Anti-inflammatory Peptide Research Articles

The secreted Ly-6/uPAR related protein-1 (SLURP1) stabilizes epithelial cell junctions and suppresses TNF-α-induced cytokine production

The secreted Ly-6/uPAR related protein-1 (SLURP1) is an anti-angiogenic and anti-inflammatory peptide highly expressed by the mucosal epithelial cells. SLURP1 is abundantly expressed by the corneal epithelial cells and is significantly downregulated when these cells are transformed and adapted for culture in vitro. Here we studied the effect of overexpressing SLURP1 in Human Corneal Limbal Epithelial (HCLE) cells cultured in vitro. The expression of DSP1, DSG1, TJP1 and E-Cadherin was significantly upregulated in two different SLURP1-overexpressing HCLE cell (HCLE-SLURP1) clones. HCLE-SLURP1 cells also displayed a significant decrease in tumor necrosis factor-α (TNF-α)-induced upregulation of (i) IL-8 from 7.4- to 2.9- and 2.1-fold, (ii) IL-1β from 4.9- to 3.9- and 2.9-fold, (iii) CXCL1 from 9- to 3.3- and 5.5-fold, and (iv) CXCL2 from 4.8- to 2.1- and 2.8-fold. ELISAs revealed a concomitant decrease in IL-8 levels in cell culture supernatants from 789 pg/ml in the control, to 503 and 352 pg/ml in HCLE-SLURP1 cells. Consistently, cytosolic IκB expression was elevated in HCLE-SLURP1 cells with a concurrent suppression of TNF-α-activated nuclear translocation of NF-κB. Collectively, these results elucidate the beneficial effects of SLURP1 in stabilizing the HCLE intercellular junctions and suppressing the TNF-α-induced upregulation of inflammatory cytokines by suppressing NF-κB nuclear translocation.

Chemical compositions and biological activities of marine invertebrates from the East Sea of South Korea

BackgroundMarine invertebrates are well known as pivotal bioresources with bioactive substances such as anti-inflammatory sterols, antitumor terpenes, and antimicrobial peptides. However, there are few scientific reports on chemical compositions and bioactivities of marine invertebrates from the East Sea of South Korea.MethodsIn this study, chemical compositions and biological activities were evaluated on both 70% EtOH and hot water extracts of 5 species of marine invertebrates (Crossaster papposus japonicus, Actinostola carlgreni, Stomphia coccinea, Actinostola sp., and Heliometra glacialis) collected from the East Sea of South Korea. The antioxidant activities were measured by ABTS radical scavenging assay. The cytotoxicity and anti-inflammatory activity were evaluated using MTT and Griess reagents. Moreover, the antibacterial effect was evaluated using paper disc assay and minimum inhibitory concentration (MIC) assay.ResultsIn the results of antioxidant activities, 70% EtOH extract of A. carlgreni showed the highest activity (IC50 0.19 ± 0.03 mg/ml) compared to other extracts. Moreover, 70% EtOH extract of A. carlgreni could significantly suppress the nitric oxide (NO) production in lipopolysaccharide-induced RAW 264.7. All extracts treated under 400 μg/ml have no cytotoxic effects on RAW 264.7 macrophages. In the antibacterial test, both 70% EtOH extracts of C. papposus japonicus and H. glacialis showed a significant antibacterial effect on Staphylococcus aureus. The MIC values were evaluated at 256 and 512 μg/ml, respectively.ConclusionsThese results suggested the bioactive potentials of marine invertebrates from the East Sea of South Korea in pharmaceutical and nutraceutical applications.

Expression and Purification of Hybrid LL-37Tα1 Peptide in Pichia pastoris and Evaluation of Its Immunomodulatory and Anti-inflammatory Activities by LPS Neutralization.

