Studies on New Activities of Enantiomers of 2-(2-Hydroxypropanamido) Benzoic Acid: Antiplatelet Aggregation and Antithrombosis.

R-/S-2-(2-Hydroxypropanamido) benzoic acid (R-/S-HPABA), a marine-derived anti-inflammatory drug, however, the antiplatelet and antithrombotic effects have not been investigated. In this paper, the in vitro antiplatelet activities and in vivo antithrombotic effects of R-/S-HPABA were investigated, for the first time. The effects of R-/S-HPABA on platelet aggregation induced by adenosine diphosphate (ADP), collagen (COLL) and arachidonic acid (AA) were evaluated. In addition, the in vivo bleeding time, clotting time, collagen-epinephrine induced pulmonary thrombosis and common carotid artery thrombosis were also investigated in rats. R-/S-HPABA significantly inhibited ADP, COLL and AA induced platelet aggregation in rabbit platelet rich plasma in vitro compared with control group, to a degree similar to that of aspirin. Besides, R-/S-HPABA prolonged bleeding time and clotting time as well as increased the recovery rate obviously in pulmonary thrombosis. Moreover, the level of thromboxane B₂ (TXB₂) was decreased while the production of 6-keto-prostaglandin F1α (6-keto-PGF1α) was increased markedly by R-/S-HPABA. Furthermore, R-/S-HPABA reduced carotid artery thrombosis weight. These results illustrated that R-/S-HPABA could be a potent antiplatelet aggregation and antithrombotic agent. [ABSTRACT FROM AUTHOR]