Fig. 1

GAH protects against PC12 cell damage caused by hydrogen peroxide. The effect of histidine-containing tripeptides on hydrogen peroxide-induced cell damage as assessed by measuring lactate dehydrogenase (LDH) release into the medium in PC12 cells in culture. PC12 cells were incubated with 5000 μM hydrogen peroxide without or with 1 μg/μL of GHH, AHH, AHA, AAH, AGH, GAH, AHG, HAG, HHH, GHA, GGH, or AH carnosine for 4 h. PC12 cells were also incubated with Triton X100 as a positive control. The quantity of released LDH was estimated in the suspension aliquot from the 96-well plate. Measurements of the means ± standard deviation (S.D.) of at least four determinations for each sample were obtained by measuring at 490 nm. All of the above additives use the letter designation for the respective amino acid (i.e., H = histidine). * indicates significant difference (p < 0.001) between no peptide and carnosine