Research progress in drugs targeting 5-lipoxygenase for age-related diseases / 生理学报

With the acceleration of aging society, delaying aging or promoting healthy aging has become a major demand for human health. 5-Lipoxygenase (5-LOX) is a key enzyme catalyzing arachidonic acid into leukotrienes (LTs), which is a potent mediator of the inflammatory response. Previous studies showed that abnormal activation of 5-LOX and overproduction of LTs are closely related to the occurrence and development of aging-related inflammatory diseases. Therefore, inhibiting 5-LOX activation is a possibly potential strategy for treating age-related diseases. In this paper, the latest research progress in 5-LOX activation, 5-LOX in mediating aging-related diseases and its small molecule inhibitors is briefly reviewed to provide scientific theoretical basis and new ideas for the prevention and treatment of aging-related inflammatory diseases.

Biological screening of herbal extracts and essential oil from Plectranthus species: α-amylase and 5-lipoxygenase inhibition and antioxidant and anti-Candida potentials

Abstract The phenolic compound content, the antioxidant and α-amylase inhibition potentials of different extracts of the Plectranthus amboinicus, P. barbatus and P. ornatus were evaluated. We also evaluated the influence of plant growth and harvest time on the chemical composition of the essential oil (EO) of P. amboinicus, its antioxidant and anti-Candida activities and the α-amylase and lipoxygenase inhibitions. The turbo-extract of P. barbatus showed the greatest phenolic compound content and antioxidant activity. No α-amylase inhibition activity was observed in the analyzed extracts, but the turbo-extraction and refluxing extracts possessed high antioxidant activities. Protected cultivation and morning harvest conditions gave the best antioxidant activities, which was associated to the highest carvacrol content. P. amboinicus EO antioxidant activity could contribute to the reduction of oxidative stress in diabetes. Causal Candida strains of diabetic foot ulcers showed sensitivity to P. amboinicus EO. C. albicans and C. dubliniensis were the most sensitive of the selected Candida strains. Turbo-extracts or refluxing of the three species extracts and the EO of P. amboinicus should be considered as a potential candidate for the management the complications of type 2 diabetes.

Evaluación in silico del efecto de compuestos fenólicos de Pleurotus ostreatus sobre la enzima 5-lipoxigenasa (5- LOX) / In silico evaluation of the effect of Pleurotus ostreatus phenolic compounds on the enzyme 5-lipoxygenase (5-LOX)

Introducción: Los hongos comestibles, en particular Pleurotus ostreatus, representan una importante fuente de metabolitos bioactivos con propiedades inmunomoduladoras, antioxidantes y antiinflamatorias. Trabajos recientes han demostrado que extractos y compuestos purificados a partir de esta seta, entre ellos, la fracción rica en fenoles, inhiben el factor nuclear kappa B(NF-κB), la cicloxigenasa (COX) y modulan cascadas de señalización relacionadas con el balance redox. De acuerdo con estos antecedentes, dichos compuestos podrían actuar, además, como inhibidores de la enzima 5- lipoxigenasa (5-LOX). Objetivo: Evaluar el efecto in silico de trece compuestos fenólicos presentes en la especie Pleurotus ostreatus sobre la enzima 5-LOX, al utilizar como compuesto de referencia la mangiferina. Métodos: El acoplamiento se llevó a cabo a través del programa AutoDock 4.2 (http://autodock.scripps.edu) y la estructura de 5 LOX se obtuvo con la base de datos de proteínas, PDB (www.wwpdb.org). Se estimaron la energía libre (ΔG), la constante de disociación (Ki) y la eficiencia de ligando (LE). Se obtuvieron los parámetros de similitud a un fármaco y los relacionados con la absorción, distribución, metabolismo, excreción y toxicidad (ADME/T) de los mejores modelos de acoplamiento. Resultados: Los mejores indicadores de ΔG y Ki, correspondieron a los ácidos homogentísico, clorogénico y gentísico, con valores de ΔG (-11,81; -12,28 y -11,67 kcal/moL) y Ki (2,19 10-9; 9,99 10-10, 2,79 10-9 M), respectivamente. La eficiencia de ligando alcanzó valores adecuados para estos tres compuestos fenólicos. El modelo de acoplamiento del ácido homogentísico mostró los mejores resultados en cuanto a la similitud a un fármaco y pruebas ADME/T. Conclusiones: El estudio in silico reveló las potencialidades de la fracción rica en fenoles de P. ostreatus, y en particular, del ácido homogentísico como inhibidor de la enzima 5 -LOX, y justifica el desarrollo de ensayos confirmativos in vitro/ in vivo que corroboren sus efectos antioxidantes y antinflamatorios(AU)

