Scavenging activity of vitamin E and edaravone on oxygen free radicals in expanded flaps after transplantation

Objective To study the scavenging activity of vitamin E and edaravone on oxygen free radicals in rats' expanded flaps after transplantation. Methods Twenty-four adult SD rats were randomly divided into control group, vitamin E treated group and edaravone treated group, eight rats in each group. A soft tissue expander of 30 ml was put into back of every rat in all the three groups. After the operation, normal saline was injected into every soft tissue expanders regularly until the total volume reached to 32 ml. All the soft tissue expanders were removed in the other operation, then formed a flap sized 2 cm×6 cm in the expanded area of back with the pedicle located at the trailing side. After flaps were formed immediately, vitamin E injection (100 mg/kg), edaravone injection (10 mg/kg) and 1 ml normal saline were respectively injected into rats in vitamin E treated group, edaravone treated group and control group via the tail veins. Samples of flaps were harvested from each group 24 hours after the operation, to detect the content of malondialdehyde (MDA), activity of superoxide dismutase (SOD) and myeloperoxidase (MPO); Observed changes in organizational structure and infiltration of inflammatory cells by hematoxylin-eosin staining (HE) staining, counted the number of inflammatory cells with polynuclear. Results The content of MDA, activity of MPO, count of inflammatory cells with multicore were respectively (9.25±0.33) nmol/mg prot, (0.47±0.05) U/mg prot, (5.36±0.29)/high power objective (HP) in vitamin E treated group and (6.12±0.53) nmol/mg prot, (0.35±0.03) U/mg prot, (3.71±0.33)/ HP in edaravone treated group; all of the data were significantly lower than that in IR group correspondingly with the data (11.74±0.29) nmol/mg prot, (0.61±0.02) U/mg prot, (7.43±0.62)/HP(P<0.05); and the content of MDA, activity of MPO, count of inflammatory cells with multicore in edaravone treated group were all significantly lower than that in vitamin E treated group. The activity of SOD was (23.36±2.01) U/mg prot in vitamin E treated group and (28.23±1.82) U/mg prot in edaravone treated group; all of the data were significantly higher than that in IR group with the data (18.61±1.32) U/mg prot (P<0.05); and the activity of SOD in edaravone treated group was significantly higher than that in vitamin E treated group. All the differences were statistically significant. Conclusion Both edaravone and vitamin E with the activity of scavenging oxygen free radicals and reducing extent of inflammation on rats' expanded flaps after transplantation, and edaravone with a stronger effect. Key words: Expanded Flap; Oxygen free radicals; Edaravone; Vitamin E