preventing high-fat diet induced obesity and is a good candidate for an anti-obesity agent.
    Korean Journal of Veterinary Service. 01/2014; 37(1).
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    ABSTRACT: Abstract Schisandra chinensis (SC), a traditional herbal medicine, has been prescribed for patients suffering from various liver diseases, including hepatic cancer, hypercholesterolemia, and CCl4-induced liver injury. We investigated whether SC extract has a protective effect on alcohol-induced fatty liver and studied its underlying mechanisms. Rats were fed with ethanol by intragastric administration every day for 5 weeks to induce alcoholic fatty liver. Ethanol treatment resulted in a significant increase in alanine aminotransferase, aspartate aminotransferase, and hepatic triglyceride (TG) levels and caused fatty degeneration of liver. Ethanol administration also elevated serum TG and total cholesterol (TC) and decreased high-density lipoprotein (HDL) cholesterol levels. However, after administration of ethanol plus SC extracts, the ethanol-induced elevation in liver TC and TG levels was reversed. Elevation in serum TG was not observed after treatment with SC. Moreover, compared with the ethanol-fed group, the rats administered ethanol along with SC extracts for 5 weeks showed attenuated fatty degeneration and an altered lipid profile with decreased serum TC and TG, and increased HDL cholesterol levels. Chronic ethanol consumption did not affect peroxisome proliferator-activated receptor γ (PPARγ) levels, but it decreased PPARα and phospho-AMP-activated protein kinase (AMPK) levels in the liver. However, SC prevented the ethanol-induced decrease in PPARα expression and induced a significant decrease in sterol regulatory element-binding protein-1 expression and increase in phospho-AMPK expression in rats with alcoholic fatty liver. SC administration resulted in a significant decrease in intracellular lipid accumulation in hepatocytes along with a decrease in serum TG levels, and it reversed fatty liver to normal conditions, as measured by biochemical and histological analyses. Our results indicate that the protective effect of SC is accompanied by a significant increase in phospho-AMPK and PPARα expression in hepatic tissue of alcoholic rats, thereby suggesting that SC has the ability to prevent ethanol-induced fatty liver, possibly through activation of AMPK and PPARα signaling.
    Journal of medicinal food 01/2014; 17(1):103-10. · 1.39 Impact Factor
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    ABSTRACT: DNA methyltransferase1o (Dnmt1o), which is specific to oocyte and preimplantation embryo, plays a role in maintaining DNA methylation in mammalian cells. Here, we investigated the methylation status of CpGs sites in the Dnmt1o 5'-flanking region in germ cells at different stages of oogenesis or spermatogenesis. The methylation levels of the CpG sites at the 5'-flanking regions were hypermethylated in growing oocytes of all follicular stages, while the oocytes in meiotic metaphase II (MII) were demethylated. The methylation pattern within the CpGs sites in the 5'-flanking region, however, was dramatically changed during spermatogenesis. We observed that there was significant non-CpG methylation both in MII oocytes and spermatocytes. Although a low methylation level in non-CpG sites was observed in primary and secondary oocytes, the CpA site of position 25 and CpT site of position 29 within the no-CpG region in the 5'-flanking region of Dnmt1o was highly methylated in MII oocytes. During spermatogenesis, the low degree of methylation at CpG sites in spermatocytes increased to a higher degree in sperm, while the high ratio of methylation in non-CpG sites in spermatocytes decreased. Together, germ cells showed inverted methylation patterns between CpG and non-CpG sites in the Dnmt1o 5'-upstream region, and the methylation pattern in oogenesis did not drastically change, remaining generally hypomethylated at the MII stage. Mol. Reprod. Dev. © 2013 Wiley Periodicals, Inc.
    Molecular Reproduction and Development 01/2013; · 2.81 Impact Factor
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    ABSTRACT: This study examined the anti-obesity effect and mechanism of action of blueberry peel extracts (BPE) in 3T3-L1 cells and high-fat diet (HFD)-induced obese rats. The levels of lipid accumulation were measured, along with the changes in the expression of genes and proteins associated with adipocyte differentiation in 3T3-L1 cells. Evidenced by Oil-red O staining and triglyceride assay, BPE dose-dependently inhibited lipid accumulation at concentrations of 0, 50, and 200 µg/ml. BPE decreased the expression of the key adipocyte differentiation regulator C/EBPβ, as well as the C/EBPα and PPARγ genes, during the differentiation of preadipocytes into adipocytes. Moreover, BPE down-regulated adipocyte-specific genes such as aP2 and FAS compared with control adipocytes. The specific mechanism mediating the effects of BP revealed that insulin-stimulated phosphorylation of Akt was strongly decreased, and its downstream substrate, phospho-GSK3β, was downregulated by BPE treatment in 3T3-L1 cells. Together, these data indicated that BP exerted anti-adipogenic activity by inhibiting the expression of PPARγ and C/EBPβ and the Akt signaling pathway in 3T3-L1 adipocytes. Next, we investigated whether BP extracts attenuated HFD-induced obesity in rats. Oral administration of BPE reduced HFD-induced body weight gain significantly without affecting food intake. The epididymal or perirenal adipose tissue weights were lower in rats on an HFD plus BPE compared with the tissue weights of HFD-induced obese rats. Total cholesterol and triglyceride levels in the rats fed BPE were modestly reduced, and the HDL-cholesterol level was significantly increased in HFD plus BP-fed rats compared with those of HFD-fed rats. Taken together, these results demonstrated an inhibitory effect of BP on adipogenesis through the down-regulation of C/EBPβ, C/EBPα, and PPARγ and the reduction of the phospho-Akt adipogenic factor in 3T3-L1 cells. Moreover, BPE reduced body weight gain and inhibited fat accumulation in an HFD-induced animal model of obesity.
