ABSTRACT
β-Amyloid deposition as fibrillar plaques in brain is the primary cause of Alzheimer’s disease. We report potency of cysteine protease ‘fruit bromelain’ from pineapple in destabilising Aβ fibrils. Bromelain peptide pool (Mw<500 Da) obtained mimicking human alimentary tract digestion inhibited fibrillation from monomeric and oligomeric states of A and irreversibly dissociated preformed fibrils into small oligomers of varied sizes. Time kinetics was followed by Thioflavin-T assay and microscopic imaging. Synthetic bromelain peptides corresponding to Aβ sticky region found using ClustalW analysis revealed specificity of peptides in destabilisation of amyloidal structures. Spectra of different molecular states of Aβ obtained from application of 8-anilino-1-naphthalenesulfonic acid, circular dichroism and Fourier-Transformed Infrared spectroscopy collectively indicated interaction dependent structural change. Probable mechanism for fibril dissociation was thus predicted. Peptides relieved Aβ cytotoxicity on pheochromcytoma cells and dissociated plaques in AD-type rats prepared by bilateral intracerebroventricular administration of Aβ in rat brain cortex. Pineapple being a phytoceutical, its efficiency to disaggregate amyloid bodies warrant further investigation.
Competing Interest Statement
The authors have declared no competing interest.