European Journal of Pharmacology (v.780, #C)

Stable gastric pentadecapeptide BPC 157 heals rat colovesical fistula by Tihomir Grgic; Dora Grgic; Domagoj Drmic; Anita Zenko Sever; Igor Petrovic; Mario Sucic; Antonio Kokot; Robert Klicek; Marko Sever; Sven Seiwerth; Predrag Sikiric (1-7).
To establish the effects of BPC 157 on the healing of rat colovesical fistulas, Wistar Albino male rats were randomly assigned to different groups. BPC 157, a stable gastric pentadecapeptide, has been used in clinical applications—specifically, in ulcerative colitis—and was successful in treating both external and internal fistulas. BPC 157 was provided daily, perorally, in drinking water (10 µg/kg, 12 ml/rat/day) until sacrifice or, alternatively, 10 µg/kg or 10 ng/kg intraperitoneally, with the first application at 30 min after surgery and the last at 24 h before sacrifice. Controls simultaneously received an equivolume of saline (5.0 ml/kg ip) or water only (12 ml/rat/day). Assessment (i.e., colon and vesical defects, fistula leaking, fecaluria and defecation through the fistula, adhesions and intestinal obstruction as healing processes) took place on days 7, 14 and 28. Control colovesical fistulas regularly exhibited poor healing, with both of the defects persisting; continuous fistula leakage; fecaluria and defecation through the fistula; advanced adhesion formation; and intestinal obstruction. By contrast, BPC 157 given perorally or intraperitoneally and in µg- and ng-regimens rapidly improved the whole presentation, with both colon and vesical defects simultaneously ameliorated and eventually healed. The maximal instilled volume was continuously raised until it reached the values of healthy rats, there were no signs of fecaluria and no defecation through the fistula, there was counteraction of advanced adhesion formation or there was an intestinal obstruction. In conclusion, BPC 157 effects appear to be suited to inducing full healing of colocutaneous fistulas in rats.
Keywords: BPC 157; Colon; Colovesical fistula; Healing; Rats;

Protective mechanisms of wogonoside against Lipopolysaccharide/D-galactosamine-induced acute liver injury in mice by Yuan-zheng Gao; Lian-feng Zhao; Jun Ma; Wei-hong Xue; Hui Zhao (8-15).
Wogonoside, a bioactive flavonoid extracted from the root of Scutellaria baicalensis Georgi, has been reported to have anti-inflammatory and antioxidant effects. In this study, we examined the protective effects of wogonoside against lipopolysaccharide (LPS) and D-galactosamine (D-GalN)-induced liver injury in mice. Mice were given an intraperitoneal injection of wogonoside 1 h before LPS and d-GalN treatment. The results showed that wogonoside inhibited the production of serum Alanine transaminase (ALT), Aspartate aminotransferase (AST), IL-1β, TNF-α, and hepatic malondialdehyde (MDA) content induced by LPS/GalN. In addition, wogonoside promoted the expression of Nrf2, NQO-1, GCLC, and HO-1. Wogonoside inhibited the expression of hepatic NLRP3, ASC, caspase-1, and IL-1β induced by LPS/GalN. In conclusion, these results suggest that wogonoside protects against LPS/GalN-induced acute liver injury by activating Nrf2 and inhibiting NLRP3 inflammasome activation.
Keywords: Wogonoside; LPSNrf2; NLRP3;

The influence of chronic nicotine treatment on proteins expressed in the mouse hippocampus and cortex by Kenji Matsuura; Mieko Otani; Masaoki Takano; Keiichi Kadoyama; Shogo Matsuyama (16-25).
Chronic treatment with nicotine, the primary psychoactive substance in tobacco smoke, affects central nervous system functions, such as synaptic plasticity. Here, to clarify the effects of chronic nicotine treatment on the higher brain functions, proteomic analysis of the hippocampus and cortex of mice treated for 6 months with nicotine was performed using two-dimensional gel electrophoresis (2-DE) followed by mass spectrometry. There was significant change in the expression of 16 proteins and one phosphoprotein in the hippocampus (increased tubulin β-5, atp5b, MDH1, cytochrome b-c1 complex subunit 1, Hsc70, dynamin, profilin-2, 4-aminobutyrate aminotransferase, mitochondrial isoform 1 precursor, calpain small subunit 1, and vacuolar adenosine triphosphatase subunit B and decreased γ-actin, α-tubulin isotype M-α-2, putative β-actin, tubulin β-2A, NDUFA10, and G6PD) and 24 proteins and two phosphoproteins in the cortex (increased spectrin α chain, non-erythrocytic 1 isoform 1, tubulin β-5, γ-actin, creatine kinase B-type, LDH-B, secernin-1, UCH-L1, 14-3-3 γ, type II peroxiredoxin 1, PEBP-1, and unnamed protein product and decreased tubulin α-1C, α-internexin, γ-enolase, PDHE1-B, DPYL2, vacuolar adenosine triphosphatase subunit A, vacuolar adenosine triphosphatase subunit B, TCTP, NADH dehydrogenase Fe-S protein 1, protein disulfide-isomerase A3, hnRNP H2, γ-actin, atp5b, and unnamed protein product). Additionally, Western blotting validated the changes in dynamin, Hsc70, MDH1, NDUFA10, α-internexin, tubulin β-5 chain, and secernin-1. Thus, these findings indicate that chronic nicotine treatment changes the expression of proteins and phosphoproteins in the hippocampus and cortex. We propose that effect of smoking on higher brain functions could be mediated by alterations in expression levels of these proteins.
Keywords: Proteomics; Nicotine; Hippocampus; Cortex;

Pinacidil-postconditioning is equivalent to ischemic postconditioning in defeating cardiac ischemia-reperfusion injury in rat by Yi hui Yang; Yu Zhang; Wei Chen; Ying Wang; Song Cao; Tian Yu; Haiying Wang (26-32).
Ischemic postconditioning (IPO) had been reported as a promising method against myocardial ischemia-reperfusion (I/R) injury, but IPO was later proved with poor clinical benefit. In this study, we compared the protective effects of pinacidil-postconditioning (PPO) and IPO against myocardial I/R injury. Langendorff rat hearts were randomly assigned to one of the following groups (n=8 each): Control group, I/R group (40 min ischemia and 60 min reperfusion), IPO group (6 successive cycles of 10 s reperfusion per 10 s occlusion before fully reperfusion), PPO group (perfused with 50 μM pinacidil for 5 min before reperfusion). Heart performance, infarct size and mitochondrial respiratory function were evaluated, and target genes/proteins of well-known Nuclear Factor-E2 Related Factor 2 (Nrf2) were assessed. Both IPO and PPO preserved heart function and myocardial ultrastructure at the end of reperfusion (all P<0.05 vs. I/R). The expression of Nrf2, NADH-quinone oxidoreductase-1 (NQO1), heme oxygenase 1 (HO-1) and superoxide dismutase 1 (SOD1) were similarly increased after IPO and PPO treatment (all P<0.05 vs. I/R). PPO exerted solid effect in defeating cardiac ischemia-reperfusion injury in rat.
Keywords: Myocardial; Ischemia-reperfusion injury; Pinacidil; Mitochondria; Nrf2;

