Isolation Of Bromelain And Its Effect Of Debridement

Bromelain can be effectively used for debridement of burns. Its preparations for clinical use have been applied widely in foreign countries. In this study, in order to prepare a bromelain ointment, crude bromelain was refined, the separated fractions' effects with debriding were tested, a preparation and its ability to debride in vivo were studied. First, crude bromelain complying with the national drug standards was used as raw material to be refined. The study of refinement includes the factors below: the concentration of crude bromelain, pH of the solution and the concentration of acetone. The product's proteolytic activity against casein was greatest when the concentration of crude bromelain was 50 mg/ml, pH was 4.0 and the concentration of acetone was 70%. The molecular weights of the fractions calculated from the positions of molecular weight makers in the same SDS-PAGE were about 27 382,16 131,14 933 and 10 846. The fractions of bromelain from national market were familiar to those of bromelain from Japan by SDS-page and chromatography with Sephadex G-75. Three fractions were pooled from chromatography with Sephadex G-75, its proteolytic activity against casein and effect on burn eschar in vitro became less as its molecular weights became lower. The preparation of bromelain was made with PEG4000 and PEG400 and a standard was established. Stability test for bromelain ointment was conducted. To investigate the efficacy of bromelain ointment in the treatment of burn eschar, three degree burn was made with guinea pigs. Refined bromelain ointment, crude bromelain ointment, MEBO and bland ointment were applied to each group respectively. The area of burned eschar after 10 days and the time for debridement of the refined bromelain ointment group was the same with that of the MEBO group, the refined bromelain ointment was more effective than crude bromelain ointment, but both were more effective than bland ointment. After debridement, the tissues of two bromelain ointment groups were same with MEBO group in the pathological analysis.The main results and conclusions of this paper were:(1) Refinement procedure of bromelain was established.(2) The fractions of bromelain were studied and it was proved that different fractions have different ability to debride in vivo.(3) Preparing procedure of bromelain ointment was established and a standard was established.(4) The test for debridement of three degree burns proved that bromelain ointment was effective.