Two novel antioxidant peptides derived from Arca subcrenata against oxidative stress and extend lifespan in Caenorhabditis elegans

Abstract Arca subcrenata has been used as a nutritious food material and traditional medicine in China for centuries. Two novel antioxidant peptides, D2-G1S-1 (VENAACTTNEECCEKK) and G2-G1S-2 (VEGGAACTTGGEEGCCEKK), were identified from A. subcrenata by de novo peptide sequencing. These peptides exhibited potent DPPH and ABTS + radical scavenging activities and ferric-reducing antioxidant ability. Thermal and pH treatments did not alter the antioxidant activities of the peptides. In addition, the peptides enhanced the mean lifespan of Caenorhabditis elegans and significantly improved age-associated physiological functions in the nematode. Furthermore, the peptides decreased the accumulation of ROS, fat and lipofuscin in nematodes under increased oxidative stress induced by paraquat. RNA-sequencing analysis and qRT-PCR experiment showed that the peptides could significantly downregulate gene age-1 and upregulate stress-inducible genes, viz., mtl-1, sod-3, ctl-1 and hsp16.2. Therefore, D2-G1S-1 and D2-G1S-2 might prolong nematode lifespan and could be developed as potential cosmetics additives.