title: Green tea polyphenols inhibit human vascular smooth muscle cell proliferation stimulated by native low-density lipoprotein.
abstract: This study investigated whether human vascular smooth muscle cell proliferation induced by native low-density lipoprotein (LDL) is affected by green tea catechins. Furthermore, the effects of native LDL on extracellular signal-regulated kinase (ERK) 1/2 activity were determined. Cell proliferation stimulated by native LDL was concentration-dependently inhibited by epigallocatechin, epigallocatechin-3-gallate, green tea polyphenon, and the nonspecific antioxidant N-acetylcysteine (P<0.05). Combined treatment of green tea polyphenon and N-acetylcysteine markedly potentiated the effect of each drug on vascular smooth muscle cell proliferation. ERK1/2 activity was only partly inhibited by green tea catechins alone or in combination with N-acetylcysteine (P<0.05). These data suggest that green tea constituents inhibit proliferation of human vascular smooth muscle cells exposed to high levels of native LDL. Green tea constituents and antioxidants may exert vascular protection by inhibiting human vascular smooth muscle cell growth associated with hypercholesterolemia.
authors.affiliation: Department of Internal Medicine, Medical Policlinic and Clinical Atherosclerosis Research Laboratory, University Hospital Zürich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Locher
authors.forename: Luca
authors.initials: L
authors.lastname: Emmanuele
authors.forename: Paolo M
authors.initials: PM
authors.lastname: Suter
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Vetter
authors.forename: Matthias
authors.initials: M
authors.lastname: Barton
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D002392:Catechin / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005419:Flavonoids; D008077:Lipoproteins, LDL / Q000037:antagonists & inhibitors*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects*; D010636:Phenols / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D013662:Tea
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D008077:Lipoproteins, LDL; D010636:Phenols; D011108:Polymers; D013662:Tea; D002392:Catechin; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D000111:Acetylcysteine