标题：GP13, an Arthrospira platensis cysteine desulfurase-derived peptide, suppresses oxidative stress and reduces apoptosis in human leucocytes and zebrafish ( Danio rerio) embryo via attenuated caspase-3 expression
摘要：AbstractArthrospira platensis(Ap) has several advantageous adaptive mechanisms including its efficient response to elevated oxidative stress (OS). This study intends to identify the antioxidant effect,in vitroandin vivo, of a novel peptide (GP13),Ap-derived cysteine-desulfurase (CDS) peptide, for antioxidant role and the associated mechanism(s) by which the GP13 elicits cytoprotection under elevated OS.Using bioinformatics tools, a short sequence of amino acids GP13 with a predicted antioxidant effect has been identified from the cysteine sulfurase domain ofApCDS between 243 and 616 amino acids. The synthesized GP13 peptide expressed significant antioxidant activity against free-radicals at various concentrations (10–80 µM), as established through the DPPH, ABTS, SARS, and HRS assays.Besides, GP13 demonstrated no cytotoxicity on Vero cells and human leucocytes. In H2O2-induced human leucocytes, the peptide exhibited maximum ROS scavenging activity at a concentration of 80 µM. Reduced apoptotic body formation was identified using Hoechst 33,342 staining in GP13-exposed Vero cells.In vivoresults revealed that pre-treated zebrafish larvae with GP13 (10–80 µM) ameliorated the H2O2-induced oxidative damage. Further, GP13 inhibited the H2O2-induced caspase-3-dependent apoptotic response at 96 h post fertilized (hpf) zebrafish larvae.Together, results demonstrated that in GP13 treated (80 µM) zebrafish there was a reduction in the expression of lipid peroxidation level; and an increase in antioxidant-enzymes. Therefore, it is possible that GP13 peptide derived fromApCDS hasin vitroandin vivoantioxidant activity and that GP13 should be further investigated for potential therapeutic utility in OS-mediated complications.