    PLoS ONE 01/2013; 8(7):e69925. · 3.73 Impact Factor
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    ABSTRACT: BACKGROUND: Skin flap survival is a major challenge in reconstructive plastic surgery. Here, we examined the effect of sustained delivery of fibroblast growth factor 2 (FGF2) using heparin-conjugated fibrin (HCF) on skin flap survival in rats. METHODS: Rats with a skin flap received either phosphate-buffered saline/FGF2 or HCF/FGF2 in the recipient bed. For the no-treatment group, a random skin flap was sutured on the back without any treatment. Seven days after surgery, angiogenesis in the skin flap was evaluated by using Visitrak system and conventional healing quality scoring method. The efficacy of HCF/FGF2 in skin flap survival was evaluated by comparing the results from different groups. RESULTS: The necrotic area of the skin flap significantly decreased in the HCF/FGF2 group as compared with the other groups. CONCLUSION: The sustained delivery of FGF2 using HCF has a therapeutic potential to improve skin flap survival.
    ANZ Journal of Surgery 09/2012; · 1.50 Impact Factor
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    ABSTRACT: In the present study, Schisandra chinensis (SC) was evaluated for inhibition effects on adipocyte differentiation in 3T3-L1 cells and anti-obesity properties in high fat diet (HFD)-induced obese rats. SC prevented lipid accumulation and impaired the differentiation of 3T3-L1 preadipocytes into adipocytes in a dose-dependent manner compared with the cells allowed to differentiate in DMII treated-control cells. SC treatment decreased expression of the key adipocyte differentiation regulator C/EBPβ, as well as C/EBPα or PPARγ, and resultant down-regulation of the terminal marker gene, aP2 during differentiation of 3T3-L1 preadipocytes into adipocytes. Moreover, Akt and GSK3β phosphorylation was down-regulated by SC treatment, which blocked adipogenesis and adipocyte differentiation. SC also inhibited HFD induced weight gain and adiposity in rats. HFD-induced obese rats showed a significant increase in the levels of serum TG and TC compared to rats on a normal diet. However, the levels of serum TG and TC in HFD + SC rats reduced significantly relative to the levels in HFD rats. Taken together, our results indicate that SC extracts inhibited preadipocyte differentiation and adipogenesis in cultured cells, leading to decreased body weight and fat tissue mass in HFD obese rats.
    Food Chemistry. 09/2012; 134(1):227–234.
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    ABSTRACT: Obesity is a health hazard that is associated with a number of diseases and metabolic abnormalities, such as type-2 diabetes, hypertension, dyslipidemia, and coronary heart disease. In the current study, we investigated the effects of Citrus aurantium flavonoids (CAF) on the inhibition of adipogenesis and adipocyte differentiation in 3T3-L1 cells. During adipocyte differentiation, 3T3-L1 cells were treated with 0, 10, and 50 μg/ml CAF, and then the mRNA and protein expression of adipogenesis-related genes was assayed. We examined the effect of CAF on level of phosphorylated Akt in 3T3-L1 cells treated with CAF at various concentrations during adipocyte differentiation. The insulin-induced expression of C/EBPβ and PPARγ mRNA and protein were significantly down-regulated in a dose-dependent manner following CAF treatment. CAF also dramatically decreased the expression of C/EBPα, which is essential for the acquisition of insulin sensitivity by adipocytes. Moreover, the expression of the aP2 and FAS genes, which are involved in lipid metabolism, decreased dramatically upon treatment with CAF. Interestingly, CAF diminished the insulin-stimulated serine phosphorylation of Akt (Ser473) and GSK3β (Ser9), which may reduce glucose uptake in response to insulin and lipid accumulation. Furthermore, CAF not only inhibited triglyceride accumulation during adipogenesis but also contributed to the lipolysis of adipocytes. In the present study, we demonstrate that CAF suppressed adipogenesis in 3T3-L1 adipocytes. Our results indicated that CAF down-regulates the expression of C/EBPβ and subsequently inhibits the activation of PPARγ and C/EBPα. The anti-adipogenic activity of CAF was mediated by the inhibition of Akt activation and GSK3β phosphorylation, which induced the down-regulation of lipid accumulation and lipid metabolizing genes, ultimately inhibiting adipocyte differentiation.
