Antiapoptotic effect of a novel synthetic peptide from bovine muscle and MPG peptide on H₂O₂-induced C2C12 cells

The objective of this study was to evaluate antioxidant and antiapoptotic effects of a novel peptide (T.peptide) isolated from bovine and commercially available MPG peptide. The amino acid sequences of the T.peptide were (Glu-Val-Pro-Glu-Val-His-Glu-Glu-Val). The antioxidant activities of these peptides were determined by measuring the 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS+•) radical scavenging assays. The in vitro cytotoxicity of T.peptide and MPG peptide was determined against H₂O₂-induced C2C12 cells. H₂O₂-induced apoptosis in C2C12 cells were determined by mRNA expression of caspase-3. Moreover, the mRNA expression of tumor necrosis factor alpha (TNF-α) and nuclear factor kappa B (NF-κB) were assayed by reverse transcription polymerase chain reaction. The findings of the study indicate that the mRNA expression of TNF-α and NF-κB are significantly (p∈<∈0.05) increased in H ₂O₂-induced C2C12 cells, whereas a significant decrease (p∈<∈0.05) in these mRNA expressions are observed when pretreated with T.peptide or MPG peptide. Pretreatment with MPG or T.peptides is also found to significantly (p∈<∈0.05) decrease the mRNA expression of caspase-3 in H₂O₂-induced C2C12 cells. The results of the study demonstrate that both T.peptide and MPG peptide could reduce the DPPH• and ABTS+• radical and inhibit cytotoxicity against H ₂O₂-induced injury, resulting in prevention of free radical generation and subsequent apoptotic cell death, which indicates the potential of bovine meat as a source of antioxidant peptides.