Biological Nature Of Platelet Inhibitors From Allium Cepa, Allium Sativum And Auricularia Polytrica

Author(s):  
Amar N Makheja ◽  
Chow Eng Low ◽  
J Bailey

Several lines of evidence indicate that extracts of onion (Allium cepa), garlic (Allium sativum) or Chinese black tree fungus (Auricularia polytrica) inhibit platelet aggregation both in-vitro and in-vivo.A systematic study showed that aqueous extracts of these vegetables produced a dose-dependent inhibition of ADP, arachidonic acid (AA) or collagen-induced platelet aggregation. Onion and garlic juices were extracted sequentially into petroleum ether and diethyl ether. The anti-platelet activity in the aqueous phases was completely inactivated by purified adenosine deaminase. The activity in the petroleum ether layer was further characterised by its effects on the metabolism of 14C-AA by platelets. This oily fraction of onion and garlic suppressed thromboxane synthesis completely and induced a redistribution in the products of the lipoxygenase pathway. Adenosine and allicin (found in the ether layer) inhibited aggregation without affecting AA metabolism. Preparative GC and GC/MS studies showed that the activity of the oily fraction was due principally to paraffinic polysulfides (PPS) of which dimethyl trisulfide was one of the most active. Authentic samples of dimethyl trisulfide duplicated the effects of onion and garlic oils on both aggregation and AA metabolism.

Author(s):  
A.N. Makheja ◽  
J.Y. Vanderhoek ◽  
J.M. Bailey

Onion (allium cepa) and garlic (allium sativum) inhibit platelet aggregation both in vitro and in vivo. An oily chloroform extract of onion was prepared and the anti-platelet activity was purified using standard chromatographic procedures. Inhibitory activity from onion is associated with a non-polar material not inactivated by mild acid or alkali and stable to heating. Similar inhibitory properties were observed with both onion oil and garlic oil (I50/ml PRP = 30-100 μg with different samples of human and rabbit platelets). Platelets incubated with onion inhibitor and 1-14C arachidonic acid showed striking changes in the pattern of radioactive metabolites formed. Most apparent was the almost complete suppression of thromboxane B2 synthesis and the appearance of a new metabolite identified as a product of the platelet lipoxygenase. Measurements of oxygen consumption of treated platelets indicate that these materials inhibit the platelet cyclooxygenase. Similar inhibition of sheep vesicular gland cyclooxygenase was observed with onion oil but not with garlic. Gas chromatographic and mass spectrometric analyses of active extracts of onion and garlic show differences in several major components which may relate to the observed differences in biological activity. The results indicate that two members of the allium family commonly used in the diet contain chemically similar compounds which inhibit platelet aggregation by blocking thromboxane synthesis.


Author(s):  
Mihir K Patel ◽  
Kiranj K. Chaudagar ◽  
Anita A. Mehta

Objective: Although recent advances in the treatment of congestive heart disease, mortality among patients’ remains a questionable remark. Therefore, we evaluated the role of capsaicin on in vitro and ex vivo platelet aggregation induced by Adenosine Di-Phosphate (ADP) as well as in in vivo thrombosis models and role of NO, KATP was also identified in the capsaicin-induced anti-platelet animal model as well as in vivo model of arterial thrombosis.Methods: According to body weight wistar rats were divided into five groups. Group I and Group II was treated with saline and capsaicin (3 mg/kg, i. v), while animals from Group III were treated with N(ω)-nitro-L-arginine methyl ester (L-NAME) (30 mg/kg, i. v) 30 min before administration of capsaicin (3 mg/kg, i. v). Group IV animals were treated with glibenclamide (10 mg/kg,i. v) 30 min before administration of capsaicin (3 mg/kg, i. v). Group V was considered as a positive control and administered clopidogrel (30 mg/kg, p. o). Animals were subjected for in vitro, ex-vivo platelet aggregation assay. ADP (30µM) was utilized as an aggregating agent in these experiments. After these assays; animals of each group were subjected for subaqueous tail bleeding time in a rat model and FeCl3-induced arterial thrombosis model in rats.Results: In ADP-induced in vitro platelet aggregation, a significant reduction in % platelet aggregation was observed at 50µM (64.35±4.641) and 100µM (52.72±4.192) concentration of capsaicin as compared to vehicle control (85.82±3.716). Capsaicin (3 mg/kg, i. v) also showed a significant reduction (49.53±4.075) in ex-vivo ADP-induced platelet aggregation as compared to vehicle control (89.38±2.057). In FeCl3 induced arterial thrombosis model, Capsaicin (3 mg/kg, i. v) exhibited an increase in time to occlusion in this rodent model and presence of the L-NAME and glibenclamide had inhibited the activity of capsaicin.Conclusion: In our study, capsaicin (50 µM, 100µM) exhibited potent anti-platelet activity in ADP-induced platelet aggregation, similarly capsaicin exhibited significant anti-platelet action in the ex-vivo study. Moreover, the presence of L-NAME and glibenclamide inhibited the anti-thrombotic and anti-platelet action of capsaicin. Therefore, it was concluded that NO and KATP may be involved in the anti-thrombotic action of capsaicin.