Introduction: Edible mushrooms, Pleurotus ostreatus in particular, are an important source of bioactive metabolites with immunomodulatory, antioxidant and anti-inflammatory properties. Recent studies have shown that extracts and compounds purified from this mushroom, among them the phenol-rich fraction, inhibit nuclear factor kappa B (NF-κB), cyclooxygenase (COX), and modulate signaling cascades related to redox balance. According to these antecedents, such compounds could also act as inhibitors of the enzyme 5-lipoxygenase (5-LOX). Objective: Evaluate the in silico effect of 13 phenolic compounds present in the species Pleurotus ostreatus on the enzyme 5-LOX using mangiferin as reference compound. Methods: Docking was carried out with the software AutoDock 4.2 (http://autodock.scripps.edu) and the 5-LOX structure was obtained with the protein database PDB (www.wwpdb.org). Estimation was performed of free energy (ΔG), dissociation constant (Kd) and ligand efficiency (LE). Drug-likeness parameters were obtained, as well as those related to absorption, distribution, metabolism, excretion and toxicity (ADMET) of the best docking models. Results: The best ΔG and Kd indicators were homogentisic, chlorogenic and gentisic acids, with ΔG and Kd values of -11.81, -12.28, -11.67 kcal/mol, and 2.19 10-9, 9.99 10-10, 2.79 10-9 M, respectively. Ligand efficiency achieved adequate values for these three phenolic compounds. The docking model for homogentisic acid showed the best results in terms of drug likeness and ADMET tests. Conclusions: The in silico study revealed the potential of the phenol-rich fraction of P. ostreatus, homogentisic acid in particular, as an enzyme 5-LOX inhibitor, and justifies the development of confirmatory in vitro / in vivo assays to corroborate its antioxidant and anti-inflammatory effects(AU)

Root canal contamination or exposure to lipopolysaccharide differentially modulate prostaglandin E 2 and leukotriene B 4 signaling in apical periodontitis

Abstract Purpose To evaluate the kinetics of apical periodontitis development in vivo , induced either by contamination of the root canals by microorganisms from the oral cavity or by inoculation of bacterial lipopolysaccharide (LPS) and the regulation of major enzymes and receptors involved in the arachidonic acid metabolism. Methodology Apical periodontitis was induced in C57BL6 mice (n=96), by root canal exposure to oral cavity (n=48 teeth) or inoculation of LPS (10 µL of a suspension of 0.1 µg/µL) from E. coli into the root canals (n= 48 teeth). Healthy teeth were used as control (n=48 teeth). After 7, 14, 21 and 28 days the animals were euthanized and tissues removed for histopathological and qRT-PCR analyses. Histological analysis data were analyzed using two-way ANOVA followed by Sidak's test, and qRT-PCR data using two-way ANOVA followed by Tukey's test (α=0.05). Results Contamination by microorganisms led to the development of apical periodontitis, characterized by the recruitment of inflammatory cells and bone tissue resorption, whereas inoculation of LPS induced inflammatory cells recruitment without bone resorption. Both stimuli induced mRNA expression for cyclooxygenase-2 and 5-lipoxygenase enzymes. Expression of prostaglandin E 2 and leukotriene B 4 cell surface receptors were more stimulated by LPS. Regarding nuclear peroxisome proliferator-activated receptors (PPAR), oral contamination induced the synthesis of mRNA for PPARδ, differently from inoculation of LPS, that induced PPARα and PPARγ expression. Conclusions Contamination of the root canals by microorganisms from oral cavity induced the development of apical periodontitis differently than by inoculation with LPS, characterized by less bone loss than the first model. Regardless of the model used, it was found a local increase in the synthesis of mRNA for the enzymes 5-lipoxygenase and cyclooxygenase-2 of the arachidonic acid metabolism, as well as in the surface and nuclear receptors for the lipid mediators prostaglandin E2 and leukotriene B4.

Análise do processo de reparo alveolar em camundongos fêmeas senescentes 129/Sv-WT e 129/Sv 5-LOKO sob terapia com bifosfonato de alta potência / Alveolar bone repair of 129/Sv WT and 129/Sv 5LOKO female senescent mice under therapy with high potency bisphosphonate

