Man-Deuk Han

Rutecarpine ameliorates bodyweight gain through the inhibition of orexigenic neuropeptides NPY and AgRP in mice

Orexigenic neuropeptides NPY and AgRP play major roles in feeding and are closely related to obesity and diabetic metabolic syndrome. This study explored the inhibitory effect of rutecarpine on feeding and obesity in high-fat-diet-induced (C57BL/6) and leptin-deficient (ob/ob) obese mice. Both mice strains developed obesity, but the obesity was inhibited by the reduced food intake resulting from rutecarpine treatment (0.01%, p<0.01). Blood cholesterol, non-fasting glucose, insulin, and leptin levels were reduced, compared with the control group. Rutecarpine inhibited the expression of NPY and AgRP in the arcuate nucleus (ARC) of the hypothalamus and suppressed the expression of both neuropeptides in N29-4 neuronal cells. These results indicate that rutecarpine ameliorates obesity by inhibiting food intake, which involves inhibited expression of the orexigenic neuropeptides NPY and AgRP.

Resveratrol, purified from the stem of Vitis coignetiae Pulliat, inhibits food intake in C57BL/6J Mice.

Neuropeptide Y (NPY) and agouti-related protein (AgRP) have powerful stimulatory effects on food intake, which suggests that the downregulation of brain NPY or AgRP may help reduce obesity and diabetes by inhibiting food intake. To search for active compounds that inhibit NPY and AgRP expression, we made two luciferase reporter assay systems consisting of NPY and AgRP promoter-driven luciferase genes, together with the puromycin resistance gene, in a plasmid vector. Each plasmid was permanently transfected into N29-4 neuronal cells. Using the systems, resveratrol was purified from the stem of Vitis coignetiae Pulliat by activityguided fractionation. Resveratrol downregulated NPY and AgRP promoter-driven luciferase activity in a dose-dependent manner. The inhibitory concentrations (IC50, 50% inhibition) of resveratrol against pNPY-luc and pAgRP-luc activities were 8.9 μM and 8.0 μM, respectively. Furthermore, one-time intraperitoneal injection of resveratrol (100 mg/kg) suppressed 20.0% and 17.2% of food intake during 24 and 48 h, respectively. These results indicated that resveratrol inhibited food intake, which may be related to the downregulation of NPY and AgRP gene expression.

Brazilin selectively disrupts proximal IL-1 receptor signaling complex formation by targeting an IKK-upstream signaling components.

The ligation of interleukin-1 receptor (IL-1R) or tumor necrosis factor receptor 1 (TNFR1) induces the recruitment of adaptor proteins and their concomitant ubiquitination to the proximal receptor signaling complex, respectively. Such are upstream signaling events of IKK that play essential roles in NF-κB activation. Thus, the discovery of a substance that would modulate the recruitment of key proximal signaling elements at the upstream level of IKK has been impending in this field of study. Here, we propose that brazilin, an active compound of Caesalpinia sappan L. (Leguminosae), is a potent NF-κB inhibitor that selectively disrupts the formation of the upstream IL-1R signaling complex. Analysis of upstream signaling events revealed that brazilin markedly abolished the IL-1β-induced polyubiquitination of IRAK1 and its interaction with IKK-γ counterpart. Notably, pretreatment of brazilin drastically interfered the recruitment of the receptor-proximal signaling components including IRAK1/4 and TRAF6 onto MyD88 in IL-1R-triggerd NF-κB activation. Interestingly, brazilin did not affect the TNF-induced RIP1 ubiquitination and the recruitment of RIP1 and TRAF2 to TNFR1, suggesting that brazilin is effective in selectively suppressing the proximal signaling complex formation of IL-1R, but not that of TNFR1. Moreover, our findings suggest that such a disruption of IL-1R-proximal complex formation by brazilin is not mediated by affecting the heterodimerization of IL-1R and IL-1RAcP. Taken together, the results suggest that the anti-IKK activity of brazilin is induced by targeting IKK upstream signaling components and subsequently disrupting proximal IL-1 receptor signaling complex formation.

