• Biomedical Science Letters
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• v.27 no.4
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• pp.270-276
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• 2021

Physiological agents trigger a signaling process called "inside-out signaling" and activated platelets promote adhesion, granule release, and conformational changes of glycoprotein IIb/IIIa (αIIb/β₃). Activated αIIb/β₃ interacts with fibrinogen and initiates a second signaling step called "external signaling". These two signaling pathways can cause hemostasis or thrombosis, and thrombosis is a possible medical problem in arterial and venous vessels, and platelet-mediated thrombosis is a major cause of cardiovascular disease (CVD). Therefore, modulating platelet activity is important for platelet-mediated thrombosis and cardiovascular disease. Esculetin is a coumarin-based physiologically active 6,7-dihydroxy derivative known to have pharmacological activity against obesity, diabetes, renal failure and CVD. Although some studies have confirmed the effects of esculetin in human platelet activation and experimental mouse models, it is not clear how esculetin has antiplatelet and antithrombotic effects. We confirmed the effect and mechanism of action of escultein on human platelets induced by collagen. As a result, esculetin decreased Ca²⁺ recruitment through upregulation of inositol 1, 4, 5-triphosphate receptor. In addition, esculetin upregulates cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP)-dependent pathways and inhibits fibrinogen binding and thrombus contraction. Our results demonstrate the antiplatelet effect and antithrombotic effect of esculetin in human platelets. Therefore, we suggest that esculetin could be a potential phytochemical for the prevention of thrombus-mediated CVD.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.5
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• pp.625-630
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• 2013

Erectile dysfunction (ED) is a highly prevalent disorder that affects millions of men worldwide. ED is now considered an early manifestation of atherosclerosis, and consequently, a precursor of systemic vascular disease. Lycii fructus extracts (LFE) were administered for 4 weeks to assess the improving effects on ED. Animals were divided into one normal group and four LFE-treated groups (0, 0.3, 0.6, and 1.2 g/kg). We induced ED in the study animals by oral administration of 20% ethanol instead of water everyday for 4 weeks. This study was designed to investigate the effects of LFE on the mRNA levels of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) expression; NO levels of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP); blood profile; and erectile response of the corpus cavernosum of the rat penis. The libido of the LFE-administered male rats was higher than that of the ethanol control group. The erectile response of the corpus cavernosum was restored after LFE administration, to a level similar to the normal group. In addition, the iNOS in the corpus cavernosum of the male rats administered LFE decreased. In contrast, compared to the control group, LFE-administered male rats showed increased eNOS, NO and cGMP levels in the corpus cavernosum. These results indicate that LFE effectively restored ethanol-induced ED in male rats.