This study pertains to the new approach for the development of hybrid peptide LL-37Tα1 and its biomedical applications. A linear cationic hybrid peptide, LL-37Tα1 was derived from two parental peptides (LL-37 and Tα1) recognized as potent anti-endotoxin without any hemolytic or cytotoxic activity. We successfully cloned the gene of hybrid peptide LL-37Tα1 in PpICZαA vector and expressed in the Pichia pastoris. The recombinant peptide was purified by Ni-affinity column and reverse-phase high performance liquid chromatography (RP-HPLC) with an estimated molecular mass of 3.9 kDa as determined by SDS-PAGE and mass spectrometry. We analyzed the LPS neutralization by limulus amebocyte lysate (LAL) activity and the results indicate that the hybrid peptide LL-37Tα1 directly binds endotoxin and significantly (p < 0.05) neutralizes the effect of LPS in a dose-dependent manner. Lactate dehydrogenase (LDH) assay revealed that LL-37Tα1 successfully reduces the LPS-induced cytotoxicity in mouse RAW264.7 macrophages. Moreover, it significantly (p < 0.05) decreased the levels of nitric oxide, proinflammatory cytokines including TNF-α, IL-6, IL-1β, and diminished the number of apoptotic cells in LPS-stimulated mouse RAW264.7 macrophages. Our results suggest that the P. pastoris expression system is cost-effective for commercial production of the immunomodulatory and anti-inflammatory hybrid peptide (IAHP) LL-37Tα1 and the peptide may serve as effective anti-endotoxin/anti-inflammatory agent with minimal cytotoxicity.

Memory consolidation impairment induced by Interleukin-1β is associated with changes in hippocampal structural plasticity

Pro-inflammatory cytokines, particularly Interleukin-1β (IL-1β), can affect cognitive processes such as learning and memory. The aim of this study was to establish whether the effect of IL-1β on contextual fear memory is associated with changes in hippocampal structural plasticity. We also studied the effect of α-melanocyte-stimulating hormone (α-MSH), a potent anti-inflammatory and neuro-protective peptide. Different groups of animals were implanted bilaterally in dorsal hippocampus (DH). After recovery they were conditioned for contextual fear memory and received the different treatments (vehicle, IL-1β, α-MSH or IL-1β + α-MSH). Memory was assessed 24 hs after conditioning and immediately after rats were perfused for dendritic spine analysis. Our results show that local hippocampal administration of IL-1β just after memory encoding induced impairment in contextual memory and a reduction in the total density of CA1 hippocampal dendritic spines, particularly the mature ones. α-MSH administration reversed the IL-1β induced changes. The results suggest that neuro-inflammation induced by IL-1β interferes with experience-dependent structural plasticity in DH whereas α-MSH has a beneficial modulatory role in preventing this effect.

Molecular binding mechanism and identification of novel anti-hypertensive and anti-inflammatory bioactive peptides from camel milk protein hydrolysates

Camel milk protein hydrolysates (CMPHs) were investigated for anti-hypertensive and anti-inflammatory activities using in-vitro assays. CMPHs with potent ACE inhibitory and anti-inflammatory activities were subjected to peptide identification and their possible binding mechanism to ACE were depicted via molecular docking. Papain generated CMPHs showed higher degradation of proteins compared to bromelain and alcalase generated CMPHs as depicted in SDS-PAGE profile. Dramatic increase in ACE inhibitory and anti-inflammatory activity was demonstrated in CMPHs with highest activity for papain and alcalase generated hydrolysates, respectively. Based on peptide ranking score, a total of 20, 3 and 43 peptides were potentially regarded as bioactive peptides in hydrolysates A9, B9 and P9, respectively. Binding studies based on pepsite-2 modelling suggested that among 20 potential bioactive peptides in A9 hydrolysate, only 1 (AEWLHDWKL) showed high binding towards three catalytic sites of ACE. While, among 43 bioactive peptides of P9, 14 peptides were found to be potent binder to ACE catalytic sites. Further insight into molecular mechanism of binding revealed that 4 peptides were able to bind to active site of ACE with good docking scores and MM-GBSA binding energies. Overall, the current report remains among very few reports on identification and molecular docking of ACE inhibitory peptides from camel milk.