O processo de senescência acarreta uma série de modificações fisiológicas com declínio das funções das atividades celulares e sistêmicas que se manifestam de maneira mais importante na população feminina pelo evento da menopausa, como a osteoporose. A fim de se minimizar tais efeitos, há a possibilidade de se utilizar medicamentos que diminuem o processo de remodelação óssea como os bifosfonatos nitrogenados (BF). Entretanto, o uso dessas drogas está intimamente relacionado ao desenvolvimento de osteonecrose dos maxilares (OM), principalmente quando associado a outros fatores de risco como as cirurgias bucais. Sabe-se que fisiologicamente a dinâmica do tecido ósseo depende também de eicosanóides derivados do metabolismo do ácido araquidônico (AA), como as enzimas cicloxigenase (COX) e 5 lipoxigenase (5LO). Deste modo, o objetivo do presente trabalho foi analisar o efeito BF ácido zoledrônico (ZL) e sua relação com o desenvolvimento da OM em camundongos fêmeas senescentes 129/Sv com e sem modificação genética para a enzima 5LO. Para tanto, foram utilizados 40 camundongos fêmeas senescentes 129/Sv, sendo 20 WT e 20 com alteração no gene 5LO (129 Alox5tm1Fun/J) (5LOKO), divididas em grupos: WT, tratadas com 0,01 ml de solução salina 0,9% estéril (SS) via intraperitoneal (IP) e ZL, tratadas com 250µg/Kg de ácido zoledrônico (ZL) IP diluído em solução salina estéril, ambas administradas 1 vez/semana por 7 semanas. Os grupos foram compostos por 5 animais cada (WT Controle ­ 7 e 21dias, WT ZL ­ 7 e 21 dias, 5LOKO Controle ­ 7 e 21 dias, 5LOKO ZL ­ 7 e 21dias), sendo as maxilas coletadas para análises em microCT, histopatológica, birrefringência, técnica imunohistoquímica e histomorfométricas. De modo geral, a microCT revelou deficiência significativa na microarquitetura óssea nos animais WT ZL em comparação com os demais. Do mesmo modo, a partir da análise histopatológica e de birrefringência da matriz colagenosa, observou-se padrão compatível com o desenvolvimento de OM no grupo WT ZL, com presença de infiltrado inflamatório intenso, atraso na neoformação óssea, presença de fraturas patológicas, e deficiência da matriz colagenosa e de células Runx-2+, TRAP+ e F4/80+. Os animais 5LOKO ZL apresentaram alterações compatíveis com atraso no processo de reparo especialmente no período de 7 dias, com menor quantidade de células Runx-2+ em comparação com o grupo 5LOKO Controle e pela qualidade da matriz óssea colagenosa com menor quantidade de fibras do espectro vermelho neste período, se igualando, porém, aos 21 dias. Deste modo, concluiu-se que o processo de reparo em camundongos fêmeas senescentes da linhagem 129/Sv WT e 5LOKO associados ao uso do BF ZL ocorreu de modo distinto, levando a quadro de OM nos animais WT e atraso nos animais 5LOKO, sem sinais histopatológicos que caracterizassem a doença. Deste modo, a inibição da enzima 5LO parece influenciar de maneira positiva o processo de reparo ósseo intramembranoso alveolar, mesmo na presença de fenótipo esqueletal osteopetrótico, sugerindo outros fatores relacionados à droga que favoreçam o desenvolvimento da OM no presente modelo animal(AU)

Senescence brings a number of physiological modifications with the decrease of cell and systemic activities and function that manifest in an important way in female population due to the event of menopause, as osteoporosis. In order to diminish these effects, there is the possibility of taking medication that decrease bone remodeling process, as the bisphosphonates containing nitrogen (BF). However, the use of these drugs is intimate related with the development of the osteonecrosis of the jaws (ON), especially when associated to other risk factors as oral surgery. It is known that physiologically, the dynamics of bone tissue also depends on the eicosanoids derivate from the arachidonic acid metabolism (AA), such as cyclooxygenase (COX) and 5 lipoxygenase (5LO) enzymes. In this way, the aim of the present study was to analyze the effects of the BF zoledrônico acid (ZL) and its relation with de development of ON in 129/SV old female mice with or without genetic modification for 5LO. Forty animals, 20 WT and 20 with 5LO gene alteration (129 Alox5tm1Fun/J) (5LOKO) were divided in groups: WT, treated with 0.01 ml of sterile 0.9% saline solution (SS) intraperitoneal (IP), and ZL, treated with 250µg/Kg of ZL IP diluted in SS, both administered once a week for 7 weeks. Groups contained 5 animals each (WT Control ­ 7 and 21 days, WT ZL ,7 and 21 days, 5LOKO Control, 7 and 21 days, and 5LOKO ZL, 7 and 21 days), and the maxillae removed for microCT, histopathology, birefringence, immunohistochemistry, and histomorphometric analysis. In general, microCT revealed significant deficiency in bone microarchitecture in WT ZL group in comparison to the other groups. In the same way, histopathological and birefringence analysis revealed histological pattern compatible with ON development in WT ZL group, presenting intense inflammatory infiltrate, late new bone formation, presence of pathological fractures, and deficiency in collagenous matrix, and also in Runx-2+, TRAP+, and F4/80. 5LOKO ZL animals presented alterations compatible with a late bone repair, especially at day 7, with decreased number of Runx-2+ cells in comparison to 5LOKO Control, and by the quality of collagenous bone matrix with decreased number of red spectra fibers in this period, however, being similar at day 21. From this, it could be concluded that alveolar bone repair of 129/SV WT and 5LOKO old female mice associated with the administration of ZL occurred in different ways, leading to a picture of ON in the WT animals, and late bone repair in the 5LOKO animals, without histopathological signs that could characterize the disease. In this way, inhibition of 5LO seems to influence intramembranous alveolar bone repair in a positive way, even in the presence of osteopetrotic skeletal phenotype, suggesting other factors related to the drug that favors the development of the ON in the present animal model(AU)

