scholarly journals Heat-Killed Lactic Acid Bacteria Inhibit Nitric Oxide Production via Inducible Nitric Oxide Synthase and Cyclooxygenase-2 in RAW 264.7 Cells

2021 ◽  
Author(s):  
Chang-Ho Kang ◽  
Jin-Seong Kim ◽  
Hyemin Kim ◽  
Hye Min Park ◽  
Nam-Soo Paek
Keyword(s):  
Nitric Oxide ◽  
Lactic Acid ◽  
Nitric Oxide Synthase ◽  
Lactic Acid Bacteria ◽  
Shelf Life ◽  
Cyclooxygenase 2 ◽  
Raw 264.7 Cells ◽  
Industrial Preparation ◽  
Oxide Synthase ◽  
Oxide Inhibition

AbstractHeat-killed lactic acid bacteria perform immunomodulatory functions and are advantageous as probiotics, considering their long product shelf-life, easy storage, and convenient transportation. In this study, we aimed to develop appropriate heat treatments for industrial preparation of probiotics with antioxidant activity. Among 75 heat-killed strains, Lactococcus lactis MG5125 revealed the highest nitric oxide inhibition (86.2%), followed by Lactobacillus acidophilus MG4559 (86.0%), Lactobacillus plantarum MG5270 (85.7%), Lactobacillus fermentum MG4510 (85.3%), L. plantarum MG5239 (83.9%), L. plantarum MG5289 (83.2%), and L. plantarum MG5203 (81.8%). Moreover, the heat-killed selected strains markedly inhibited lipopolysaccharide-induced nitric oxide synthase and cyclooxygenase-2 expression. The use of heat-killed bacteria with intact bio-functionality can elongate the shelf-life and simplify the food processing steps of probiotic foods, given their high stability. The antioxidant and immune-modulatory activities of the heat-killed strains selected in this study indicate a strong potential for their utilization probiotic products manufacturing.

scholarly journals Melatonin suppresses macrophage cyclooxygenase-2 and inducible nitric oxide synthase expression by inhibiting p52 acetylation and binding

Blood ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 518-524 ◽  
Author(s):  
Wu-Guo Deng ◽  
Shao-Tzu Tang ◽  
Hui-Ping Tseng ◽  
Kenneth K. Wu
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Nuclear Translocation ◽  
Cyclooxygenase 2 ◽  
Raw 264.7 Cells ◽  
Dependent Manner ◽  
Cox 2 ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Melatonin has been shown to be produced by nonpineal cells and possess anti-inflammatory actions in animal models. In the present study, we tested the hypothesis that melatonin suppresses the expression of proinflammatory genes such as cyclooxygenase-2 (COX2) and inducible nitric oxide synthase (INOS) by a common transcriptional mechanism. Melatonin but not tryptophan or serotonin inhibited lipopolysaccharide (LPS)–induced COX-2 and iNOS protein levels and promoter activities in RAW 264.7 cells in a time- and concentration-dependent manner. LPS or LPS plus interferon-γ (IFNγ) increased binding of all 5 isoforms of NF-κB to COX-2 and iNOS promoters. Melatonin selectively inhibited p52 binding without affecting p100 expression, p52 generation from p100, or p52 nuclear translocation. p52 acetylation was enhanced by LPS, which was abrogated by melatonin. Melatonin inhibited p300 histone acetyltransferase (HAT) activity and abrogated p300-augmented COX-2 and iNOS expression. HAT inhibitors suppressed LPS-induced p52 binding and acetylation to an extent similar to melatonin, and melatonin did not potentiate the effect of HAT inhibitors. These results suggest that melatonin inhibits COX-2 and iNOS transcriptional activation by inhibiting p300 HAT activity, thereby suppressing p52 acetylation, binding, and transactivation.

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