Open AccessLicochalcones extracted from Glycyrrhiza inflata inhibit platelet aggregation accompanied by inhibition of COX-1 activity
Author(s) -
Asa Okuda-Tanino,
Daiki Sugawara,
Takumi Tashiro,
Masaya Iwashita,
Yutaro Obara,
Takuya Moriya,
Chisato Tsushima,
Daisuke Saigusa,
Y. Tomioka,
Kuniaki Ishii,
Norimichi Nakahata
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0173628
Subject(s) - chemistry , arachidonic acid , platelet , cyclooxygenase , thromboxane a2 , pharmacology , thromboxane , thrombin , biochemistry , thromboxane a synthase , prostaglandin , inhibitory postsynaptic potential , thromboxane b2 , enzyme , receptor , medicine , endocrinology , biology
Licochalcones extracted from Glycyrrhiza inflata are known to have a variety of biological properties such as anti-inflammatory, anti-bacterial, and anti-tumor activities, but their action on platelet aggregation has not yet been reported. Therefore, in this study we investigated the effects of licochalcones on platelet aggregation. Collagen and U46619, a thromboxane A 2 receptor agonist, caused rabbit platelet aggregation, which was reversed by pretreatment with licochalcones A, C and D in concentration-dependent manners. Among these compounds, licochalcone A caused the most potent inhibitory effect on collagen-induced platelet aggregation. However, the licochalcones showed marginal inhibitory effects on thrombin or ADP-induced platelet aggregation. In addition to rabbit platelets, licochalcone A attenuated collagen-induced aggregation in human platelets. Because licochalcone A also inhibited arachidonic acid-induced platelet aggregation and production of thromboxane A 2 induced by collagen in intact platelets, we further examined the direct interaction of licochalcone A with cyclooxygenase (COX)-1. As expected, licochalcone A caused an inhibitory effect on both COX-1 and COX-2 in vitro . Regarding the effect of licochalcone A on COX-1 enzyme reaction kinetics, although licochalcone A showed a stronger inhibition of prostaglandin E 2 synthesis induced by lower concentrations of arachidonic acid, Vmax values in the presence or absence of licochalcone A were comparable, suggesting that it competes with arachidonic acid at the same binding site on COX-1. These results suggest that licochalcones inhibit collagen-induced platelet aggregation accompanied by inhibition of COX-1 activity.