Crocetin regulates Th1/Th2 and Th17/Treg balances, nitric oxide production, and nuclear localization of NF‐κB in Th2‐provoked and normal situations in human‐isolated lymphocytes

Abstract

Crocetin is a natural carotenoid dicarboxylic acid derived from Crocus sativus. It has been utilized as natural biomedicine with healing effects. The immunoregulatory and anti-inflammatory properties may cause the biological activities of crocetin. Nevertheless, it is not still clear how this compound acts and causes an immune-modulatory impact on human lymphocytes. The effects of three concentrations (5, 10, and 20 μM) of crocetin or dexamethasone (0.1 mM) were assessed on gene expression and secretion of cytokines, nuclear factor kappalight-chain-enhancer of activated B cells (NF-κB) level, and nitric oxide (NO) production in phytohaemagglutinin (PHA)-stimulated and nonstimulated lymphocytes. By incubation with PHA, gene expression and cytokine concentration comprising interferon (IFN)-γ, interleukin (IL)-17A, IL-10, and IL-4 were increased, along with NF-κB concentration and NO production (all, p < 0.001). In comparison with the controls, an alteration occurred in the T-helper (Th)2/Th1 and Th17/Treg balance in the stimulated lymphocyte toward a Th2 and Th17 response. In stimulated cells, crocetin and dexamethasone decreased pro-inflammatory significantly and increased anti-

Anti-inflammatory effects of Mentha pulegium L. extract on human peripheral blood mononuclear cells are mediated by TLR-4 and NF-κB suppression

“…The isolated cell pellets were resuspended in 1 mL of cold PBS [ 21 ]. PBMCs were then counted with a hemocytometer and their viability was measured by the trypan blue dye exclusion test [ [22] , [23] , [24] , [25] ]. Samples with viability greater than 95 % were selected for further analysis and experimentation.…”

“…PBMCs were pre-treated and incubated with three different concentrations of Mentha pulegium L. (10, 30, and 90 μg/mL) for 2 h before stimulation with 1.0 μg/mL of LPS (Escherichia coli O55: B5; Sigma-Aldrich, St. Louis, MO, USA). The contents of the well plate were mixed once with sampling after the ingredients were combined, followed by incubation at 37 °C in a 95 % humidified atmosphere incubator with 5 % CO 2 [ 24 , 25 ]. For gene expression analysis, 6 h later, cultured cells were harvested and centrifuged at 400× g for 10 min and transferred into the TRIzol ™ reagent (Thermo Fisher Scientific Inc. Waltham, MA USA) for total RNA isolation.…”