Investigation of the effect of melatonin administration on calpain-1 expression and atrophic morphology on atrophy of mouse Myoblast cell line exposed to hydrogen peroxide

It is known that oxidative stress is the main factor in the formation of disuse muscle atrophy which is the most common type of muscle atrophy. Various treatment options are available to eliminate this effect. The first important damage which is done by oxidative stress on contractile protein integrity induced by proteases such as calpain-1 has been demonstrated in several studies. Antioxidant treatment is an effective treatment option to prevent atrophy due to oxidative stress. In the antioxidant, a more effective treatment option of the "mitochondrial targeted antioxidants" group such as Melatonin is prominent. In our study, the effects of melatonin application on the expression of the calpain-1 protease and the effects of melatonin on the redox balance and morphology were first investigated in the literature. We have used H2O2 to generate oxidative stress in our study. Four groups of C2C12 cells were created under the same conditions and in the same passage number. K (Control), M (Melatonin), H (H2O2), M + H (Melatonin+H2O2) groups were formed as described in the experimental protocol and the diameters of the myotubes were measured for morphological evaluation. Morphological evaluation revealed a significant difference between the groups (p<0.05). After morphological evaluation, Calpain-1 protein amounts were measured in total protein lysates. Calpain 1 protein amount was less in group K compared to other groups. TAS and TOS kits were used to find out the antioxidant/oxidant statuses of the cells. H group showed higher increase when we compared with other groups in TOS amounts. The highest mean TAS value that could be explained by the rebound effect was observed in the H group. These results suggest that H2O2 produces muscle atrophy in C2C12 cells and that melatonin morphologically prevents atrophy. Melatonin may be involved other mechanisms which cause disuse muscle atrophy other than calpain-1 protein effect. Functional studies need to be carried out to better explain this effect. Key words: Muscle atrophy, Calpain 1, Melatonin, Mitochondria targeted antioxidants, Redox balance