AMP Kinase Activation and Inhibition of Nuclear Factor-Kappa B (NF-κB) Translocation Contribute to the Anti-Inflammatory Effect of Tricin

Abstract

Tricin is a methylated flavone widely distributed in cereal crops. The mechanism underlying the anti-inflammatory effects of tricin was examined using RAW 264.7 macrophages. Tricin up to 50 lg/mL showed no cytotoxic effects and significantly decreased the levels of nitric oxide (NO) and prostaglandin E2 (PGE 2 ). The inhibition of inducible NO synthase (iNOS) and cyclooxygenase (COX-2) expression were determined by western blotting. The level of iNOS expression was decreased by 80% with tricin concentration as low as 3 lg/mL. Moreover, treatment with tricin significantly decreased the production of pro-inflammatory cytokines, including tumor necrosis factor a (TNF-a), interlukin 1b (IL-1b), and IL-6. These effects were mediated by inhibition of the nuclear factor-kappa B (NFjB) translocation through stimulation of adenosine monophosphate-activated protein kinase (AMPK) in macrophages. PRACTICAL APPLICATIONSTricin is a flavonoid found in the outer layer of cereal crops including cereal byproducts. This study demonstrated that anti-inflammatory activity mediated by tricin was related to AMPK activation that inhibits NF-jB translocation. Since AMPK activation is a promising target to modulate lipid and glucose metabolism, tricin has great potential as anti-diabetic and anti-obesity agent. Cereal bran fraction containing high tricin content can be a practical source to deliver valuable bioactive compounds.

Anti-Inflammatory Effect of Ecklonia cava Extract on Porphyromonas gingivalis Lipopolysaccharide-Stimulated Macrophages and a Periodontitis Rat Model

“…Polymerase chain reaction (PCR) was performed using RAW 264.7 cell lysates harvested after P. gingivalis LPS and sample treatment for 3 h, and the gingival tissue specimens were collected after the completion of the animal study. Total RNA in cells and tissues was extracted using QiAzol ® lysis reagent (QIAGEN, Valencia, CA, USA), and qRT-PCR was performed using a StepOne Plus real-time PCR system (Applied Biosystems) as previously described [11]. The primers used in the analysis were as follows: β-actin (Mm00607939_s1 and Rn00667869_m1), iNOS (Mm00440502_m1), TNF-α (Mm00437214_m1), IL-1β (Mm00434228_m1 and Rn00580432_m1), IL-6 (Mm00446190_m1), RANKL (Rn00589289_m1), OPG (Rn00563499_m1), MMP-2 (Rn01538170_m1), and MMP-9 (Rn00579162_m1).…”

Ecklonia cava Extract Containing Dieckol Suppresses RANKL-Induced Osteoclastogenesis via MAP Kinase/NF-��B Pathway Inhibition and Heme Oxygenase-1 Induction

“…The medium was changed every 2 days during a 4~10 day incubation period. Cell viability was determined using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrzolium bromide (MTT) assay after 10 days in the presence of samples as previously described [13].…”

“…Total RNA was extracted and qRT-PCR was performed using a StepOne Plus real-time RCR system (Applied Biosystems) as previously described [13]. The following primers were used in the analysis; β-actin (Mm00607939_s1), TRAP (Mm00475698_m1), cathepsin K (Mm00484039_m1), MMP-9 (Mm00442991_m1), NFATc1 (Mm00479445_m1), and c-fos (Mm00487425_m1).…”

Biosynthesis of silver nanoparticles mediated by Houttuynia cordata leaf extract: Characterization and improvement of anti-inflammatory activity

“…RAW 264.7 macrophages were cultured as previously described (Lee & Imm, 2017). After 24 h from cell seeding, the cells were further incubated for 24 h in the presence of samples and LPS (0.5 μg/mL).…”