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Drug-induced bronchospasm
Published in Philippe Camus, Edward C Rosenow, Drug-induced and Iatrogenic Respiratory Disease, 2010
K Suresh Babu, Jaymin Morjaria
Cysteinyl leukotrienes (Cys LT) are derived from arachidonic acid via the 5-lipoxygenase (5-LO) pathway. The cellular biosynthesis of leukotrienes (LTs) involves a protein named FLAP (five lipoxygenase activating protein) which transports arachidonic acid into the cytosol to be acted on by the enzyme 5-LO. Sequential catalytic action of 5-LO on arachidonic acid yields LTA4, which is further hydroxylated to LTB4 or converted into the first of the cysteinyl LTs, LTC4, by LTC4 synthase. LTC4 is exported to the extracellular space where it forms LTD4, which in turn is cleaved to form the 6-cysteinyl analogue of LTC4 known as LTE4. The cysteinyl LTs exert their biological action by binding to two types of G-protein coupled 7-transmembrane receptors, Cys LT1 and Cys LT2.
Imaging of Cardiovascular Disease
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Aleksandra Kalinowska, Lawrence W. Dobrucki
Active inflammatory cells produce a leukotriene B4 (LTB4) and secrete it as a potent chemotactic agent. In leukocytes, the leukotriene induces the adhesion and activation of the cells on the endothelium, while in neutrophils, LTB4 induces the formation of reactive oxygen species and the release of lysosome enzymes by these cells, contributing to the progression of inflammatory processes. Recently, a radiolabeled LTB4 receptor antagonist, 99mTc-RP517, has been developed for in vivo imaging of acute inflammation or infection. The tracer 99mTc-RP517 has a unique ability to label white blood cells in vivo after intravenous injection and has been noted to selectively localize to areas of inflammation (Serhan and Prescott 2000).
Drug Discovery in Microbial Metabolites: The Search for Microbial Products with Bioactive Properties
Published in Nduka Okafor, Benedict C. Okeke, Modern Industrial Microbiology and Biotechnology, 2017
Nduka Okafor, Benedict C. Okeke
Leukotrienes are produced by a variety of white blood cells. Among them, LTB4 is a powerful mediator of inflammatory reactions causing the loss of granules in granule- containing white blood cells leading to allergic reactions. LTB4 antagonists may therefore be useful in treating inflammatory diseases. In the search for LTB4 antagonists, labeled LTB4 is incubated with a suspension of membrane from white blood cells and the test microbial metabolite. After the incubation, the bound labeled LTB4 is separated from the free ligand by filtration and centrifugation.
Cecropia pachystachya Trécul: identification, isolation of secondary metabolites, in silico study of toxicological evaluation and interaction with the enzymes 5-LOX and α-1-antitrypsin
Published in Journal of Toxicology and Environmental Health, Part A, 2022
Penina Sousa Mourão, Rafael de Oliveira Gomes, Clara Andrezza Crisóstomo Bezerra Costa, Orlando Francisco da Silva Moura, Herbert Gonzaga Sousa, George Roberto Lemos Martins Júnior, Danniel Cabral Leão Ferreira, Antônio Luiz Martins Maia Filho, Johnnatan Duarte de Freitas, Mahendra Rai, Francisco Das Chagas Alves Lima, Antonio Euzébio Gourlart Santana, Mariana Helena Chaves, Wellington Dos Santos Alves, Valdiléia Teixeira Uchôa
Plants with antioxidant and anti-inflammatory pharmacological activities are highly targeted in studies involving the search for alternative treatments for chronic obstructive pulmonary disease (COPD) (Mourão et al. 2021). CPOD constitutes a group of chronic respiratory diseases, characterized by persistent lung inflammation, airway obstruction, and destruction of the lung alveoli (Dourado et al. 2006; Luna et al. 2020). This inflammation is marked by the presence of inflammatory cells such as lymphocytes, macrophages and neutrophils, and by interleukins 1β and 6 (Prasher et al. 2020). Leukotrienes, lipid markers of inflammation derived from arachidonic acid, are also related to lung inflammation. In leukotrienes biosynthesis the enzyme 5-lipoxygenase (5-LOX), acts as a catalyst and is expressed in various polymorphonuclear leukocytes (neutrophils and eosinophils), macrophages and lymphocytes, these being previously cited as inflammatory cells identified in COPD (Olsen and Martins 2012; Rådmark and Samuelsson 2008). The main causative factors for COPD are active and passive smoking, inhalation of noxious gases, small particles (PM2.5), and genetic deficiency of α-1-antitrypsin enzyme (Mourão et al. 2021).
Neuroprotective effect of peanut against oxidative stress in streptozotocin-induced diabetic rats
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Norhan H. Mohamed, Hassan Elsayad, Yasser M. Elsherbini, Mohamed E. Abdraboh
Literature survey indicated the role of 5-lipoxygenase upregulation in promoting lipid peroxidation in an in vitro model as well as in brain tissue [38,39]. On the other hand, it is responsible for the transformation of essential fatty acids into leukotrienes, which play a pivotal role in stimulating immune cell chemotaxis and induction of inflammatory responses in patients with asthma and allergy [40].
Biocompatibility of subcutaneously implanted marine macromolecules cross-linked bio-composite scaffold for cartilage tissue engineering applications
Published in Journal of Biomaterials Science, Polymer Edition, 2018
A. S. Sumayya, G. Muraleedhara Kurup
The inflammatory response related to anesthetized surgery and to trauma (accidental or unanesthetized injury) could be considered a surgical inflammation. In the immune phase of the inflammatory response, the interstitium is infiltrated first by platelets and later by leukocytes. Acute inflammation following surgery is the site for abundant production of ROS by phagocytic NADPH oxidase [46]. Natural biodegradable polymer scaffold can prevent the chronic inflammation, since it permits the scaffolds to retain their structural stability for a longer time after implantation [47]. COX and LOX are two significant enzymes which catalyze the formation of mediators involved in the inflammatory process. COX pathway converts arachidonic acid into the prostaglandins. Two types of cyclooxygenases (COX-1 and COX-2) have been identified as the key enzymes regulating the production of prostaglandins. COX-2 is an inducible enzyme whose expression is enhanced in response to inflammatory stimuli. LOX enzyme catalyzes the production of leukotrienes from arachidonic acid, which is also involved in the inflammatory process [48]. Nitric oxide (NO) is a signaling molecule that plays a key role in the pathogenesis of inflammation. It gives an anti-inflammatory effect under normal physiological conditions. On the other hand, NO is considered as a pro-inflammatory mediator that induces inflammation due to over production in abnormal situations [49]. NO is extensively produced by most of the cells of immune system such as dendritic cells, Natural Killer cells, mast cells and macrophages up on a pro-inflammatory stimulation. Among various isoforms of nitric oxide synthase, inducible nitric oxide synthase (iNOS) is responsible for the formation of NO in immune cells [50]. HACF containing chitosan and fucoidan plays a significant role in the control of acute and chronic inflammation via enzyme inhibition and inhibition of the complement cascade [51,52]. In the present study, activities of major inflammatory mediators such as COX, 5/15-LOX and NOS were found to be significantly increased in HACF and SMI implanted groups when compared to control after 1st week of implantation surgery. But after 4th and 8th week, their levels were found to be normal indicating decreased inflammatory response due to anti-inflammatory properties exerted by HACF scaffold (Figure 6A–C).