Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry - Volume 11, Issue 2, 2012

Macrobiomolecular treatments for ocular inflammatory diseases have been described in a previous review. This article mainly discusses the application of small molecules in uveitis therapy, which includes corticosteroids, salicylic acid (aspirin), metabolite analogs, and anti-oxidative agents. Additionally, we update recent advances in peptide and nucleic acid related therapies, and focus mainly on the calcineurin inhibitor, cyclosporine, oral tolerant retinal proteins/peptides, gene therapy and ribonucleic acid interference strategies. We classify these immunomodulatory agents by their molecular signatures and highlight the molecular structure and mechanisms of function. These developments in understanding molecular mechanisms of the diseases, with the advent of new technologies, advance current therapeutic approaches. The future direction is to tailor treatments to individual patients in order to provide the safest and most effective therapies for ocular inflammatory diseases.

Sepsis is a systemic inflammatory response syndrome with a suspected or proven infection caused by any pathogen or a clinical syndrome associated with a high probability of infection. The definition of septic shock includes sepsis-induced hypotension despite adequate fluid resuscitation, along with the presence of organ perfusion abnormalities, and ultimately cell dysfunction. As the most common causes of morbidity and mortality in intensive care units worldwide, the societal and economic costs of sepsis and septic shock are staggering. The molecular pathophysiology of sepsis and septic shock and the complex roles played by cytokines, reactive oxygen and nitrogen species, and eicosanoids remain controversal despite decades of study. The lipid A part of lipopolysaccharide, also known as endotoxin, is the most potent microbial mediator of the pathogenesis of sepsis and septic shock. 20-Hydroxyeicosatetraenoic acid (20-HETE) is a vasoconstrictor ω-hydroxylation product of arachidonic acid that is produced by cytochrome P450 (CYP) enzymes, mainly by CYP4A and CYP4F isoforms. Studies from our laboratory and others have provided substantial evidence that administration of a synthetic analog of 20-HETE, N-[20-hydroxyeicosa-5(Z),14(Z)-dienoyl]glycine, prevents endotoxininduced vascular hyporeactivity, hypotension, and mortality associated with increased formation of inducible nitric oxide synthase-derived nitric oxide (NO) and cyclooxygenase-2-derived vasodilator prostanoids as well as decreased expression and activity of CYP4A1 and 20-HETE production in a rodent model of septic shock. CYP4A- and CYP4F-derived 20- HETE is also a proinflammatory mediator of endotoxin-induced acute systemic inflammation. In this review, we will present an overview of our current understanding of the interactions between prostanoids, NO, and 20-HETE in sepsis, and provide a rationale for the development of synthetic 20-HETE analogs for the treatment of sepsis and septic shock.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a group of agents important for their analgesic, anti-inflammatory, and antipyretic properties. This study presents several approaches to predict and elucidate new molecular structures of NSAIDs based on 36 known and proven anti-inflammatory compounds. Based on 36 known NSAIDs the mean value of Log P is found to be 3.338 (standard deviation= 1.237), mean value of polar surface area is 63.176 Angstroms2 (standard deviation = 20.951 A2), and the mean value of molecular weight is 292.665 (standard deviation = 55.627). Nine molecular properties are determined for these 36 NSAID agents, including Log P, number of -OH and -NHn, violations of Rule of 5, number of rotatable bonds, and number of oxygens and nitrogens. Statistical analysis of these nine molecular properties provides numerical parameters to conform to in the design of novel NSAID drug candidates. Multiple regression analysis is accomplished using these properties of 36 agents followed with examples of predicted molecular weight based on minimum and maximum property values. Hierarchical cluster analysis indicated that licofelone, tolfenamic acid, meclofenamic acid, droxicam, and aspirin are substantially distinct from all remaining NSAIDs. Analysis of similarity (ANOSIM) produced R = 0.4947, which indicates low to moderate level of dissimilarity between these 36 NSAIDs. Non-hierarchical K-means cluster analysis separated the 36 NSAIDs into four groups having members of greatest similarity. Likewise, discriminant analysis divided the 36 agents into two groups indicating the greatest level of distinction (discrimination) based on nine properties. These two multivariate methods together provide investigators a means to compare and elucidate novel drug designs to 36 proven compounds and ascertain to which of those are most analogous in pharmacodynamics. In addition, artificial neural network modeling is demonstrated as an approach to predict numerous molecular properties of new drug designs that is based on neural training from 36 proven NSAIDs. Comprehensive and effective approaches are presented in this study for the design of new NSAID type agents which are so very important for inhibition of COX-2 and COX-1 isoenzymes.

