• Journal of Korean Public Health Nursing
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• v.14 no.1
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• pp.172-181
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• 2000

This study was designed to evaluate the degree of the anxiety and discomfort experienced by first-time donors in platelet donation. The subject of this study was 309 first-time platelet donors visiting apheresis unit of St. Mary hospital in Seoul. The data was collected from Questionnaire during period of 28 April to 10 September 1999. The statistical methods used were t-test. ANOVA and stepwise multiple regression. The results were as follows. 1. The most common group were 21-30 years of age and soldier of job. 2. The mean scores of the platelet donor's anxiety was $1.60\pm0.32$. 3. The mean scores of platelet donor's discomfort was $1.72\pm0.44$. 4. The variables influencing anxiety were the physical condition. the level of education and donation experience. 5. The variables influencing discomfort were the job. diet before donation and physical condition. As the result above. the student group of the first time platelet donor experienced highest anxiety. It is important to assess the physical condition and diet before donation for more comfortable platelet donation. Furthermore. the developments of nursing interventions are required to reduce anxiety and discomfort of platelet donors.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.887-894
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• 1996

Cyclopiazonic acid(CPA) known as stimulating the release of intracellular calcium, aflatoxin $B_1(AFB_1)$ causing gastrointestinal hemorrhage frequently were used as model toxic mycotoxins in these studies. First of all, the effects of various mycotoxins on the platelet aggregation response were determined. The effects of mycotoxins on the ATP release from platelet by aggregating factors were investigated. The results and conclusions obtained from these studies are : 1) CPA promoted ADP, collagen, thrombin, A.A. and PAF-induced rabbit platelet aggregation. $AFB_1$ inhibited collagen, A.A. and PAF-induced rabbit platelet aggregation only. 2) CPA increased both aggregation and disaggregation time, whereas $AFB_1$ decreased in a dose dependent manner. 3) CPA increased ADP, thrombin, A.A. and PAF-induced ATP release. $AFB_1$ increased A.A.-induced ATP release and decreased PAF-induced release in a dose dependent manner. In conclusion, CPA promoted platelet aggregation by the increase of ATP. Antiaggregating effects of AFB1 may be due to decreases of ATP. These data provide the basis for the future study of roles of ATP release in platelet aggregation.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.1-10
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• 2019

This Dietary cholesterol augments lipid profile and primes production and activation of platelets, leading to development of atherosclerosis which produce several detrimental effects on cardiovascular health. Ethnomedicine and Mediterranean diet are natural sources and cost effective modes against several ailments including cardiovascular diseases while fermented foods have gained interest due to their increased nutrient profile, enhanced bioavailability and efficacy. Garlic has been known to reduce cholesterol and inhibit platelet activation. We examined whether fermented garlic ameliorates effects of hypercholesterolemia and platelet functions in rats. Methodology: Male SD rats were fed with hypercholesterolemia diet and treated with spirulina, fermented and non-fermented preparations of garlic for one month. Platelet aggregation and granule secretion were assessed to evaluate platelet activation. Liver and kidney weights, lipid and enzymatic profile of serum and whole blood analysis was performed. Expressions of SREBP, ACAT-2 and HMG-CoA were assessed using RT-PCR while liver and adipose tissues were analyzed for histological changes. Both fermented and non-fermented garlic inhibited platelet aggregation and granule secretion while fermented garlic showed greater inhibitor tendency. Fermented garlic significantly reduced liver weight and triglycerides concentrations than non-fermented garlic. Similarly, fermented garlic greatly abrogated the detrimental effects of steatosis on liver and adipose tissues. Fermented garlic significantly improved lipid profile and modulated platelet functions, thereby inhibiting atherosclerosis and platelet related cardiovascular disorders.

