Abstract: In the present study, the effect of tilapia skin hydrolysates (TSCH) produced with neutral enzyme (NE), alkaline enzyme and pancreatin enzyme on the growth of human skin keratinocyte HaCaT cells was investigated as well as the relationship between antioxidant capacity and cell growth stimulation of TSCH. Results showed that neutral enzymatic hydrolysate (NEH) had significant antioxidant capacity in vitro and cell growth-promoting effect (P < 0.05). When treated by NEH (1–5 ku) at 25 mg/mL, the proliferation of HaCaT cells was most significantly promoted when compared with other hydrolysates (P < 0.05), and NEH also could promote cell scratch healing ((81.10 ± 5.77)%) after treatment for 24 h. Two major peptide components (1–5 ku) were detected from NEH by Sephadex G-25 gel ?ltration chromatography and amino acid composition analysis. The contents of antioxidant amino acids such as phenylalanine, leucine, tyrosine, lysine, arginine and histidine in NEH 1–5 ku were much higher than those in other molecular mass amino acid residues (P < 0.05). The study suggests that the growth-promoting effect of NEH from tilapia skin collagen on HaCaT cells may be related to the significant amount of antioxidant amino acid residues in the peptides.

Key words: tilapia skin, collagen hydrolysate, antioxidant activity, cell growth, HaCaT cell