Anti-inflammatory effects of extracts from some traditional Mediterranean diet plants.

It is believed that bioactive compounds from plant foods may have health beneficial effects and reduce the risk of chronic inflammatory diseases. In this study extracts of 121 plants typical for the traditional Mediterranean diet have been screened for their potential anti-inflammatory activities. The ability of the extracts to inhibit cytokine-stimulated, iNOS-dependent synthesis of nitric oxide in murine endothelial cells, without affecting cell viability, was the primary indicator of their anti-inflammatory properties. Based on these experiments we selected eight plant extracts for further analysis: Chrysanthemum coronarium L., Scandix pecten-veneris L., Urospermum picroides (L.) Scop. Ex F. W. Smith, Amaranthus cf. graecizans L., Onopordum macracanthum Schousboe, Eryngium campestre L., Artemisia alba Turra and Merendera pyrenaica (Pourret) Fourn. Only the effects of Onopordum macracanthum could be non-specific since the extract strongly inhibited total protein synthesis. All remaining 7 extracts decreased nitric oxide and TNFalpha synthesis in the cells of monocyte origin activated with LPS, and 4 of them significantly reduced surface expression of VCAM1 on TNFalpha-stimulated endothelial cells. All seven plant extracts decreased cytokine or LPS-stimulated iNOS mRNA levels in both cell types. Further research to identify bioactive compounds influencing intracellular signaling pathways activated by cytokines and LPS will consequently be needed in order to better understand these in vitro effects.