Vardenafil and cilostazol can improve vascular reactivity in rats with diabetes mellitus and rheumatoid arthritis co-morbidity

Endothelial dysfunction and vascular reactivity defects secondary to metabolic and immunological disorders carry risk of serious cardiovascular complications. Here, the effects of the phosphodiesterase (PDE) inhibitors vardenafil and cilostazol were examined against rheumatoid arthritis (RA)/diabetes mellitus (DM)-co-morbidity-induced endothelial dysfunction and vascular reactivity defects. After setting of RA/DM-co-morbidity model, rats were divided into a normal control group, an RA/DM-co-morbidity group, and two treatment groups receiving oral vardenafil (10 mg/kg/day) and cilostazol (30 mg/kg/day) for 21 days after RA/DM-co-morbidity induction. Aorta was isolated for biochemical estimations of the pro-inflammatory vasoconstrictor molecules angiotensin-II (Ang-II) and endothelin-1 (ET-1), the adhesion molecules P-selectin and vascular cell adhesion molecule-1 (VCAM-1), the energy sensor adenosine-5′-monophosphate-activated protein kinase (AMPK), and the vasodilator anti-inflammatory molecule vasoactive intestinal peptide (VIP) using enzyme-linked immunosorbent assay (ELISA) and western blot analysis. Immunohistochemical estimations of endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase (MMP)-2 were performed coupled with histopathological examination using routine hematoxylin and eosin (H&E) and special Masson trichrome staining. The in vitro study was conducted using aortic strips where cumulative concentration response curves were done for the endothelium-dependent relaxing factor acetylcholine and the endothelium-independent relaxing factor sodium nitroprusside after submaximal contraction with phenylephrine. Vardenafil and cilostazol significantly improved endothelial integrity biomarkers in vivo supported with histopathological findings in addition to improved vasorelaxation in vitro. Apart from their known PDE inhibition, up-regulation of vascular AMPK and eNOS coupled with down-regulation of Ang-II, ET-1, P-selectin, VCAM-1 and MMP-2 may explain vardenafil and cilostazol protective effect against RA/DM-co-morbidity-induced endothelial dysfunction and vascular reactivity defects.

Localization and induced release of potentially therapeutic components of the rat submandibular salivary gland

The salivary glands release multiple compounds into the saliva and blood that have potentially therapeutic properties. One aim of this study was to localize rat submandibular gland protein SMR1, a prohormone known to contain anti‐inflammatory and analgesic peptides, and compare to the distribution of other known components within the rat submandibular gland (SMG). We also explored the feasibility of releasing SMR1 by local neurostimulation using electrodes. Our hypothesis is that SMR1 would be found in discrete regions of the SMG and could be stimulated to be released into the saliva and blood using localized electrostimulation.Salivary glands serve as a source of multiple compounds that are essential to health. The prohormone SMR1 is an example of such a compound that is present in the rat SMG and is secreted into the saliva or blood as peptides that have been shown to have analgesic and anti‐inflammatory properties. Neuroactivation using systemically applied drugs have been shown to release these and other SMG components. Focused electrode‐based neurostimulation of specific sites of the autonomic system may be a better strategy to more specifically release therapeutic compounds without affecting off‐target systems. Previous studies supported differential release of components from the acini compared to the duct system. In this study we evaluated the tissue distribution of SMR1 compared to other known components of the rat SMG, a major salivary gland.SMGs from young and mature rats were fixed, cryosectioned and immunostained. SMR1 peptides were immunohistologically detected in the serous acinar cells of the rat SMG with heterogeneous distribution within any particular acinus. The location of other components alpha‐amylase, EGF (marker of the tubogranular duct system), lactoferrin, lysozyme, were compared to the location of SMR1. Smooth muscle cell (anti‐smooth muscle actin), neuronal components (anti‐TuJ1, anti‐TH, anti‐ChAT, and anti‐synapsin) were also localized or co‐localized.Neurostimulation of the superior cervical ganglion (SCG) and adjacent nerve trunk by bipolar electrodes induced marked increases in SMR1 content in the saliva as determined by Western blot. We also discovered that placement of the electrode altered the level of peptide secretion. Intriguingly, the electrode stimulation increased levels of SMR1 collected from adjacent blood vessels. These findings set the stage for additional studies to refine the stimulation parameters and to map the SCG innervation of the SMG.Support or Funding InformationSupported by grants from GSK‐GalvaniThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Recent Progress in Machine Learning-based Prediction of Peptide Activity for Drug Discovery.

