Carvacrol suppresses LPS-induced pro-inflammatory activation in RAW 264.7 macrophages through ERK1/2 and NF-kB pathway

• Published in: International immunopharmacology 2019-10, Vol.75, p.105743-105743, Article 105743
• Main Authors: Somensi, Nauana, Rabelo, Thallita Kelly, Guimarães, Adriana Gibara, Quintans-Junior, Lucindo José, de Souza Araújo, Adriano Antunes, Moreira, José Cláudio Fonseca, Gelain, Daniel Pens
• Format: Article
• Language: English
• Subjects: Animals; Anti-Inflammatory Agents - pharmacology; Antigens; Antioxidants; Carvacrol; Cell activation; Cell viability; Cymenes - pharmacology; Cytoplasm; ERK; Essential oils; Extracellular signal-regulated kinase; Extracellular Signal-Regulated MAP Kinases - metabolism; Gram-negative bacteria; IL-1β; Immune system; Incubation; Inflammation; Lipopolysaccharides; LPS; Macrophage; Macrophages; Medical treatment; Mice; NF-kappa B - metabolism; NF-κB; NF-κB protein; Nitric oxide; Nitrites - metabolism; Oxidation; Pattern recognition; Phagocytes; Phagocytosis - drug effects; Phenolic compounds; Phenols; Phosphorylation; RAW 264.7 Cells; Receptors; TLR4 protein; Toll-like receptors; Transcription activation; Translocation; Tumor necrosis factor-α
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2019.105743

Macrophages are immune system cells that respond to various pathogenic insults. The recognition of antigens is performed through receptors such as TLR4 and RAGE, which recognize pathogen-associated patterns (PAMPs), including lipopolysaccharide (LPS) from Gram-negative bacteria. Carvacrol (CAR) is a phenolic compound found in some essential oils commonly used in folk medicine for treatment of inflammation-related diseases. Previous works observed strong antioxidant actions and some anti-inflammatory effects by CAR in in vivo and in vitro assays. However, the potential pharmacological application of CAR remains limited as details on its mechanisms of action are still missing. Here we investigated the molecular pathways by which CAR acts on LPS-mediated pro-inflammatory activation of RAW 264.7 macrophages. CAR 100 μM protected cells against loss of cell viability induced by LPS (1 μg/mL). Pre-incubation with CAR prevented LPS-induced ERK1/2 phosphorylation, but it had no effect on p38 and JNK activation. The effect of LPS on NF-kB (p65) translocation from cytoplasm to nucleus was inhibited by CAR, as well as NF-kB transcriptional activation. Moreover, LPS-elicited release of TNF-α and IL-1β were inhibited by CAR, as well as activation of phagocytic activity. Such effects may be related to the antioxidant effect of CAR, as the LPS-induced increase in reactive species (RS) production (assessed by DCFH oxidation) and nitric oxide (NO) production (assessed by nitrite quantification) were inhibited by CAR. Altogether, these results demonstrate that CAR exerts relevant anti-inflammatory actions through a cellular mechanism involving ERK1/2 and NF-kB inhibition and possibly related to the antioxidant properties of this phenolic compound. •Carvacrol protects RAW 264.7 macrophages against LPS-driven inflammation.•Carvacrol prevents LPS-induced ERK1/2 phosphorylation, but not p38 and JNK.•Carvacrol blocks NF-kB nuclear translocation and transcriptional activation.•Carvacrol inhibits LPS-elicited release of TNF-α and IL-1β, along with phagocytosis.•Carvacrol has anti-oxidant effects, inhibiting RS and NO production in macrophages.