In Silico System Pharmacology for the Potential Bioactive Ingredients Contained in Xingnaojing Injection () and Its Material Basis for Sepsis Treatment / 中国结合医学杂志

OBJECTIVE@#To elucidate the action mechanism of Xingnaojing Injection (, XNJI) for sepsis, and to target screen the potential bioactive ingredients.@*METHODS@#An integrated protocol that combines in silico target screen (molecular docking) and database mapping was employed to find the potential inhibitors from XNJI for the sepsis-related targets and to establish the compound-target (C-T) interaction network. The XNJI's bioactive components database was investigated and the sepsis-associated targets were comprehensively constructed; the 3D structure of adenosine receptor A2a and 5-lipoxygenase proteins were established and evaluated with homology modeling method; system network pharmacology for sepsis treatment was studied between the bioactive ingredients and the sepsis targets using computational biology methods to distinguish inhibitors from non inhibitors for the selected sepsis-related targets and C-T network construction.@*RESULTS@#Multiple bioactive compounds in the XNJI were found to interact with multiple sepsis targets. The 32 bioactive ingredients were generated from XNJI in pharmacological system, and 21 potential targets were predicted to the sepsis disease; the biological activities for some potential inhibitors had been experimentally confirmed, highlighting the reliability of in silico target screen. Further integrated C-T network showed that these bioactive components together probably display synergistic action for sepsis treatment.@*CONCLUSIONS@#The uncovered mechanism may offer a superior insight for understanding the theory of the Chinese herbal medicine for combating sepsis. Moreover, the potential inhibitors for the sepsis-related targets may provide a good source to find new lead compounds against sepsis disease.

Rhamnazin inhibits LPS-induced inflammation and ROS/RNS in raw macrophages / 한국영양학회지

PURPOSE: The aim of this work was to investigate the beneficial effects of rhamnazin against inflammation, reactive oxygen species (ROS)/reactive nitrogen species (RNS), and anti-oxidative activity in murine macrophage RAW264.7 cells. METHODS: To examine the beneficial properties of rhamnazin on inflammation, ROS/ RNS, and anti-oxidative activity in the murine macrophage RAW264.7 cell model, several key markers, including COX and 5-LO activities, NO•, ONOO-, total reactive species formation, lipid peroxidation, •O₂ levels, and catalase activity were estimated. RESULTS: Results show that rhamnazin was protective against LPS-induced cytotoxicity in macrophage cells. The underlying action of rhamnazin might be through modulation of ROS/RNS and anti-oxidative activity through regulation of total reactive species production, lipid peroxidation, catalase activity, and •O₂, NO•, and ONOO• levels. In addition, rhamnazin down-regulated the activities of pro-inflammatory COX and 5-LO. CONCLUSION: The plausible action by which rhamnazin renders its protective effects in macrophage cells is likely due to its capability to regulate LPS-induced inflammation, ROS/ RNS, and anti-oxidative activity.

Sclerotiorin is non-mutagenic and inhibits human PMNL 5-lipoxygenase and platelet aggregation.

Sclerotiorin, isolated from the fermented broth of Penicillium frequentans, exhibited potent inhibition against human polymorphonuclear leukocytes 5-lipoxygenase and human platelet aggregation with a half maximal value 36 µM and 250 µM, respectively. Further, the Ames test has demonstrated the sclerotiorin to be non-mutagenic.

Expression of 5-lipoxygenase in human tissues and its association with disease / 中南大学学报(医学版)

5-Lipoxygenase, one of lipoxygenase isozymes, is a well-studied oxidative metabolism enzyme. It widely exists in various human tissues and cells, participates in the oxidative metabolism of endogenous and exogenous chemicals, and produces a variety of metabolites, all of which contribute to the occurrence of human diseases, such as inflammation, asthma, atherosclerosis, and tumor and so on. The expression of 5-lipoxygenase is at low level in normal human tissues while at high level in abnormal tissues. 5-Lipoxygenase is closely related to many kinds of diseases in human ovary, brain, cardiovascular system, lung, liver, pancreas and other tissues. The abnormal expression of 5-lipoxygenase tends to promote the development of the disease.