Over the past decades, peptide as a therapeutic candidate has received increasing attention in drug discovery, especially for antimicrobial peptides (AMPs), anticancer peptides (ACPs) and antiinflammatory peptides (AIPs). It is considered that the peptides can regulate various complex diseases which are previously untouchable. In recent years, the critical problem of antimicrobial resistance drives the pharmaceutical industry to look for new therapeutic agents. Compared to organic small drugs, peptide- based therapy exhibits high specificity and minimal toxicity. Thus, peptides are widely recruited in the design and discovery of new potent drugs. Currently, large-scale screening of peptide activity with traditional approaches is costly, time-consuming and labor-intensive. Hence, in silico methods, mainly machine learning approaches, for their accuracy and effectiveness, have been introduced to predict the peptide activity. In this review, we document the recent progress in machine learning-based prediction of peptides which will be of great benefit to the discovery of potential active AMPs, ACPs and AIPs.

PreAIP: Computational Prediction of Anti-inflammatory Peptides by Integrating Multiple Complementary Features

Numerous inflammatory diseases and autoimmune disorders by therapeutic peptides have received substantial consideration; however, the exploration of anti-inflammatory peptides via biological experiments is often a time-consuming and expensive task. The development of novel in silico predictors is desired to classify potential anti-inflammatory peptides prior to in vitro investigation. Herein, an accurate predictor, called PreAIP (Predictor of Anti-Inflammatory Peptides) was developed by integrating multiple complementary features. We systematically investigated different types of features including primary sequence, evolutionary and structural information through a random forest classifier. The final PreAIP model achieved an AUC value of 0.833 in the training dataset via 10-fold cross-validation test, which was better than that of existing models. Moreover, we assessed the performance of the PreAIP with an AUC value of 0.840 on a test dataset to demonstrate that the proposed method outperformed the two existing methods. These results indicated that the PreAIP is an accurate predictor for identifying AIPs and contributes to the development of AIPs therapeutics and biomedical research. The curated datasets and the PreAIP are freely available at http://kurata14.bio.kyutech.ac.jp/PreAIP/.

Abstract P049: Circulating Adiponectin Levels and Risk of Type 2 Diabetes, Cardiovascular Disease, and All-Cause Mortality in US Women

