Oral administration of polyphenolic compounds from cognac decreases ADP-induced platelet aggregation and reduces chronotropic effect of isoprenaline in rats

This study sought to evaluate whether consumption ofpolyphenol extract from Cognac (CPC) modulates plateletactivation and cardiovascular reactivity in rats. Male Wistar ratswere treated daily for 4 weeks by intra-gastric gavage receivingCPC at 80 mg/kg/day or vehicle (5 % glucose). Platelet adhesionand aggregation in response to different activators wereassessed. Cardiac and vascular reactivity in response to variousagonists as well as NO measurement by electron paramagneticresonance technique were investigated in isolated heart andthoracic aorta. Oral administration of CPC decreased plateletaggregation induced by ADP but not by collagen. CPC did notaffect adhesion to collagen. The chronotropic but not theinotropic response to isoprenaline was reduced without alterationof NO production in hearts from CPC-treated rats. CPC treatmentdid not affect ex vivo relaxation to acetylcholine nor NO contentof rat aorta. CPC did not significantly alter the response tophenylephrine in aorta despite the participation of endothelialvasoconstrictor products. In summary, chronic treatment withCPC has no impact on ex vivo vascular and cardiac reactivity;however, it reduced heart work and platelet aggregation. Thesedata suggest the existence of compounds in Cognac that maydecrease the risk of coronary thrombosis and protect againstsome cardiac diseases.