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Seongnam, South Korea

Rhim J.W.,Mokpo National University | Wang L.F.,Mokpo National University | Hong S.I.,Korea Food Research Institute
Food Hydrocolloids | Year: 2013

Composite films with silver nanoparticles (AgNPs), obtained by reduction of AgNO3 using an environmentally friendly method (combined reduction of AgNO3 by trisodium citrate solution and heating), and agar as a polymer matrix and a capping agent were prepared by solvent casting method. The surface color of the resulting agar/AgNPs films exhibited the characteristic plasmonic effect of the silver nanoparticles, and the characteristic properties of the composite films were greatly influenced by changing the concentration of AgNPs added. Significant increase in water vapor barrier properties and surface hydrophobicity were observed with increase in the concentration of AgNPs without reduction in the mechanical strength. In addition, the agar/AgNPs films loaded with more than 1wt% of silver nanoparticles exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli O157:H7) bacterial pathogens. •Agar/silver nanoparticle composite films were prepared by reduction of AgNO3.•Film properties were dependent on the concentration of silver nanoparticles.•The composite film exhibited improved water vapor, gas barrier and mechanical properties.•The composite film with 1 and 2% of AgNPs showed strong antimicrobial activity.•The film can be potentially used as active packaging systems for preserving food quality and extending the shelf life. © 2013 Elsevier Ltd.

Um M.Y.,Korea Food Research Institute
The British journal of nutrition | Year: 2013

Coumarin is a natural compound abundant in plant-based foods such as citrus fruits, tomatoes, vegetables and green tea. Although coumarin has been reported to exhibit anti-coagulant, anti-inflammation and cholesterol-lowering properties, the effect of coumarin on hepatic lipid metabolism remains unclear. In the present study, we evaluated the ability of coumarin to protect against hepatic steatosis associated with a high-fat diet (HFD) and investigated potential mechanisms underlying this effect. C57BL/6J mice were fed a normal diet, HFD and HFD containing 0·05 % courmarin for 8 weeks. The present results showed that coumarin reduced weight gain and abdominal fat mass in mice fed the HFD for 8 weeks (P< 0·05). Coumarin also significantly reduced the HFD-induced elevation in total cholesterol, apoB, leptin and insulin (P< 0·05). In the liver of HFD-fed mice, coumarin significantly reduced total lipids, TAG and cholesterol (38, 22 and 9 % reductions, respectively; P< 0·05), as well as lipid droplet number and size. Additionally, thiobarbituric acid-reactive substance levels, as an indicator of hepatic steatosis, were attenuated by coumarin (P< 0·05). Finally, coumarin suppressed the HFD-induced up-regulation in fatty acid synthase (FAS) activity, and the expression of sterol regulatory element-binding protein-1, FAS, acetyl-CoA carboxylase 1, PPARγ and CCAAT/enhancer-binding protein-α in the liver. Taken together, these results demonstrate that coumarin could prevent HFD-induced hepatic steatosis by regulating lipogenic gene expression, suggesting potential targets for preventing hepatic steatosis.

Jeon T.-I.,Korea Food Research Institute | Osborne T.F.,Sanford Burnham Institute for Medical Research
Trends in Endocrinology and Metabolism | Year: 2012

Recent advances have significantly increased our understanding of how sterol regulatory element binding proteins (SREBPs) are regulated at the transcriptional and post-transcriptional levels in response to cellular signaling. The phosphatidyl inositol-3-kinase (PI3K) and SREBP pathways intersect at multiple points, and recent insights demonstrate the importance of tight regulation of the PI3K pathway for regulating SREBPs in the adaptation to fluctuating dietary calorie load in the mammalian liver. In addition, genetic and genome-wide approaches highlight new functions for SREBPs in connecting lipid metabolism with other cellular processes where lipid pathway flux affects physiologic or pathophysiologic adaptation, such as cancer, steatosis, and innate immunity. This review focuses on recent advances and new roles for mammalian SREBPs in physiology and metabolism. © 2011 Elsevier Ltd.

Ma J.Y.,Korea Food Research Institute
African Journal of Traditional, Complementary and Alternative Medicines | Year: 2011

Ssanghwa-tang (SHT) is a traditional herbal medicine formula that has been used for the development of physical strength, relief of pain, and the reduction of fatigue. In this study, we fermented SHT with Lactobacillus fermentum (L. fermentum), Lactobacillus gasseri (L.gasseri), or Lactobacillus casei (L.casei) to investigate the hepatoprotective effects of SHT and fermented SHT with Lactobacillus on carbon tetrachloride (CCl 4)-induced liver injury in rats. Rats were given CCl 4 (1 ml/kg, 50% CCl 4 in olive oil) intraperitoneally and either SHT or fermented SHTs (15 ml/kg) was administered 30 min before CCl 4. At 24 hr after CCl 4 injection, the levels of transaminases in the serum were markedly increased. These increases were significantly attenuated by either SHT + L. fermentum or SHT+ L.gasseri. However, SHT and SHT + L.casei showed slight suppression of the increase of transaminases. The liver histological changes were diminished by treatment with SHT + L. fermentum. Additionally, the potential hepatoprotective effect of fermented-SHTs correlated with the amount of unknown metabolite which is produced during fermentation process with L. fermentum, L.gasseri, or L.casei. Therefore, these results suggest that the hepatoprotective effect of SHT may be improved by fermentation with L. fermentum and the intestinal bacterial enzyme activities may likely play an important role in the pharmacological action of herbal medicines.

A persimmon leaf-derived polysaccharide fraction consisting of 60-80 wt % of neutral sugar and 18-39 wt % of uronic acid, and 0.5-10 wt % of 3-deoxy-D-manno-2-octulosonic acid (KDO) analogs, the wt % based on the total weight of the polysaccharide fraction.

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