• Biomedical Science Letters
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• v.25 no.2
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• pp.123-130
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• 2019

Platelet aggregation is essential for hemostatic process in case of blood vessels damages. However, excessive platelet aggregation can cause cardiovascular disorders including atherosclerosis, thrombosis and myocardial infarction. Scopoletin is usually found in the roots of genus Scopolia or Artemisia, and is known to have anticoagulant and anti-malarial effects. This study investigated the effect of scopoletin on human platelet aggregation induced by U46619, an analogue of thromboxane $A_2(TXA_2)$. Scopoletin had anti-platelet effects by down-regulating $TXA_2$ and intracellular $Ca^{2+}$ mobilization ($[Ca^{2+}]_i$), the aggregation-inducing molecules generated in activated platelets. On the other hand, scopoletin increased the levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are known to be intracellular $Ca^{2+}$ antagonists. This resulted in inhibition of fibrinogen binding to ${\alpha}IIb/{\beta}_3$ in U46619-induced human platelet aggregation. In addition, scopoletin inhibited the release of adenosine trisphosphate (ATP) in dose-dependent manner. This result means that the aggregation amplification activity through the granule secretion in platelets was suppressed by scopoletin. Therefore, we demonstrated that scopoletin has a potent antiplatelet effect and is highly likely to prevent platelet-derived vascular disease.

• Korean Journal of Pharmacognosy
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• v.52 no.3
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• pp.127-133
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• 2021

Platelet activation plays a major role in cardiovascular disorders (CVDs). Thus, disrupting platelet activation represents an attractive therapeutic target on CVDs. Esculetin, a bioactive 6,7-dihydroxy derivative of coumarin, possesses pharmacological activities against obesity, diabetes, renal failure, and CVDs. In other report, the effect of esculetin has been examined in human platelet activation and experimental mouse models, and esculetin inhibited collagen- and arachidonic acid-induced platelet aggregation in washed human platelets. However, it had no effects on other agonists such as thrombin and U46619, and its mechanism is not also clearly known. This study investigated the effect of esculetin on collagen-induced human platelet aggregation, and we clarified the mechanism. Esuletin has effects on the down regulation of PI3K/Akt and MAPK, phosphoproteins that act in the signaling process in platelet aggregation. The effects of esculetin reduced of TXA₂ production and phospholipase A₂ activation, and intracellular granule secretion including ATP and serotonin, leading to inhibit platelet aggregation. These results clearly clarified the effect of esculetin in inhibiting platelet activity and thrombus formation in humans.

• Korean Journal of Pharmacognosy
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• v.53 no.2
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• pp.64-69
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• 2022

When blood vessels are damaged, a rapid hemostatic response should occur in order to lower blood loss and keep normal circulation, and platelet activation and aggregation are essential. Nevertheless, abnormal or excessive platelet aggregation can be a reason of cardiovascular diseases including thrombosis, atherosclerosis, and stroke. Therefore, the screening for a substance which can regulate platelet activation and suppress aggregation reaction is very important for treatment and prevention of cardiovascular diseases. Artemether is a methyl ether derivative of artemisinin, which is isolated from the antimalarial plant Artemisia annua, but research on platelet aggregation or its mechanisms is still insufficient. This study identified the effects of artemether on U46619-induced human platelet aggregation and their granule secretion (ATP and serotonin release). In addition, the effects of artemether on the phosphorylation of PI3K/Akt or MAPK, which are related to signal transduction in platelet aggregation, were studied. As the results, artemether significantly lowered PI3K/Akt and MAPK phosphorylation, which inhibited platelet aggregation through granule secretion (ATP and serotonin release) dose-dependently. Therefore, we suggest that artemether is an antiplatelet substance that regulates PI3K/Akt and MAPK pathway and is of value as a therapeutic and preventive agent for platelet-derived cardiovascular diseases.

• Journal of Food Hygiene and Safety
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• v.19 no.3
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• pp.167-170
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• 2004

