On the pharmacology of bromelain: an update with special regard to animal studies on dose-dependent effects.

Bromelain, a standardized complex of proteases from the pineapple plant, is absorbed unchanged from the intestine of animals at a rate of 40%; in animal experiments it was found to have primarily anti-edema, antiinflammatory, and coagulation-inhibiting effects. These effects are due to an enhancement of the serum fibrinolytic activity and inhibition of the fibrinogen synthesis, as well as a direct degradation of fibrin and fibrinogen. Bromelain lowers kininogen and bradykinin serum and tissue levels and has an influence on prostaglandin synthesis, thus acting antiinflammatory. In in vitro and in animal studies, experimentally induced tumours could be inhibited by bromelain. Although many studies do not give extensive statistical data, the effects of bromelain in animal studies seem to be dose-dependent. Further investigations have to be carried out.