Modulation of human monocyte/macrophage activity by tocilizumab, abatacept and etanercept: An in vitro study by Joyce Afrakoma Obeng; Angela Amoruso; Gian Luca Ermanno Camaschella; Daniele Sola; Sandra Brunelleschi; Luigia Grazia Fresu (33-37).
Tocilizumab, etanercept and abatacept are biological drugs used in the therapy of Rheumatoid Arthritis (RA). Their mechanism of action is well documented but their direct effects on human monocytes/macrophages have not been fully investigated. The objective of this study was to evaluate in vitro the influence of these drugs on monocytes/macrophages from healthy volunteers.Human monocytes were isolated from healthy anonymous volunteers and cultured as such or differentiated to monocyte-derived macrophages (MDMs). The effect of tocilizumab, etanercept and abatacept (at concentrations similar to those in plasma of patients) on superoxide anion production, matrix metalloproteinase-9 (MMP-9) gene expression and activity, Peroxisome Proliferator-Activated Receptor (PPAR)γ expression and cell phenotype was evaluated.Exposure of monocytes/macrophages to tocilizumab, etanercept or abatacept resulted in a significant decrease of the PMA-induced superoxide anion production. Interestingly, the expression of PPARγ was significantly increased only by tocilizumab, while etanercept was the only one able to significantly reduce MMP-9 gene expression and inhibit the LPS-induced MMP-9 activity in monocytes. When etanercept and abatacept were added to the differentiating medium, both significantly reduced the amount of CD206+MDM.This study demonstrates that etanercept, abatacept and tocilizumab affect differently human monocytes/macrophages. In particular, the IL-6 antagonist tocilizumab seems to be more effective in inducing an anti-inflammatory phenotype of monocytes/macrophages compared to etanercept and abatacept, also in light of the up-regulation of PPARγ whose anti-inflammatory effects are well recognised.
Keywords: Monocytes/macrophages; Inflammation; Biological drugs;

Gamma-decanolactone inhibits iNOS and TNF-alpha production by lipopolysaccharide-activated microglia in N9 cells by Pricila Pflüger; Cassiana Macagnan Viau; Vanessa Rodrigues Coelho; Natália Alice Berwig; Renata Bartolomeu Staub; Patrícia Pereira; Jenifer Saffi (38-45).
Activated microglia that produce reactive nitrogen species (RNS), inflammatory factors, reactive oxygen species (ROS), and other neurovirulent factors may lead to the development of neurodegenerative diseases. Certain compounds can inhibit the activation of microglia. However, these mechanisms remain unclear. In the present study, we investigated the inhibitory effect of Gamma-decanolactone (GD) on the production of reactive oxygen species and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS) - stimulated N9 murine microglial cells through the p38 MAPK signaling pathway. The results showed that GD attenuated the activation of N9 cells and inhibited intracellular reactive oxygen species and the expression of iNOS and TNF-α induced by LPS in the cells. In addition, GD blocked the phosphorylation of p38 and inhibited cleaved caspase-9 and DNA damage. These data indicate that GD has therapeutic potential for the treatment of neurodegenerative diseases, and that it exerts its effects by inhibiting inflammation.
Keywords: Gamma-decanolactone (GD); Epilepsy; NOS; Cleaved caspase-9; Reactive oxygen species; DNA damage;

Evidence for neural contribution to islet effects of DPP-4 inhibition in mice by Linda Ahlkvist; Bilal Omar; Giovanni Pacini; Bo Ahrén (46-52).
It has been suggested that neural mechanisms may contribute to effects of the incretin hormones, and, therefore, also to the effects of dipeptidyl peptidase (DPP-4) inhibition. We therefore examined whether muscarinic mechanisms are involved in the stimulation of insulin secretion by DPP-4 inhibition. Fasted, anesthetized mice were given intraperitoneal saline or the muscarinic antagonist atropine (5 mg/kg) before duodenal glucose (75 mg/mouse), with or without the DPP-4 inhibitor NVPDPP728 (0.095 mg/mouse), or before intravenous glucose (0.35 g/kg) with or without co-administration with GLP-1 or glucose-dependent insulinotropic polypeptide (GIP) (both 3 nmol/kg). Furthermore, isolated islets were incubated (1 h) in 2.8 and 11.1 mM glucose, with or without GIP or GLP-1 (both 100 nM), in the presence or absence of atropine (100 µM). Duodenal glucose increased circulating insulin and this effect was potentiated by DPP-4 inhibition. The increase in insulin achieved by DPP-4 inhibition was reduced by atropine by approximately 35%. Duodenal glucose also elicited an increase in circulating intact GLP-1 and GIP and this was augmented by DPP-4 inhibition, but these effects were not affected by atropine. Atropine did also not affect the augmentation by GLP-1 and GIP on glucose-stimulated insulin secretion from isolated islets. Based on these findings, we suggest that muscarinic mechanisms contribute to the stimulation of insulin secretion by DPP-4 inhibition through neural effects induced by GLP-1 and GIP whereas neural effects do not affect the levels of GLP-1 or GIP or the islet effects of the two incretin hormones.
Keywords: Insulin; DPP-4 inhibition; GLP-1; GIP; Vagus nerve;

Targeting the 19S proteasomal subunit, Rpt4, for the treatment of colon cancer by Karen Boland; Lorna Flanagan; Niamh McCawley; Ritesh Pabari; Elaine W. Kay; Deborah A. McNamara; Frank Murray; Annette T. Byrne; Zebunnissa Ramtoola; Caoimhín G. Concannon; Jochen H.M. Prehn (53-64).
Deregulation of the ubiquitin-proteasome pathway has been frequently observed in a number of malignancies. Using quantitative Western blotting of normal and matched tumour tissue, we here identified a significant increase in the 19S proteasome subunit Rpt4 in response to chemoradiation in locally advanced rectal cancer patients with unfavourable outcome. We therefore explored the potential of Rpt4 reduction as a therapeutic strategy in colorectal cancer (CRC). Utilizing siRNA to down regulate Rpt4 expression, we show that silencing of Rpt4 reduced proteasomal activity and induced endoplasmic reticulum stress. Gene silencing of Rpt4 also inhibited cell proliferation, reduced clonogenic survival and induced apoptosis in HCT-116 colon cancer cells. We next developed a cell penetrating peptide-based nanoparticle delivery system to achieve in vivo gene silencing of Rpt4. Administration of Rpt4 siRNA nanoparticles reduced tumour growth and improved survival in a HCT-116 colon cancer xenograft tumour model in vivo. Collectively, our data suggest that inhibition of Rpt4 represents a novel strategy for the treatment of CRC.
Keywords: Proteasome; Colorectal cancer; Rpt4; Nanocomplexes; Chemotherapy;

