Bromelain and Ficin proteolytic effects on gliadin cytotoxicity and expression of genes involved in cell-tight junctions in Caco-2 cells

Abstract

Abstract Enzyme therapy for Celiac disease (CeD), which digests gliadin into non-immunogenic and non-toxic peptides, can be an appropriate treatment option for CeD. Here we have investigated the effectiveness of Bromelain and Ficin on gliadin digestion using in vitro such as SDS-PAGE, HPLC, and circular dichroism (CD). Furthermore, the cytotoxicity of gliadin and 19-mer peptide before and after digestion with these enzymes was evaluated using the MTT assay in the Caco-2 cell line. Finally, we examined the effect of these treatments along with Larazotide Acetate (LA) on the expression of genes involved in cell tight junctions such as Occludin (OCCL), Claudin 3 (CLDN), Tight junction protein-1 (TGP), and Zonulin (ZON) in the Caco-2 cell line. Our study demonstrated Bromelain and Ficin digestion effects on the commercial and wheat-extracted gliadin by SDS-PAGE, HPLC, and Circular Dichroism (CD). Also, the cytotoxicity results on Caco-2 showed that toxicity of the gliadin and synthetic 19-mer peptide was decreased by adding Bromelain and Ficin. Furthermore, the proteolytic effects of Bromelain and Ficin on gliadin indicated the expression of genes involved in cell-tight junctions was improved. This study confirms that ‌Bromelain and Ficin mixture could be effective in improving the symptoms of CeD.