Search results for "Lipoxygenase"
showing 10 items of 72 documents
Monohydroxylated fatty acid substrate specificity of human leukocyte 5-lipoxygenase and ω-hydroxylase
1988
Various monohydroxylated fatty acids were synthesized from eicosapolyenoic acids, namely arachidonic (20:4 omega-6), timnodonic (20:5 omega-3), dihomogammalinolenic (20:3 omega-6) and mead (20:3 omega-9) acids. 12-Hydroxy derivatives, as well as 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT), were produced with platelets as the enzyme source, and 15-hydroxy derivatives were produced by soya bean lipoxygenase treatment. Each monohydroxylated fatty acid was incubated with human leukocytes in the presence or absence of the calcium ionophore A23187, and dihydroxylated products were analysed by h.p.l.c. 12-Hydroxy derivatives of 20:4 omega-6, 20:5 omega-3 and 20:3 omega-9 were similarly oxygenat…
LTB4 is present in exudative pleural effusions and contributes actively to neutrophil recruitment in the inflamed pleural space
2004
SUMMARY The pleural space is a virtual compartment between the lung and chest wall that becomes filled with fluid and inflammatory cells during a variety of respiratory diseases. Here, we study the potential role of the eicosanoid metabolite leukotriene B4 (LTB4) in disparate diseases leading to acute (pneumonia) or chronic (tuberculosis, cancer) inflammation of the pleural space. LTB4 concentrations were significantly higher in pleural fluid due to pneumonia, tuberculosis and cancer with respect to congestive heart failure and correlated with neutrophil elastase, which is used as an indication of state of activation of neutrophils in the pleural space. Moreover, pleural LTB4 was biological…
Inhibition of leukocyte functions by the alkaloid isaindigotone from Isatis indigotica and some new synthetic derivatives.
2001
The alkaloid isaindigotone (1a) and seven derivatives have been synthesized to study their influence on several leukocyte functions and the generation of inflammatory mediators. Isaindigotone (1a) was found to be a scavenger of superoxide generated either by the hypoxanthine/xanthine oxidase system or stimulated human neutrophils. Isaindigotone (1a) and its acetylated derivative (1b) also inhibited 5-lipoxygenase activity and leukotriene B(4) production in these cells, whereas none of the compounds affected degranulation. In RAW 264.7 macrophages stimulated with lipopolysaccharide, synthetic derivatives exerted higher inhibitory effects on prostaglandin E(2) (PGE(2)) and nitric oxide (NO) g…
Synthesis and evaluation of 2-tosylamino and 2-tosyliminopyrimidine derivatives as inhibitors of some leukocyte functions
2003
Abstract We have studied the potential anti-inflammatory effects of 20 2-tosylamino and 2-tosyliminopyrimidine new derivatives in human neutrophils. We have evaluated their interference with some leukocyte functions and 5-lipoxygenase activity. All the compounds reduced neutrophil degranulation process at concentrations in the μM range. Besides, compounds with a phenolic substitution inhibited leukotriene B 4 biosynthesis in neutrophils and decreased the cell-free 5-lipoxygenase activity. This study demonstrates that 2-tosylamino and 2-tosyliminopyrimidine derivatives can reduce the activation of neutrophil cells which may have relevance for the modulation of the inflammatory response.
Arachidonate 5-lipoxygenase (ALOX5) gene polymorphism is associated with Alzheimer's disease and body mass index
2016
IF 2.126; International audience; Dementias of old age, in particular Alzheimer's disease (AD), pose a growing threat to the longevity and quality of life of individuals as well as whole societies world-wide. The risk factors are both genetic and environmental (lifestyle) and there is an overlap with similar factors predisposing to cardiovascular diseases (CVD). Using a case control genetic approach, we have identified a SNP (rs10507391) in ALOX5 gene, previously associated with an increased risk of stroke, as a novel genetic risk factor for AD. ALOX5 gene encodes a 5'-lipoxygenase (5'-LO) activating protein (FLAP), a crucial component of the arachidonic acid/leukotriene inflammatory cascad…
SARS CoV2 infection _The longevity study perspectives
2021
Graphical abstract
Relaxant activity of three aporphine alkaloids from Annona cherimolia on isolated aorta of rat.
1995
Abstract In the present study we tested the relaxant effect of three aporphine alkaloids—roemerine, anonaine and dehydroroemerine—isolated from the roots of Annona cherimolia, on isolated strips of rat thoracic aorta. All compounds completely relaxed KCl- and noradrenaline-induced contractions with different potencies depending on their structural characteristics. The experiments, carried out in Ca2+-free medium using two different agonists (noradrenaline and caffeine) which mobilize calcium intracellularly by different mechanisms of action, showed that the alkaloids made no contribution to intracellular calcium processes. The present study provides evidence that the relaxant effects produc…
Role of cyclooxygenae-2 and 5-lypoxygenase polymorphisms in Alzheimer's disease in a population from northern Italy:implications for pharmacogenomics
2010
Alzheimer's disease (AD) is a neurodegenerative disorder clinically characterized by cognitive deficit with progressive worsening of memory. Recent data indicate that neurons, as well as other brain cells, can express enzymes such as cyclooxygenases (COXs) and 5-lipoxygenase (5-LO) which are considered important in inflammatory cells. Moreover, it has been demonstrated that COX-2 and 5-LO enzymes play a considerable role in the pathophysiology of AD. In order to assess the possible role of COX-2 and 5-LO single nucleotide polymorphisms (SNPs) in AD, we examined their distribution in 341 AD patients and 190 controls from Northern Italy. A significant difference was observed in the distributi…
1-imidazolyl(alkyl)-substituted di- and tetrahydroquinolines and analogues: syntheses and evaluation of dual inhibitors of thromboxane A(2) synthase …
2000
A series of 1-imidazolyl(alkyl)-substituted quinoline, isoquinoline, naphthalene, benzo[b]furan, and benzo[b]thiophene derivatives was synthesized as dual inhibitors of thromboxane A(2) synthase (P450 TxA(2)) and aromatase (P450 arom). Dual inhibition of these enzymes could be a novel strategy for the treatment of mammary tumors and the prophylaxis of metastases. The most potent dual inhibitors, 5-(2-imidazol-1-ylethyl)-7,8-dihydroquinoline (31) (P450 TxA(2): IC(50) = 0.29 microM; P450 arom: IC(50) = 0.50 microM) and its 5, 6-saturated analogue 30 (P450 TxA(2): IC(50) = 0.68 microM; P450 arom: IC(50) = 0.38 microM), showed a stronger inhibition of both target enzymes than the reference comp…
Suppression of leukotriene B4 and tumour necrosis factor alpha release in acute inflammatory responses by novel prenylated hydroquinone derivatives.
1998
A series of prenyl hydroquinone derivatives synthesized as structural analogs of marine products were tested for their effects on inflammatory responses in vitro and in vivo. 2-Prenyl-1,4-hydroquinone (H1), 2-diprenyl-1,4-hydroquinone (H2), 2-triprenyl-1,4-hydroquinone (H3) and 2-tetraprenyl-1,4-hydroquinone (H4) scavenged reactive oxygen species and inhibited 5-lipoxygenase (5-LO) activity in human neutrophils. The inhibition of 5-LO activity was demonstrated in vivo in the mouse air pouch injected with zymosan and arachidonic acid-induced ear inflammation. The four compounds suppressed the production of tumour necrosis factor alpha (TNFalpha) in J774 cells stimulated with lipopolysacchari…