Clinical, histopathological and immunohistochemical evaluation of the effects of topical NPH-insulin on full-thickness open wounds: an in vivo study in diabetic and non-diabetic mice

Abstract

In diabetic patients, wound healing is disrupted due to impaired local circulation and infection or healing becomes impossible due to the gangrene. Recently, wound treatment models based on the use of topical insulin have been the subject of some studies. In this study, we aimed to evaluate the efficacy of topical NPH insulin use on wound healing for the treatment of full-thickness open wounds in diabetic and non-diabetic mice. A total of 72, non-diabetic and diabetic adult male Swiss Albino mice were used in the study. A full-thickness skin excision with a diameter of 1 cm was practiced on the back of all mice. Animals in diabetic and nondiabetic groups were divided into two sub-groups as NPH insulin used and control group. After the wound surface areas were digitally measured, the animals were sacrificed for histopathological and immunohistochemical examinations. Wound measurements revealed a significant reduction in the non-diabetic insulin treatment group at 7th and 14th days and at 3rd, 7th and 14th days of treatment in the diabetic insulin treatment group. Histopathological examinations showed that there was a significant increase in granulomatous inflammation in the wound site in the non-diabetic insulin treatment group at 3rd days and in the diabetic insulin treatment group at 14thdays. Immunohistochemical analyses showed that there was an increase in α-SMA at 3rd days and a decrease in TGF-β1 at 14th days in the diabetic insulin treatment group, while there was a significant decrease in IGF-I at 7th days in all diabetic groups. Topical NPH insulin application significantly accelerated healing in the treatment of diabetic and non-diabetic wounds with tissue loss in mice