Protective effects of combined vitamins C and PEG-E on peripheral nerves during hypothermic storage at 4 °C: histological study and oxidative stress status.

Oxidative stress plays a crucial role in cellular damage during nerve graft storage, impairing optimal regeneration after transplantation. This study evaluated the effects of the association of vitamins C (Vit C) and polyethylene glycol encapsulated vitamin E (PEG-Vit E) on histological changes and oxidative stress markers during nerve preservation under hypothermic conditions (4 °C) in vitro. Sciatic nerve segments extracted from male red chickens (Gallus domesticus) were stored in either a saline solution (0.9 % NaCl) or a saline solution supplemented with combined doses of Vit C (0.1 mg/mL) and PEG-Vit E (2.5 mg/mL). The segments were divided into subgroups based on preservation duration: 0 days, 1 day, 2 days, 3 days, 5 days, and 7 days. Malondialdehyde (MDA) levels, as an indicator of lipid peroxidation, were measured in stored tissues using the TBARS assay. Total antioxidant status (TAS), which reflects total effect of all antioxidants, was assessed in tissue samples and vitamin-supplemented storage solutions using the ABTS assay. Structural changes were evaluated by histological analysis, and the percentage of degenerated axons was determined by counting morphologically altered fibers on stained transverse nerve sections. The results indicated that the Vit C/PEG-Vit E complex offered the most protective effect on days 2 and 3. On day 3, MDA levels decreased significantly in the treated group (0.29 ± 0.02 vs. 1.42 ± 0.15 nmol/mL; p < 0.001), and axonal degeneration was reduced to (24.97 ± 0.42 % vs. 66.40 ± 2.26 %; p < 0.001). On day 2, TAS was higher in the treated tissues (66.59 % ± 0.32 % vs. 52.65 % ± 4.91 %; p < 0.01). From day 5, the TAS of the solution declined by 26.53 % (p < 0.0001), along with its protective effects. In conclusion, supplementing the preservation medium with Vit C and PEG-Vit E may improve the conservation of nerve segments and prevent axonal degeneration.