A New Nβ‐alkanoyl‐5‐hydroxytryptamide Induces Anti‐inflammatory Activity in a Mice Subcutaneous Air Pouch Model of Inflammation

Abstract

The C18‐5HT, a new Nβ‐alkanoyl‐5‐hydroxytryptamide is naturally found in the surface wax of coffee beans (Speer et al., 2006). Some amides of the serotonin class demonstrated an anti‐inflammatory effect by inhibiting the expression of caspases participants in inflammatory process (Meijerink et al., 2013). The aim of this study was to evaluate the anti‐inflammatory activity of C18‐5HT, a new fatty acid amide of serotonin.C18‐5HT (0.1–10 mg/kg, p.o.) effects were assessed in the carrageenan‐induced cell migration into the subcutaneous air pouch (SAP) with quantification of total leukocyte number, total proteins, nitric oxide (NO), tumor necrosis factor α (TNF‐α), interleukin 1β (IL‐1β), interferon γ (IFN‐γ) and interleukin 10 (IL‐10). A possible inhibitory effect in reactive oxygen species (ROS) production was evaluated ex vivo, after activation of leukocytes collected from the SAP with phorbolmyristate acetate (PMA). Cells were pretreated ex vivo with C18‐5HT (1–10 μM). The fluorescence was captured in the FL‐1 channel of a flow cytometer and expressed as fluorescence intensity. The protocol for the use of animals was approved by CAUAP/UFRJ and received the number DFBCICB015‐04/16. Statistical analysis was performed by ANOVA and Bonferroni's test (*p<0.05).Pretreatment of animals with different doses of C18‐5HT significantly reduced cell migration to the SAP: PBS in SAP=3.5±1.4×106cells/mL; carrageenan in SAP=69.2±9.9×106cells/mL; 0.1 mg/kg= 51.9±8.4×106cells/mL; 1 mg/kg= 41.7±6.7×106*cells/mL; 10 mg/kg=37.1±3.1×106*cells/mL. C18‐5HT also significantly decrease the amount of total proteins and NO (Table 1) With respect to quantification of TNF‐α, IFN‐γ and IL‐1β, C18‐5HT were able to reduce the values when compared with carrageenan group in SAP (Table 1). Even though C18‐5HT was able to significantly increase the release of IL‐10 only at the dose of 10 mg/kg (table 1).C18‐5HT also reduced ROS production (control=0.19×105±0.12×104, PMA stimulated=1.54×105±0.62×104; 1 μM=0.24×105±0.80×104*; 3 μM=0.21×105±0.30×104*; 10 μM=0.11×105±0.20×104*.Thereby we can conclude that C18‐5HT inhibited leukocyte migration, production of total proteins, NO, TNF‐α, IFN‐γ and IL‐1β. In addition, increase the release of IL‐10 and decreased ROS production. Data suggest that this substance could be used as new prototype forthe development of new anti‐inflammatory drugs.Support or Funding InformationAlan Minho for technical assistance, Instituto Vital Brazil (Niterói, Brazil) for donation of mice. Financial support: CAPES, CNPq and FAPERJ Effect of C18‐5HT on inflammatory mediators accumulated in the subcutaneous air pouch after carrageenan injection. Injection in SAP Treatment mg/kg Total protein (μg/ml) NO (μM) TNF‐α (pg/ml) IFN‐γ (pg/ml) IL‐1β (pg/ml) IL‐10 (pg/ml) PBS ‐ ‐ 24.5±13.3 34.6±14.6 55.6±9.0 62.5±25.6 768.5±149.4 905.6±59.3 Carrageenan Vehicle ‐ 244.5±36.0 330.0±32.4 599.7±83.1 1,301.5±132.6 1,584.0±350.7 2,525.3±215.7 C18‐5HT 0.1 206.3±52.2 164.1±30.7* 386.1±40.8* 1,212.2±185.6 1,322.9±192.3 2,274.4±462.3 1 186.4±13.0* 118.8±39.5* 317.5±58.0* 1,272.5±151.1 733.8±69.1* 2,580.8±268.8 10 158.5±31.9* 82.3±14.0* 271.5±36.1* 808.0±128.2* 622.9±53.2* 4,213.8±453.8* Statistical significance was calculated by ANOVA followed by Bonferroni's test (n = 6–8). p < 0.05 when compared C18‐5HT ‐treated mice with vehicle‐treated group.