• Journal of Life Science
• /
• v.31 no.10
• /
• pp.898-904
• /
• 2021

Locusta migratoria is a widespread locust species in many parts of the world and is considered an alternative source for the production of protein for value-added ingredients. We previously identified putative antimicrobial peptides derived from L. migratoria through an in silico analysis of its transcriptome. However, its anti-inflammatory effect has not been studied. In this study, we investigated the anti-inflammatory activities of the antimicrobial peptide locustacin (KTHILSFFPSFLPLFLKK-NH₂) derived from L. migratoria on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Locustacin (50, 100, and 200 ㎍/ml) significantly reduced the production of nitric oxide (NO) in LPS-stimulated macrophages without any cytotoxicity. Locustacin also inhibited the mRNA and protein expression of pro-inflammatory mediators, such as inducible NO synthase and cyclooxygenase-2, in contrast to the presence of LPS alone. Locustacin decreased the release of LPS-induced pro-inflammatory cytokines, including interleukin (IL)-6 and IL-1β, and their gene expression in a dose-dependent manner. Furthermore, locustacin (100 and/or 200 ㎍/ml) inhibited phosphorylation levels of extracellular signal regulated kinase, p38, and c-Jun N-terminal kinase. Locustacin also suppressed the degradation of inhibitory kappa B alpha, which was considered to be an inhibitor of nuclear factor kappa B (NF-κB). Collectively, these results demonstrate that locustacin can exert anti-inflammatory effects through the inhibition of mitogen-activated protein kinase (MAPK) phosphorylation, activation of NF-κB, and downstream inflammatory mediators in LPS-stimulated macrophage cells.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.6
• /
• pp.783-796
• /
• 1997

The relaxation induced by stimulation of the inhibitory non-adrenergic, non-cholinergic (iNANC) nerve is mediated by the release of iNANC neurotransmitters such as nitric oxide (NO), vasoactive intestinal peptide (VIP) and adenosine triphosphate (ATP). The mechanisms of NO, VIP or ATP-induced relaxation have been partly determined in previous studies, but the detailed mechanism remains unknown. We tried to identify the nature of iNANC neurotransmitters in the smooth muscle of guinea pig ileum and to determine the mechanism of the inhibitory effect of nitric oxide. We measured the effect of NO-donors VIP and ATP on the intracellular $Ca^{2+}$ concentration$([Ca^{2+}]_i)$, by means of a fluorescence dye(fura 2) and tension simultaneously in the isolated guinea pig ileal smooth muscle. Following are the results obtained. 1. Sodium nitroprusside $(SNP:10^{-5}\;M)$ or S -nitro-N-acetyl-penicillamine $(SNP:10^{-5}\;M)$ decreased resting $[Ca^{2+}]_i$ I and tension of muscle. SNP or SNAP also inhibited rhythmic oscillation of $[Ca^{2+}]_i$ and tension. In 40mM $K^+$ solution or carbachol ($(CCh:10^{-6}\;M)$-induced precontracted muscle, SNP decreased muscle tension. VIP did not change $[Ca^{2+}]_i$ and tension in the resting or precontracted muscle, but ATP increased resting $[Ca^{2+}]_i$ and tension in the resting muscle. 2. 1H-[1,2,4]oxadiazol(4,3-a)quinoxalin-1-one $(ODQ:1\;{\mu}M)$, a specific inhibitor of soluble guanylate cyclase, limited the inhibitory effect of SNP 3. Glibenclamide $(10\;{\mu}M)$, a blocker of $K_{ATP}$ channel, and 4-aminopyridine (4-AP:5 mM), a blocker of delayed rectifier K channel, apamin $(0.1\;{\mu}M)$, a blocker of small conductance $K_{Ca}$ channel had no effect on the inhibitory effect of SNP. Iberiotoxin $(0.1\;{\mu}M)$, a blocker of large conductance $K_{Ca}$ channel, significantly increased the resting $[Ca^{2+}]_i$, and tension, and limited the inhibitory effect of SNP. 4. Nifedipine $(1\;{\mu}M)$ or elimination of external $Ca^{2+}$ decreased not only resting $[Ca^{2+}]_i$ and tension but also oscillation of $[Ca^{2+}]_i$ and tension. Ryanodine $(5\;{\mu}M)$ and cyclopiazonic acid $(10\;{\mu}M)$ decreased oscillation of $[Ca^{2+}]_i$ and tension. 5. SNP decreased $Ca^{2+}$ sensitivity of contractile protein. In conclusion, these results suggest that 1) NO is an inhibitory neurotransmitter in the guinea pig ileum, 2) the inhibitory effect of SNP on the $[Ca^{2+}]_i$ and tension of the muscle is due to a decrease in $[Ca^{2+}]_i$ by activation of the large conductance $K_{Ca}$ channel and a decrease in the sensitivity of contractile elements to $Ca^{2+}$ through activation of G-kinase.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.9
• /
• pp.1492-1500
• /
• 2004