The present study was undertaken to investigate the effects of Moutan Cortex Radicis extracts and paeonol, a major component, on rabbit platelet aggregation and thromboxane (TX) $A_2$ formation. Moutan Cortex Radicis methanol and butanol layers (100 ${\mu}g/mL$) showed the weak inhibitions, and water layer (100 ${\mu}g/mL$) had no effect on the collagen-induced platelet aggregation. Whereas, hexane and EtOAc layers potently inhibited the collagen (3 ${\mu}g/mL$)-induced platelet aggregation with the $IC_{50}$ values of 10.9${\pm}$1.0 and 31.5${\pm}$0.8 ${\mu}g/mL$, respectively. Paeonol isolated from the hexane-acetone layer specifically inhibited the collagen-induced platelet aggregation with the $IC_{50}$ value of 113.1 ${\pm}$ 0.9 ${\mu}M$, whereas it had little effects on the other agonists such as AA-, thrombin-, A23187- and thapsigargin-induced platelet aggregations. Paeonol also potently inhibited the collagen-induced TXB formation in rabbit platelet in a concentration-dependent manner. These results suggest that paeonol may inhibit rabbit platelet aggregation by interfering with an essential step in collagen-induced platelet activation and $TXA_2$ formation. Paeonol may be a promising candidate for an antiplatelet agent.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.4
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• pp.281-290
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• 2003

Platelet-rich plasma which is made with the newly developed technique concentrating platelets 3-folds or more is also proven to be very effective method to stimulate and accelerate the healing of bone and soft tissue. This study is aimed to investigate the effect of platelet-rich plasma on the attachment of osteoblast. To evaluate the effect on human, human osteoblast cell line was cultured. Platelet-rich plasma was extracted from the blood of a healthy volunteer. The effect on the attachment was evaluated by MTT assay. To evaluate autocrine and paracrine effect on osteoblast, conditioned medium was made and compared with platelet-rich plasma. By western blot analysis, the expression of fibronectin and vitronectin in experimental groups was examined. The results were as following: The cellular attachment of osteoblast cell line increased depending on the concentration of platelet-rich plasma and conditioned medium. The amount of increasing was similar between two groups. The expression of fibronectin and vitronectin in platelet-rich plasma and conditioned medium is more than control group in western blot analysis. These findings imply that platelet-rich plasma enhance the cellular attachment by inducing fibronectin, vitronectin from osteoblast and maximize the cellular attachment by using the autocrine and paracrine effect of platelet-rich plasma.

• Biomedical Science Letters
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• v.12 no.4
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• pp.337-341
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• 2006

Platelets clearly play an important role in inflammatory responses. In this study, we aimed to evaluate the relationship between aging and platelet activation. A total number of 799 persons (383 males and 416 females), who were apparently healthy and aged more than 20 years were recruited by a health promotion center in a community-based hospital in Seoul, Korea. We collected material data about their medical history and health behavior. Platelet parameters including mean platelet component (MPC), mean platelet volume (MPV), and platelet component distribution width (PCDW) were determined within 1 hour after blood collection using the ADVIA 120 automated hematology analyzer. The MPC of the women ($27.2{\pm}1.2$) was significantly love. than that of the men ($27.5{\pm}1.3$). The MPC of all participants was found to decrease with increasing age (P<0.01). Study participants in their twenties had the highest MPC ($27.7{\pm}1.1$), followed by those in their thirties ($27.6{\pm}1.1$), forties ($27.4{\pm}1.3$), fifties ($27.2{\pm}1.3$), sixties ($27.2{\pm}1.2$) and seventies ($27.1{\pm}1.2$). Multiple regression analysis showed that aging and gender were related with MPC after adjusting for confounding factors, including age, gender, smoking habit, hypertension, diabetes, body mass index and total cholesterol level. The this study shows that aging is related to platelet activation. Future research will need to determine the implications of increased platelet activation with aging, especially regarding the increased incidence of cardiovascular diseases and related mortalities that occur in older age groups.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.980-985
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• 2009

The study was designed to test anti-platelet effect and find out anti-platelet mechanism of extract from Gamisopunghwalheol-tang in vitro. The extract was investigated for the inhibition against the aggregation of human platelet suspensions induced from collagen by aggregometer. And also the extract was investigated for the inhibition against the aggregation of human platelet suspensions who is taking aspirin or clopidogrel induced from collagen by aggregometer. In collagen-induced platelet aggregation test, the extract significantly inhibited collagen-induced platelet aggregation in a concentration-dependent manner(p<0.05). The extract significantly inhibited collagen-induced platelet aggregation of human platelet who is taking aspirin or clopidogrel ing 0 mg/ml concentration(p<0.05). And the extract inhibited more ingpatients who is taking aspirin. These results show that the extract from Gamisopunghwalheol-tang has anti-platelet aggregation effect.