Osteoarthritis is a degenerative joint disease that is characterized by the inflammation of synovium. Schisantherin A (SchA), a dibenzocyclooctadiene lignan isolated from the fruit of Schisandra sphenanthera, has been shown to have anti-inflammatory activity. The aim of this study was to investigate the anti-inflammatory effects of SchA on interleukin-1β (IL-1β)-stimulated human osteoarthritis chondrocytes. Human osteoarthritis chondrocytes were pretreated with SchA 1 h before IL-1β treatment. The effects of SchA on NO, PGE2, iNOS, COX-2, and TNF-α production were detected in this study. The production of MMP-1, MMP3, MMP13 were measured by ELISA. The expression of NF-κB and MAPKs were detected by western blotting. Our results showed that SchA inhibited IL-1β-induced NO, PGE2, and TNF-α production in a dose-dependent manner. Moreover, IL-1β-induced MMP1, MMP3, and MMP13 expression were significantly inhibited by treatment of SchA. In addition, SchA significantly inhibited IL-1β-induced NF-κB and MAPKs activation. Taken together, these results suggest that SchA exhibits anti-inflammatory effects against IL-1β-stimulated chondrocytes by blocking NF-κB and MAPKs signaling pathways.
Keywords: Schisantherin A; Osteoarthritis chondrocyte; IL-1β; NF-κB;

Involvement of nitric oxide-cyclic guanosine monophosphate pathway in the antidepressant-like effect of tropisetron and ondansetron in mice forced swimming test and tail suspension test by Arya Haj-Mirzaian; Nastaran Kordjazy; Shayan Amiri; Arvin Haj-Mirzaian; Hossien Amini-khoei; Sattar Ostadhadi; AhmadReza Dehpour (71-81).
Antidepressant-like effects of 5-hydroxytryptamine subtype 3 (5-HT3) antagonists including tropisetron and ondansetron have been previously demonstrated in the literature. It was reported that stimulation of 5-HT3 receptors activate the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, which is involved in regulation of behavioral and emotional functions. In our study, treating animals with tropisetron (5, 10, and 30 mg/kg) and ondansetron (0.01 and 0.1 µg/kg) significantly decreased the immobility time in forced swimming test (FST) and tail-suspension test (TST). Co-administration of subeffective doses of tropisetron (1 mg/kg) and ondansetron (0.001 µg/kg) with subeffective dose of l-NAME (10 mg/kg, nonselective NO synthase (NOS) inhibitor) and 7-nitroindazole (25 mg/kg, neural NOS inhibitor) exerted antidepressant-like effect in FST and TST, while aminoguanidine (50 mg/kg, inducible NOS inhibitor) did not enhance the antidepressant-like effect of 5-HT3 antagonists. Besides, l-arginine (750 mg/kg, NO precursor) and sildenafil (5 mg/kg, phosphodiesterase inhibitor) suppressed the anti-immobility effect of 5-HT3 antagonists. None of the treatments altered the locomotor behavior of mice in open-field test. Also, hippocampal (but not cortical) nitrite level was significantly lower in tropisetron and ondansetron-treated mice compared with saline-injected mice. Also, co-administration of 7-nitroindazole with tropisetron or ondansetron caused a significant decrease in hippocampal nitrite levels. In conclusion, we suggest that antidepressant-like effect of tropisetron and ondansetron are partially mediated by modulation of NO-cGMP pathway.Display Omitted
Keywords: Antidepressant; Tropisetron; Ondansetron; Nitric oxide cyclic-guanosine monophosphate (NO-cGMP); Forced swimming test (FST); Tail suspension test (TST);

This work was designed to investigate the effects of levocetirizine, a histamine H1 receptor antagonist, on diabetes-induced nephropathy and vascular disorder, in comparison to an angiotensin II receptor antagonist, losartan. Diabetes was induced in male Sprague Dawley rats by a single intraperitoneal injection of streptozotocin (50 mg/kg). Diabetic rats were divided into three groups; diabetic, diabetic-levocetirizine (0.5 mg/kg/day) and diabetic-losartan (25 mg/kg/day). Treatments were started two weeks following diabetes induction and continued for additional eight weeks. At the end of the experiment, urine was collected and serum was separated for biochemical measurements. Tissue homogenates of kidney and aorta were prepared for measuring oxidative stress, nitric oxide (NO), transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α). Moreover, histological analyses were conducted and aortic vascular reactivity was investigated.Levocetirizine improved renal function in diabetic rats (evidenced by mitigation of diabetes-induced changes in kidney to body weight ratio, serum albumin, urinary proteins and creatinine clearance). Moreover, levocetirizine attenuated the elevated renal levels of TNF-α and TGF-β1, ameliorated renal oxidative stress and restored NO bioavailability in diabetic kidney. These effects were comparable to or surpassed those produced by losartan. Moreover, levocetirizine, similar to losartan, reduced the enhanced responsiveness of diabetic aorta to phenylephrine. Histological evaluation of renal and aortic tissues further confirmed the beneficial effects of levocetirizine on diabetic nephropathy and revealed a greater attenuation of diabetes-induced vascular hypertrophy by levocetirizine than by losartan. In conclusion, levocetirizine may offer comparable renoprotective effect to, and possibly superior vasculoprotective effects than, losartan in streptozotocin-diabetic rats.
Keywords: Diabetes; Streptozotocin; Levocetirizine; Oxidative stress; Vascular dysfunction; Nephropathy; Phenylephrine; TGF-β1; TNF-α; Aortic rings;

