Effects of a diet containing Brazilian propolis on lipopolysaccharide-induced increases in plasma plasminogen activator inhibitor-1 levels in mice

BACKGROUND Brazilian propolis has many biological activities including the ability to help prevent thrombotic diseases, but this particular effect has not been proven. Plasma levels of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of fibrinolysis, increase under inflammatory conditions such as infection, obesity and atherosclerosis and such elevated levels predispose individuals to a risk of developing thrombotic diseases. AIM This study aimed to determine the effects of a diet containing Brazilian propolis on lipopolysaccharide (LPS)-induced increases in plasma PAI-1 levels. MATERIALS AND METHODS Mice were fed with a diet containing 0.5% (w/w) Brazilian propolis for 8 weeks. Thereafter, the mice were subcutaneously injected with saline containing 0.015 mg/kg of LPS and sacrificed 4 h later. RESULTS Orally administered Brazilian propolis significantly suppressed the LPS-induced increase in PAI-1 antigen and its activity in mouse plasma. CONCLUSION This study indicated that Brazilian propolis contains natural products that can decrease thrombotic tendencies in mice.