Introduction: Adiponectin is an anti-inflammatory peptide hormone secreted by adipocytes and has been related with decreased risk of type 2 diabetes (T2D) and cardiovascular disease (CVD), but longitudinal data are limited and inconsistent. Hypothesis: Higher circulating adiponectin levels are associated with lower risk of T2D, CVD, and all-cause mortality in healthy women. Methods: Baseline adiponectin levels, measured by an immunoassay, were available on 15,131 women from the Nurses’ Health study I and II, who were part of 11 separate nested case-control studies and free of T2D, CVD, and cancer at study baseline. Associations of adiponectin levels with incident T2D, CVD (including coronary heart disease [CHD], stroke, and CVD death), and all-cause mortality were estimated using Cox regressions adjusted for study design characters, established risk factors and confounders including menopausal status, hormone therapy, and continuous body mass index. We also analyzed associations of 26 adiponectin expression-associated variants (in adipose tissue) with T2D, CVD, and all-cause mortality in the UK Biobank study. Results: During up to 22 years (289,408 person-years) of follow-up, 2,578 T2D cases, 1,827 CVD cases (including 745 CHD, 1,108 stroke and 428 CVD deaths), and 2,741 deaths occurred. In multivariable models, hazard ratios (95% confidence intervals) comparing the highest quartile of plasma adiponectin to the lowest were 0.17 (0.14-0.21; P trend &lt;0.001) for T2D, 0.82 (0.69-0.96; P trend =0.005) for CVD, 0.66 (0.51-0.86; P trend &lt;0.001) for CHD, 0.91 (0.73-1.12; P trend =0.34) for stroke, 0.69 (0.48-0.98; P trend =0.10) for CVD death, and 0.77 (0.66-0.90; P trend =0.005) for all-cause mortality. Genetic alleles associated with increased adiponectin expression in adipose tissue were associated with decreased risk of CVD, but no associations were observed for T2D and all-cause mortality. Conclusions: Higher adiponectin levels are associated with decreased risk of cardiometabolic diseases and all-cause mortality.

An anti-inflammatory peptide and brain-derived neurotrophic factor-modified hyaluronan-methylcellulose hydrogel promotes nerve regeneration in rats with spinal cord injury.

BackgroundTraumatic spinal cord injury (SCI) causes neuronal death, demyelination, axonal degeneration, inflammation, glial scar formation, and cystic cavitation resulting in interruption of neural signaling and loss of nerve function. Multifactorial targeted therapy is a promising strategy for SCI.MethodsThe anti-inflammatory peptide KAFAKLAARLYRKALARQLGVAA (KAFAK) and brain-derived neurotrophic factor (BDNF)-modified hyaluronan-methylcellulose (HAMC) hydrogel was designed for minimally invasive, localized, and sustained intrathecal protein delivery. The physical and biological characteristics of HAMC-KAFAK/BDNF hydrogel were measured in vitro. SCI model was performed in rats and HAMC-KAFAK/BDNF hydrogel was injected into the injured site of spinal cord. The neuronal regeneration effect was evaluated by inflammatory cytokine levels, behavioral test and histological analysis at 8 weeks post operation.ResultsHAMC-KAFAK/BDNF hydrogel showed minimally swelling property and sustained release of the KAFAK and BDNF. HAMC-KAFAK/BDNF hydrogel significantly improved the proliferation of PC12 cells in vitro without cytotoxicity. Significant recovery in both neurological function and nerve tissue morphology in SCI rats were observed in HAMC-KAFAK/BDNF group. HAMC-KAFAK/BDNF group showed significant reduction in proinflammatory cytokines expression and cystic cavitation, decreased glial scar formation, and improved neuronal survival in the rat SCI model compared to HAMC group and SCI group.ConclusionThe HAMC-KAFAK/BDNF hydrogel promotes functional recovery of rats with spinal cord injury by regulating inflammatory cytokine levels and improving axonal regeneration.

Potential anti-inflammatory and lipase inhibitory peptides generated by in vitro gastrointestinal hydrolysis of heat treated millet grains

ABSTRACTThe influence of heat treatment (65°C and 100°C) on the activities of potential anti-inflammatory peptides obtained from a millet protein fraction was investigated. The molecular mass of proteins was found to be in the range of 6.5–100 kDa. The protein fractions were in vitro hydrolyzed in gastrointestinal-like conditions. The highest peptide content was noted for albumin in the control sample (2.03 mg/mL). The peptide fraction obtained from globulin 7S derived from grains heated at 65°C was characterized by the highest COX-1 and COX-2 inhibitory activity (IC50 = 0.08 and 0.12 mg/mL, respectively). The peptide fraction obtained from the prolamin treatment at 100°C exhibited the highest LOX inhibitory activity (IC50 = 0.14 mg/mL). Peptides from the prolamin treatment at 65°C were characterized by the highest pancreatic lipase inhibitory activity (IC50 = 0.03 mg/mL). Peptide fractions with highest anti-inflammatory activity were rich in Gly.