    BMC Complementary and Alternative Medicine 04/2012; 12:31. · 2.08 Impact Factor
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    ABSTRACT: The treatment of pressure sores represents a significant challenge to health care professionals. Although, pressure wound management demands a multidisciplinary approach, soft tissue defects requiring reconstruction are often considered for surgical management. Myocutaneous and fasciocutaneous flaps can provide stable coverage of pressure sores. Here, we describe our experience using a recent fasciocutaneous flap, which is named 'reading man' flap, in sacral, ischial, and trochanteric pressure sores. During a period of 1 year the authors operated 16 patients, 11 men, and 5 women, using the reading man flap. The ages of the patients ranged from 24 to 78 years. The location of pressure sores was 8 sacral, 5 ischial, and 3 trochanteric pressure sores. The mean size of pressure sores was 8 cm × 9 cm. All pressure sores covered bt the Reading Man flap healed asymptomatically. After follow-up of 2-8 months, no recurrences were encountered and no further surgical intervention was required. The reading man flap was found to be a useful technique for the closure of pressure sore in different anatomic locations. The advantage of tension-free closure and the minimal additional healthy skin excision made this flap a useful tool in pressure sore reconstructions.
    Indian Journal of Plastic Surgery 09/2011; 44(3):448-52.
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    ABSTRACT: We identified a 3.4-kb 5'-flanking region of the rPL-I gene and examined its promoter activity using rat trophoblast Rcho-1 cells. A regulatory element between base pairs (bp) -2,487 and -2,310 in the 5'-flanking region was essential for maximum promoter activity of the rPL-I gene. This regulatory element was further characterized between bp -2,443 to -2,415 and -2,374 to -2,345. Electrophoretic mobility shift analysis showed that the interaction of nuclear extract proteins from differentiated Rcho-1 cells was inhibited by competition with a GATA-like sequence in the promoter, but not by a mutated GATA sequence. Moreover, the promoter activity of 2487 eLuc containing two novel GATA sites was significantly elevated by co-transfection of a GATA-2 expression vector in proliferating Rcho-1 cells. Our results demonstrate that GATA-2 is involved in multiple promoter regions to activate the specific expression of the rPL-I gene in placental tissue.
    Biotechnology Letters 05/2009; 31(8):1173-81. · 1.85 Impact Factor
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    ABSTRACT: Background Centipede grass (CG) originates from China and South America and is reported to contain several C-glycosyl flavones and phenolic constituents, including maysin and luteolin derivatives. This study aimed to investigate, for the first time, the antiobesity activity of CG and its potential molecular mechanism in 3T3-L1 cells. Methods To study the effect of CG on adipogenesis, differentiating 3T3-L1 cells were treated every day with CG at various concentrations (0–100 μg/ml) for six days. Oil-red O staining and triglyceride content assay were performed to determine the lipid accumulation in 3T3-L1 cells. The expression of mRNAs or proteins associated with adipogenesis was measured using RT-PCR and Western blotting analysis. We examined the effect of CG on level of phosphorylated Akt in 3T3-L1 cells treated with CG at various concentration s during adipocyte differentiation. Results Differentiation was investigated with an Oil-red O staining assay using CG-treated 3T3-L1 adipocytes. We found that CG suppressed lipid droplet formation and adipocyte differentiation in 3T3-L1 cells in a dose-dependent manner. Treatment of the 3T3-L1 adipocytes with CG resulted in an attenuation of the expression of adipogenesis-related factors and lipid metabolic genes. The expression of C/EBPα and PPARγ, the central transcriptional regulators of adipogenesis, was decreased by the treatment with CG. The expression of genes involved in lipid metabolism, aP2 were significantly inhibited following the CG treatment. Moreover, the CG treatment down-regulated the phosphorylation levels of Akt and GSK3β. Conclusions Taken collectively, these data indicated that CG exerts antiadipogenic activity by inhibiting the expression of C/EBPβ, C/EBPα, and PPARγ and the Akt signaling pathway in 3T3-L1 adipocytes.
    BMC Complementary and Alternative Medicine 12(1). · 2.08 Impact Factor

Publication Stats

16 Citations
15.45 Total Impact Points

Institutions

  • 2013
    • National Institute of Animal Science
      Sŏul, Seoul, South Korea
  • 2012–2013
    • Gyeongsang National University
      • College of Veterinary Medicine
      Chinju, South Gyeongsang, South Korea
    • Seoul National University Bundang Hospital
      • Department of Plastic and Reconstructive Surgery
      Seoul, Seoul, South Korea
  • 2009
    • Jinju National University
      Gyeongju, North Gyeongsang, South Korea