LPS Increases 5-LO Expression on Monocytes via an Activation of Akt-Sp1/NF-kappaB Pathways

5-Lipoxygenase (5-LO) plays a pivotal role in the progression of atherosclerosis. Therefore, this study investigated the molecular mechanisms involved in 5-LO expression on monocytes induced by LPS. Stimulation of THP-1 monocytes with LPS (0~3 microg/ml) increased 5-LO promoter activity and 5-LO protein expression in a concentration-dependent manner. LPS-induced 5-LO expression was blocked by pharmacological inhibition of the Akt pathway, but not by inhibitors of MAPK pathways including the ERK, JNK, and p38 MAPK pathways. In line with these results, LPS increased the phosphorylation of Akt, suggesting a role for the Akt pathway in LPS-induced 5-LO expression. In a promoter activity assay conducted to identify transcription factors, both Sp1 and NF-kappaB were found to play central roles in 5-LO expression in LPS-treated monocytes. The LPS-enhanced activities of Sp1 and NF-kappaB were attenuated by an Akt inhibitor. Moreover, the LPS-enhanced phosphorylation of Akt was significantly attenuated in cells pretreated with an anti-TLR4 antibody. Taken together, 5-LO expression in LPS-stimulated monocytes is regulated at the transcriptional level via TLR4/Akt-mediated activations of Sp1 and NF-kappaB pathways in monocytes.

The relevance of leukotriene D4 synthase gene A(-444)C polymorphism to clinical responsiveness of leukotriene receptor antagonist in patients with allergic rhinitis / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the leukotriene D4 synthase gene A (LTD4S A)-444 C polymorphism in persistent allergic rhinitis (AR) of Chinese Han nationality and to evaluate its relevance to clinical responsiveness of leukotriene receptor antagonist.@*METHOD@#There were 150 patients [87 males, 63 females, average age (38 +/- 14)] diagnosed with persistent AR in Allergy clinic in our hospital from March 2010 to March 2012; 146 healthy controls (78 males, 68 females, mean age (39 +/- 12)). We detected LT D4SA-444C polymorphism and allele frequencies with Polymerase Chain Reaction (PCR) and-Restriction Fragment Length polymorphism (RELP). The treatment group received monotherapy leukotriene receptor antagonist (montelukast) for 4 weeks. Urinary leukotriene D4 (LTD4) levels were detected by enzyme-linked immunosorbent assay (ELISA) before and after treatment, respectively. We evaluated anti-leukotriene treatment response according to the changement of symptoms, signs PTS and urinary LTD4. We tested correlation between LT D4S gene-444C allele frequency and the treatment response by multivariate analysis of variance.@*RESULT@#(1) LTD4S gene-444 genotype AA/CC, AC/CC frequency is 70.7% (106/150) and 29.3% (44/150), allele A, C frequencies is 67.3% (101/150) and 32.7% (49/150) in AR group, and LTD4S gene-444 genotype AA/CC, AC/CC frequency is 76.7% (112/146) and 23.3% (34/ 146), allele A, C frequencies is 74.0% (108/146) and 26.0% (38/146) in healthy control group, there is not statistically significant difference between two groups. (2) Among 150 AR patients, compared to patients with AA/CC genotype, the genotype AC/CC patients are younger [average age (35 +/- 9), and (50 +/- 18) respectively, F = 5.891, P < 0.05], with earlier age of onset [(31 +/- 4), and (46 +/- 6) respectively, F = 6.985, P < 0.05], longer course of disease [(8.7 +/- 2.1), and (3.1 +/- 2.0) respectively, F = 11.43, P < 0.05], higher symptom scores (8.2 +/- 0.2; 4.8 +/- 0.3), higher signs score (7.3 +/- 3.3; 3.4 +/- 5.1), and the difference was statistically significant. (3) After 4 weeks of montelukast treatment in AR patients, treatment response of anti-leukotriene in genotype AC/ CC patients is better than those in AA/CC genotype patients (F = 11.01, P < 0.05), the differences of treatment response between two groups were correlated with LTD4 levels in vivo, clinical symptoms and signs of patients.@*CONCLUSION@#In a Chinese Han population the LTD4SA-444B polymorphism might be one of the factors in the clinical response to leukotriene receptor antagonists in persistent AR patients.

