Bromelain's penetration into the blood and sinonasal mucosa in patients with chronic rhinosinusitis.

SUMMARY: The aim of this research is to investigate penetration of Bromelain into sinonasal mucosa in patients with chronic rhinosinusitis (CRS) versus a control group. Bromelain is derived from pineapple (Ananas comosus) and has various pharmacological effects. 40 patients (20 patients and 20 controls) were enrolled in the study. Bromelain 500 mg tablet twice daily was administered for 30 days. We scored bromelain presence in turbinate and ethmoid mucosas and in the serum of both the groups. Bromelain has an excellent distribution from blood to rhinosinusal mucosa. Its diffusion ability may allow the use of bromelain as an anti-inflammatory agent in paranasal sinus pathologies.

Intestinal absorption of undegraded proteins in men: presence of bromelain in plasma after oral intake.

The human adult intestinal epithelium has traditionally been described as nonpermeable to proteins. However, indirect evidence suggests that reduced absorption of undegraded proteins might take place under physiological conditions. Using bromelain (an enzyme obtained from pineapple stems) as a model protein, we studied the extent of this mucosal permeation in 19 healthy men. The protein was detected in plasma by immunoassay and by its proteolytic activity after oral administration. The estimated plasma half-life was 6-9 h. After oral multidosing (3 g/day), plasma concentration reached as much as 5,000 pg/ml by 48 h. From the plasma concentration curve, it could be estimated that an average of 10.8 micrograms of bromelain was present in plasma in the 3- to 51-h period. The presence of undegraded bromelain in plasma was shown unequivocally by immunoprecipitation of plasma samples with antibromelain antibodies, followed by gel electrophoresis and immunodetection. Moreover, the enzyme retained its biological activity, at least in part. Circulating bromelain was found associated with alpha 2-macroglobulin and alpha 1-antichymotrypain. The results of this work confirm the existence of a small but significant intestinal transport of undegraded proteins in healthy men.

Bioavailability of 125I bromelain after oral administration to rats.

Bromelain is a sulphydral protease, derived from the stem and fruit of pineapples. Semi-purified preparations of bromelain are used in the treatment of inflammation and oedema. There is however no unequivocal proof of the absorption of the enzyme after oral administration. In this study, 125I-bromelain was administered orally to rats and blood sampled at various times. The total radioactivity, the TCA precipitable 125I-compounds and the molecular weight profile of 125I-proteins in the plasma were determined. A maximum level, equivalent to 270 ng ml-1 bromelain was found at 1 h after administration. Approximately 40 per cent of the 125I in plasma could be precipitated by 10 per cent trichloroacetic acid. Electrophoretic analysis showed one major peak of radioactivity in the plasma samples, with a molecular weight of 26-32,000 daltons. This is identical to the main molecular weight fraction in the Bromelain mixture and corresponds to the molecular weight of the purified enzyme. In the 1 h plasma sample this peak contained 0.003 per cent of the administered dose per millilitre.

[Absorption of a proteolytic enzyme originating from plants out of the gastro-intestinal tract into blood and lymph of rats (author's transl)]. / Die Resorption eines proteolytischen Enzyms pflanzlichen Ursprunges aus dem Magen-Darm-Trakt in das Blut und in die Lymphe von erwachsenen Ratten.

The absorption of the proteolytic enzyme bromelain was investigated in adult rats. Bromelain was labelled radioactively with 125-Iodine and intraduodenally applied. During the observation time of 6 hours blood- and lymphsamples were collected and their radioactivity measured. By radiochromatography high molecular protein could be separated from low molecular protein fragments. By means of a rabbit-anti-bromelainserum bromelain could be identified in the agar-double diffusion technique. Results show that adult rats can absorb bromelain up to 40% in a high molecular form. This observation explains the increased proteolytic activity in serum after oral application as well as the clinical effect concerning the treatment of edema or hematoma.