Interference in Macrophage Balance (M1/M2): The Mechanism of Action Responsible for the Anti-Inflammatory Effect of a Fluorophenyl-Substituted Imidazole.

Traditionally, the treatment of inflammatory conditions has focused on the inhibition of inflammatory mediator production; however, many conditions are refractory to this classical approach. Recently, an alternative has been presented by researchers to solve this problem: The immunomodulation of cells closely related to inflammation. Hence, macrophages, a critical key in both innate and acquired immunity, have been presented as an alternative target for the development of new medicines. In this work, we tested the fluorophenyl-imidazole for its anti-inflammatory activity and possible immunomodulatory effect on RAW 264.7 macrophages. We also evaluated the anti-inflammatory effect of the compound, and the macrophage repolarization to M2 was confirmed by the ability of the compound to reduce the M1 markers TNF-α, IL-6, MCP-1, IL-12p70, IFN-γ, and TLR4, the high levels of p65 phosphorylated, iNOS and COX-2 mRNA expression, and the fact that the compound was not able to induce the production of M1 markers when used in macrophages without lipopolysaccharide (LPS) stimulation. Moreover, fluorophenyl-imidazole had the ability to increase the M2 markers IL-4, IL-13, CD206, apoptosis and phagocytosis levels, arginase-1, and FIZZ-1 mRNA expression before LPS stimulation. Similarly, it was also able to induce the production of these same M2 markers in macrophages without being induced with LPS. These results reinforce the affirmation that the fluorophenyl-imidazole has an important anti-inflammatory effect and demonstrates that this effect is due to immunomodulatory activity, having the ability to trigger a repolarization of macrophages from M1 to M2a. These facts suggest that this molecule could be used as an alternative scaffold for the development of a new medicine to treat inflammatory conditions, where the anti-inflammatory and proregenerative properties of M2a macrophages are desired.

The anti-inflammatory activity of 2-iminothiazolidines: evidence for macrophage repolarization.

Nowadays, macrophages are recognized as key cells involved in chronic inflammatory conditions, and play central roles in all inflammatory diseases and cancer. Due to their extensive involvement in the pathogenesis of inflammatory diseases, they are now considered a relevant therapeutic target in the development of new therapeutic strategies. 2-Iminothiazolidines are associated with important anti-inflammatory activity and represent a rich source for the development of new drugs and treatments. Our research focuses on evaluating the anti-inflammatory capacity of these compounds and their relationship with M1/M2 macrophage polarization. The results demonstrate that 2-iminothiazolidines have the capacity to decrease the levels of anti-inflammatory biomarkers, such as cytokines (IL-1ß, TNF-α, and IL-6), nitric oxide synthase (with impact on NOx production), and COX-2, following a significant decline in NF-kB activation. We also observed an increase in levels of anti-inflammatory cytokines (IL-4 and IL-13) in the in vitro model of RAW 264.7 macrophages induced by LPS. Moreover, this is the first report, suggesting that the anti-inflammatory activity of 2-iminothiazolidines is associated with the ability to enhance phagocytosis, increase Arginase-1 and CD206 expression, and increase the secretion of IL-10. Furthermore, an in vivo study using the acute lung injury model induced by LPS proved the anti-inflammatory activity of a selected 2-iminothiazolidine, named methyl 2-(benzoylimino)-3-methyl-4-(4-nitrobenzyl)-1,3-thiazolidine-4-carboxylate. All these results, taken together, lead us to hypothesize that the mechanism of anti-inflammatory effect observed with this compound is closely related to the ability of this compound to produce macrophage repolarization, from the M1 to the M2 phenotype.

Inflammatory biomarkers on an LPS-induced RAW 264.7 cell model: a systematic review and meta-analysis.

