Preliminary study comparing the effects of locally and systemically app lied L-carnitine on the healing of full-thickness skin defects

Background and Aims: L-carnitine as an endogenous cofactor has a role in the regulation of energy flow between different oxidative sources. The purpose of this study is to investigate that the clinical and histopathologic effects of L-carnitine locally and systemically on secondary healing in wounds of full thickness defects. We also measured the effects of L-carnitine on wound tensile strength as mechanical. Material and Methods: Sixty adult male Sprague-Dawley rats were divided into three groups randomly; group 1 (control group, n = 20), group 2 (local experimental group, n = 20), group 3 (systemic experimental group, n = 20). Group 1 was not given any pharmacologic agents. L-carnitine was administered locally in the group 2, and systemically in group 3 for a total of 14 days. The healing days of all groups were recorded. On the 7^th, 10^th,14^th and 21^st postoperative days, biopsy specimens, including tissue samples both from healing wound sites and surrounding healthy skin were evaluated for neovascularization, inflammation, the amount of collagen deposit, fibroblast migration and reepithelization. Tensile strength was measured in the samples which completed healing on the 30^th day. The results were evaluated by nonparametric Kruskall-Wallis test followed by Mann Whitney-U test. Results: The mean clinical healing days were 18.25 days, 16.5 days, 15 days for the control group, local experimental and systemic group, respectively. The differences between groups were statistically significant (p <0.005). Mean tensile strength values were 762.10 centinewton (cN), 801.69 cN and 786.13 cN for the control group, local experimental group and systemic experimental group, respectively. There were no statistically significant differences between groups (p > 0.05). There was no statistically significant difference in the histopathologic examination on the 7^th, 10^th, 14^th and 21^st days in the neovascularization, inflammation and fibroblast migration. Collagen deposit was most prevalent in the systemic experimental group and was least in the control group. Complete wound closure rate was observed on the 7^th day in the systemic administration group, on the 10^th day in local administration group and on the 14^th day in the control group. Re-epithelization thickness in the systemic carnitine group was more than the other groups. Conclusions: L-carnitine administered locally or systemically has positive effects on wound healing rate and tensile strength in rats.