Antioxidant and cytotoxic activities of peptides obtained by enzymatic and microbial hydrolysis of Liza klunzingeri muscle

Oxidative stress reflects an imbalance in the redox status of the body and plays an important role in the pathogenesis and development of several human diseases such as cancer. This study aimed to evaluate the antioxidant and cytotoxic effects of peptides derived from enzymatic and microbial hydrolysis of Liza klunzingeri muscle. L. klunzingeri muscle was hydrolyzed using enzymatic hydrolysis with alkalase and microbial hydrolysis by Bacillus licheniformis. The antioxidant activity of samples was measured using DPPH, ABTS and hydroxyl radical scavenging, Fe3+ reduction and Fe2+ chelating effects. The cytotoxic effects of hydrolysates on 4T1 cell line were evaluated using MTT assay. The molecular weight distribution of hydrolysates was determined using HPLC. The microbial sample showed better antioxidant activity in the inhibition of ABTS, chelating and reducing of iron (P<0.05). The cytotoxic activity of the microbial sample was significantly higher than that of the enzymatic sample (P<0.05). The percentage of peptides with a molecular weight of less than 1000 Da was 26.15% in enzymatically prepared protein hydrolysate and 75.15% in the microbial sample. The protein hydrolyate derived from microbial hydrolysis shows better antioxidant and cytotoxic activity, probably due to the presence of low molecular weight peptides.