The in vitro anti-inflammatory activity of N-antipyrine-3,4-dichloromaleimide derivatives is due to an immunomodulatory effect on cytokines environment.

BACKGROUND AND AIM: Inflammation is the immune response to a harmful stimulus, and its purpose is to destroy foreign agents so that the affected site can be repair. When uncontrolled or unresolved, inflammation can lead to significant tissue damage. Many classes of compounds are used today as anti-inflammatory drugs. However, there is an ongoing demand for new, more effective molecules with higher safety margins. In this regard, the anti-inflammatory effect of six synthetic compounds of N-antipyrine-3,4-dichloromaleimide was evaluated. METHODS: RAW 264.7 cells were used to evaluate the cytotoxicity and the anti-inflammatory activity, by measuring the effect of these molecules on nitric oxide, IL-1ß, IL-6, MCP-1 (CCL2), TNF-α, INF-γ, IL-4, and IL-13 levels, as well as under NF-κB activation. RESULTS: Some of the tested compounds showed significant cytotoxicity (CC50 < 100 µM). Subsequently, the potential of nitric oxide (NO) inhibition as screening for potential anti-inflammatory action was evaluated. Three of the compounds tested showed a promising profile (1, 3, and 5). When the effect of these compounds was evaluated on the production of IL-1ß, IL-6, MCP-1 (CCL2), TNF-α, and INF-γ, only N-antipyrine-3,4-dichloromaleimide (1) and N-antipyrine-3-chloro-4-(3,4-dichloroaniline) maleimide (3) showed significant inhibition profiles. These two compounds were also able to increase the production of cytokines known for having an anti-inflammatory profile (IL-4 and IL-13) and inhibit the phosphorylation of the p-p65 NF-κB subunit significantly. CONCLUSION: In conclusion, these two compounds present a significant and unusual anti-inflammatory mechanism (increasing the production of anti-inflammatory mediators). They are therefore considered promising prototypes for the development of new anti-inflammatory drugs with immunomodulatory characteristics.

In Vitro Free Radical Scavenging Properties and Anti-Inflammatory Activity of Ilex paraguariensis (Maté) and the Ability of Its Major Chemical Markers to Inhibit the Production of Proinflammatory Mediators.

Ilex paraguariensis A. St. Hil. (Aquifoliaceae), popularly known as "yerba mate," has great economic and social significance for the population of Southern Latin America. This study was conducted (1) to investigate the phytochemical composition of four different standardized extracts, (2) to investigate its free radical scavenging properties, and (3) to investigate the anti-inflammatory action of I. paraguariensis and its major chemical markers. The chemical profile was achieved by Folin-Ciocalteu, by LC/DAD, and by LC/MS assays, while the antioxidant and anti-inflammatory properties were investigated, respectively, by DPPH assay and by inhibition of nitric oxide (Griess reaction) and TNF-α (ELISA). Our results demonstrated that the IA (aqueous infusion extract) showed higher amounts of total phenolic contents (266.62 ± 10.85 mg CAE·g-1 DE), the highest amounts of all six chemical markers (theobromine, 5-O-caffeoylquinic acid, 4-O-caffeoylquinic acid, 3-O-caffeoylquinic acid, caffeine, and rutin), and stronger antioxidant activity (EC50 = 54.4 ± 5.14 µg · mL-1). The IA extract also showed the lowest inhibition of NOx secretion (50.10 ± 8.97%) as well as inhibition of TNF-α (83.33 ± 4.01%). Regarding the chemical markers, all compounds showed strong inhibition of NOx secretion, especially theobromine, which was 200x more potent than dexamethasone. Furthermore, TNF-α secretion was also significantly decreased by THEO at 0.033 µM (22.15 ± 6.49%), NCA at 1.97 µM (27.46 ± 3.98%), CCA at 0.35 µM (39.76 ± 5.73%), CGA at 0.56 µM (23.58 ± 5.79%), CAF at 0.52 µM (26.45 ± 5.34%), and RUT at 0.16 µM (40.18 ± 3.70%). Our results suggest that I. paraguariensis and its major chemical markers have strong free radical scavenging properties as well as showed important anti-inflammatory activity and that these compounds in a plant extract may work based on several different mechanisms synergistically, resulting in moderating the immune system.

Sexually dimorphic responses of rats to fluoxetine in the forced swimming test are unrelated to the function of the serotonin transporter in the brain.

Due to the prevalence of depression in women, female rats may be a better models for antidepressant research than males. In male rats, fluoxetine inhibited the serotonin (5-hydroxytryptamine, 5-HT) transporter (SERT) which is reducing the immobility time in the repeated forced swimming test (rFST). The performance of female rats in this test is unknown. In this study, responses of male and female rats in the rFST under chronic treatment with fluoxetine and the function of SERT in their brains were examined. Wistar rats received oral fluoxetine (females: 0, 1, 2.5, or 5 mg kg-1  day-1 ; males: 0 or 2.5 mg kg-1  day-1 ; in sucrose 10%, 1.5 ml/rat) 1 hr before the test daily for 12 days over the course of the rFST. rFST consisted of a 15 min pretest followed by 5 min sessions of swimming at 1 (test), 7 (retest 1), and 14 (retest 2) days later. SERT functioning was assessed by ex vivo assays of the frontal cortex and hippocampus of rats. Fluoxetine reduced immobility time of males in the rFST while it failed to do so in females. In vitro treatment with fluoxetine inhibited the uptake of 5-HT of both sexes similarly, while in vivo chronic administration of fluoxetine failed to do so. In summary, rats responded to the chronic treatment with fluoxetine in a sexually dimorphic fashion during the rFST despite the functioning of SERT in their brains remaining equally unchanged. Hence, our data suggest that sexually dimorphic responses to fluoxetine in rFST may be unrelated to the function of SERT in rat brains.

Failure to detect the action of antidepressants in the forced swim test in Swiss mice.

OBJECTIVE: The aims of this study were to replicate previously published experiments and to modify the protocol to detect the effects of chronic antidepressant treatment in mice. METHODS: Male Swiss mice (n=6-8/group) housed in reversed light/dark cycle were randomly assigned into receive vehicle (10% sucrose), sub-effective doses (1 and 3 mg/kg) or effective doses (10 and 30 mg/kg) of bupropion, desipramine, and fluoxetine and a candidate antidepressant, sodium butyrate (1-30 mg/kg) per gavage (p.o.) 1 h before the forced swim test (FST). Treatments continued daily for 7 and 14 days during retests 1 and 2, respectively. In an additional experiment, mice received fluoxetine (20 mg/kg) or vehicle (10% sucrose or 0.9% saline) p.o. or i.p. before the FST. Mice housed in reversed or standard light/dark cycles received fluoxetine (20 mg/kg) prior FST. Video recordings of behavioural testing were used for blind assessment of the outcomes. RESULTS: According to the expected, doses of antidepressants considered sub-effective failed to affect the immobility time of mice in the FST. Surprisingly, acute and chronic treatment with the high doses of bupropion, desipramine, and fluoxetine or sodium butyrate also failed to reduce the immobility time of mice in the FST. Fluoxetine 20 mg/kg was also ineffective in the FST when injected i.p. or in mice housed in normal light/dark cycle. CONCLUSION: Data suggest the lack of efficacy of orally administered bupropion, desipramine, fluoxetine in the FST in Swiss mice. High variability, due to high and low immobility mice, may explain the limited effects of the treatments.