TNF-α and IL-10 modulation induced by polyphenols extracted by olive pomace in a mouse model of paw inflammation

Background. Polyphenols from olive are known to possess antioxidant and anti-inflammatory properties. Aim. The aim of this study was to study whether or not 10 consecutive days i.p. administration of a blend of olive (Olea europaea L.) polyphenols (10 mg/kg) containing mostly hydroxytyrosol could have an effect on cytokines playing important roles in inflammatory processes as TNF-alpha and IL-10. Materials and methods. Inflammation was induced in the mouse paw by 2 carrageenan injections (50 mu l vol, 5 mg/kg each). TNF-alpha and IL-10 were measured by enzyme-linked immunosorbent assay. Results. Carrageenan decreased IL-10 in the paws, however, this reduction appeared to be less evident in mice treated with carrageenan but administered with polyphenols. As for TNF-alpha, our findings did not reveal differences between groups but an increase in the polyphenol and carrageenan group if compared to the carrageenan only group. As for antioxidant polyphenols' properties, no differences between groups in the serum glutathione were found. Conclusions. Altogether, this investigation shows that olive polyphenols in the mouse may modulate the levels of cytokines having a role in the process of inflammation as TNF-alpha and IL-10.