IJUP08 - Universidade do Porto

Angiogenesis modulation by catechin
Duarte DD, Silva RP, Azevedo I, Soares R and Negrão R
Department of Biochemistry (U38/FCT), Faculty of Medicine, University of Porto, Portugal.
Angiogenesis, the formation of new blood vessels from pre-existing ones, is a process that
occurs in many physiological conditions, like wound healing and pregnancy, but also in
pathological situations such as cancer and cardiovascular disease. Deficient angiogenesis
results in deficient blood flow as in coronary heart disease and acute myocardial infarction.
Recent Western diet is believed to contribute to an increased lifetime risk of cancer and
cardiovascular disorders. On the other hand, diets high in plant-derived foods offer a
protective effect. Recent studies indicate that the development of these pathologies is
inversely associated with the consumption of natural polyphenolic compounds, which are
known to affect angiogenesis. Identification and characterization of dietary phytochemicals
able to block, slow or reverse angiogenesis may, thus, constitute an important strategy for
prevention of cancer and cardiovascular disease. Catechin is a bioactive phytochemical
abundant in some beverages like tea and wine and also in fruits and vegetables.
The purpose of this study was to investigate the effect of catechin in angiogenesis, namely
evaluating its effects on human umbilical vein endothelial cells (HUVEC) and human
aortic smooth muscle cells (HASMC) viability, apoptosis, proliferation, migration,
invasion and also capillary-like structures formation.
Treatment of cells with 10-100 µM catechin resulted in a significant increase in both
HUVEC (165.34±31.12%) and HASMC (165.58±5.04%) viability assessed by MTT (3-
(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and confirmed by
measuring lactate dehydrogenase activity released to the extracellular medium.
Furthermore, the number of apoptotic cells determined by TUNEL (Terminal
deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling) assay
diminished slightly in HUVEC (to 46.55±12.88%), and drastically in HASMC (to
7.35±4.85%). Proliferation evaluation by measuring Brdu cellular incorporation as well as
determination of cell invasive capacity using Transwell BD-Matrigel basement membrane
matrix insert are still under analysis. Catechin treatment led to a slight reduction in
HASMC cell migration to injured areas (injury assay) but it seemed to increase HUVEC
migration in the same conditions. Incubation of HUVEC on growth factor reduced-
Matrigel-coated plates for 24 h with 10 µM catechin led to the formation of highly
ramified cord-like structures (174.07% ±14.93%).
The results obtained so far indicate that catechin decreased cell apoptosis and exerted
stimulatory effects on endothelial and vascular smooth muscle cell’s viability and on
HUVEC migration and capillary-like structures formation, processes that are required for
the development of physiological and pathological angiogenesis.
Supported by ERAB (EA0641) and FCT (POCTI/SAU-BMA/55556/2004).
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