• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.83-89
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• 2001

Recent advances in the structural and molecular biology uncovered that a set of translation factors resembles a tRNA shape and, in one case, even mimics a tRNA function for deciphering the genetic ：ode. Nature must have evolved this 'art' of molecular mimicry between protein and ribonucleic acid using different protein architectures to fulfill the requirement of a ribosome 'machine'. Termination of protein synthesis takes place on the ribosomes as a response to a stop, rather than a sense, codon in the 'decoding' site (A site). Translation termination requires two classes of polypeptide release factors (RFs)： a class-I factor, codon-specific RFs (RFI and RF2 in prokaryotes; eRFI in eukaryotes), and a class-IT factor, non-specific RFs (RF3 in prokaryotes; eRF3 in eukaryotes) that bind guanine nucleotides and stimulate class-I RF activity. The underlying mechanism for translation termination represents a long-standing coding problem of considerable interest since it entails protein-RNA recognition instead of the well-understood codon-anticodon pairing during the mRNA-tRNA interaction. Molecular mimicry between protein and nucleic acid is a novel concept in biology, proposed in 1995 from three crystallographic discoveries, one, on protein-RNA mimicry, and the other two, on protein-DNA mimicry. Nyborg, Clark and colleagues have first described this concept when they solved the crystal structure of elongation factor EF- Tu：GTP：aminoacyl-tRNA ternary complex and found its overall structural similarity with another elongation factor EF-G including the resemblance of part of EF-G to the anticodon stem of tRNA (Nissen et al. 1995). Protein mimicry of DNA has been shown in the crystal structure of the uracil-DNA glycosylase-uracil glycosylase inhibitor protein complex (Mol et al. 1995; Savva and Pear 1995) as well as in the NMR structure of transcription factor TBP-TA $F_{II}$ 230 complex (Liu et al. 1998). Consistent with this discovery, functional mimicry of a major autoantigenic epitope of the human insulin receptor by RNA has been suggested (Doudna et al. 1995) but its nature of mimic is. still largely unknown. The milestone of functional mimicry between protein and nucleic acid has been achieved by the discovery of 'peptide anticodon' that deciphers stop codons in mRNA (Ito et al. 2000). It is surprising that it took 4 decades since the discovery of the genetic code to figure out the basic mechanisms behind the deciphering of its 64 codons.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.5-20
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• 2008

GLP-1-based drugs (GLP-1 analogues and DPP IV inhibitors) and incretin mimetics are currently one of the most exciting classes of agents for type II diabetes. GLP-1, a gut peptide, is an incretin that potentiates glucose-dependent insulin release from the pancreas, slows GI-transit and stimulates the proliferation of beta-cells. DPP IV inhibitors act like incretins by inhibiting DPP IV which inactivates GLP-1. LC15-0133 is a competitive, reversible DPP IV inhibitor ($IC_{50}$ = 24 nM, Ki=0.247 nM) with excellent selectivity over other critical human proteases such as DPP II, DPP 8, elastase, trypsin. and urokinase. LC15-0133 showed long half-life and good bioavailability in rats and dogs. Inhibition of plasma DPP IV activity by LC15-0133 was kept more than 50% 24 hours after oral dosing in rats and dogs at 0.1 mg/kg and 0.02 mg/kg, respectively. The Minimum effective doses of LC15-0133 were 0.01 mg/kg for lowering blood glucose excursion during oral glucose tolerance test and 0.1 mg/kg for increasing glucose-induced GLP-1 response in C57BL/6 mice. Repeat oral administration of LC15-0133 for 1 month delayed the progression to diabetes and reduced HbA1c levels in a dose-dependent manner in Zucker Diabetic Fatty rats. In conclusion, LC15-0133 is a novel, potent, selective and orally active DPP IV inhibitor and showed an excellent blood glucose lowering effects in various animal models.

• The Korea Journal of Herbology
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• v.28 no.4
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• pp.83-92
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• 2013

Objectives : Lespedeza Cuneata has been used to treat leukorrhea, asthma, stomach pain, diarrhea, acute mastitis, in Korean traditional medicine. According to recent studies, Lespedeza Cuneata has antioxidation, hypoglycemia, cell protective, insulin secretion, whitening, corpora cavernosa smooth muscle relaxation and antimicrobial activities, but it has been rarely conducted to evaluate the immuno-biological activity. The present study was examined to evaluate the anti-inflammatory effects of the Lespedeza Cuneata MeOH extract (LCE) in vivo and in vitro. Methods : In vitro, inflammatory mediators, such as cytokines, nitric oxide and prostaglandin $E_2$ were detected after the addition of LPS with or without LCE in Raw 264.7 macrophage cell line. In vivo, anti-edema effect of LCE was determined in the carrageenan-induced paw edema model in rats. Results : In vitro assay, LCE decreased release of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) via suppression of iNOS and COX-2 expression. LCE inhibited the phosphorylation of $I{\kappa}B$ indicating the suppression of NF-${\kappa}B$ pathway. In vivo assay, LCE significantly inhibited the formation of paw edema induced by carrageenan injection in rats. LCE effectively inhibited increases of hind paw skin thickness and inflammatory cell infilterations. Conclusion : These findings demonstrate that LCE has inhibitory effect on inflammatory mediators in LPS-activated Raw 264.7 cells and on paw edema in carrageenan-stimulated rats, showing the possibility of anti-inflammatory use of Lespedeza Cuneata.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1189-1195
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• 2008

