Green tea catechins improve human forearm vascular function and have potent anti-inflammatory and anti-apoptotic effects in smokers.
OBJECTIVE
Several epidemiological investigations have reported that green tea reduces cardiovascular and cerebral vascular risks. Green tea catechins may improve peripheral endothelial dysfunction in smokers. The purpose of this study was to elucidate the beneficial effect of green tea catechins on the repair of endothelial dysfunction in smokers.


METHODS
Thirty healthy male smokers divided into three groups ingested a green tea beverage containing 0 mg (control group), 80 mg (middle dose group) or 580 mg (high dose group) of green tea catechins (GTC) daily for two weeks, and endothelial-dependent vasodilatation was investigated by measuring forearm blood flow (FBF) response to reactive hyperemia (RH) by venous occlusion strain-gauge plethysmography.


RESULTS
An acute effect was that the FBF response to RH significantly increased 2 hr after GTC intake in the high dose group. However, no increase was observed in the other groups. The chronic administration of GTC for one or two weeks ameliorated the FBF responses to RH in the high dose group. On the other hand, no significant increase was observed in the FBF responses to RH in the other groups. Moreover, the plasma concentration of 8-OHdG, IL-6, TNF-alpha, and soluble Fas decreased significantly for two weeks in the high dose group, however, the level of IL-1 beta remained unchanged over this period.


CONCLUSIONS
Green tea consumption over short and long periods appears to ameliorate endothelial dysfunction by scavenging free radicals with anti-inflammatory and anti-apoptotic properties in healthy male smokers.
Department of Cardiovascular, Respiratory, and Geriatric Medicine, Kyushu University Hospital, Beppu. joyama@tsurumi.beppu.kyushu-u.ac.jp
Jun-ichi
J
Oyama
Toyoki
T
Maeda
Makoto
M
Sasaki
Kazuya
K
Kozuma
Ryuji
R
Ochiai
Ichiro
I
Tokimitsu
Sachiyo
S
Taguchi
Yoshihiro
Y
Higuchi
Naoki
N
Makino
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000302:isolation & purification; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002392:Catechin / Q000008:administration & dosage* / Q000302:isolation & purification; D005542:Forearm / Q000098:blood supply* / Q000502:physiology; D006801:Humans; D008297:Male; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012907:Smoking / Q000473:pathology* / Q000503:physiopathology* / Q000628:therapy; D013662:Tea
D000894:Anti-Inflammatory Agents, Non-Steroidal; D013662:Tea; D002392:Catechin