Interaction between policosanol and prostacyclin on platelet aggregation in rats

Resumen

Policosanol is a mixture of higher molecular aliphatic primary alcohols, isolated from sugar cane wax, (Saccharum officinarum, L.) whose main component is octacosanol. Oral treatment with policosanol reduced serum cholesterol levels in different experimental models, healthy volunteers and patients with type II hiperliproteinemia. Previous results showed that policosanol orally administered inhibits platelet aggregation induced in vivo by collagen and induced
ex vivo by ADP in rats as well as significantly reduces serum thromboxane B2 levels in rats, Mongolian gerbils and mice and increases prostacyclin serum
levels in Mongolian gerbils. It has been shown that policosanol also exhibits antiplatelet properties in human beings. Prostacyclin (PgI2) is the most potent
endogenous inhibitor of platelet aggregation discovered so far. This study was undertaken to investigate the effect of the interaction of policosanol and PgI2 on
ex vivo platelet aggregation in rats. The sensitivity of PRP to exogenous PgI2 was tested measuring the percentage of inhibition on ADP-induced aggregation (preincubationwith PgI2) and the percentage of disaggregation after addition of PgI2 when the maximal and irreversible response of ADP was reached. The results showed that not only, as has been previously reported, ADP induced aggregation in platelet rich plasma (PRP) of policosanol (200 mg/kg) pretreated animals was significantly lower than in control animals but also that the sensitivity to exogenous PgI2 of PRP in policosanol pretreated animals was also higher than in the controls.