RM12 similar to substance P from tachykinin of freshwater murrel Channa striatus influence intracellular ROS in vitro fish erythrocytes and developmental toxicity and antioxidant enzymes in vivo zebrafish embryo

In this study, substance P, an antioxidant peptide of tachykinin, was identified using bioinformatics tools from the earlier established muscle transcriptome of a freshwater murrel Channa striatus and the peptide was named RM12. The antioxidant properties of RM12 were screened using various colorimetric assays. The toxicity of RM12 was experimented using fish erythrocytes, and it is observed that the maximum concentration (320 μM) of RM12 was found to have 15 or 20% of hemolytic activity; however, it was not significant with other tested concentrations (10, 20, 40, 80, and 160 μM). Further, the in vivo antioxidant properties of RM12 were experimented on zebrafish embryo, the intracellular ROS level was estimated by 5 mM H 2 O 2 stress in the zebrafish embryo, and inhibition of apoptosis was evaluated. The antioxidant enzymes were extracted from the H 2 O 2 -stressed zebrafish embryo, and the intracellular ROS was eliminated due to RM12. Collectively, the experiment showed that the substance P from the freshwater murrel C. striatus possessed potent antioxidant properties; thus, it can further be focused to develop it as antioxidant molecule in aquaculture organisms.