Bromelain - Comprehensive Review of Biological Activity

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Re: Bromelain - Comprehensive Review of Biological Activity

 

Maurer HR. Bromelain: biochemistry, pharmacology and medical use.

Cellular and Molecular Life Sciences. 2001; 58:1234-1245.

http://www.herbalgram.org/iherb/herbclip/review.asp?i=43369

 

Bromelain, a proteolytic (protein-cleaving) enzyme derived from

pineapple, has shown antiedematous, anti-inflammatory,

antithrombotic, and fibrinolytic activities. Some recent evidence

points toward a possible immunomodulative function, suggesting that

bromelain may be useful as an adjunct to traditional tumor therapy.

This review article addresses the pharmacology, mechanism of action,

and safety of bromelain.

 

Many claims have been made for bromelain, including efficacy in the

treatment of angina pectoris, bronchitis, sinusitis, surgical

trauma, thrombophlebitis, pyelonephritis, and enhanced absorption of

drugs, particularly antibiotics. While not strongly supported by

clinical studies, proteinases such as bromelain are currently used

in chemotherapy, radiotherapy, surgery, and as lymphedema prevention

due to their ability to reduce inflammation and edema and improve

wound healing.

 

Bromelain's proteolytic activity, including platelet aggregation

inhibition and anti-inflammatory effects, is accompanied by other

non-proteolytic effects such as inhibition of tumor cell growth,

metastasis, and debridement of burns. Anecdotal reports from the

1970s and current in vitro and animal studies suggest that bromelain

has an inhibitory effect on proliferation of malignant cells that is

not limited to its proteolytic or platelet aggregation-inhibitory

activity. Its effects on the immune system also inhibit malignant

cells through increased cellular immune response and reduction of

tumor cell adhesion to endothelial walls. In experimental rats,

debridement of burns by topical bromelain was found to be much

quicker than collagenase and showed no side effects or damage to

adjacent burned tissue.

 

Controlled clinical studies have supported the pharmacological

effects noted in in vitro and animal experiments. Several studies

have shown improvement in symptoms of sinusitis with bromelain

compared to placebo; significant reduction of edema and ecchymoses

in facial and head trauma; reduction in pain, edema, and hematoma in

lower extremity trauma compared to control drug; equivalence to

control drug in reduction of hematoma, edema, flexibility, and pain

from posttraumatic inflammation and swelling; significant

improvement over placebo in reduction of edema, inflammation, and

pain from mediolateral episiotomy; and reduction in pain and

swelling from tooth extraction.

 

While it is clear that bromelain is absorbed after oral ingestion in

a functionally intact form, particularly when tablets are enteric

coated, the amount absorbed and its form in the circulation remains

to be clarified. However, even in view of clinical studies that seem

to support evidence-based pharmacological efficacy of proteinases

such as bromelain, many physicians are skeptical that proteinases

are absorbed in a functionally intact form and doubt any efficacy of

orally ingested enzymes. There currently are no known toxic effects

of bromelain, and side effects, including gastrointestinal disorders

and urticaria, are mild. Therefore, the author states that bromelain

can be used without concern in daily doses up to 2000 mg for

prolonged periods of time. It is suggested that bromelain should be

taken 48 hours prior to a possible trauma from sports activities or

surgery.

 

This article presents several arguments for the use of bromelain for

medical indications. The reversible platelet aggregation inhibition

displayed by bromelain may be of interest in cardiovascular surgery.

The potential for safe and rapid debridement of burns may prove

beneficial for early skin grafting. Proof that bromelain is absorbed

intact after oral administration, as well as its safety and lack of

undesirable side effects, has increased the use of bromelain as a

phytotherapeutic drug. However, further well-designed clinical

studies are required to provide the basis for evidence-based medical

interventions in cancer treatment, inhibition of tumor growth and

invasiveness, skin debridement, inhibition of platelet aggregation,

and other indications.

 

— Diane S. Graves, MPH, RD