Isolation and effects of some ginger components of platelet aggregation and eicosanoid biosynthesis

Aqueous ginger extract was extracted in three organic solvents viz., n-hexane, chloroform and ethyl acetate with increasing polarity. The extracted materials from these solvents reduced platelet thromboxane formation from exogenous arachidonate (AA) and also inhibited platelet aggregation induced by AA, epinephrine, ADP and collagen; in this respect they were most effective against AA-induced aggregation. The extracted material in n-hexane was further resolved by thin-layer chromatography into various fractions some of which were effective in inhibiting platelet thromboxane formation and platelet aggregation. Aqueous ginger extract reduced the formation of TxB2 from AA-labelled platelets without showing effects on platelet phospholipase activity. Thromboxane formation in labelled platelets on activation with calcium ionophore A23187 was reduced by ginger components, isolated from two TLC bands, in a dose-dependent manner (10-100 ug/500 ml). At the higher dose lipoxygenase products were also reduced. Interestingly the incorporation of AA into platelet phospholipids increased in platelets treated with aqueous ginger extract.