Anti-Inflammatory Effects of Gingerol on Lipopolysaccharide-Stimulated RAW 264.7 Cells by Inhibiting NF-κB Signaling Pathway.
Inflammation. 2018 Mar 5. Epub 2018 Mar 5. PMID: 29508185
Gingerol was the main functional substance of Zingiberaceous plant which has been known as traditional medicine for thousands of years. The purpose of this experiment was to explore anti-inflammatory effects of gingerol and study the possible mechanism in lipopolysaccharide (LPS)-stimulated RAW246.7 cells. The cells were treated with 10 μg/mL LPS and 300, 200, 100, and 50 μg/mL gingerol for 24 h. The cytotoxicity of gingerol was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetra-zoliumbromide (MTT) method. Nitric oxide (NO) production was observed using Griess assays. Prostaglandin E(PGE) and pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 have been analyzed by ELISA. Real-time PCR was used to detect the mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), IL-6, and IL-1β in LPS-induced RAW246.7 cells. Nuclear transcription factor kappa-B (NF-κB) signaling pathway-related proteins have been assessed by western blot assays. The determination of MTT showed that cell viability was not significantly affected by up to 300 μg/mL gingerol. Compared with LPS group, 50, 100, 200, and 300 μg/mL gingerol can inhibit the production of NO and the inhibitory rate was 10.4, 29.1, 58.9, and 62.4%, respectively. The results indicated gingerol existed anti-inflammatory effect. In addition, gingerol also observably inhibited LPS-induced TNF-α, IL-1β, IL-6, and PGE(p < 0.01) expression and secretion in a dose-dependent manner. At the genetic level, after the intervention of gingerol, mRNA transcriptions of iNOS, COX-2, IL-6, and IL-1β were all decreased. The protein expressions of iNOS, NF-κB, p-p65, and p-IκB were significantly increased in LPS-induced cells, while these changes were reversed by the treatment with gingerol. This study suggested that gingerol exerts its anti-inflammatory activities in LPS-induced macrophages which can inhibit the production of inflammatory cytokines by targeting the NF-κB signaling pathway.