This paper aimed to explore the mechanism of tetrapeptide VTPY in improving alcoholic gastric injury. VTPY has the potential to enhance the growth and movement of normal GES-1 cells. Following ethanol-induced impairment, VTPY effectively improved migration of GES-1 and HUVEC cells, enhanced angiogenesis, eliminated cellular and mitochondrial ROS, inhibited excessive mitochondrial division, enhanced F-actin polymerization and mitochondrial respiratory capacity. To counteract excessive mitochondrial fission, VTPY primarily restores the mitochondria dynamics by reducing the expression of Drp1 and Fis1, while increasing Mfn2. Further studies utilizing inhibitors clarifies that the inhibition of excessive mitochondrial fission can markedly reduce F-actin depolymerization, consequently enhancing cell migration. Additionally, VTPY can inhibit the apoptosis pathway by maintaining potential of mitochondrial membrane, preventing the release of mitochondrial cytochrome c, bolstering the levels of Bcl-XL, while reducing the levels of Bax and cleaved-caspase3. Further investigations using inhibitors demonstrates that excessive mitochondrial fission could activate apoptotic pathway. However, VTPY counteracts this effect and enhance cells viability. Further evidence suggests that VTPY effectively improves ulcer index and pathologic changes, relieves inflammation, enhances the balance of oxidation and anti-oxidation, promotes angiogenesis, improves the expression of mitochondrial dynamics factors, blocks apoptotic pathway, and subsequently ameliorates gastric damage in mice through Fis-1/Bcl-2 pathway.

Enzymatic hydrolysis, isolation, and purification might make a great deal of difference in antioxidant activity and antigenicity of peptide components. This study aimed to isolate and purify antioxidant peptide components from Antarctic krill and evaluate their allergenicity of them. Electron paramagnetic resonance (EPR) spectroscopy results indicated 310 kDa Antarctic krill hydrolysates (AKHs) had higher DPPH and ·OH radical scavenging rates. And the second component (N2-2) purified 310 kDa hydrolysate showed better ability to scavenge DPPH and ·OH radicals (P < 0.05), which were (47.43 ± 2.18)% and (34.33 ± 1.25)%, respectively. Additionally, indirect-ELISA results revealed that N2-1 had a weaker ability to bind specific IgE and that N2-2 had a lower binding capability to specific IgG1 (P < 0.05). And N2-2 had a higher EC₅₀ value of (5.29 ± 0.95) ng/mL (P < 0.05) in cell degranulation assay, which was about 13.80 times that of Antarctic krill. Therefore, N2-2 might be the potential source of the antioxidant peptides with lower allergenicity.