A study was conducted with 48 weaned barrows ($28{\pm}3d$, $8.45{\pm}0.14kg$) to determine the effect of Achyranthes bidentata polysaccharide (ABPS) supplementation on pig performance, immunological, adrenal and somatotropic responses following Escherichia coli lipopolysaccharide (LPS) challenge. The experiment was a $2{\times}2$ factorial design; the main factors included diet (supplementation with 0 or 500 mg/kg ABPS) and immunological challenge (LPS or saline). On d 14 and 21 of the trial, pigs were given an intraperitoneal injection with either $100{\mu}g/kg$ BW of LPS or an equivalent amount of sterile saline. Blood samples were obtained 3 h after injection for analysis of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), prostaglandin $E_2$ ($PGE_2$), cortisol, growth hormone (GH), insulin-like growth factor (IGF)-I and immunoglobulin G (IgG). On d 2 after LPS challenge, peripheral blood lymphocyte proliferation (PBLP) was measured. LPS administration decreased average daily feed intake (ADFI) (p<0.05), had a tendency to decrease average daily gain (ADG) (p<0.10) during both the first and second challenge periods and increased (p<0.05) feed:gain ratio only during the first challenge period. ABPS tended to improve ADG (p<0.10) during the first challenge period, and improved ADG (p<0.05) and tended to improve ADFI (p<0.10) during the second challenge period. ABPS did not affect feed:gain ratio. An interaction (p<0.05) between LPS challenge and diet was observed for the plasma concentrations of TNF-${\alpha}$, $PGE_2$ and cortisol after both LPS challenges such that, among LPS-treated pigs, pigs fed the ABPS diet were lower for these indices than those receiving the control diet. In contrast, pigs fed the ABPS diet had higher IGF-I (p<0.05) compared with those fed the control diet. No effect of diet, LPS challenge or both on GH and IgG was observed after both LPS administrations. LPS challenge increased PBLP when these cells were incubated with $8{\mu}g/ml$ of LPS during both the challenge periods, and did likewise when incubated with $8{\mu}g/ml$ of concanavalin A only after the first challenge. ABPS had no effect on PBLP. These data demonstrate that ABPS alters the release of pro-inflammatory cytokines following an immunological challenge, which might enable pigs to achieve better performance.

• Journal of Nutrition and Health
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• v.47 no.4
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• pp.221-228
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• 2014

Purpose: Citron seed oil (CSO) has been reported to have high antioxidant activity. However, the composition and other biologically activities of CSO have not been reported. In this study, we confirmed the fatty acid composition of CSO, which may be beneficial to vascular disease and obesity. Methods: We investigated the oil composition of CSO using gas chromatography coupled with mass spectrometry (GC-MS) analysis, and cytotoxicity was confirmed by Cell Counting Kit-8 (CCK-8) assay. Nitric oxide (NO) production in human umbilical vein endothelial cells (HUVECs) was measured using Griess reagent, and lipid accumulation and leptin secretion in 3T3-L1 cells were measured by Oil-Red O staining and commercial ELISA kit, respectively. Results: GC-MS analysis indicated that CSO contains several components, including linoleic acid, oleic acid, palmitic acid, stearic acid, linolenic acid, palmitoleic acid, and arachidic acid. In physiological activity analysis, CSO did not induce cytotoxic effects in HUVECs and 3T3-L1 cells. Further, CSO significantly induced nitric oxide and leptin secretion as well as inhibited lipid accumulation. Conclusion: CSO increased NO release, inhibited lipid accumulation, and induced leptin secretion, suggesting it may be useful for the management of vessels and weight gain. Although further studies are required to investigate the safety and mechanism of action of CSO, our results show that the composition and physiological activity of CSO are sufficient for its use as functional edible oil.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.411-416
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• 2013

This study aimed to examine the mechanisms underlying the effects of Garcinia cambogia extract on the adipogenic differentiation of 3T3-L1 cells and long-chain saturated fatty acid-induced lipotoxicity of HepG2 cells. 3T3-L1 preadipocytes, mouse embryonic fibroblast-adipose like cell line, were treated with MDI solution (0.5 mM IBMX, 1 ${\mu}M$ dexamethasone, 10 ${\mu}g/mL$ insulin) to generate a cellular model of adipocyte differentiation. Using this cellular model, the anti-obesity effect of Garcinia cambogia extract was evaluated. MDI-induced lipid accumulation and expression of adipogenesis-related genes were detected by Oil red O staining, Nile Red staining, and Western blot analysis. Effects Garcinia cambogia extract on palmitate-induced lipotoxicity was also analyzed by MTT assay, LDH release, and DAPI staining in HepG2 cells. Garcinia cambogia extract significantly suppressed the adipogenic differentiation of preadipocytes and intracellular lipid accumulation in the differentiating adipocytes. Garcinia cambogia extract also markedly inhibited the expression of peroxisome proliferator- activated receptor ${\gamma}2$ ($PPAR{\gamma}2$), CCAT/enhancer-binding protein ${\alpha}$ ($C/EBP{\alpha}$), and adipocyte protein aP2 (aP2). In addition, Garcinia cambogia extract significantly attenuated palmitate-induced lipotoxicity in HepG2 cells. Palmitateinduced cellular damage and reactive aldehydes were also significantly reduced in the presence of Garcinia cambogia extract. These findings suggest that the Garcinia cambogia extract inhibits the adipogenic differentiation of 3T3-L1 preadipocytes, probably by regulating the expression of multiple genes associated with adipogenesis such as $PPAR{\gamma}2$, $C/EBP{\alpha}$, aP2, and thereby modulating fatty acid-induced lipotoxicity to reduce cellular injury in hepatocytes.