Inhibition of c-Rel DNA binding is critical for the anti-inflammatory effects of novel PIKfyve inhibitor by Masaomi Terajima; Yoko Kaneko-Kobayashi; Naoto Nakamura; Masatoshi Yuri; Masashi Hiramoto; Masanori Naitou; Kazuyuki Hattori; Hiroyuki Yokota; Hidekazu Mizuhara; Yasuyuki Higashi (93-105).
Aberrant production of proinflammatory cytokines is linked to many autoimmune diseases, and their inhibition by small molecule compounds is considered beneficial. Here, we performed phenotypic screening in IFNγ/LPS-activated RAW264.7, mouse macrophage cells, and discovered AS2677131 and AS2795440 as novel and potent inhibitors of IL-12p40, a subunit of IL-23. Interestingly, these compounds exhibited unique pharmacological activities in their inhibition of the production of IL-12p40, IL-6 and IL-1β but not TNFα in activated macrophages or dendritic cells, and expression of IgM-induced MHC class II on B cells. To reveal these mechanisms, we synthesized two different activity probes which were structurally related to the AS compounds, and identified probe-specific binding proteins, including PIKfyve, a Class III PI kinase. The AS compounds inhibited PIKfyve activity and mimicked the properties of PIKfyve-deficient cells, eventually validating PIKfyve as target molecule. Regarding mechanism, AS2677131 regulated DNA binding activity of c-Rel on IL-12p40 and IL-1β promoter. As expected, a PIKfyve inhibitor prevented the development of arthritis in rats. Taken together, our findings of the novel and potent PIKfyve inhibitors AS2677131 and AS2795440 reveal the critical role of PIKfyve in proinflammatory cytokine production and B cell activation, and may indicate a potential new therapeutic option for treatment of inflammatory diseases.
Keywords: PIKfyve; c-Rel; DNA binding; IL-12p40; Proinflammatory cytokine; Chronic inflammation;

Coptis chinensis has been used for the treatment of inflammatory diseases in China and other Asian countries for centuries. However, the chemical constituents and mechanism underlying the anti-inflammatory activity of this medicinal plant are poorly understood. Here, coptisine, the main constituent of C. chinensis, was shown to potently inhibit the production of nitric oxide (NO) by suppressing the protein and mRNA expressions of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Coptisine also inhibited the production of the pro-inflammatory cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6) by suppressing expression of cytokine mRNA. Coptisine suppressed the degradation of inhibitor of nuclear factor κBα (IκBα) and phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase/Akt (PI3K/Akt). Coptisine had no effect on the expression of toll-like receptor 4 (TLR-4) and myeloid differentiation factor 88 (MyD88) as well as LPS binding to TLR-4. Coptisine also inhibited carrageenan-elicited rat paw edema and reduced the release of TNF-α and NO in rat inflamed tissue. These results suggest that coptisine inhibits LPS-stimulated inflammation by blocking nuclear factor-kappa B, MAPK, and PI3K/Akt activation in macrophages, and can be used as an agent for the prevention and treatment of inflammatory diseases.
Keywords: Coptisine; Coptis chinensis; Inflammation; Nitric oxide; Macrophage;

Go is required for the release of IL-8 and TNF-α, but not degranulation in human mast cells by Yangyang Yu; Zhenhe Huang; Zhuo Mao; Yarui Zhang; Meiling Jin; Wenwen Chen; Wei Zhang; Bo Yu; Weizhen Zhang; Hang Yung Alaster Lau (115-121).
Mast cells activated by IgE-dependent and -independent mechanisms play important roles in innate and acquired immune responses. Activation of pertussis toxin (PTX)-sensitive Gi/o proteins is the key step in mast cell degranulation and release of de novo synthesized inflammatory mediators through IgE-independent mechanism. However, the roles of Gi and Go proteins in mast cells activation have not yet been differentiated. In the current study, the functional roles of Go proteins in the activities of LAD2 cells, a human mast cell line, are identified. Knockdown of Gαo expression significantly inhibited the synthesis of IL-8 and TNF-α from substance P activated LAD2 cells but demonstrated no effect on degranulation. This effect was associated with the activation of Erk and JNK/MAPKs signaling, whereas PI3K-Akt, calcium mobilization and NFAT translocation remained unchanged. These results suggest that Gi and Go proteins differentially regulate human mast cells activities through activating distinct signaling cascades.
Keywords: Mast cells; Go protein; GNAO1; Gi protein; GPCR;

4-Phenylselenyl-7-chloroquinoline, a new quinoline derivative containing selenium, has potential antinociceptive and anti-inflammatory actions by Mikaela Pinz; Angélica S. Reis; Vanessa Duarte; Márcia J. da Rocha; Bruna S. Goldani; Diego Alves; Lucielli Savegnago; Cristiane Luchese; Ethel A. Wilhelm (122-128).
The development of new drugs to treat painful and inflammatory clinical conditions continues to be of great interest. The present study evaluated the antinociceptive and anti-inflammatory effects of 4-phenylselenyl-7-chloroquinoline (4-PSQ). Mice were orally (p.o.) pretreated with 4-PSQ (0.1–25 mg/kg), meloxicam (25 mg/kg, a reference drug) or vehicle, 30 min prior to the acetic acid, formalin, hot-plate and open-field tests. 4-PSQ reduced abdominal writhing induced by acetic acid and it caused an increase in latency time in the hot-plate test. 4-PSQ inhibited early and late phases of nociception and reduced the paw edema caused by formalin. Locomotor and exploratory activities in the open field test were not altered by treatments. In addition, a time–response curve was carried out by administration of 4-PSQ (25 mg/kg; p.o.) at different times before the acetic acid injection. The antinociceptive effect in inhibiting acetic acid-induced abdominal writhing of 4-PSQ started at 0.5 h and remained significant up to 4 h after administration. Indeed, the anti-inflammatory and antioxidant properties of 4-PSQ were investigated. 4-PSQ diminished the edema formation and decreased the myeloperoxidase activity and reactive species levels induced by croton oil in the ear tissue. 4-PSQ partially protected against the decrease of the 2,2′-Azinobis-3-ethylbenzothiazoline 6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) levels induced by croton oil. Meloxicam presented similar results for 4-PSQ in tests evaluated. These results demonstrated that 4-PSQ exerts acute anti-inflammatory and antinociceptive actions, suggesting that it may represent an alternative in the development of future new therapeutic strategies.Display Omitted
Keywords: Nociception; Inflammation; Selenium; Quinoline; Myeloperoxidase; Mice;

Advances and challenges in pharmacotherapeutics for amphetamine-type stimulants addiction by Dan-Ni Cao; Jing-Jing Shi; Wei Hao; Ning Wu; Jin Li (129-135).
Addiction to amphetamine-type stimulants (ATS) is a serious worldwide public health problem with major medical, psychiatric and socioeconomic consequences. However, no approved pharmacological therapies are available to treat ATS addiction. Based on the neurobiological mechanisms underlying ATS addiction, the recent research works about pharmacological strategies have been focused on monoamine, glutamate, endogenous opioid peptide and γ-amino butyric acid (GABA) systems. This review summarizes the recent advances in the medications being developed to treat ATS addiction and discusses the remaining challenges. Although no substantial evidence for efficacious medications has emerged, some of these agents, including bupropion, naltrexone and mirtazapine, have demonstrated promise in clinical studies. Moreover, some challenges, such as the development of new preclinical animal models of drug addiction, the design of large-scale clinical trials with strict quality control, and the distinction of patients' genetic polymorphisms, need further attention. Despite the lack of success to date, much effort is being made to develop efficacious medications for treating ATS addiction.
Keywords: Amphetamine-type stimulants; Addiction; Medication development;