INTRODUCTION: Several experimental models have been designed to promote the development of new anti-inflammatory drugs. The in vitro model using RAW 264.7 cells has been widely used. However, there is still no consensus on which inflammatory mediators should initially be measured to screen for possible anti-inflammatory effects. To determine the rationality of measuring inflammatory mediators together with NO, such as the levels of tumor necrosis factor (TNF)-α, and interleukins (IL) 1ß and 6, we carried out this systematic review (SR) and meta-analysis (MA). METHODOLOGY: We conducted this SR and MA in accordance with the Preferred Reporting of Systematic Reviews and Meta-Analysis and the Cochrane Handbook for Systematic Reviews of Intervention. This review was registered in the Open Science Framework ( https://doi.org/10.17605/OSF.IO/8C3HT ). RESULTS: LPS-induced cells produced high NO levels compared to non-LPS induced, and this production was not related to cell density. TNF-α, IL-1ß, and IL-6, also showed high levels after cells had been stimulated with LPS. Though with some restrictions, all studies were reliable, as the risk of bias was detected in the test compounds and systems. CONCLUSION: Measurement of NO levels may be sufficient to screen for possible anti-inflammatory action in the context of LPS-induced RAW 264.7 cells.

Investigation of phenolic compounds, antioxidant and anti-inflammatory activities in stingless bee honey (Meliponinae).

The objective of this study was to investigate and quantify the composition phenolic, reducing capacity, the free radical scavenging activity, as well as, the anti-inflammatory effect evaluated against lipopolysaccharides-stimulated RAW264.7 macrophages through modulation of inflammatory mediators, in eight stingless bee honey types (Meliponinae) from southern Brazil. Stingless bee honey did not show to be cytotoxic at the tested concentrations (1-100 µM) and also reduced nitric oxide and the secretion of the pro-inflammatory cytokine in the inflamed macrophages. Two honey samples showed the ability to increase the secretion of anti-inflammatory cytokine (interleukin-10), suggesting a significant anti-inflammatory effect. All these findings indicate that stingless bee honey could be an important source of natural compounds presenting anti-inflammatory and antioxidant effect, which could would provide health benefits when included in the diet.

Evidence That the Anti-Inflammatory Effect of Rubiadin-1-methyl Ether Has an Immunomodulatory Context.

BACKGROUND: In spite of the latest therapeutic developments, no effective treatments for handling critical conditions such as acute lung injuries have yet been found. Such conditions, which may result from lung infections, sepsis, multiple trauma, or shock, represent a significant challenge in intensive care medicine. Seeking ways to better deal with this challenge, the scientific community has recently devoted much attention to small molecules derived from natural products with anti-inflammatory and immunomodulatory effects. AIMS: In this context, we investigated the anti-inflammatory effect of Rubiadin-1-methyl ether isolated from Pentas schimperi, using an in vitro model of RAW 264.7 macrophages induced by LPS and an in vivo model of acute lung injury (ALI) induced by LPS. METHODS: The macrophages were pretreated with the compound and induced by LPS (1 µg/mL). After 24 h, using the supernatant, we evaluated the cytotoxicity, NOx, and IL-6, IL-1ß, and TNF-α levels, as well as the effect of the compound on macrophage apoptosis. Next, the compound was administered in mice with acute lung injury (ALI) induced by LPS (5 mg/kg), and the pro- and anti-inflammatory parameters were analyzed after 12 h using the bronchoalveolar lavage fluid (BALF). RESULTS: Rubiadin-1-methyl ether was able to inhibit the pro-inflammatory parameters studied in the in vitro assays (NOx, IL-6, and IL-1ß) and, at the same time, increased the macrophage apoptosis rate. In the in vivo experiments, this compound was capable of decreasing leukocyte infiltration; fluid leakage; NOx; IL-6, IL-12p70, IFN-γ, TNF-α, and MCP-1 levels; and MPO activity. In addition, Rubiadin-1-methyl ether increased the IL-10 levels in the bronchoalveolar lavage fluid (BALF). CONCLUSIONS: These findings support the evidence that Rubiadin-1-methyl ether has important anti-inflammatory activity, with evidence of an immunomodulatory effect.