Purification and Identification of Bioactive Oligopeptide from Indian Halibut (Psettodes erumei) Muscle Tissue and Its Inflammation Suppressing Effect In Vitro

In this study, sole fish (Psettodes erumei) muscle mass was used for the isolation of inflammation suppressing peptide through the enzymatic hydrolysis process. The amino acid composition revealed high amount of histidine, alanine, lysine in the crude muscle tissue. The anti-inflammatory assays performed on enzymatic hydrolysates showed that protein inhibition and membrane protection activity was highest for 12th h trypsin hydrolysate to be 81.64 ± 1.54% and 73.3 ± 1.03% respectively. This active hour hydrolysate was subjected to partial separation and chromatographic purification where the peak showing the highest anti-inflammatory activity was subjected to liquid chromatography-mass spectrometry (LC–MS/MS) which revealed a short novel peptide sequence of MTQML with a molecular weight 622 Da. The peptide was observed to be functionally stable and in vitro study revealed that the peptide was non-cytotoxic and reduced the expression of nitric oxide as well as nuclear factor kappa B (NFκB) complex. This leads to the downregulation of the NFκB signaling pathway and suppression of inflammation. Furthermore, molecular docking analysis confirmed the binding of peptide to cytokine and NFκB-p65 receptors to their inhibiting site at lower binding energy. This novel bioactive peptide could be used as non-toxic inflammation suppressing therapeutic in nutraceutical as well as pharmaceutical applications.