2021 ◽  
Vol 1 (1) ◽  
pp. 41-52
Author(s):  
Chioma E. Irozuru Irozuru ◽  
Janet O. Olugbodi ◽  
Uche Okuu Arunsi ◽  
Olusola Ladeji

Background: Allium cepa, Allium sativum, and Monodora myristica are commonly sourced food condiments in every household in Nigeria. In the present study, we investigated the phytochemical compositions, in vitro and in vivo antioxidant activity of these plants. Methods: The aqueous extracts from the A. cepa, A. sativum, and M. myristica were evaluated for phytochemical composition using standard protocols while the antioxidant activities were evaluated using the reducing power assay. Forty-five (45) Male Wistar rats (weighing 185±10 g) were divided into five groups (n=9) and were orally administered with 100 mg/kg BW each of A. sativum, M. myristica, A. cepa, and ascorbic acid while the control group received 0.5 mL/kg BW distilled water alone. Animals (n=3) from each group were sacrificed after the 20th, 25th, and 30th days of oral administration. The blood and tissue samples were collected for the analysis of biochemical parameters. Result: Our results revealed the presence of flavonoids, alkaloids, tannins, saponins, and terpenes in the plant extracts. A. sativum had the highest reducing power capacity followed by M. myristica and then A. cepa. The in vitro antioxidants activities demonstrated by the plant extracts were higher than that of ascorbic acid but less than butylated hydroxytoluene. In vivo antioxidant studies showed a marked increase (p<0.05) in the level of catalase with a concurrent decrease (p<0.05) in the levels of MDA and H2O2 in the liver and kidney of rats administered with aqueous extracts of the condiments compared to the normal control and ascorbic acid in the following order control < ascorbic acid < A. cepa < M. myristica < A. sativum. Conclusion: Based on these findings, we infer that the aqueous extracts of A. cepa, A. sativum, and M. myristica are rich in antioxidants and as a result could serve as promising novel functional foods and nutraceuticals


2017 ◽  
Vol 4 (1) ◽  
pp. 1098 ◽  
Author(s):  
Atta-ur Rehman ◽  
Sara Naz ◽  
Muhammad Zaman ◽  
Syed Saeed-ul-Hassan ◽  
Javed Iqbal ◽  
...  

Introduction: Hemostasis is a process which preserves the stability of a closed and high-pressure circulatory system after any vascular injury. Circulating platelets are recruited to the site of injury, where they develop a major component of the developing thrombus, blood clotting, started by tissue factor, concludes in the generation of thrombin and fibrin. Thrombosis is a serious event in the arterial diseases and a major cause in the development of myocardial infarction, stroke and venous thrombo-embolism which justify prominent morbidity and mortality rate. The knowledge of molecular and cellular mechanism of the formation of thrombus has developed considerably in the recent studies by using different in-vitro and in-vivo models of diseases. P. gerardiana nut oil has been reported to possess anti-bacterial, anti-fungal, anti-viral, anti-septic, anti-neuralgic, diuretic, expectorant, hypertensive properties. However, hardly, any data is available regarding effects of nut oil on platelet function. In this study, fibrinolytic activity and effect on platelet aggregation were investigated. Method: P. gerardiana nut oil was extracted by using n-Hexane and then concentrated by rotary evaporator. Anti-thrombotic and fibrinolytic activities were evaluated on blood clot formation. Effects on platelet aggregation of the oil were determined based on collagen or epinephrine induced platelet aggregation. Results: P. gerardiana caused blood clot lysis in-vitro. P. gerardiana nut oil inhibited collagen dependent platelet aggregation while accelerated the epinephrine dependent platelet aggregation. In vitro whole blood coagulation was also reduced. In vivo P. gerardiana nut oil has no significant effect on blood cell indices. Conclusion: P. gerardiana nuts oil can be an effective therapy for the treatment of cardiovascular disorders and thromboembolism.