Brazilin Limits Inflammatory Responses through Induction of Prosurvival Autophagy in Rheumatoid Fibroblast-Like Synoviocytes

Brazilin is an active compound of Caesalpinia sappan L. (Leguminosae), which possesses pro-apoptotic and anti-inflammation potentials depending on the specific cell type. However, it is largely unknown whether autophagy is implicated in the mechanism underlying its chemotherapeutic and anti-inflammatory effects in rheumatoid arthritis (RA). Here, we show that treatment of RA fibroblast-like synoviocytes (FLS) with brazilin results in enhanced level of autophagic flux, evidenced by accumulation of autophagosome and increased level of lipidated LC3 (LC3-II), which is mainly mediated by enhanced production of reactive oxygen species (ROS). Interestingly, long-term exposure of brazilin was able to restore cell survival against the cytotoxity, exclusively in RA FLS, but not in normal fibroblast. Importantly, such a restoration from brazilin-induced cytotoxity in RA FLS was completely abrogated after co-treatment with autophagy inhibitors including NH4Cl or chloroquine. Furthermore, we found that the pretreatment of RA FLS with brazilin reduced LPS- or TNF-induced NF-κB activation and the secretion of inflammatory cytokines in parallel with the enhanced autophagic flux. Such anti-NF-κB potentials of brazilin were drastically masked in RA FLS when autophagy was suppressed. These results suggest that brazilin is capable of activating autophagy exclusively in RA FLS, and such inducible autophagy promotes cell survival and limits inflammatory response.

Bacterial Community Dynamics of Salted and Fermented Shrimp based on Denaturing Gradient Gel Electrophoresis

The Korean traditional seafood jeotgal is consumed directly or as an additive in other foods to improve flavor or fermentation efficiency. Saeujot, made from salted and fermented tiny shrimp (SFS; Acetes japonicus), is the best-selling jeotgal in Korea. In this study, we reveal the microbial diversity and dynamics in naturally fermented shrimp by denaturing gradient gel electrophoresis (DGGE). The population fingerprints of the predominant microbiota and its succession were generated by DGGE analysis of universal V3 16S rDNA polymerase chain reaction (PCR) amplicons. Overall, 17 strains were identified from sequencing of 30 DGGE bands. The DGGE profiles showed diverse bacterial populations in the sample, throughout the fermentation of SFS. Staphylococcus equorum, Halanaerobium saccharolyticum, Salimicrobium luteum, and Halomonas jeotgali were the dominant bacteria, and their levels steadily increased during the fermentation process. Certain other bacteria, such as Psychrobacter jeotgali and Halomonas alimentaria appeared during the early-fermentation process, while Alkalibacterium putridalgicola, Tetragenococcus muriaticus, and Salinicoccus jeotgali appeared during the late-fermentation process. The members of the order Bacillales were found to be predominant during the fermentation of SFS. Furthermore, S. equorum was identified as the dominant bacterial isolate by the traditional method of culturing under aerobic and facultative anaerobic conditions. We expect that this information will facilitate the design of autochthonous starter cultures for the production of SFS with desired characteristic sensory profiles and shorter ripening times.

Isolation and Characterization of Chitinase‐Producing Bacillus and Paenibacillus Strains from Salted and Fermented Shrimp, Acetes japonicus