Curcumin Inhibits the Activation of Immunoglobulin E-Mediated Mast Cells and Passive Systemic Anaphylaxis in Mice by Reducing Serum Eicosanoid and Histamine Levels

Curcumin is naturally occurring polyphenolic compound found in turmeric and has many pharmacological activities. The present study was undertaken to evaluate anti-allergic inflammatory activity of curcumin, and to investigate its inhibitory mechanisms in immunoglobulin E (IgE)/Ag-induced mouse bone marrow-derived mast cells (BMMCs) and in a mouse model of IgE/Ag-mediated passive systemic anaphylaxis (PSA). Curcumin inhibited cyclooxygenase-2 (COX-2) dependent prostaglandin D2 (PGD2) and 5-lipoxygenase (5-LO) dependent leukotriene C4 (LTC4) generation dose-dependently in BMMCs. To probe the mechanism involved, we assessed the effects of curcumin on the phosphorylation of Syk and its downstream signal molecules. Curcumin inhibited intracellular Ca2+ influx via phospholipase Cgamma1 (PLCgamma1) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappaB (NF-kappaB) pathway. Furthermore, the oral administration of curcumin significantly attenuated IgE/Ag-induced PSA, as determined by serum LTC4, PGD2, and histamine levels. Taken together, this study shows that curcumin offers a basis for drug development for the treatment of allergic inflammatory diseases.

Curcumin Inhibits the Activation of Immunoglobulin E-Mediated Mast Cells and Passive Systemic Anaphylaxis in Mice by Reducing Serum Eicosanoid and Histamine Levels

Curcumin is naturally occurring polyphenolic compound found in turmeric and has many pharmacological activities. The present study was undertaken to evaluate anti-allergic inflammatory activity of curcumin, and to investigate its inhibitory mechanisms in immunoglobulin E (IgE)/Ag-induced mouse bone marrow-derived mast cells (BMMCs) and in a mouse model of IgE/Ag-mediated passive systemic anaphylaxis (PSA). Curcumin inhibited cyclooxygenase-2 (COX-2) dependent prostaglandin D2 (PGD2) and 5-lipoxygenase (5-LO) dependent leukotriene C4 (LTC4) generation dose-dependently in BMMCs. To probe the mechanism involved, we assessed the effects of curcumin on the phosphorylation of Syk and its downstream signal molecules. Curcumin inhibited intracellular Ca2+ influx via phospholipase Cgamma1 (PLCgamma1) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-kappaB (NF-kappaB) pathway. Furthermore, the oral administration of curcumin significantly attenuated IgE/Ag-induced PSA, as determined by serum LTC4, PGD2, and histamine levels. Taken together, this study shows that curcumin offers a basis for drug development for the treatment of allergic inflammatory diseases.

Gastroprotective Effect of Cochinchina momordica Seed Extract in Nonsteroidal Anti-Inflammatory Drug-Induced Acute Gastric Damage in a Rat Model

BACKGROUND/AIMS: The major compounds of Cochinchina momordica seed extract (SK-MS10) include momordica saponins. We report that the gastroprotective effect of SK-MS10 in an ethanol-induced gastric damage rat model is mediated by suppressing proinflammatory cytokines and downregulating cytosolic phospholipase A2 (cPLA2), 5-lipoxygenase (5-LOX), and the activation of calcitonin gene-related peptide. In this study, we evaluated the gastroprotective effects of SK-MS10 in the nonsteroidal anti-inflammatory drug (NSAID)-induced gastric damage rat model. METHODS: The pretreatment effect of SK-MS10 was evaluated in the NSAID-induced gastric damage rat model using aspirin, indomethacin, and diclofenac in 7-week-old rats. Gastric damage was evaluated based on the gross ulcer index by gastroenterologists, and the damage area (%) was measured using the MetaMorph 7.0 video image analysis system. Myeloperoxidase (MPO) was measured by enzyme-linked immunosorbent assay, and Western blotting was used to analyze the levels of cyclooxygenase (COX)-1, COX-2, cPLA2, and 5-LOX. RESULTS: All NSAIDs induced gastric damage based on the gross ulcer index and damage area (p<0.05). Gastric damage was significantly attenuated by SK-MS10 pretreatment compared with NSAID treatment alone (p<0.05). The SK-MS10 pretreatment group exhibited lower MPO levels than the diclofenac group. The expression of cPLA2 and 5-LOX was decreased by SK-MS10 pretreatment in each of the three NSAID treatment groups. CONCLUSIONS: SK-MS10 exhibited a gastroprotective effect against NSAID-induced acute gastric damage in rats. However, its protective mechanism may be different across the three types of NSAID-induced gastric damage models in rats.