Author(s):  
H. Johnson ◽  
J. B. Heywood

Ticlopidine (T) is weakly active in vitro, but is a potent inhibitor of platelet aggregation induced by ADP, collagen, thrombin, adrenaline, arachidonic acid, prostaglandin (PG) endoperoxide and thromboxane A2 with a sustained effect, when administered to a variety of animal species, including man. Platelets from treated animals were normal in ultrastructure and 14C-ADP binding was not modified by T. Basal PG synthesis was unaffected, whereas aspirin (A) had a marked inhibitory effect. Platelet cyclo-oxygenase and thromboxane synthetase activities were 90.6±12.9 and 96.1±5.3% of control following T treatment. In contrast to A, T had no effect on vascularprostacyclin (PGI2) synthesis, this being 1.4±0.1, 0.5±0.1 and 1.3±0. 3ng/mg wet weight aorta in T and A-treated and control animals respectively. Platelets from T-treated rats were significantly more responsive to inhibition by exogenous PGI2 (0.2-4 ng/ml) and PGE1 (4- 20 ng/ml). when compared with controls. T administration (30-300 mg/kg) resulted in a dose-dependent inhibition of ADP-induced platelet aggregation (26.0- 87. 5%) and enhancement of platelet reactivity to PGI2 (37.0-159.8%). There was a good correlation between these parameters (r=+0.994). T is a potent inhibitor of platelet aggregati on with a novel mode of action. It is not aspirin-like, but may act to potentiate endogenous PGI2 in vivo, possibly through an effect on platelet adenylate cyclase.


1977 ◽  
Author(s):  
Mary P. Wiedeman ◽  
Ronald F. Turna ◽  
Harvey N. Mayrovitz

A survey of the literature concerning the effect of vasoactive drugs on platelet aggregation would support the generalization that, vasoconstrictors enhance platelet aggregation while vasodilators inhibit the action. Some of the information comes from in vitro studies and some from in vivo studies. Using the bat wing as the experimental site, microscopic observation of the effect of intra-arterial injections of vasoconstrictor drugs (epinephrine and serotonin) and vasodilator drugs (dipyridamole and phenoxybenzamine) confirmed the concept. Platelet activity induced by laser beam after administration of vasoconstrictors showed an increased response while vasodilator drugs produced the converse. In addition, denervated vessels showed diminished activity in platelet aggregate formation. Experimental procedures and responses will be shown by cinemicrophotography.


1981 ◽  
Author(s):  
H D Lehmann ◽  
J Gries ◽  
D Lenke

6- [p-(2-(Chiorpropionylamino)phenyl] -4.5-dihydro-5-methyl-3(2H)-pyridazinone, LU 23051, is primarily characterized by its strong inhibition of platelet aggregation under in vitro and in vivo conditions. In vitro there is a concentration-dependent inhibition of ADP and collagen induced aggregation in platelet rich plasma of man, rat and dog. The inhibitory concentration EC 33 % is 0.0010-0.030 mg/1 (man: ADP-0.030, col 1.-0.013 mg/l) depending on species and type of aggregation. When administered orally in ex vivo experiments on rats and dogs the substance is found to have a dose-dependent antiaggregatory effect in the range from 0.1-3.16 mg/kg. The ED 33 % is 0.27-0.63 mg/kg.-In addition after oral administration the substance has a good inhibitory effect in models being based on intravascular platelet aggregation. Thus, a dose of 1 mg/kg inhibits laser-induced aggregation in mesenteric venules of rats. Mortality after i.v. injection of collagen in mice is reduced by 50 % after a dose of 0.02 mg/kg. A dose of 0.039 mg/kg prolongs the bleeding time of rats by 50 %. The aggregation-inhibiting action is of long duration (0.1 mg/kg p.o.∼24 h). The substance does not interfere with clotting.Besides its effect on platelet aggregation LU 23051 acts as vasodilatator as well. Dilatation of coronary vessels by 100 % is seen in isolated guinea-pig hearts at a concentration of 0.1 mg/l. In spontaneously hypertensive rats the substance has an anti hypertensive effect. The ED 20 % is 0.36 mg/kg p.o.The combination of antiaggregatory and vasodilatatory effects opens up interesting aspects with respect to the pharmacotherapeutic use of the new substance


