Flavonoids purified from parsley inhibit human blood platelet aggregation and adhesion to collagen under flow.

INTRODUCTION: Blood platelets are directly involved in both haemostatic and pathologic thrombotic processes, through their adhesion, secretion and aggregation. In this study, we investigated the effect of genins (aglycone flavonoids without sugar group) isolated from parsley (Petroselinum crispum) leaves in vitro on human platelet aggregation and adhesion to a collagen-coated surface under physiologic flow conditions. MATERIALS AND METHODS: The aggregation and adhesion studies were monitored after pre-incubation of platelets with genins. RESULTS: Genins inhibited dose dependently aggregation induced by thrombin, ADP and collagen. The strongest effect was observed in collagen induced aggregation (IC50 = 0.08 ± 0.01 mg/ml). The HPLC identification of genins compounds revealed the presence of keampferol, apigenin and other not identified compounds. The aggregation tests showed that these compounds have anti-aggregating activity. In addition, adhesion of human platelets to collagen was greatly decreased (over 75 %) by genins (0.3 mg/ml). While the mechanism by which genins act is unclear, we suggest that these compounds may interfere with a multiple target step in the haemostasis process. CONCLUSION: These results show that genins isolated from parsley has a potent antiplatelet activity. It may be an important source of beneficial antiplatelet compounds that decrease thrombosis and cardiovascular diseases.

Vasorelaxant and anti-platelet aggregation effects of aqueous Ocimum basilicum extract.

AIM OF THE STUDY: In this work the endothelium-dependant vasorelaxant and anti-platelet aggregation activities of an aqueous extract from Ocimum basilicum were studied. MATERIALS AND METHODS: The vasorelaxant effect was undertaken in thoracic aorta from three experimental groups of rats: one of them (NCG) fed with standard diet, the second (HCG) with hypercholesterolemic diet (HCD) and the third (BTG) with hypercholesterolemic diet together with an intragastric administration of Ocimum basilicum extract at a dose of 0.5 g/kg body weight for a period of 10 weeks. The in vitro anti-platelet aggregation of Ocimum basilicum extract was studied using thrombin (0.5 U/ml) and ADP (5 microM) as agonists. RESULTS: The results show that the HCD statistically decreases vascular relaxation in HCG compared to NCG (p<0.001) and increases the vascular responses to phenylephrine (p<0.02). Ocimum basilicum extract exerts a significant vasorelaxant effect at 10(-5) M (p<0.01) and 10(-4) M carbachol (p=0.001). The plant extract also tends to suppress the elevated contractions induced by HCD (p=0.05). The extract inhibits ADP-induced platelet aggregation by 13%, 28.2%, 30.5%, 44.7% and 53% at a dose of 1, 2, 3, 4 and 5 g/l, respectively. Thrombin-induced platelet activation was also reduced by 15%, 23%, 40%, 38.4%, and 42% at the same doses of extract described above. CONCLUSION: The use of Ocimum basilicum as medicinal plant could be beneficial for cardiovascular system.

Parsley extract inhibits in vitro and ex vivo platelet aggregation and prolongs bleeding time in rats.

Many cardiovascular diseases are associated with an increase in blood platelet activity. In Morocco, parsley (Petroselinum crispum, Apiaceae) is one of the medicinal herbs used to treat cardiovascular diseases such as arterial hypertension. In this study, crude aqueous extract (CAE) of parsley was evaluated for its anti-platelet activity in experimental animals on platelet aggregation in vitro and ex vivo; and on bleeding time in vivo. The in vitro aggregation was monitored after pre-incubation of platelets with CAE. The bleeding time and ex vivo aggregation were performed after oral treatment. CAE inhibited dose dependently platelet aggregation in vitro induced by thrombin, ADP, collagen and epinephrine. The oral administration of CAE (3g/kg) inhibited significantly (p<0.001) platelet aggregation ex vivo and prolonged bleeding time (p<0.001) without changes in the platelet amount. The prolongation of bleeding time by CAE may be attributed to the observed inhibition of platelet aggregation. These effects could be related in part to the polyphenolic compounds present in the extract. These results support the hypothesis that the dietary intake of parsley may be benefit in the normalization of platelet hyperactivation, in the nutritional prevention of cardiovascular diseases and are potentially interesting in the development of new prevention strategies.