Abstract
Successful vascular healing after percutaneous coronary interventions is related to
the inhibition of abnormal vascular smooth muscle cell proliferation and efficient
re-endothelialization. In the search for vascular smooth muscle cell anti-proliferative
agents from natural sources we identified piperine (1), the main pungent constituent of the fruits from Piper nigrum (black pepper). Piperine inhibited vascular smooth muscle cell proliferation with
an IC50 of 21.6 µM, as quantified by a resazurin conversion assay. Investigations of ten
piperamides isolated from black pepper fruits and 15 synthesized piperine derivatives
resulted in the identification of three potent vascular smooth muscle cell proliferation
inhibitors: the natural alkaloid pipertipine (4), and the two synthetic derivatives (2E,4E)-N,N-dibutyl-5-(3,5-dimethoxyphenyl)penta-2,4-dienamide
(14) and (E)-N,N-dibutyl-3-(naphtho[2,3-d][1,3]dioxol-5-yl)acrylamide (20). They showed IC50 values of 3.38, 6.00, and 7.85 µM, respectively. Furthermore, the synthetic compound
(2E,4E)-5-(4-fluorophenyl)-1-(piperidin-1-yl)penta-2,4-dien-1-one (12) was found to be cell type selective, by inhibiting vascular smooth muscle cell proliferation
with an IC50 of 11.8 µM without influencing the growth of human endothelial cells.
Key words
Piper nigrum
- Piperaceae - Piperine - vascular smooth muscle cells - inhibition of VSMC proliferation
- SAR - restenosis