Role of nitric oxide in inflammatory diseases

Abstract

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. NO is synthesized and released into the endothelial cells by the help of NOSs that convert arginine into citrulline producing NO in the process. Oxygen and NADPH are necessary co-factors in such conversion. NO is believed to induce vasodilatation in cardiovascular system and furthermore, it involves in immune responses by cytokine-activated macrophages, which release NO in high concentrations. In addition, NO is a potent neurotransmitter at the neuron synapses and contributes to the regulation of apoptosis. NO is involved in the pathogenesis of inflammatory disorders of the joint, gut and lungs. Therefore, NO inhibitors represent important therapeutic advance in the management of inflammatory diseases. Selective NO biosynthesis inhibitors and synthetic arginine analogues are proved to be used for the treatment of NO-induced inflammation. Finally, the undesired effects of NO are due to its impaired production, including in short: vasoconstriction, inflammation and tissue damage.

Anti‐inflammatory and anti‐insulin resistance activities of aqueous extract from Anoectochilus burmannicus

“…The overproduction of these mediators has been related in several diseases caused by inflammation, such as obesity‐related insulin resistance (Xu et al., 2003), rheumatoid arthritis (Shrivastava et al., 2015), cancer (Chua, Chong, Liauw, Zhao, & Morris, 2012), atherosclerosis (Hamirani et al., 2014), and hepatitis (Connoy, Turner, & Nunez, 2011). Increasing in NO in the activated macrophages could induce a host‐defense mechanism and cellular or tissues damages leading to an inflammation (Ialenti, Ianaro, Moncada, & Di Rosa, 1992; Sampaio et al., 2013; Sharma, Al‐Omran, & Parvathy, 2007). Moreover, the level of NO has been used as a marker for the diagnosis and monitoring of response to anti‐inflammatory therapy (Zitt, 2005).…”

“…Inducible NO synthase (iNOS), a key enzyme in NO production, is highly expressed during inflammation (Sharma et al., 2007). Several phenolic compounds, such as gallic acid, vanillic acid, coumaric acid, and ferulic acid, have been shown to directly inhibit the iNOS gene and protein expressions leading to the decreased level of NO production (Wang & Mazza, 2002).…”

Synthesis of N-Pyridin-2-ylmethyl and N-Quinolin-2-ylmethyl ­Substituted Ethane-1,2-diamines

“…A solution of 4 (1.00 g, 4.90 mmol) in 48% HBr (20 mL) was heated to reflux for 4 h. The mixture was cooled to r.t. and the solid was filtered and recrystallized from EtOH to give 6-hydroxyquinoline-2-carboxylic acid 5 as a white solid (0.70 g, 84.3% yield, 98.2% purity). 1 …”

“…After removal of solvent, the crude product was purified by silica gel chromatography, eluting with chloroform/methanol (20:1) to afford 9 as a colorless semi-solid (0.77 g, 85% yield, 97.7% purity), 1 …”

“…It plays important roles in a variety of physiological functions. [1][2][3][4][5][6][7] At low concentrations, NO plays its normal physiological roles as an anti-inflammatory, neurological signaling, and vasodilative agent. At high concentrations, NO is pro-inflammatory and pro-apoptotic.…”