Inhibitory effects of purified green tea epicatechins on contraction and proliferation of arterial smooth muscle cells.
OBJECTIVE
The present study was aimed to examine the vasorelaxant and antiproliferative responses to purified green tea epicatechin mixture, (-)epicatechin and (-)epigallocatechin gallate on rat arterial smooth muscle cells.


METHODS
Changes in isometric force were measured by Grass force transducer and effects on cell proliferation were evaluated using [3H]thymidine incorporation assay.


RESULTS
Epicatechin mixture, (-)epicatechin and (-)epigallocatechin gallate, which we isolated and purified from jasmine green tea, concentration-dependently, reduced the contractile response to phenylephrine in rat isolated aortic rings with (-)epigallocatechin gallate being more effective. These three agents also inhibited [3H]thymidine incorporation into DNA in cultured rat aortic smooth muscle cells in a concentration-dependent manner.


CONCLUSIONS
The purified epicatechin derivatives from jasmine green tea relaxed the isolated rat arteries preconstricted by phenylephrine and inhibited aortic smooth muscle cell proliferation.
Chen
Z Y
ZY
Departments of Biochemistry and Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, Shatin, Hong Kong, China.
Law
W I
WI
Yao
X Q
XQ
Lau
C W
CW
Ho
W K
WK
Huang
Y
Y
D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology; D002392:Catechin / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013662:Tea / Q000737:chemistry; D014665:Vasodilator Agents / Q000494:pharmacology
D013662:Tea; D014665:Vasodilator Agents; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate