Intracellular free radical scavenging activity and protective role of mammalian cells by antioxidant peptide from thioredoxin disulfide reductase of Arthrospira platensis

In this study, we have analyzed the antioxidant role of thioredoxin disulfide reductase (TR) identified from Arthrospira platensis (Ap). A short peptide (VH12) derived from thioredoxin domain between Val(368) and His(379) of ApTR and it named as VH12. The peptide expressed the antioxidant activity against hydroxyl radical and superoxide radical at the concentration of 6.25 mu M. Cytotoxic activity was performed on human leucocytes which showed that VH12 is not cytotoxic to any of the cellular population of human leucocytes. In addition, we determined the intracellular ROS level in cardiac myocytes to know the ROS scavenging level of VH12 peptide; the level of ROS scavenging was nearly 55% by the peptide at a concentration of 12.5 mu M. Finally, the ROS scavenging of the VH12 peptide was tested against H2O2 stress induced zebrafish embryo, in which the intracellular ROS was reduced by the peptide at a concentration of 20 mu M.