Cornus officinalis var. koreana Kitam polyphenol extract decreases pro-inflammatory markers in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages by reducing Akt phosphorylation.
ETHNOPHARMACOLOGICAL RELEVANCE
Cornus officinalis var. koreana Kitam (CO) is found predominantly in China but also in Korea and Japan and has been used in Eastern medicine for over 2000 years to treat several conditions including diabetes, cardiovascular disease and kidney disease. Chronic inflammation underlies the pathogenesis of these diseases. The mechanisms by which CO may exert its anti-inflammatory effects have not been well defined.


AIM OF THE STUDY
We aimed to determine whether Cornus officinalis var. koreana Kitam extract (COE) attenuate the inflammatory response induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages, and to elucidate the mechanisms which contribute to these anti-inflammatory effects.


MATERIALS AND METHODS
COE was prepared using ethanolic extraction, followed by solvent evaporation and freeze-drying. RAW 264.7 macrophages were treated with 0, 50, 100, 200 and 400 μg/ml of COE. After 2 h, cells were treated with 100 ng/ml of LPS for 6 h. Cells were then collected for whole cell protein expression analysis of signaling and inflammatory molecules via western blot.


RESULTS
Pre-treatment with 100, 200 and 400 μg/ml of COE significantly reduced Akt phosphorylation in LPS stimulated macrophages compared to LPS alone (P ≤ 0.003). NF-κB expression was significantly attenuated with 400 μg/ml of COE compared to LPS treatment alone (P = 0.01). LPS induced cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) expression, which was significantly decreased by treatment with 400 μg/ml COE (P = 0.0001 and 0.02, respectively). COE dose-dependently decreased LPS-induced expression of interleukin (IL)-1β (P ≤ 0.0008) and IL-6 (P = 0.01).


CONCLUSION
In summary, COE attenuated the inflammatory response induced by LPS in RAW 264.7 macrophages, likely due to Akt inhibition.
['Najjar|Rami S|RS|', 'Akhavan|Neda S|NS|', 'Pourafshar|Shirin|S|', 'Arjmandi|Bahram H|BH|', 'Feresin|Rafaela G|RG|']
D000818:Animals D000893:Anti-Inflammatory Agents D015415:Biomarkers D002470:Cell Survival D029768:Cornus D016207:Cytokines D007249:Inflammation D008070:Lipopolysaccharides D020935:MAP Kinase Signaling System D051379:Mice D052002:NF-kappa B p50 Subunit D009569:Nitric Oxide D052247:Nitric Oxide Synthase Type II D010766:Phosphorylation D010936:Plant Extracts D059808:Polyphenols D011451:Prostaglandin-Endoperoxide Synthases D051057:Proto-Oncogene Proteins c-akt D000067996:RAW 264.7 Cells D014409:Tumor Necrosis Factor-alpha
Cornus Polyphenols Macrophages Akt Inflammation LPS Berries