Srivastava K C
Prostaglandins Leukot Med. 1986 Sep;24(1):43-50. doi: 10.1016/0262-1746(86)90205-2.
In vitro effects of an oily extract of onion were examined on the metabolism of arachidonic acid (AA) in human platelets. Onion was found to reduce the formation of thromboxane and lipoxygenase products from exogenous arachidonic acid in platelets; it did not inhibit the incorporation of AA into platelet phospholipids. While not affecting the platelet phospholipase activity it did reduce the formation of thromboxane B2 and lipoxygenase products in platelets that were prelabelled with arachidonic acid and then activated by A23187. This suggests that onion inhibits the formation of AA metabolites by exerting its effect at steps later than the liberation of AA. With concentrations of onion extract producing abolition of AA-induced aggregation, only partial inhibition of aggregation was observed with ADP- and epinephrine-induced aggregation. Onion did not inhibit A23187 induced aggregation. The results suggest that inhibition of platelet aggregation by onion is mediated largely by its effect on platelet thromboxane production.
研究了洋葱油提取物对人血小板中花生四烯酸（AA）代谢的体外作用。发现洋葱可减少血小板中外源性花生四烯酸生成血栓素和脂氧合酶产物；它不抑制花生四烯酸掺入血小板磷脂。虽然不影响血小板磷脂酶活性，但它确实减少了预先用花生四烯酸标记然后用A23187激活的血小板中血栓素B2和脂氧合酶产物的形成。这表明洋葱通过在花生四烯酸释放之后的步骤发挥作用来抑制花生四烯酸代谢产物的形成。在洋葱提取物浓度导致花生四烯酸诱导的聚集消失的情况下，观察到对ADP和肾上腺素诱导的聚集只有部分抑制作用。洋葱不抑制A23187诱导的聚集。结果表明，洋葱对血小板聚集的抑制作用主要是通过其对血小板血栓素生成的影响来介导的。