Cysteinyl Leukotrienes and Their Receptors; Emerging Concepts

Cysteinyl leukotrienes (cys-LTs) are potent mediators of inflammation derived from arachidonic acid through the 5-lipoxygenase/leukotriene C4 synthase pathway. The derivation of their chemical structures and identification of their pharmacologic properties predated the cloning of their classical receptors and the development of drugs that modify their synthesis and actions. Recent studies have revealed unanticipated insights into the regulation of cys-LT synthesis, the function of the cys-LTs in innate and adaptive immunity and human disease, and the identification of a new receptor for the cys-LTs. This review highlights these studies and summarizes their potential pathobiologic and therapeutic implications.

Short-term intensive atorvastatin therapy improves endothelial function partly via attenuating perivascular adipose tissue inflammation through 5-lipoxygenase pathway in hyperlipidemic rabbits / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Atherosclerosis is a kind of disease with multiple risk factors, of which hyperlipidemia is a major classical risk factor resulting in its pathogenesis and development. The aim of this study was to determine the effects of short-term intensive atorvastatin (IA) therapy on vascular endothelial function and explore the possible mechanisms that may help to explain the clinical benefits from short-term intensive statin therapy.</p><p><b>METHODS</b>After exposure to high-fat diet (HFD) for 8 weeks, the animals were, respectively, treated with IA or low-dose atorvastatin (LA) for 5 days. Blood lipids, C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nitric oxide (NO), endothelin-1 (ET-1), and endothelium-dependent vasorelaxation function were, respectively, measured. mRNA and protein expression of CRP, TNF-α, IL-6, macrophage chemoattractant protein-1 (MCP-1), and 5-lipoxygenase (5-LO) were also evaluated in pericarotid adipose tissue (PCAT) and cultured adipocytes.</p><p><b>RESULTS</b>HFD increased serum inflammatory factor levels; induced significant hyperlipidemia and endothelial dysfunction, including imbalance between NO and ET-1; enhanced inflammatory factors and 5-LO expression; and promoted macrophage infiltration into adipose tissue. Five-day IA therapy could significantly decrease serum inflammatory factor levels and their expression in PCAT; restore the balance between NO and ET-1; and improve endothelial function and macrophage infiltration without significant changes in blood lipids. However, all of the above were not observed in LA therapy. In vitro experiment found that lipopolysaccharide (LPS) enhanced the expression of inflammatory factors and 5-LO in cultured adipocytes, which could be attenuated by short-time (6 hours) treatment of high-dose (5 µmol/L) but not low-dose (0.5 µmol/L) atorvastatin. In addition, inhibiting 5-LO by Cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC, a potent and direct 5-LO inhibitor) could significantly downregulate the above-mentioned gene expression in LPS-treated adipocytes.</p><p><b>CONCLUSION</b>Short-term IA therapy could significantly ameliorate endothelial dysfunction induced by HFD, which may be partly due to attenuating inflammation of PCAT through inhibiting 5-LO pathway.</p>

Association of 5-lipoxygenase expression and clinicopathological factors in colorectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To examine the association of 5-lipoxygenase (5-LOX) expression with clinicopathological factors in colorectal cancer.</p><p><b>METHODS</b>Immunohistochemical stain was used to detect the 5-LOX expression in 52 resected specimens of colorectal cancer. The association between 5-LOX expression and clinicopathological factors was examined.</p><p><b>RESULTS</b>The positive rate of 5-LOX expression in 52 specimens of colorectal carcinoma was 73.1% (38/52). In 41 colorectal cancer specimens with lymph node metastasis, the positive rate of 5-LOX expression was higher than that in the specimens without metastasis (87.8% vs. 18.2%, P<0.05). The positive rate of 5-LOX expression in the specimens with deep infiltration (T3 and T4) was higher than that in the specimens with superficial infiltration (T1 and T2) (81.1% vs. 53.3%, P<0.05). The positive rate of 5-LOX expression in TNM stage III and IIII cancer was higher than that in stage I and II (79.5% vs. 53.8%, P<0.05). The positive rate of 5-LOX expression in cancers of poor differentiation and non-differentiation adenocarcinoma was higher than that of well and moderately differentiated cancer (100% vs. 50.0%, P<0.05). There were no significant differences of 5-LOX expression with tumor size,vascular invasion and peritoneal dissemination.</p><p><b>CONCLUSION</b>5-LOX expression in colorectal carcinoma is closely associated with lymph node metastasis, infiltration depth, differentiation degree and TNM stage.</p>