Anti-inflammatory marine cyclic peptide stylissatin A and its derivatives inhibit differentiation of murine preadipocytes.

Stylissatin A, an anti-inflammatory cyclic heptapeptide, and its derivatives potently inhibited the differentiation of preadipocytes and reduced triglyceride accumulation in mature adipocytes, with little cytotoxicity. Our studies might contribute to the development of leads for new anti-inflammatory and anti-obesity agents.

Clinical and laboratory evaluation of the Elgydium Protection caries toothpaste effectiveness in patients with high intensity of dental caries

The aim of the work was to evaluate the effectiveness of rehabilitation after the complete elimination of carious cavities in patients with dentin caries according to clinical and laboratory indicators when using the ELGYDIUM Protection caries toothpaste for cleaning teeth for 6 months. 29 patients with high intensity of dental caries were examined and received treatment. Depending on the organization of daily hygienic measures after treatment the patients were divided into two groups. The main group included 14 patients who used Elgydium Protection caries paste ('Pierre Fabre Medicament', France) for brushing their teeth twice a day for 6 months. The control group included 15 patients who used toothpastes with fluoride of the first generation. All patients underwent clinical dental examination with the determination of the DMFT index and the amount of soft dental plaque according to the Silness-Lohe index, as well as in the gingival fluid bacteriological examination of cariogenic microbiota, determination of the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) and an immunoassay for anti-inflammatory peptides α-defensins 1-3. Effective change in the concentration of antimicrobial peptides α-defensins 1-3 and TNF-α after treatment along with successful eradication of cariogenic bacteria from carious cavities, the absence of recurrent dental caries in the main group compared with the control group proved the successful anti-caries action of long-term use of fluorenol capable of forming a uniform film on the surface of the tooth in the presence of silyglycol. The protective film helps to increase the resistance of the tooth to demineralization and prevents plaque formation. Thus, the study results proved the effectiveness of ELGYDIUM Protection caries toothpaste used for 6 months for the reduction of caries.

Antioxidant and anti-inflammatory polyphenols and peptides of common bean (Phaseolus vulga L.) milk and yogurt in Caco-2 and HT-29 cell models

Common bean milks and their corresponding probiotic yogurts were developed and subjected to simulated gastrointestinal digestion before characterization and assessment of bioactivities. Only digestates fractions of molecular weight <10 kDa showed strong cellular antioxidant activity and anti-inflammatory activity as demonstrated in suppressed TNF-α-induced IL-8 secretion in Caco-2 and HT-29 cell lines. Phenolic and peptide fractions were purified from the digestates. Yogurts showed significantly stronger cellular antioxidant and anti-inflammatory activities compared to their corresponding milks because of the significantly higher total and individual phenolic and peptide contents (P < 0.05). Eleven phenolic compounds and five amino acids/peptides were identified in the phenolic and peptide fractions, respectively using LC-MS/MS. Among them, two γ-glutamyl-dipeptides are reported for the first time for their antioxidant and anti-inflammatory activities. Peptide fractions of yogurts containing higher concentrations of γ-glutamyl-peptides showed stronger anti-inflammatory activity in Caco-2 cells than in HT-29 cells, suggesting the involvement of a peptide transporter PepT1.

