The invention provides a fruit extract or active fraction thereof for use inthe prophylaxis or treatment of a disease state initiated or characterised byplatelet aggregation, including for use in the manufacture of a correspondingpharmaceutical composition. The fruit extract or active fraction thereof ispreferably a tomato fruit extract or active fraction thereof which comprises aheatstable, colourless or straw-coloured water soluble compound or compoundshaving a molecular weight cut-off of 1000 and having platelet aggregationinhibiting activity.