Effect of amlodipine on mouse renal interstitial fibrosis by Shigeyoshi Honma; Kazuki Nakamura; Masahiro Shinohara; Satoru Mitazaki; Sumiko Abe; Makoto Yoshida (136-141).
Unilateral ureteral obstruction (UUO) is a well-established method to study interstitial fibrosis of the kidney. In this study, we investigated the effects of a calcium channel blocker, amlodipine, on UUO-induced renal interstitial fibrosis in mice. UUO significantly increased the fibrotic area in the obstructed kidney, but this change was inhibited by amlodipine (6.7 mg/kg/day in drinking water). mRNA expression of heat shock protein (HSP) 47 and type IV collagen was increased in the kidneys of UUO mice. Amlodipine reduced the expression of both HSP47 and type IV collagen mRNAs. Phosphorylation of c-jun-N-terminal kinase (JNK) was significantly increased by UUO, but the change was inhibited by amlodipine. Collectively, these results suggest that amlodipine may inhibit the expression of HSP47 and type IV collagen by reducing phosphorylation of JNK and ameliorating the renal interstitial fibrosis induced by UUO.
Keywords: Unilateral ureteral obstruction; Amlodipine; Fibrosis; Heat shock protein 47; Type IV collagen; c-jun-N-terminal kinase (JNK);

Myeloperoxidase (MPO) and MPO-catalyzed hypochlorous acid (HOCl) is elevated in many neurodegenerative diseases, and lead to severe tissue injuries. Nitrite (NO2 ) is a widespread inorganic molecule that has recently been proposed as a direct NO donor to exert antioxidant properties in vivo and vitro. Since NO2 and MPO (and/or HOCl) were important mediators in brain function and disease, we investigated the effects of NO2 on MPO-mediated damage to human neuroblastoma SH-SY5Y cells. Here, we showed that exposure of SH-SY5Y cells to MPO (or HOCl) resulted in a significant loss in viability, ATP and glutathione levels, and treatment of neuronal cells with NO2 substantially attenuated MPO (or HOCl)-dependent cellular toxicity. The protective effects of NO2 on MPO (or HOCl)-induced cytotoxicity were because that (1) NO2 at high concentrations competed effectively with Cl for MPO, thus limiting OCl production by the enzyme; (2) HOCl was removed by reacting with NO2 , forming less damaging compound; (3) NO2 significantly inhibited MPO-mediated inactivation of brain protein (enolase) and protein oxidation. Therefore, NO2 could show novel protective effects in some neurodegenerative diseases by preventing MPO-mediated oxidative damage.
Keywords: MPO; Nitrite; Anti-oxidant; Oxidative/nitrative stress; Neurochemistry;

The endothelial cyclooxygenase pathway: Insights from mouse arteries by Wenhong Luo; Bin Liu; Yingbi Zhou (148-158).
To date, cyclooxygenase-2 (COX-2) is commonly believed to be the major mediator of endothelial prostacyclin (prostaglandin I2; PGI2) synthesis that balances the effect of thromboxane (Tx) A2 synthesis mediated by the other COX isoform, COX-1 in platelets. Accordingly, selective inhibition of COX-2 is considered to cause vasoconstriction, platelet aggregation, and hence increase the incidence of cardiovascular events. This idea has been claimed to be substantiated by experiments on mouse models, some of which are deficient in one of the two COX isoforms. However, results from our studies and those of others using similar mouse models suggest that COX-1 is the major functional isoform in vascular endothelium. Also, although PGI2 is recognized as a potent vasodilator, in some arteries endothelial COX activation causes vasoconstrictor response. This has again been recognized by studies, especially those performed on mouse arteries, to result largely from endothelial PGI2 synthesis. Therefore, evidence that supports a role for COX-1 as the major mediator of PGI2 synthesis in mouse vascular endothelium, reasons for the inconsistency, and results that elucidate underlying mechanisms for divergent vasomotor reactions to endothelial COX activation will be discussed in this review. In addition, we address the possible pathological implications and limitations of findings obtained from studies performed on mouse arteries.
Keywords: Arachidonic acid metabolism; Prostacyclin; Thromboxane-prostanoid receptors; Prostacyclin receptors; Contraction; Relaxation;

Inflammation is the hallmark of Staphylococcus aureus (S. aureus)-induced mastitis. Given the interesting relationship between selenium levels and inflammation, this study aimed to demonstrate that selenium modulated the inflammation reaction by suppressing the nuclear factor kappa B (NF-κB) and mitogen activated protein kinase (MAPK) signalling pathways. RAW264.7 macrophages were treated with three different concentrations (1 μmol/l, 1.5 μmol/l, and 2 μmol/l) of Na2SeO3 for 12 h before infection with S. aureus for 6 h, 8 h, and 10 h. The results showed that selenium significantly reduced the mRNA expression levels of tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6). Furthermore, the release of TNF-α, IL-1β, and IL-6 was decreased significantly with selenium supplementation. In addition, selenium influenced the NF-κB signalling pathway by suppressing the activation of NF-κB p65 and degradation of inhibitory kappa-B (IκB). Selenium also suppressed extracellular regulated protein kinase (Erk), c-Jun N-terminal kinase (Jnk), and p38 phosphorylation through the MAPK signalling pathway. In conclusion, selenium played an anti-inflammation role in RAW264.7 macrophages infected with S. aureus by suppressing the activation of the NF-κB and MAPK signalling pathways.
Keywords: Selenium; Staphylococcus aureus; Inflammation; NF-κB; MAPK;

