The Anti-Inflammatory and Antithrombotic Properties of Bioactives from Orange, Sanguine and Clementine Juices and from Their Remaining By-Products

The anti-oxidant properties of vitamin C and of phenolic compounds of citrus fruits are well established. However, the evaluation of the anti-inflammatory and antithrombotic potential of both vitamin C and of the more amphiphilic and lipophilic components of citrus fruits needs further attention. In this study, the anti-inflammatory and antithrombotic properties of vitamin C and of freshly squeezed juices and their lipid bioactives from the Navalina and Sanguine orange varieties and the Clementine variety of mandarins, as well as from their remaining by-products, were evaluated against the inflammatory and thrombotic pathways of the platelet-activating factor (PAF) and thrombin in platelets, as well as against PAF-biosynthesis in leukocytes. The non-oxidized juices of these citrus fruits and a vitamin C supplement showed stronger anti-PAF and antithrombin effects than their oxidized versions through their general anti-oxidant effect in platelets. The total lipids (TLs) and the HPLC-derived fractions of phenolic compounds and of polar lipid bioactives from both juices and their peels’ by-products showed a more specific stronger inhibitory effect against the inflammatory and thrombotic pathways of PAF and thrombin in platelets, while these bioactives strongly inhibited also the specific enzyme activities of the main biosynthetic enzymes of PAF in leukocytes. The stronger bioactivity of the dietary bioactives found in the juices of these citrus fruits against specific biochemical pathways of inflammation and thrombosis seems to act with synergy with the anti-oxidant potential of their vitamin C content, which further supports the notion that these juices are functional foods with anti-inflammatory protective health benefits. In addition, the presence of these dietary bioactive phenolic compounds and polar lipid bioactives in the remaining peels’ wastes further enhance the valorization of such food industry by-products as potential sources of anti-inflammatory bioactives to be used as ingredients for novel functional products