The purpose of this study was to evaluate the effects of low calorie meal substitute and weight control preparation containing dietary fibers, ${\alpha}$-amylase inhibitor and hydroxycitrate on the reduction of body weight and visceral fat in obese women. Sixteen pre-menoposal healthy women (age: 20∼50 y, body mass index >25) who were living in the Daejeon area participated in this study. We replaced one meal of the subject with low calorie meal substitute and fed the weight control preparation twice a day for 9 weeks. Anthropometric indices, body composition, dietary intake and stool movements were investigated every 3 weeks during the dietary intervention. The blood was collected before and after the dietary intervention. Results are as follows: 1) The subjects' body weight, body fat, BMI, waist, hip and abdominal adipose tissue decreased gradually and significantly between 3rd and 9th week after intervention. 2) The levels of fasting blood glucose, triglyceride and cholesterol, the indicators of liver dysfunction such as activities of ALT, AST and ALP, and bilirubin level were within a normal range and not affected significantly by dietary intervention. 3) Hemoglobin levels increased significantly and blood urea nitrogen level decreased. 4) Their stool movement was improved 5) Compared with the baseline values, calorie intake decreased by 17.5∼21.9% and the intakes of vitamin A, vitamin B2, folate, Ca, Fe, and Zn were below 80% of Korean RDA. In conclusion, the intake of low calorie meal substitute and weight control preparation could be effective in reduction of body weight and fat mass, improving the stool movement and the general physical symptoms.

• Journal of Chest Surgery
• /
• v.23 no.2
• /
• pp.222-230
• /
• 1990

Protamine, a polycationic peptide extracted from fish, has been widely used for the reversal of anticoagulant action of heparin. However it may cause untoward circulatory side effects including hypotension and bradyarrhythmia. Nowadays, histamine and prostacyclin are regarded as one of the causative agents in the underlying mechanism of hemodynamic changes. To certify the possible role of histamine and prostacyclin, we observed simultaneous changes of the hemodynamic status, plasma concentration of thromboxane B, and circulating platelet count before and after intravenous injection of protamine. Experimental dogs, weighing 12-14kg, were divided into 2 groups; group A animals [n=10], were pretreated with indomethacin[2.5mg/kg] and group B animals[n=10] were pretreated with chlorpheniramine[0.5mg/kg] Heparin[3mg/kg] and protamine [3mg/kg] were administered sequentially in both groups. The results were as follows ; 1. The mean systemic arterial pressure was maintained well in groups A, whereas in group B it decreased from 165\ulcorner18mmHg to 138\ulcorner30mmHg[p<0.01] and 151\ulcorner21 mmHg[p<0.05] at 1 minute and 2 minutes after protamine injection. The mean pulmonary arterial pressure was not changed significantly in group A, whereas in group B it increased from 852 mmHg to 11\ulcorner3 mmHg[p<0.05], 11\ulcorner3 mmHg[p<0.05] and 10\ulcorner3 mmHg[p<0.05] at 1 minute, 3 minutes and 5 minutes after protamine injection. 2 The thromboxane B2 was not changed significantly in group A, whereas in group B it increased from 399\ulcorner401 \ulcornerg/ml to 744\ulcorner615 \ulcornerg/ml[p<0.05] and 814\ulcorner1070 \ulcornerg/ml [p<0.0 5] at 1 minute and 3 minutes after protamine injection without concomitant changes of pulmonary vascular resistance and pulmonary capillary wedge pressure. 3. The number of circulating platelet was not changed in group A, whereas in group B it decreased from 207100\ulcorner103600/\ulcornerl to 159700\ulcorner90900/\ulcornerl [p<0.05] at 1 minute after protamine injection, Although thromboxane B2 and platelet count were changed significantly after protamine injection, they did not cause the remarkable hemodynamic changes. Considering the above results, hemodynamic changes may be caused mainly by prostacyclin rather than thromboxane or platelet. Therefore, the pretreatment with cyclooxygenase inhibitor would be beneficial to prevent circulatory adverse effects of protamine for the patients undergoing cardiac surgery.

