Bromelain exerts anti-inflammatory effects in an ovalbumin-induced murine model of allergic airway disease.
OBJECTIVE
Bromelain, a clinically used pineapple extract and natural product, has reported anti-inflammatory and immunomodulatory activities. The purpose of this study was to determine the effect of bromelain treatment in an ovalbumin (OVA)-induced murine model of allergic airway disease (AAD).


METHODS
To establish AAD, mice were sensitized with intraperitoneal (i.p.) OVA/alum and challenged with daily OVA aerosols. Mice were treated i.p. with either saline, 2 or 6 mg/kg bromelain, twice daily for four consecutive days. Bronchoalveolar lavage leukocytes and cytokines, lung histology, airway hyperresponsiveness, and lymphocyte populations via flow cytometry were compared between groups.


RESULTS
Bromelain treatment of AAD mice resulted in reduced total BAL leukocytes, eosinophils, CD4+ and CD8+ T lymphocytes, CD4+/CD8+ T cell ratio, and IL-13.


CONCLUSIONS
Bromelain attenuated development of AAD while altering CD4+ to CD8+ T lymphocyte populations. The reduction in AAD outcomes suggests that bromelain may have similar effects in the treatment of human asthma and hypersensitivity disorders.
Secor
Eric R
ER
Department of Immunology, University of Connecticut, School of Medicine, Farmington, CT, USA.
Carson
William F
WF
Cloutier
Michelle M
MM
Guernsey
Linda A
LA
Schramm
Craig M
CM
Wu
Carol A
CA
Thrall
Roger S
RS
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001963:Bromelains / Q000494:pharmacology*; D016535:Bronchial Hyperreactivity / Q000188:drug therapy* / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D018960:Hyaluronan Receptors / Q000187:drug effects; D006967:Hypersensitivity / Q000188:drug therapy* / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D018960:Hyaluronan Receptors; D001963:Bromelains; D010047:Ovalbumin