Antiinflammatory peptides: current knowledge and promising prospects

Inflammation is part of the regular host reaction to injury or infection caused by toxic factors, pathogens, damaged cells, irritants, and allergens. Antiinflammatory peptides (AIPs) are present in all living organisms, and many peptides from herbal, mammalian, bacterial, and marine origins have been shown to have antimicrobial and/or antiinflammatory properties. In this study, we investigated the effects of antiinflammatory peptides on inflammation, and highlighted the underlying mechanisms responsible for these effects. In multicellular organisms, including humans, AIPs constitute an essential part of their immune system. In addition, numerous natural and synthetic AIPs are effective immunomodulators and can interfere with signal transduction pathways involved in inflammatory cytokine expression. Among them, some peptides such as antiflammin, N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), and those derived from velvet antler proteins, bee venom, horse fly salivary gland, and bovine β-casein have received considerable attention over the past few years. This article presents an overview on the major properties and mechanisms of action associated with AIPs as immunomodulatory, chemotactic, antioxidant, and antimicrobial agents. In addition, the results of various studies dealing with effects of AIPs on numerous classical models of inflammation are reviewed and discussed.

Functional Characterization of a Novel Lipopolysaccharide-Binding Antimicrobial and Anti-Inflammatory Peptide in Vitro and in Vivo.

Antimicrobial peptides (AMPs) are key components of host immune defense of vertebrates against microbial invasions. Here, we report a new AMP (esculentin-1GN) characterized from the skin of the frog Hylarana guentheri. Esculentin-1GN (GLFSKKGGKGGKSWIKGVFKGIKGIGKEVGGDVIRTGIEIAACKIKGEC) with high amphipathic α-helical structure in membrane-mimetic environments has the microbial-killing activity by destruction of the cell membrane. Moreover, esculentin-1GN inhibits LPS-induced expression of proinflammatory nitric oxide, interleukin-1β, interleukin-6, and tumor necrosis factor while it enhances expression of interleukin-10. Furthermore, esculentin-1GN can bind to d-(+)-galacturonic acid and LPS. Meanwhile, esculentin-1GN suppresses the activation of inflammatory response pathway induced by LPS. In addition, esculentin-1GN significantly reduces acute inflammation in carrageenan-induced mice paw. Taken together, the novel LPS-binding esculentin-1GN with antimicrobial and anti-inflammatory activities will be an excellent temple for designing new antibiotic formulations.

Engineering of an Anti-Inflammatory Peptide Based on the Disulfide-Rich Linaclotide Scaffold.

Inflammatory bowel diseases are a set of complex and debilitating diseases, for which there is no satisfactory treatment. Peptides as small as three amino acids have been shown to have anti-inflammatory activity in mouse models of colitis, but they are likely to be unstable, limiting their development as drug leads. Here, we have grafted a tripeptide from the annexin A1 protein into linaclotide, a 14-amino-acid peptide with three disulfide bonds, which is currently in clinical use for patients with chronic constipation or irritable bowel syndrome. This engineered disulfide-rich peptide maintained the overall fold of the original synthetic guanylate cyclase C agonist peptide, and reduced inflammation in a mouse model of acute colitis. This is the first study to show that this disulfide-rich peptide can be used as a scaffold to confer a new bioactivity.

From the Chief Executive and News

From the Chief Executive and News

Identification of anti-inflammatory active peptide from black soybean treated by high hydrostatic pressure after germination

This study was conducted to isolate and identify the anti-inflammatory active peptide in black soybean treated by high hydrostatic pressure after germination. The anti-inflammatory activity was examined using RAW 264.7 macrophages. Black soybean was germinated for 4 days and subjected to 150 MPa for 24 h, followed by preparation of protein extracts. The extracts were sequentially filtered using membranes with a molecular weight cutoff of 30, 10, and 3 kDa. A strong inhibitory effect was observed with the 3–10 kDa fraction. The active peptide from this fraction was purified by gel permeation column chromatography and first and second semi-preparative HPLC. After isolation and purification of the active peptide, secretion of inflammatory markers (nitric oxide, TNF-α, IL-1β, and IL-6) by LPS-stimulated RAW 264.7 macrophages was measured. The purified anti-inflammatory peptide was analyzed by UV, LC–MS, 1H and 13C NMR, COSY, HMBC, and HSQC and was identified as a tripeptide.