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

• The Korean Journal of Physiology and Pharmacology
• /
• v.2 no.4
• /
• pp.521-527
• /
• 1998

An important property of the intestine is the ability to secrete fluid. The intestinal secretion is regulated by a number of substances including vasoactive intestinal peptide (VIP), ATP and different inflammatory mediators. One of the most important secretagogues is adenosine during inflammation. However, the controversy concerning the underlying mechanism of adenosine-stimulated $Cl^-$ secretion in intestinal epithelial cells still continues. To investigate the effect of adenosine on $Cl^-$ secretion and its underlying mechanism in the rabbit colon mucosa, we measured short circuit current ($I_{SC}$) under automatic voltage clamp with DVC-1000 in a modified Ussing chamber. Adenosine, when added to the basolateral side of the muocsa, increased $I_{SC}$ in a dose-dependent manner. The adenosine-stimulated $I_{SC}$ response was abolished when $Cl^-$ in the bath solution was replaced completely with gluconate. In addition, the $I_{SC}$ response was inhibited by a basolateral Na-K-Cl cotransporter blocker, bumetanide, and by apical $Cl^-$ channel blockers, dephenylamine-2-carboxylate (DPC), 5-nitro-2-(3-phenyl-propylamino)-benzoate (NPPB), glibenclamide. Amiloride, an epithelial $Na^+$ channel blocker, and 4,4-diisothiocyanato-stilbene-2,2-disulphonate (DIDS), a $Ca^{2+}-activated$ $Cl^-$ channel blocker, had no effect. In the mucosa pre-stimulated with forskolin, adenosine did not show any additive effect, whereas carbachol resulted in a synergistic potentiation of the $I_{SC}$ response. The adenosine response was inhibited by 10 ${\mu}M$ H-89, an inhibitor of protein kinase A. These results suggest that the adenosine-stimulated $I_{SC}$ response is mediated by basolateral to apical $Cl^-$ secretion through a cAMP-dependent $Cl^-$ channel. The rank order of potencies of adenosine receptor agonists was $5'-(N-ethylcarboxamino)adenosine(NECA)＞N^6-(R-phenylisopropyl)adenosine(R-$ PIA)＞2-[p-(2-carbonylethyl)-phenyl-ethylamino]-5'-N-ethylcarboxaminoadenosine(CGS21680). From the above results, it can be concluded that adenosine interacts with the $A_{2b}$ adenosine receptor in the rabbit colon mucosa and a cAMP-dependent signalling mechanism underlies the stimulation of $Cl^-$ secretion.

• Food Science of Animal Resources
• /
• v.29 no.6
• /
• pp.659-667
• /
• 2009

Casein is considered to be the main source of protein in milk; therefore, many studies have been conducted to identify casein-derived bioactive peptides and their physiological effects. Casein is inactive within the parent protein but can be liberated by various proteases and enzymatic hydrolysis during microbial fermentation and gastrointestinal digestion. Once absorbed, casein exhibits different bioavailabilities in the body. Specifically, casein-derived peptides function as angiotensin converting enzyme (ACE) inhibitor in the cardiovascular system; thus, they are expected to reduce and prevent hypertension. Additionally, casein-derived peptides behave as opioid-like peptides in the nervous system, which impacts relaxation. These peptides are also expected to modulate various aspects of immune functions. Finally, caseinophosphopeptide (CPP) and glycomacropeptide (GMP) may exhibit a number of nutritional effects such as the absorption of calcium, iron or zinc. Many studies have been conducted to evaluate casein-derived peptides due to their multifunctional properties and the results of these studies have contributed to the development of a wide variety of functional dairy products. The purpose of this paper was to review the generation of bioactive peptides, their absorption and metabolism, and their specific bioactive effects.

