Identification of MMP-1 inhibitory peptides from cod skin gelatin hydrolysates and the inhibition mechanism by MAPK signaling pathway

- Cod skin gelatin hydrolysates (CGH) was prepared by alkaline protease and trypsin.
- A UVB-induced fibroblasts photoaging model was established to determine activity.
- The active central fragments were GEIGPSGGRGKPGKDGDAGPK and GFSGLDGAKGD.
- The purified peptides significantly inhibited p-ERK and p-p38 in the MAPK pathway.
- The peptides can act as functional supplements for skin protection products.

Cod skin gelatin hydrolysates (CGH) could serve as a source of peptides with anti-photoaging activity. To prepare CGH, alkaline protease and trypsin were used for enzymatic hydrolysis. The anti-photoaging effects of CGH were evaluated using a UVB-induced mouse skin fibroblasts photoaging model in vitro. CGH could efficiently inhibit the expression of MMP-1, especially at the concentration of 0.1 mg/mL, in the fibroblasts irradiated with UVB of 20 mJ/cm2. In addition, the MMP-1 inhibitory peptides were purified using ion-exchange chromatography and RP-HPLC. The fractions which exhibited the highest activity, were identified using LC-ESI-MS/MS. Finally, two peptides GEIGPSGGRGKPGKDGDAGPK and GFSGLDGAKGD were found to exhibit a significant inhibition of MMP-1, p-ERK and p-p38 and the first purified peptide significantly inhibited p-JNK in MAPK signaling pathways. Therefore, this study provided a scientific basis for the preparation of MMP-1 inhibitory peptides and bioactive peptides can be used as functional supplements for marine skin protection products.