2017 ◽  
Vol 95 (8) ◽  
pp. 719-723
Author(s):  
Il’ya N. Medvedev

This work was aimed to elucidate the level of in vitro and in vivo aggregation activity of platelets and the functional significance of individual mechanisms of its regulation in patients with grade III arterial hypertension and metabolic syndrome. The study included 29 adult patients (15 men and 14 women) and 25 clinically healthy subjects of similar age. Biochemical, hematological and statistical methods were used. Marked dyslipidemia was associated with active lipid peroxidation. Plasma thromboxane B2 level was increased by 84,8% while 6-ketoprostaglandin F1α level was decreased by 17,9% and the total amount of NO metabolites by 28,7%. The degree of platelet aggregation and their aggregation with collagen 25,0 and 27,5% lower than the respective control values while the respective indices of their aggregation with ristomycin were 25,7 and 46,4% higher. The degree of platelet aggregation and their aggregation with ADP inducer were 25,7 and 58,4% higher than in control while the platelet-discocyte levels were reduced to 48,6 ± 0,4%. The sum of active platelet forms reached 51,4 ± 0,12% vs 17,9 ± 0,09% in control was, the number of small and large aggregates 18,6 ± 0,08 and 5,4 ± 0,04 per 1000 free platelets respectively vs 2,9 ± 0,06 и 0,2 ± 0,06 in control. Excess platelet activity in the patients was due to their enhanced adhesive and aggregative potential and reduced ability to disaggregate. The most important causs of thrombocytopathy was AH, negative changes in plasma lipid composition, and enhanced lipid peroxidation.


2021 ◽  
Vol 53 (1) ◽  
pp. 46-54
Author(s):  
Roxana Elizabeth González ◽  
Verónica Carolina Soto ◽  
María Mirta Sance ◽  
Claudio Rómulo Galmarini

Platelets are essential elements of human blood. In addition to their normal role, platelets are involved in causing myocardial infarction, stroke and other thrombotic disorders. Platelet activation in vivo, probably involves a combination of agonists. Garlic has beneficial effects due to its ability to inhibit platelet aggregation and thromboxane formation. The aim of this work was to evaluate the ability of garlic extracts to inhibit platelet aggregation induced by different agonists and their mixtures in different donors. Significant differences were found in platelet aggregation in response to each agonist (P ≤ 0.05). The highest antiaggregatory effect was observed with arachidonic acid and the lowest effect with collagen-arachidonic acid mixture. Interaction effects between donor and agonist (or mixtures) were detected. The study showed the potential of aqueous garlic extracts to prevent platelet aggregation induced by different agonist. Highlights Platelets play a central role in the progression of atherosclerotic lesions. Blood from nine non-smoker healthy donors was used for in vitro platelet aggregation study. Significant differences were found in platelet aggregation in response to each agonist. Aqueous garlic extracts could prevent platelet aggregation induced by different agonist.


2018 ◽  
Vol 7 (11) ◽  
pp. 440 ◽  
Author(s):  
Wan Lu ◽  
Chi Chung ◽  
Ray Chen ◽  
Li Huang ◽  
Li Lien ◽  
...  

Phospholipase D (PLD) is involved in many biological processes. PLD1 plays a crucial role in regulating the platelet activity of mice; however, the role of PLD in the platelet activation of humans remains unclear. Therefore, we investigated whether PLD is involved in the platelet activation of humans. Our data revealed that inhibition of PLD1 or PLD2 using pharmacological inhibitors effectively inhibits platelet aggregation in humans. However, previous studies have showed that PLD1 or PLD2 deletion did not affect mouse platelet aggregation in vitro, whereas only PLD1 deletion inhibited thrombus formation in vivo. Intriguingly, our data also showed that the pharmacological inhibition of PLD1 or PLD2 does not affect mouse platelet aggregation in vitro, whereas the inhibition of only PLD1 delayed thrombus formation in vivo. These findings indicate that PLD may play differential roles in humans and mice. In humans, PLD inhibition attenuates platelet activation, adhesion, spreading, and clot retraction. For the first time, we demonstrated that PLD1 and PLD2 are essential for platelet activation in humans, and PLD plays different roles in platelet function in humans and mice. Our findings also indicate that targeting PLD may provide a safe and alternative therapeutic approach for preventing thromboembolic disorders.


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