• Journal of Ginseng Research
• /
• v.45 no.3
• /
• pp.433-441
• /
• 2021

Background: Multiple sclerosis (MS) and its animal model, the experimental autoimmune encephalomyelitis (EAE), are primarily characterized as dysfunction of the blood-brain barrier (BBB). Ginsenoside-Rg3-enriched Korean Red Ginseng extract (Rg3-KRGE) is known to exert neuroprotective, anti-inflammatory, and anti-oxidative effects on neurological disorders. However, effects of Rg3-KRGE in EAE remain unclear. Methods: Here, we investigated whether Rg3-KRGE may improve the symptoms and pathological features of myelin oligodendroglial glycoprotein (MOG)_35-55 peptide - induced chronic EAE mice through improving the integrity of the BBB. Results: Rg3-KRGE decreased EAE score and spinal demyelination. Rg3-KRGE inhibited Evan's blue dye leakage in spinal cord, suppressed increases of adhesion molecule platelet endothelial cell adhesion molecule-1, extracellular matrix proteins fibronection, and matrix metallopeptidase-9, and prevented decreases of tight junction proteins zonula occludens-1, claudin-3, and claudin-5 in spinal cord following EAE induction. Rg3-KRGE repressed increases of proinflammatory transcripts cyclooxygenase-2, inducible nitric oxide synthase, interleukin (IL)-1 beta, IL-6, and tumor necrosis factor-alpha, but enhanced expression levels of anti-inflammatory transcripts arginase-1 and IL-10 in the spinal cord following EAE induction. Rg3-KRGE inhibited the expression of oxidative stress markers (MitoSOX and 4-hydroxynonenal), the enhancement of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) and NOX4, and NADPH activity in the spinal cord of chronic EAE mice. Furthermore, apocynin, a NOX inhibitor, mimicked beneficial effects of Rg3-KRGE in chronic EAE mice. Conclusion: Our findings suggest that Rg3-KRGE might alleviate behavioral symptoms and pathological features of MS by improving BBB integrity through modulation of NOX2/4 expression.

• Animal Bioscience
• /
• v.35 no.12
• /
• pp.1892-1903
• /
• 2022

Objective: A series of experiment were conducted to evaluate the effects of replacing a part of soybean meal (SBM) at 6% of broiler diets with fermented soybean meal (FSBM) obtained by single or two-stage fermentation by measuring growth performance, antioxidant activity in the jejunum and distal intestinal microflora. Methods: Soybean meal samples were prepared by single-stage fermentation using Bacillus velezensis (Bv) (FSBM_B), or Lactobacillus spp. (as commercial control) (FSBM_L). Additional SBM sample was prepared by two-stage fermentation using Bv and subsequently using Lactobacillus brevis ATCC 367 (Lb) (FSBM_B+L). Enzyme activity, chemical composition, trichloroethanoic acid-nitrogen solubility index (TCA-NSI) and antioxidant activity were measured. Then, in an in vivo study, 320 Ross308 broilers were divided into four groups with ad libitum supply of feed and water. Four groups were fed either a corn-soybean meal diet (SBM), or one of fermented SBM diets (FSBM_B+L, FSBM_B, and FSBM_L). Growth, serum characteristics, microflora, and the mRNA expression of selected genes were measured. Results: Compared to SBM, FSBM_B+L contained lower galacto-oligosaccharide, allergic protein, and trypsin inhibitor, and higher TCA-NSI by about three times (p<0.05). Reducing power and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging ability correlated positively with the TCA-NSI content in FSBM. Growth performances were not significantly different among four groups. In jejunum of 35-day-old broilers, partial replacement of SBM by FSBM_B+L increased the activity of superoxide dismutase and catalase (CAT), and the FSBM_B group had the highest catalase activity (p<0.05). Partial replacement of SBM by FSBM increased relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and peptide transporter 1 (PepT1) (p<0.05); however, FSBM_B+L increased CAT mRNA level to 5 times of the control (p<0.05). Conclusion: Using Bv- and Lb-processed SBM through two-stage fermentation to partially replace 6% of diets will improve the gut's antioxidant activity under commercial breeding in broilers.

• Journal of Animal Science and Technology
• /
• v.45 no.2
• /
• pp.319-326
• /
• 2003

Angiotensin-I converting enzyme(ACE)inhibitor was isolated from beef by-products. The beef by- product hydrolysates prepared with various proteases were tested for the inhibitory effects against ACE. The proteases used were proteinase A from bakers yeast, protease type ⅩIII fungal and thermolysin. The maximum inhibitory effect was observed after hydrolysis for 12hrs(beef heart) and 24hrs(beef spleen), respectively. After gel filtration, IC50 value was 0.37mg/ml in beef heart and 1.84mg/ml in beef spleen. After RP-HPLC, the IC50 value of peak 1, peak 2, peak 3 and peak-4 were 0.28mg/ml, 0.26mg/ml, 0.25mg/ml and 0.35mg/ml, respectively. In the results of amino acid composition of peak 1, peak 2, peak 3 and peak 4, it was observed that peak 1 was consisted mainly of glycine and methionine, peak 2 was proline, cystine and methionine, peak 3 was proline and peak 4 was alanine, methionine and leucine. In conclusion, beef heart hydrolysate treated with thermolysin+ proteinase A was shown to have the highest inhibitory effect for 12hrs incubation at 37$^{\circ}C$.