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9‐trans,11‐trans ‐CLA: Antiproliferative and proapoptotic effects on bovine endothelial cells
Author(s) -
Lai KuanLin,
TorresDuarte Armida P.,
Vanderhoek Jack Y.
Publication year - 2005
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-005-1474-1
Subject(s) - lipidology , clinical chemistry , apoptosis , chemistry , microbiology and biotechnology , cancer research , biochemistry , biology
Endothelial cell function can be influenced by nutrition, especially dietary FA and antioxidants. One class of dietary FA that is found in meat and dairy products derived from ruminant animals is conjugated linoleic acids (CLA). We have examined the effects of several CLA isomers on endothelial cell proliferation. 9 t ,11 t ‐CLA was the only isomer that inhibited bovine arotic endothelial cell (BAEC) [ 3 H]methylthymidine incorporation (I 50 =35 μM), and this antiproliferative effect was time‐dependent. A small decrease (20%) in cell number was observed only at the highest concentration (60 μM) tested. The 9 c ,11 t ‐, 9 c ,11 c ‐, 10 t 12 c ‐, and 11 c ,13 t ‐CLA isomers did not exhibit any antiproliferative effects over a 5–60 μM concentration range. α‐Tocopherol and BHT decreased BAEC proliferation, but pretreatment of cells with either of these antioxidants substantially attenuated the antiproliferative effect of 9 t ,11 t ‐CLA. No difference in lipid peroxidation, as measured by the thiobarbituric acid assay for malondialdehyde, was observed on treatment of endothelial cells with either 9 t ,11 t ‐ or 9 c ,11 t ‐CLA. However, a 43% increase in caspase‐3 activity was observed after incubating BAEC with 9 t ,11 t ‐CLA, suggesting that the antiproliferative effect of this isomer is partially due to an apoptotic pathway. In contrast to the above results with normal endothelial cells, these five CLA isomers all inhibited proliferation of the human leukemic cell line THP‐1, with the 9 t ,11 t isomer again being the most (I 50 =60 μM) effective. These results confirm that different CLA isomers have different inhibitory potencies on the proliferation of normal and leukemic cells.