Gastrointestinal absorption and antiinflammatory effect of bromelain.

The clinical utility of proteolytic enzymes is reported as anti-inflammatory agent in literature (1-3) on the therapy for traumatic or infectious diseases. The anti-inflammatory action is considered to be effectual even with oral administration. Such being the case, gastrointestinal absorption of the enzymes is essential. Qualitative evidence of the gastrointestinal absorption of small amounts of proteins has been reported by a number of workers. Schloss et al. (4-6) employed a qualitative precipitin reaction and an indirect anaphylaxis test to demonstrate that ingested proteins were absorbed from the gastrointestinal tract, and additional studies involving complement fixation methods7) and passive transfer tests8) were also performed to demonstrate the absorption of intact proteins. Lamanna9) studied the gastrointestinal absorption of botulin given rats orally in connection with its toxic reaction. Quantitative absorption studies on bromelain were made by Smyth et al.10) in details with the use of I131-labelled bromelain, but questions remain as to their findings: 1) the maximum absorption level in the blood was as high as 6.3% absorption of the administered dose; 2) no radioactivity was detected of the low molecular I131-tagged substances in the circulation; and (3) excretion of the absorbed I131-bromelain was to the extent of 26% of the administered radio-activity in 4 hr. This communication is primarily concerned with the anti-inflammatory effect of orally administered bromelain, and also deals with the gastrointestinal absorption of bromelain determined by a radioisotope iodine-125 tracer method in combination with immunological techniques of precipitin and Ouchterlony, gel filtration, and electrofocusing.