Green Tea Catechins Improve Human Forearm Endothelial Dysfunction and Have Antiatherosclerotic Effects in Smokers

Abstract

Background: Because green tea reduces cardiovascular and cerebrovascular risk, the purpose of this study aimed to elucidate the effect of green tea catechins (GTC) on endothelial dysfunction in smokers. Methods and Results:The 30 healthy male smokers were divided into 3 groups and given green tea beverages containing 0 mg (control group), 80 mg (medium-dose group) or 580 mg (high-dose group) of GTC daily for 2 weeks. Endothelial-dependent and-independent vasodilatation was investigated by measuring the forearm blood flow (FBF) responses to acetylcholine and sodium nitroprusside using venous occlusion strain-gauge plethysmography. The FBF response to acetylcholine significantly increased at 2 h and 1 and 2 weeks after GTC intake in the high-dose group, but no increase was observed in the other groups. FBF responses to sodium nitroprusside did not alter in any group at any time point. A significant increase in plasma nitric oxide and a decrease in asymmetrical dimethylarginine, malondealdehyde and 4-hydroxynonenal, C-reactive protein, monocyte chemotactic protein-1, and soluble CD40 ligand levels were detected after chronic consumption of high-dose GTC.Conclusions: GTC have antiatherosclerotic effects on dysfunctional vessels in smokers through increasing the level of nitric oxide and reducing oxidative stress. (Circ J 2010; 74: 578 - 588)

Smoking Promotes Subclinical Atherosclerosis in Apparently Healthy Men

“…27 In contrast, it is widely accepted that the impairment of MetS status substantially promotes the progression of atherosclerosis 28 and increases the risk of CVD. 1 Also, another study on a cohort of 5,033 individuals with the same characteristics as the present subjects suggested that the exposure to MetS would explain at least in part the increasing risk of excessive carotid plaque in past smokers.…”

Up-regulation of thromboxane A2 impairs cerebrovascular eNOS function in aging atherosclerotic mice

“…Catechin is, however, a non-specific antioxidant that displays large cardio-protective properties [45], including anti-inflammatory properties [35,52]. To achieve significant beneficial effects against cardiovascular diseases, frequent and habitual consumption of catechins present in green tea is required [35,38,54]. In the present study, beneficial functional effects of long-term chronic catechin treatment were associated with reduced aortic plaque formation and aortic oxidative stress (but not cerebral oxidative stress), as we previously reported [12], and normalization of blood pressure in ATX mice.…”

(−)-Epigallocatechin gallate selectively inhibits adenosine diphosphate-stimulated human platelet activation: Suppression of heat shock protein 27 phosphorylation via p38 mitogen-activated protein kinase

“…Catechins are important components of green tea polyphenols with numerous favorable biological functions, including anti-inflammatory, anti-oxidative, anti-atherosclerotic, anticarcinogenic and anti-arthritic effects in humans (1)(2)(3). Green tea mainly contains four catechins, epicatechin, epigallocatechin, epicatechin gallate and (-)-epigallocatechin gallate (EGCG), and among them EGCG is the most abundant (4).…”