Taurine and Vitamin C Modify Monocyte and Endothelial Dysfunction in Young Smokers

Abstract

Background-Endothelial dysfunction initiated by monocyte-endothelial interactions has previously been observed in many vasculopathies, including chronic cigarette smoking. Taurine, a semiessential amino acid, and vitamin C, a naturally occurring antioxidant, have previously been shown to have endothelial protective effects when exposed to proinflammatory insults. Therefore, we hypothesized that taurine and vitamin C would restore endothelial function in young smokers by modifying monocyte-endothelial interactions. Methods and Results-Endothelial-dependent vasodilatation was assessed in vivo using duplex ultrasonography, and monocyte-endothelial interactions were assessed in vitro using endothelial cell culture (human umbilical vein endothelial cells [HUVECs]) with monocyte-conditioned medium (MCM). Endothelial-dependent vasodilatation was significantly impaired in young smokers compared with nonsmokers. Pretreatment of young smokers for 5 days with 2 g/d vitamin C and, more significantly, with 1.5 g/d taurine attenuated this response. MCM taken from smokers impaired the release of nitric oxide and increased the levels of endothelin-1 release from HUVECs. When HUVECs were cultured with MCM from smokers who had been treated with taurine, the levels of nitric oxide and endothelin-1 returned toward control levels. This was attributed to an upregulation in endothelial nitric oxide synthase expression. Conclusions-These observations suggest that taurine supplementation has a beneficial impact on macrovascular endothelial function, and an investigation of its effect on altered endothelial function in dyslipidemic states is warranted.

Taurine Supplementation Reduces Oxidative Stress and Improves Cardiovascular Function in an Iron-Overload Murine Model

“…23 Moreover, we cannot rule out a role of taurine in mediating anti-inflammatory effects, 60 maintaining cellular metabolism (via its effect on mitochondria), 61 and/or protection of coronary endothelium and blood flow. 62 In our murine model, taurine treatment also led to reductions in myocardial iron levels. Reduced cardiac iron levels may be related to the tonic inhibition of L-type Ca 2ϩ channels by taurine, 29,31 which is an important transferrin-independent pathway for iron transport in iron-overload conditions.…”

The Effects of Taurine on Permethrininduced Cytogenetic and Oxidative Damage in Cultured Human Lymphocytes

“…The fi rst is that TA acts as an antioxidant in a dose-dependent manner (24). Through antioxidative pathways it seems to modify both target and receptor cell homeostasis (64)(65)(66). Plasma and extracellular fl uid TA concentrations typically range from 10 μmol L -1 to 100 μmol L -1 (67).…”

Taurine Attenuates Hepatic and Cardiac Damage and Apoptosis in Rabbits Fed a High-Fat Diet

“…Several studies have demonstrated that dietary taurine showed a notable cholesterollowering effect in hypercholesterolemic rats fed a high cholesterol diet (Masuda and Horisaki, 1986;Murakami et al, 1999;Park and Lee, 1998;Hagar, 2004). It has been shown that taurine improves endothelial function and inhibits apoptosis of endothelial cell as well as decreases plasma level of LDL, which prevents initiation and progression of atherosclerosis (Fennessy et al, 2003;Murakami et al, 2002). Taurine exhibits antioxidative properties, membrane stabilizing effect, regulates intracellular Ca2+ concentration, inhibits apoptosis, reduces the levels of pro-inflammatory cytokines in various organs and controls blood pressure (Das et al, 2008;Manna et al, 2008;2009).…”