Expression of 5-lipoxygenase in hippocampal CA1 neuronal damage following global cerebral ischemia in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To determine 5-lipoxygenase (5-LOX) expression and the effect of zileuton, a selective 5-LOX inhibitor,on hippocampal neuron injury induced by global cerebral ischemia in rats.</p><p><b>METHODS</b>Global cerebral ischemia was induced by bilateral common carotid artery occlusion combined with hypotension in rats. 5-LOX expression was detected by Western blot analyses and 5-LOX localization was visualized by immunohistochemistry and double immunofluorescence methods. The 5-LOX inhibitor zileuton (10, 30, 50 mg/kg) was orally administered for 3 d after ischemia.</p><p><b>RESULTS</b>The 5-LOX expression was increased in the ischemic hippocampus on d1-7 (peaked at d3), and 5-LOX protein was primarily localized in neurons and translocated to the nuclei in the hippocampal CA1 region after ischemia. The 5-LOX inhibitor zileuton (30, 50 mg/kg) reduced ischemia-induced hippocampal neurons death 3d after ischemia.</p><p><b>CONCLUSION</b>5-LOX is involved in global cerebral ischemic damage in rats, and the 5-LOX inhibitor zileuton has a protective effect on neuronal damage in the rat hippocampus following global cerebral ischemia.</p>

Benzoxazole Derivative B-98 Ameliorates Dextran Sulfate Sodium-induced Acute Murine Colitis and the Change of T Cell Profiles in Acute Murine Colitis Model / 대한소화기학회지

BACKGROUND/AIMS: The unique role of enzyme 5-lipoxygenase (5-LO) in the production of leukotrienes makes it a therapeutic target for inflammatory bowel disease (IBD). The aim of this study was to evaluate the effects of B-98, a newly synthesized benzoxazole derivatives and a novel 5-LO inhibitor, in a mouse model of IBD induced by dextran sulfate sodium (DSS). METHODS: C57BL/6 mice were randomly assigned to four groups: normal control, DSS colitis (DSS+saline), low dose B-98 (DSS+B-98 20 mg/kg) and high dose B-98 (DSS+B-98 100 mg/kg). B-98 was administered with 3% DSS intraperitoneally. The severity of the colitis was assessed via the disease activity index (DAI), colon length, and histopathologic grading. The production of inflammatory cytokines interleukin (IL)-6 was determined by RT-PCR. Th cells were examined for the proportion of Th1 cell, Th2 cell, Th9 cell, Th17 cell and Treg cell using intracellular cytometry. RESULTS: The B-98 group showed lower DAI, less shortening of the colon length and lower histopathologic grading compared with the DSS colitis group (p<0.01). The expression of IL-6 in colonic tissue was significantly lower in the B-98 groups than the DSS colitis group (p<0.05). The cellular profiles revealed that the Th1, Th9 and Th17 cells were increased in the DSS colitis group compared to the B-98 group (p<0.05). CONCLUSIONS: Our results suggest that acute intestinal inflammation is reduced in the group treated with B-98 by Th1, Th9 and Th17 involved cellular immunity.

Protective mechanisms of sevoflurane against one-lung ventilation-induced acute lung injury: role of cyclooxygenase-2 and 5-lipoxygenase pathways / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the protective mechanisms of sevoflurane against acute lung injury (ALI) induced by one-lung ventilation (OLV) in view of cyclooxygenase-2 (COX2) and 5-lipoxygenase (5-LOX) pathways.</p><p><b>METHOD</b>Eighteen healthy Japanese white rabbits were randomized into sham-operated group (S group), OLV group (O group) and OLV + sevoflurane group (OS group). COX2 and 5-LOX protein and mRNA expressions in the lungs were detected by Western blotting and real-time PCR, respectively. Prostaglandin I2 (PGI2), thromboxane A2 (TXA2) and leukotrienes B2 (LTB2) in the lung tissues were quantified with ELISA. Histological scores and lung wet/dry weight (W/D) ratios were determined for lung injury assessment.</p><p><b>RESULTS</b>COX2 and 5-LOX protein and mRNA expressions and the contents of LTB2, TXA2 and PGI2 in the lungs, lung W/D ratio and histological scores were significantly higher while PGI2/TXA2 ratio was significantly lower in O group and OS group than in S group (P<0.05). Compared with those in O group, COX2 and 5-LOX expressions, pulmonary contents of LTB2, TXA2 and PGI2, and lung W/D ratio all decreased significantly but PGI2/TXA2 ratio was significantly elevated in OS group (P<0.05).</p><p><b>CONCLUSION</b>OLV may activate COX2 and 5-LOX pathways to result in increased production of arachidonic acid metabolites. Sevoflurane protects against OLV-induced ALI probably by reducing AA metabolites and regulating PGI2/TXA2 ratio through inhibitions of COX2 and 5-LOX pathways.</p>