Effects of the dimeric PSD-95 inhibitor UCCB01-144 in mouse models of pain, cognition and motor function by Jesper T. Andreasen; Arafat Nasser; Maitane Caballero-Puntiverio; Maj Sahlholt; Anders Bach; Mikko Gynther; Kristian Strømgaard; Darryl S. Pickering (166-173).
NMDAR antagonism shows analgesic action in humans and animal pain models, but disrupts cognitive and motor functions. NMDAR-dependent NO production requires tethering of the NMDAR to neuronal NO synthase (nNOS) by the postsynaptic density protein-95 (PSD-95). Perturbing the NMDAR/PSD-95/nNOS interaction has therefore been proposed as an alternative analgesic mechanism. We recently reported that UCCB01-125, a dimeric PSD-95 inhibitor with limited blood-brain-barrier permeability, reduced mechanical hypersensitivity in the complete Freund's adjuvant (CFA) inflammatory pain model, without disrupting cognitive or motor functions. Here, we investigated the analgesic efficacy in the CFA model of UCCB01-144, a PSD-95 inhibitor with improved blood-brain-barrier permeability. To extend the comparison of UCCB01-125 and UCCB01-144, we also tested both compounds in the spared nerve injury (SNI) model of neuropathic pain. Potential cognitive effects of UCCB01-144 were examined using the social transmission of food preference (STFP) test and the V-maze test, and motor coordination was assessed with the rotarod test. UCCB01-144 (10 mg/kg) reversed CFA-induced mechanical hypersensitivity after 1 h, and completely normalised sensitivity after 24 h. In the SNI model, UCCB01-144 (30 mg/kg) partially reversed hypersensitivity after 1 h, but no effect was observed after 24 h. UCCB01-125 did not affect SNI-induced hypersensitivity. Rotarod performance was unaffected by UCCB01-144, but 30 mg/kg UCCB01-144 impaired performance in the STFP test. Collectively, UCCB01-144 reversed both CFA and SNI-induced hypersensitivity, but the efficacy in the SNI model was only transient. This suggests that enhanced BBB permeability of PSD-95 inhibitors improves the analgesic action in neuropathic pain states.
Keywords: Inflammatory pain; Neuropathic pain; PSD-95 inhibition; Behaviour; Cognition; Mice;

Protective effect of zingerone on increased vascular contractility in diabetic rat aorta by Salah A. Ghareib; Hany M. El-Bassossy; Ahmed A. Elberry; Ahmad Azhar; Malcolm L. Watson; Zainy M. Banjar; Abdulrahman M. Alahdal (174-179).
The aim of the present study was to investigate the effect and possible mechanism of action of zingerone, the main constituent of ginger, on vascular reactivity in isolated aorta from diabetic rats. The results show that incubation of aortae with zingerone alleviates the exaggerated vasoconstriction of diabetic aortae to phenylephrine, as well as the impaired relaxatory response to acetylcholine in a concentration-dependent manner. Furthermore, Zingerone directly relax phenylephrine-precontracted aortae. The vasorelaxatory response is significantly attenuated by the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester hydrochloride and the guanylate cyclase inhibitor methylene blue but no effect of either the potassium channels blocker tetraethylammonium chloride, or the cyclooxygenase inhibitor indomethacin was observed. Zingerone had no effect on advanced glycation end product formation as well. In conclusion, zingerone ameliorates enhanced vascular contraction in diabetic aortae which may be mediated by its vasodilator effect through NO– and guanylate cyclase stimulation.
Keywords: Diabetes; Zingerone; Vasorelaxant; Nitric oxide; Advanced glycation end products; Vascular complications;

Effects of Buscopan on human gastrointestinal smooth muscle activity in an ex vivo model: Are there any differences for various sections? by Lei Zhang; Jun Song; Tao Bai; Xiaoming Lu; Guanghai Yang; Wei Qian; Ruiyun Wang; Xiaohua Hou (180-187).
Hyoscine butylbromide (Buscopan ®) is clinically used as an anticholinergic antispasmodic for the treatment of abdominal cramping or visceral pain associated with cramps. However, the spasmolytic efficacy on contractile activity of human gastrointestinal smooth muscle from various sections remains unclear. We aimed to investigate the potentially selective actions of Buscopan on different bowel segments, as well as muscular layers and contractile states. Human smooth muscle tissues of the esophagus, gastric corpus and antrum, jejunum, ileum and colon were obtained. Isometric measurements of circular and longitudinal muscle strips were performed to determine effects of Buscopan on spontaneous activity and induced-contractions by 30 mM KCl, 10 μM bethanechol and electrical field stimulation (EFS). Buscopan concentration-dependently (10−9–10−5  M) inhibited smooth muscle activity, particularly in spasticity evoked by bethanechol and EFS but not high K+. The inhibiting effects were mainly responsible for the antagonism on muscarinic M2 and M3 receptors (IC50 values: 3.1×10−5  M vs. 0.9×10−5  M). The sensitivity toward Buscopan revealed a tendency of increasing from the esophagus, gastric corpus and antrum to the colon, jejunum and ileum. There was a reversed gradient of mRNA and protein expression of muscarinic M2 and M3 receptors from the blocking effects of Buscopan, which could be ascribed to the fact that a higher concentration of Buscopan was needed to antagonize the spastic contraction to reach the equipotent inhibitory rate in the region with higher muscarinic receptor activity. The findings of different inhibitory effectiveness on various parts of the gastrointestinal tract provide a potential guideline for the clinical application.
Keywords: Hyoscine butylbromide; Buscopan; Antispasmodics; Gastrointestinal smooth muscle; Abdominal cramps;

Modeling interactions between blocking and permeant cations in the NavMs channel by Vyacheslav S. Korkosh; Boris S. Zhorov; Denis B. Tikhonov (188-193).
Mechanisms of sodium channel block by local anesthetics (LAs) are still a matter of intensive studies. In the absence of high-resolution structures of eukaryotic channels, atomic details of LA-channel interactions are analyzed using homology modeling. LAs are predicted to access the closed channel through a sidewalk (fenestration) between the channel repeats, bind in a horizontal orientation, and leave its aromatic moiety in the interface. Recent X-ray structure of a bacterial sodium channel NavMs with a cationic molecule Pl1, which is structurally similar to LAs, has confirmed this theoretical prediction and demonstrated a reduced selectivity filter occupancy by the permeant ions in the Pl1-bound channel. However, the nature of the antagonism between LAs and permeant ions is still unclear. Here we used the NavMs structure and Monte Carlo energy minimizations to model Pl1 binding. Our computations predict that Pl1 can displace permeant ion(s) from the selectivity filter by both steric and electrostatic mechanisms. We hypothesize that the electrostatic mechanism is more general, because it is applicable to many LAs and related drugs, which lack a moiety capable to enter the selectivity filter and sterically displace the permeant ion. The electrostatic mechanism is also consistent with the data that various cationic blockers of potassium channels bind in the inner pore without entering the selectivity filter.
Keywords: Sodium channels; Ion channel block; Mechanism of action; Local anesthetics;

