Effects of Brazilin on the phospholipase A2 activity and changes of intracellular free calcium concentration in rat platelets.
Brazilin (7,11b-dihydrobenz[b]indeno[1,2-d]pyran-3,6a,9,10 (6 H)-tetrol) inhibited thrombin-,collagen- and ADP-induced aggregation of washed rat platelets. Thrombin- and collagen-induced ATP release were also inhibited by brazilin in a concentration-dependent manner. Brazilin inhibited the formation of platelet thromboxane A2 caused by thrombin, whereas it had no effect on the prostaglandin D2 formation. Brazilin inhibited [3H]-arachidonic acid liberation from membrane phospholipids of thrombin-stimulated platelets. Brazilin inhibited the rise of intracellular free calcium caused by thrombin. These results indicate that the inhibition of phospholipase (PLA2) activity and [Ca2+]i elevation might be at least a part of antiplatelet mechanism of brazilin.
Hwang
G S
GS
College of Oriental Medicine, Kyung Won University, Seongnam, Korea.
Kim
J Y
JY
Chang
T S
TS
Jeon
S D
SD
So
D S
DS
Moon
C K
CK
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001578:Benzopyrans / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D010974:Platelet Aggregation; D015230:Prostaglandin D2 / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013929:Thromboxane B2 / Q000378:metabolism
D001578:Benzopyrans; D016718:Arachidonic Acid; D013929:Thromboxane B2; D000255:Adenosine Triphosphate; D010741:Phospholipases A; D054467:Phospholipases A2; C044362:brazilin; D015230:Prostaglandin D2; D002118:Calcium