Chitinases catalyze the conversion of chitin and are produced by a wide range of bacteria. The biological applications of these enzymes have been exploited in food and pharmaceutical industries. We isolated 2 halophilic chitinase-producing novel strains of bacteria-SCH-1 and SCH-2 from Saeu-jeot, a traditional Korean salted and fermented food made with shrimp (Acetes japonicus). The isolated strains- SCH-1 and SCH-2 were Gram-positive, rod-shaped, endospore-forming facultative anaerobes, with strain SCH-2 showing peritrichous flagella. Molecular characterization of the 16S rRNA gene identified the strains SCH-1 and SCH-2 as Bacillus sp. and Paenibacillus sp. respectively. Basic Local Alignment Search Tool and subsequent phylogenetic analysis of strain SCH-1 showed an identity of 97.83% with Bacillus cereus ATCC 14579 (NR_074540), whereas strain SCH-2 showed an identity of 99.16% with Paenibacillus lautus JCM 9073 (NR_040882). Furthermore, the SCH-1 strain could use glucose, N-acetyl glucosamine, esculin, and maltose as carbon source substrates. Cellular fatty acid analysis showed that iso-C15:0 and anteiso-C15:0 are the major acids in strain SCH-1 and SCH-2, respectively. The SCH-1 strain showed a higher chitinase activity at 15.71 unit/mg protein compared with SCH-2 strain. Chitinase isozymes of Bacillus sp. SCH-1was expressed as 2 bands having sizes of 41 and 50 kDa, and as 4 bands with sizes of 30, 37, 45.7, and 50 kDa in Paenibacillus sp. SCH-2. The rich chitinase activity with the isozyme profiles of the isolated Bacillus and Paenibacillus strains provide advancement in the study of fermentation and may play putative functions in the chitin bioconversion of sea crustacean foods.

Antihyperlipidemic Activities of a Chemically Engineered Sulfated Mushroom β-glucan on High Fat Dietary-induced Hyperlipidemia in Sprague-Dawley Rats

-glucan (SBG) obtained from Ganoderma lucidum mycelia on the antihyperlipidemic and serum lipid levels in high-fat diet-in-duced obese rats. Five-week-old male Sprague-Dawley rats were fed a high-fat diet for two weeks to induce obesity. They were ten divided into five groups－normal control diet group (NC), high-fat con-trol diet group (HC), high-fat diet and 200 mg/kg of SBG group (HC-HSBG), high-fat diet and 20 mg/kg of SBG group (HC-LSBG), and high-fat diet and 20 mg/kg of lovastatin group (HC-Lov)－and fed one of five diets for two more weeks. Although food intake and final body weight after four weeks of SBG consumption were similar in the five experimental groups, food efficiency ratio was higher in the high-fat diet groups(2, 3, 4, and 5) than in the NC group. In evaluating the hemato-logical parameters of the rats, the neutrophil and monocyte ratios were higher in the HC-HSBG, HC-LSBG, and HC-Lov groups than in the HC group. Serum lipid profiles were analyzed after a 12 hr fast at the end of the study. Total cholesterol, triglyceride, and low-density lipoprotein cholesterol (LDL-C) levels were significantly lower in the HC-HSBG and HC-LSBG groups than in the HC group. These results suggest that chemically engineered sulfated mushroom

Screening of Hyaluronidase Inhibitor in Korean Medicinal Plants

Mammalian hyaluronidases (HAase, EC 3.2.1.35) are a family of enzymes that hydrolyse N-acetyl-D-glucosamine (1-4) glycosidic bonds in hyaluronic acid, which is found in skin, cartilage, and the vitreous body. Although HAase is generally present in an inactive form within subcellular lysosomes, it is released in an active form in some types of inflammation and tissue injuries, thereby contributing to the inflammatory response. The HAase inhibitory activity of 500 methanolic extracts of 500 species from medicinal plants was screened using a Morgan microplate assay. The viscosity of the hyaluronic acid was measured with an Ubbelohde viscometer. Three MeOH extracts inhibited more than 50% of HAase activity at a concentration of 2 mg/ml. HAase inhibitory rates (%) of three species of medicinal plant extracts, Styrax japonica, Deutzia coreana, and Osmanthus insularis were 57.28%, 53.50%, and 53.19%, respectively. The rate of HAase inhibition of the extracts was dose dependent. In the HAase inhibitory assay using the Ubbelohde viscometer, the results were in good agreement with the results from the Morgan assay. The results suggest that HAase inhibitory compounds extracted from the stem of S. japonica, D. coreana, and O. insularis might be multifunctional and prevent the degradation of hyaluronic acid and the induction of allergic reactions and inflammation.