Emodin ameliorates high-fat-diet induced insulin resistance in rats by reducing lipid accumulation in skeletal muscle by Yanni Cao; Shufang Chang; Jie Dong; Shenyin Zhu; Xiaoying Zheng; Juan Li; Rui Long; Yuanda Zhou; Jianyu Cui; Ye Zhang (194-201).
Emodin, an anthraquinone derivative isolated from root and rhizome of Rheum palmatum, has been reported to have promising anti-diabetic activity. The present study was to explore the possible mechanism of emodin to ameliorate insulin resistance. Insulin resistance was induced by feeding a high fat diet to Sprague-Dawley rats. The blood glucose and lipid profiles in serum were measured by an enzymatic method, and a hyperinsulinaemic-euglycaemic clamp was used to evaluate insulin resistance. L6 cells were cultured and treated with palmitic acid and emodin. The lipid content was assayed in the soleus muscle and L6 cells by Oil Red O staining. Western blot, qRT-PCR, and immunohistochemical staining were used to detect the following in the rat soleus muscle and L6 cells: protein levels, mRNA levels of FATP1, FATP4, transporter fatty acid translocase (FAT/CD36), and plasma membrane-associated fatty acid protein (FABPpm). We found that blood glucose, triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly decreased in the emodin group. Oil Red O staining and the level of TG in skeletal muscle and L6 cells confirmed that lipid deposition decreased after treatment with emodin. Furthermore, the protein levels and mRNA levels of FATP1 in skeletal muscle and in L6 cells of rats were significantly decreased, yet the protein levels and mRNA levels of FATP4, FAT/CD36 and FABPpm did not drop off significantly. The study suggest that emodin ameliorates insulin resistance by reducing FATP1-mediated skeletal muscle lipid accumulation in rats fed a high fat diet.Display Omitted
Keywords: Insulin resistance; Emodin; FATP1; Skeletal muscle; Lipid accumulation;

Inhibition of acetyl-CoA carboxylases by soraphen A prevents lipid accumulation and adipocyte differentiation in 3T3-L1 cells by Elizabeth L. Cordonier; Sarah K. Jarecke; Frances E. Hollinger; Janos Zempleni (202-208).
Acetyl-CoA carboxylases (ACC) 1 and 2 catalyze the carboxylation of acetyl-CoA to malonyl-CoA and depend on biotin as a coenzyme. ACC1 localizes in the cytoplasm and produces malonyl-CoA for fatty acid (FA) synthesis. ACC2 localizes in the outer mitochondrial membrane and produces malonyl-CoA that inhibits FA import into mitochondria for subsequent oxidation. We hypothesized that ACCs are checkpoints in adipocyte differentiation and tested this hypothesis using the ACC1 and ACC2 inhibitor soraphen A (SA) in murine 3T3-L1 preadipocytes. When 3T3-L1 cells were treated with 100 nM SA for 8 days after induction of differentiation, the expression of PPARγ mRNA and FABP4 mRNA decreased by 40% and 50%, respectively, compared with solvent controls; the decrease in gene expression was accompanied by a decrease in FABP4 protein expression and associated with a decrease in lipid droplet accumulation. The rate of FA oxidation was 300% greater in SA-treated cells compared with vehicle controls. Treatment with exogenous palmitate restored PPARγ and FABP4 mRNA expression and FABP4 protein expression in SA-treated cells. In contrast, SA did not alter lipid accumulation if treatment was initiated on day eight after induction of differentiation. We conclude that loss of ACC1-dependent FA synthesis and loss of ACC2-dependent inhibition of FA oxidation prevent lipid accumulation in adipocytes and inhibit early stages of adipocyte differentiation.
Keywords: Acetyl-CoA carboxylase; Adipogenesis; Peroxisome-proliferator-activated receptor gamma; Soraphen A; Lipid metabolism;

Reversal of morphine-induced respiratory depression by doxapram in anesthetized rats by Akira Haji; Satoko Kimura; Yoshiaki Ohi (209-215).
The present study was undertaken to investigate whether doxapram, a blocker of tandem pore K+ (TASK-1/−3) channels, is a useful tool for recovery from morphine-induced ventilatory disturbances. Spontaneous ventilation and the hind leg withdrawal response against noxious thermal stimulation were recorded simultaneously in anesthetized rats. Morphine (1.0 mg/kg, i.v.) decreased the minute volume resulting from depression of the ventilatory rate and tracheal airflow. Concomitantly, it prolonged the latency of withdrawal response against the thermal stimulation. Subsequent intravenous injection of doxapram recovered the morphine-induced ventilatory depression. This effect of doxapram declined rapidly after a single injection (1.0–3.0 mg/kg, i.v.) but persisted with a continuous infusion (0.33 mg/kg/min). Neither single injection nor continuous infusion of doxapram had any detectable effect on the analgesic potency of morphine. The central respiratory activity was recorded from the phrenic nerve in anesthetized, vagotomized, paralyzed and artificially ventilated rats. Morphine (3.0 mg/kg, i.v.) induced respiratory depression, characterized by a prolonged plateau-like inspiratory discharge (apneustic discharge) in the phrenic nerve. Doxapram (10 mg/kg, i.v.) restored the morphine-induced apneustic discharge to an augmenting inspiratory discharge. This study demonstrated that doxapram counteracted morphine-induced respiratory depression by stimulating the central respiratory network without compromising morphine antinociception. These results support the clinical use of doxapram for amelioration of ventilatory disturbances in patients treated with opioids.
Keywords: Morphine; Doxapram; Ventilatory depression; Analgesia; Phrenic nerve discharge;

The role of D-serine in peripheral tissues by Camila Montesinos Guevara; Ali R. Mani (216-223).
A considerable level of D-serine (a free D-amino acid) was discovered, surprisingly, in the mammalian brain in the early 1990s. Since then, D-serine has been considered to be a co-agonist of glutamate at the glycine site of NMDA receptors. D-serine is synthetized by racemization of L-serine in most neural and non-neural cells, and modulates a variety of physiological functions in mammals. In addition to the central nervous system, NMDA receptors have an important function in the modulation of physiological processes in peripheral tissues. Thus, investigations on the functions of D-serine in the peripheral nervous system, as well as the visceral organs, have gained attention in recent years. In this review we summarize the current knowledge on the role of D-serine in the kidneys, skeletal system, skin as well as on the non-adrenergic, non-cholinergic transmission within the autonomic nervous system.
Keywords: D-serine; Serine racemase; NMDA;

