Cysteine, histidine and glycine exhibit anti-inflammatory effects in human coronary arterial endothelial cells

The activation of nuclear factor-kappa B (NF-?B) in vascular endothelial cells may be involved in vascular pathogeneses such as vasculitis or atherosclerosis. Recently, it has been reported that some amino acids exhibit anti-inflammatory effects. We investigated the inhibitory effects of a panel of amino acids on cytokine production or expression of adhesion molecules that are involved in inflammatory diseases in various cell types. The activation of NF-?B was determined in human coronary arterial endothelial cells (HCAECs) because NF-?B modulates the production of many cytokines and the expression of adhesion molecules. We examined the inhibitory effects of the amino acids cysteine, histidine and glycine on the induction of NF-?B activation, expression of CD62E (E-selectin) and the production of interleukin (IL)-6 in HCAECs stimulated with tumour necrosis factor (TNF)-a. Cysteine, histidine and glycine significantly reduced NF-?B activation and inhibitor ?Ba (I?Ba) degradation in HCAECs stimulated with TNF-a. Additionally, all the amino acids inhibited the expression of E-selectin and the production of IL-6 in HCAECs, and the effects of cysteine were the most significant. Our results show that glycine, histidine and cysteine can inhibit NF-?B activation, I?Ba degradation, CD62E expression and IL-6 production in HCAECs, suggesting that these amino acids may exhibit anti-inflammatory effects during endothelial inflammation.