The in vitro Effects of a Tomato Extract on Neoangiogenesis-Controlling Molecules in Colon Carcinoma Cells

The aim of this study was to reveal the antiproliferative effect of two tomato extracts on colorectal cancer cells in vitro, and to show their influence on the secretion of growth factors involved in tumor neoangiogenesis: VEGF and Endothelin-1, in order to reveal some of the inhibitory mechanisms exerted by the lycopene-containing tomato extracts. Human colon cancer cell lines DLD1 and HT29 were treated with two different tomato extracts, obtained from fresh and frozen tomato fruits. The cytotoxicity of the compounds was measured using the MTT test, while the expression of VEGF and Endothelin-1 was assessed by ELISA. Results showed that the extract from frozen tomatoes was more cytotoxic as the analogue from fresh tomatoes on both cell types, and both extracts were more toxic against DLD-1 cell line. VEGF and Endothelin-1 expression was also reduced by the tomato extracts, especially in DLD1. In vitro tests demonstrated that the lycopene-containing tomato extracts reduce the growth of malignant cells by tumor neovascularization hindrance, opening new perspectives to their employment in human therapeutic purposes.