Aim In this study, we investigated the protective effect of ferulic acid (FA) on nitric oxide (NO) production in tumor necrosis factor (TNF)-α-stimulated inflammatory human umbilical vein endothelial cells (HUVECs), and elucidated the mechanism(s) involved. Main methods The TNF-α-stimulated inflammatory HUVECs were treated with acetylcholine (ACh) and/or FA. NO productions were measured by monitoring nitrite and nitrate using a 2,3-diaminonaphthalene Kit. Expressions of mRNA and proteins were evaluated by RT-PCR and Western blotting, respectively. Key findings FA treatment resulted in a dose-dependent (10-200 μM) restoration of ACh-mediated NO production in TNF-α-treated HUVECs, whereas treatment with the FA analogues, coumaric acid, and apocynin resulted in no significant effect. FA treatment had no effect on O2- production in TNF-α-stimulated HUVECs. NG-monomethyl-l-arginine acetate (a nitric oxide synthase (NOS) inhibitor) and α-methyl-dl-aspartic acid (an argininosuccinate synthase (ASS) inhibitor) counteracted the effects of FA on the NO production. While FA treatment did not significantly affect the protein expression of p-eNOS or eNOS, the protein expression of ASS as well as mRNA expression was restored to normal levels upon exposure to FA in TNF-α-stimulated HUVECs. In nucleus, FA attenuated the increase of nuclear factor-kappa B (NF-κB) expression by TNF-α. Significance FA treatment rescues the defect in ACh-induced NO production resulting from TNF-α-stimulation in inflammatory HUVECs. This effect was likely due, in part, to the FA-mediated up-regulation of ASS expression via the suppression of NF-κB inflammatory signaling cascade.
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)