Endotoxemic shock is a systemic inflammatory response that is associated with increased nitric oxide (NO) production by inducible NO synthase (iNOS) which contributes to hypotension, vascular hyporeactivity, and multiple organ failure. Oxidative stress (OS) is a major contributing factor to high morbidity and mortality in endotoxemic shock. We have previously demonstrated that endotoxin-induced fall in blood pressure is associated with an increase in nitrite levels in serum, kidney, heart, thoracic aorta (TA), and superior mesenteric artery (SMA), a decrease in malondialdehyde (MDA) levels in the kidney, heart, TA, and SMA, and an increase in myeloperoxidase (MPO) activity in the heart and TA, but a decrease in the kidney and SMA of rats. In this study, we further investigated whether increased production of iNOS-derived NO contributes to endotoxin induced changes in the biomarkers of OS in the liver, lungs, brain, spleen, and femoral artery (FA) of rats. Endotoxin-induced increase in nitrite production was associated with a decrease in reduced glutathione levels in the liver, lungs, brain, spleen, and FA. MPO activity was increased by endotoxin in the lungs, spleen, and FA, but decreased in the liver and brain. MDA levels were increased by endotoxin in the lungs, brain, spleen, and FA, but were decreased in the liver. Activities of superoxide dismutase and catalase were decreased in the liver and spleen, but were increased in the lungs, brain, and FA. These effects of endotoxin were prevented by a selective iNOS inhibitor, phenylene-1,3-bis[ethane-2-isothiourea] dihydrobromide. These data suggest that iNOS-derived NO mediates selective organ-specific effects of endotoxin on OS.

The development of antibodies for diagnostic and therapeutic applications in inflammatory diseases is a major focus for biotechnology and pharmaceutical companies. Production of monoclonal antibodies requires the development of fast, high-throughput methodologies for screening and selecting appropriate candidate antibodies for development. Capture (sandwich) enzyme linked immunosorbent assay (ELISA) provides a quick and reliable method that could be used for hybridoma screening of potential candidates accompanied with surface plasmon resonance (SPR) biosensor technology for identifying high affinity biomolecular interactions. A sensitive, cost-effective, robust and accurate capture ELISA for detection of murine monoclonal antibodies in culture supernatants was developed. This assay was optimized for high sensitivity and specificity with a capture anti-mouse polyclonal antibody. Using serial dilutions of a defined murine IgG antibody, a linear dose-response was observed between 2 and 1200 ng/ml antibody with a coefficient of determination r2 of 0.98. The detection limit of the assay was established as 2ng/ml (12.5pM). A similar concentration-dependent doseresponse was also observed using serial dilutions of antibody-containing supernatants from anti-alpha glycophorinproducing hybridomas (detection limit 1:2000). Specific capture of antibodies from supernatants in a similar setting was also confirmed using SPR biosensor technology and correlated well with the immunoassay results. The latter technology can be performed in order to provide quick screening results and kinetic analysis of antibody binding interactions aiming at identifying candidates with high affinity and specificity.

A series of structurally novel compounds possessing 2-phenylpiperazin-1-yl nicotinamide template was synthesized and evaluated for neuropathic pain activity. After the assessment of neurotoxicity and peripheral analgesic activity, the compounds were evaluated in a peripheral neuropathic pain model, the chronic constriction injury (CCI) to assess their antiallodynic and antihyperalgesic potential. Studies carried out to assess the underlying mechanism revealed that the compounds (5 and 6) suppressed the inflammatory component of the neuropathic pain and inhibited oxidative and nitrosative stress.

This study was designed to evaluate and compare the inhibitory property of extracts of Andrographis paniculata leaves [methanolic (AP1), hydroalcoholic (AP2), successive water (AP3)] and non-leaves [methanolic (AP4), hydroalcoholic (AP5), successive water (AP6)] towards inflammatory mediators (NO, IL-1 beta, IL-6, TNF alpha, PGE2, TXB2 and LTB4). Stimulant induced J774A.1 murine macrophages and HL-60 promyelocytic leukemic cells were used to study the inhibitory potential of extracts of A. paniculata on inflammatory mediators. Results revealed that AP1 and AP4 exhibited inhibitory effect on all the inflammatory mediators excluding PGE2 and TNF-alpha. AP2 and AP5 exhibited inhibitory effect towards IL-1 beta, TXB2 and did not show inhibitory effect towards other mediators. However, AP3 and AP6 failed to show inhibitory activity against any of the inflammatory mediators at the tested concentrations. Further, we observed that the magnitude of inhibitory effect displayed by A. paniculata extracts depends on the andrographolide content, although, it does not appear to influence the inhibitory effect towards LTB4 production.