The influence of bromelain on platelet count and platelet activity in vitro

Bromelain is a general name for a family of sulfhydryl-containing, proteolytic enzymes from the pineapple plant. The aim of the present study was to investigate the influence of bromelain on platelet count, platelet aggregation and platelet activity in vitro. Blood samples were taken from the antecubital vein of 10 healthy male non-smokers. Platelet count decreased after incubation with 2.5 and 5 mg bromelain/ml from 277 +/- 17 platelets/nl before to 256 +/- 21 and 247 +/- 19 platelets/nl after the treatment. The ADP and TRAP-6 induced platelet aggregation led to a significant decrease after the incubation with 2.5 mg (ADP: 48.6 +/- 25.7%; TRAP-6: 49.6 +/- 28.9%) or 5 mg (ADP: 5.0 +/- 4.6%; TRAP-6: 9.0 +/- 4.9%) bromelain/ml in comparison to control (ADP: 81.4 +/- 5.0%; TRAP-6: 77.4 +/- 10.4%). The percentage of unstimulated CD62P positive platelets which were investigated by flow cytometry was minimally higher after incubation with 5 mg bromelain/ml (0.57 +/- 0.48% PC) in comparison to control (0.22 +/- 0.11% PC), but after TRAP-6 stimulation the incubation with 5 mg bromelain/ml led to a remarkable decrease in comparison to the untreated control (50.4 +/- 20.2 to 0.9 +/- 0.8% PC). The changes of CD62P (TRAP-stimulated) and the results of platelet aggregation after incubation with bromelain in vitro may demonstrate the potential of bromelain as a substance for platelet inhibition.