Cytoprotective Effects and Gene Expression Patterns Observed Based on the Antioxidant Activity of Lonicera japonica Extract

In this study, based on the antioxidative effects in organic solvent fractions obtained from the main methanolic extract of L. japonica, the protective cellular effects and gene expression patterns of ethyl acetate fractions on H₂O₂-induced Raw 264.7 cell death (IC 50 ) were analyzed. The antioxidant activity of the fractions measured using DPPH free radical scavenging activity increased in a dose-dependent manner, and the ED 50 exhibited the highest 39.56 μg/ml in the ethyl acetate fraction. In addition, the ethyl acetate fractions’ cell viability on H₂O₂-induced Raw 264.7 cell damage increased in a concentration- dependent manner, showed a visible cell survival rate of 82.49% at a concentration of 100 μg/ml. The gene expression patterns related to the ethyl acetate fractions’ cytoprotective effect in H₂O₂-induced Raw 264.7 cell damage presented similar patterns to those of BHA. In comparative analysis for antioxidant activity-related genes affected by ethyl acetate fractions and BHA in H₂O₂-induced Raw 264.7 cells, both ethyl acetate fractions and BHA showed very similar gene expression patterns, but the gene expression level of the heme oxygenase 1 (Hmox1) gene making antioxidant enzymes in cells was four times higher in ethyl acetate fractions than BHA. In inflammation-related genes in H₂O₂induced Raw 264.7 cells, the T-box transcription factor (Tbx21) gene was expressed about two times more frequently in the ethyl acetate fraction treatment group, while it was expressed half as frequently in the BHA treatment group.Antioxidant Activity of Lonicera japonica Extract Won June Cho, Hee Seung Yoon, Yong Hyun Kim, Jung Min Kim, Il Jae Yoo, Man-Deuk Han and In Seok Bang 1 * Department of Biological Science and the Research Institute for Basic Sciences, Hoseo University, Asan 336-795, Korea Department of Biology, Soonchunhyang University, Asan 350-646, Korea NAR Center, Inc., Daejeon Oriental Hospital of Daejeon University, Daejeon 301-724, Korea Institute of Nanoproduct Safety Research, Hoseo University, Asan 336-795, Korea

Expression of recombinant hybrid peptide hinnavin II/α-melanocyte-stimulating hormone in Escherichia coli : Purification and characterization

The increasing problem of antibiotic resistance among pathogenic bacteria requires novel strategies for the construction of multiple, joined genes of antimicrobial agents. The strategy used in this study involved synthesis of a cDNA-encoding hinnavin II/α-melanocyte-stimulating hormone (hin/MSH) hybrid peptide, which was cloned into the pET32a (+) vector to allow expression of the hybrid peptide as a fusion protein in Escherichia coli BL21 (DE3). The resulting expression of fusion protein Trx-hin/MSH could reach up to 20% of the total cell proteins. More than 50% of the target protein was in a soluble form. The target fusion protein from the soluble fraction, Trx-hin/MSH, was easily purified by Ni2+-chelating chromatography. Then, enterokinase cleavage effectively cleaved the Trx-hin/MSH to release the recombinant hin/MSH (rhin/MSH) hybrid peptide. After removing the contaminants, we purified the recombinant hybrid peptide to homogeneity by reversed-phase FPLC and obtained 210 mg of pure, active rhin/MSH from 800 ml of culture medium. Antimicrobial activity assay demonstrated that rhin/MSH had a broader spectrum of activity than did the parental hinnavin II or MSH against fungi and Gram-positive and Gram-negative bacteria. These results suggest an efficient method for producing high-level expression of various kinds of antimicrobial peptides that are toxic to the host, a reliable and simple method for producing different hybrid peptides for biological studies.