Efficacy of topical application of PTD-SOD on wound healing in mice with mechanical injury

Abstract

Objective To study the role of the oxidative stress in the development of wound healing and observe the effect of the antioxidant PTD-SOD on damage and inflammation reaction after mechanical wound. Methods In this experiment,acute wound healing model by removal the whole layer dorsal skin of the mice was prepared,SOD(3 000 U and 6 000 U)and the fusion protein PTD-SOD with different concentrations(1 000 U,3 000 U,6 000 U and 10 000 U)were used to deal with the wounds continuously for 13 days.The mice were divided into different concentration SOD treatment group and PTD-SOD treatment group,model control group,physiological saline treatment group and compound iodine solution control group.The wound healing situation and healing percentage of the fight and left skin wounds of each mouse in every group was recorded every day.At day 14 after wound,the wound healing skin of each group was removed and some were used to make 10%tissues homogenate for detecting the activities of superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-Px)and contents of malondialdehyde(MDA)and hydroxyproline(Hyp);in the meantime,the other removed skin were fixed in 10% formalin for observing the histopathological changes of the tissues. Results Compared with the model control group,the physiological saline treatment group and the compound iodine solution control group,the skin wound healing percentage was significantly(P<0.05 or P<0.01)improved,with increase of the activities of SOD,CAT,GSH-Px and contents of Hyp (P<0.05 or P<0.01)and decrease of MDA(P<0.05 or P<0.01) in the SOD groups or PTD-SOD groups (except for 10 000 U PTD-SOD group).When compared with the physiological saline treatment group or the compound iodine solution treatment group,the effect was similar to the model control group.In comparison to the SOD groups,under the same dosage and environment condition,the PTD-SOD groups were much better than SOD groups with regard to promoting skin wound healing percentage,increasing activities of antioxidases and contents of Hyp,decreasing contents of MDA.Among the PTD-SOD groups,the effect of high dosage 10 000 U on promoting skin wound healing was declined. Conclusions The oxidative stress may playan important role in the development of wound healing.Proper application of treatment with antioxidants is a alternative strategy in the early stage of wound.PTD-SOD is able to prevent the oxidative stress damage,inhibit inflammatory infiltration and promote skin wound healing efficiently. Key words: Wound healing; Antioxidants; Oxidative stress; Reactive oxygen species