Supercritical CO2-Extracted Tomato Oleoresins Enhance Gap Junction Intercellular Communications and Recover from Mercury Chloride Inhibition in Keratinocytes

A nutritionally relevant phytochemical such as lycopene, found in tomatoes and other fruits, has been proposed to have health-promoting effects by modulating hormonal and immune systems, metabolic pathways, and gap junction intercellular communication (GJIC). This work analyzes lycopene extracts, obtained from tomato and tomato added with grape seeds by using a safe and environmentally friendly extraction process, based on supercritical carbon dioxide technology (S-CO2). Analysis of the innovative S-CO2-extracted oleoresins showed peculiar chemical composition with high lycopene concentration and the presence of other carotenoids, lipids, and phenol compounds. The oleoresins showed a higher in vitro antioxidant activity compared with pure lycopene and beta-carotene and the remarkable ability to enhance the GJIC and to increase cx43 expression in keratinocytes. The oleoresins, (0.9 mu M lycopene), were also able to overcome, completely, the GJIC inhibition induced by 10 nM HgCl2, mercury(II) chloride, suggesting a possible action mechanism.