Effect of elamipretide and methylprednisolone treatment on optic nerve, retina and brain damage in a methanol poisoning model: biochemical and histopathological evaluation.

Purpose: This study aimed to biochemically and histopathologically evaluate the protective and therapeutic effects of elamipretide and methylprednisolone on methanol poisoning-induced brain, optic nerve, and retinal toxicity.

Method: In this study, 40 male Wistar Albino rats were divided into six groups: healthy control (HC), methotrexate (MTX, 0.3 mg/kg/d for 7 d), methotrexate + methanol (MTX-M, 0.3 mg/kg/d for 7 d + methanol 3 g/kg on Day 8), methotrexate + methanol + methylprednisolone (MTX-M-MPZ, 0.3 mg/kg/d for 7 d + methanol 3 g/kg on Day 8 + MPZ 1 mg/kg/d for 3 d), methotrexate + methanol + elamipretide (MTX-M-E, 0.3 mg/kg/d for 7 d + methanol 3 g/kg on Day 8 + elamipretide 5 mg/kg/d for 3 d), and methotrexate + methanol + methylprednisolone + elamipretide (MTX-M-MPZ-E, 0.3 mg/kg/d for 7 d + methanol 3 g/kg on Day 8 + MPZ 1 mg/kg/d + Elamipretide 5 mg/kg/d for 3 d). The rats were euthanized 8 h after the last drug administration. Histopathological and biochemical evaluations were performed on serum, caudatoputamen, and ocular tissues. Retinal degeneration was assessed using a scoring system where higher scores indicate less degeneration, with a score of 5 representing normal structure and 1 reflecting severe degeneration.

Results: In the MTX-M-MPZ-E group, the retinal degeneration score was higher than in MTX-M group ( = 0.002). The apoptosis index in the retina was highest in MTX-M group, while it was lower in MTX-M-MPZ-E group compared to MTX-M group ( = 0.018). In addition, the apoptosis index in the caudatoputamen was lower in MTX-M-MPZ-E group compared to MTX-M group ( = 0.009).

Conclusion: Combined elamipretide and methylprednisolone treatment improved optic nerve and retinal degeneration, reduced neuronal degeneration in the caudatoputamen, decreased oxidative stress and lipid peroxidation, and reduced apoptosis in the retina and caudatoputamen.