Effects of topiroxostat and febuxostat on urinary albumin excretion and plasma xanthine oxidoreductase activity in db/db mice by Takashi Nakamura; Takayo Murase; Mai Nampei; Nobutaka Morimoto; Naoki Ashizawa; Takashi Iwanaga; Ryusuke Sakamoto (224-231).
Topiroxostat, a xanthine oxidoreductase (XOR) inhibitor, has been shown to decrease the urinary albumin-to-creatinine ratio compared with placebo in hyperuricemic patients with stage 3 chronic kidney disease. Thus, we aimed to ascertain the albuminuria-lowering effect of topiroxostat in diabetic mouse. Db/db mice were fed standard diets with or without topiroxostat (0.1, 0.3, 1, and 3 mg/kg/day) and febuxostat (0.1, 0.3, and 1 mg/kg/day) for four weeks. Urinary albumin and purine bodies levels, XOR activities, and drug concentrations in the liver, kidney, and plasma were measured. Moreover, the XOR inhibitory activity of each XOR inhibitor was evaluated with or without an exogenous protein in vitro. Topiroxostat decreased dose-dependently the urinary albumin excretion, but febuxostat did not show such a tendency. Treatment with topiroxostat inhibited plasma XOR activity with dose-dependent increase in plasma purine levels, which was not observed by febuxostat. Pharmacokinetic/pharmacodynamic analysis revealed that topiroxostat and febuxostat concentration in each tissue showed a good correlation with both the hypouricemic effect and plasma drug concentration, whereas the change in albuminuria correlated neither with the change in uric acid nor with drug concentration in plasma. However, the change in urinary albumin and plasma XOR activity showed good correlation in topiroxostat group. The 50% inhibitory concentration (IC50 value) of febuxostat against plasma XOR in vitro was 12-fold higher than that of topiroxostat, and increased by approximately 13-fold by interfering with an exogenous protein. Topiroxostat caused reduced urinary albumin excretion, in which potent inhibition of the plasma XOR activity might be involved.
Keywords: Topiroxostat; Xanthine oxidoreductase; Diabetic nephropathy; Albuminuria;

Uvaol attenuates pleuritis and eosinophilic inflammation in ovalbumin-induced allergy in mice by Lais Costa Agra; Marvin Paulo Lins; Patrícia da Silva Marques; Salete Smaniotto; Christianne Bandeira de Melo; Vincent Lagente; Emiliano Barreto (232-242).
Uvaol, a triterpene present in olives and virgin olive oil, has been shown to possess anti-inflammatory properties and antioxidant effects. However, until now, no studies have demonstrated its potential effects on allergic inflammation. The aim of this study was to evaluate the anti-inflammatory effects of uvaol in a mouse model of allergy characterized by eosinophil-dominant inflammation in actively sensitized mice. The anti-inflammatory effect of uvaol was analyzed in two murine models of allergic inflammation (pleurisy and asthma). In these models, Swiss mice were sensitized and challenged with ovalbumin (OVA). In the pleurisy model, the pleural eosinophilic inflammation and IL-5 concentrations were examined 24 h after the OVA challenge, while in the asthma model were examined the airway inflammation via bronchoalveolar lavage (BAL) fluid cytology and lung histopathology analyses. Our results showed that uvaol decreased the accumulation of eosinophils and the concentration of IL-5 in pleural effluent. Uvaol also demonstrated important anti-inflammatory activity by inhibiting production of IL-5 and influx of leukocytes, mainly of eosinophils, in BAL fluid, but without interfering with levels of reactive oxygen species in leukocytes. Moreover, the eosinophil infiltration, mucus production, number of alveoli that collapsed, and IL-5 levels in the lung were clearly decreased by uvaol treatment. These findings indicate that uvaol can be a good candidate for the treatment of allergic inflammation by inhibiting eosinophil influx and IL-5 production in ovalbumin-induced allergy.
Keywords: Uvaol; Triterpene; Eosinophil; IL-5; Inflammation;

The effect of the phenol compound ellagic acid on Ca2+ homeostasis and cytotoxicity in liver cells by Wei-Zhe Liang; Chiang-Ting Chou; Jin-Shiung Cheng; Jue-Long Wang; Hong-Tai Chang; I-Shu Chen; Ti Lu; Jeng-Hsien Yeh; Daih-Huang Kuo; Pochuen Shieh; Fu-An Chen; Chun-Chi Kuo; Chung-Ren Jan (243-251).
Ellagic acid, a natural phenol compound found in numerous fruits and vegetables, causes various physiological effects in different cell models. However, the effect of this compound on Ca2+ homeostasis in liver cells is unknown. This study examined the effect of ellagic acid on intracellular Ca2+ concentration ([Ca2+]i) and established the relationship between Ca2+ signaling and cytotoxicity in liver cells. The data show that ellagic acid induced concentration-dependent [Ca2+]i rises in HepG2 human hepatoma cells, but not in HA22T, HA59T human hepatoma cells or AML12 mouse hepatocytes. In HepG2 cells, this Ca2+ signal response was reduced by removing extracellular Ca2+ and was inhibited by store-operated Ca2+ channel blockers (2-APB, econazole or SKF96365) and the protein kinase C (PKC) inhibitor GF109203X. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished ellagic acid-induced [Ca2+]i rises. Conversely, incubation with ellagic acid abolished thapsigargin-induced [Ca2+]i rises. Inhibition of phospholipase C (PLC) with U73122 also abolished ellagic acid-induced [Ca2+]i rises. Ellagic acid (25–100 μM) concentration-dependently caused cytotoxicity in HepG2, HA22T or HA59T cells, but not in AML12 cells. Furthermore, this cytotoxic effect was partially prevented by prechelating cytosolic Ca2+ with BAPTA-AM only in HepG2 cells. Together, in HepG2 cells, ellagic acid induced [Ca2+]i rises by inducing PLC-dependent Ca2+ release from the endoplasmic reticulum and Ca2+ entry via PKC-sensitive store-operated Ca2+ channels. Moreover, ellagic acid induced Ca2+-associated cytotoxicity.Display Omitted
Keywords: Ca2+; Cytotoxicity; Ellagic acid; Liver cells; Phenolic compound;

Identification and characterization of heptapeptide modulators of the glycine receptor by Garrett L. Cornelison; Natasha C. Pflanz; Megan E. Tipps; S. John Mihic (252-259).
The glycine receptor is a member of the Cys-loop receptor superfamily of ligand-gated ion channels and is implicated as a possible therapeutic target for the treatment of diseases such as alcoholism and inflammatory pain. In humans, four glycine receptor subtypes (α1, α2, α3, and β) co-assemble to form pentameric channel proteins as either α homomers or αβ heteromers. To date, few agents have been identified that can selectively modulate the glycine receptor, especially those possessing subtype specificity. We used a cell-based method of phage display panning, coupled with two-electrode voltage-clamp electrophysiology in Xenopus laevis oocytes, to identify novel heptapeptide modulators of the α1β glycine receptor. This involved a panning procedure in which the phage library initially underwent subtractive panning against Human Embryonic Kidney (HEK) 293 cells expressing alternative glycine receptor subtypes before panning the remaining library over HEK 293 cells expressing the target, the α1β glycine receptor. Peptides were identified that act with selectivity on α1β and α3β, compared to α2β, glycine receptors. In addition, peptide activity at the glycine receptor decreased when zinc was chelated by tricine, similar to previous observations of a decrease in ethanol's enhancing actions at the receptor in the absence of zinc. Comparisons of the amino acid sequences of heptapeptides capable of potentiating glycine receptor function revealed several consensus sequences that may be predictive of a peptide's enhancing ability.
Keywords: Glycine receptor; Phage display; Allosteric modulator; Electrophysiology; Xenopus oocytes;