Effects of topical insulin on second-intention wound healing in the red-eared slider turtle (Trachemys scripta elegans) – a controlled study

Abstract

BackgroundCompared with mammals, wound healing in reptiles is characterized by reduced wound contraction and longer healing times. The aim of this study is to describe the clinical and histopathological effects of topical insulin on second-intention healing of experimentally induced wounds in skin without dermal bony plates of Trachemys scripta elegans exposed to daily variations in ambient temperature and in an aquatic environment. Forty-four healthy adult females were assigned to two groups: Group 1 (n = 24) was used to assess clinical features such as wound contraction; Group 2 (n = 20) was used for histological evaluation and morphometric analysis. Topical porcine insulin (5 IU/ml diluted in glycerol) was applied daily 1 week. For each control time (2, 7, 14, 21 and 28 days post-wounding), re-epithelisation and wound remodelling were evaluated histologically and the number of main inflammatory cells (heterophils, macrophages, lymphocytes and fibroblasts) was scored.ResultsMean wound contraction was higher in the insulin-treated group at each time point and differences were significant at day 28 (P < 0.0001). Histologically, these clinical findings were associated with better re-epithelisation, inflammatory response, collagen synthesis and remodelling of the wounds. Morphometrically, insulin-treated wounds had significantly higher mean counts of heterophils (day 7), macrophages (days 2, 7 and 14) and fibroblasts (days 14 and 21), whereas lymphocyte counts were significantly lower at day 21. These results demonstrate that topical insulin modifies the inflammatory response of turtle skin up-regulating inflammatory cells at early stages and promoting wound healing.ConclusionsTopical insulin is a potentially useful therapy in skin wounds of Trachemys scripta and should be evaluated in non-experimental wounds of turtles and other reptiles.

Effect of topical ozonated sunflower oil on second intention wound healing in turtles: a randomised experimental study

“…At day 28, ozone-treated wounds achieved a 19.01% greater reduction in mean wound size. The magnitude of this difference is lower than the 24.26% obtained in a similarly designed study using topical insulin [ 14 ]. Although wound contraction is not a major feature of second-intention wound healing in reptiles, it is an objective outcome used in most studies and the significantly higher wound contraction of the ozone-treated wounds may be an important finding bearing in mind the limited wound contraction reported in reptiles.…”

“…Samples were fixed in buffered 10% formaldehyde for 16 to 20 h, hemisectioned and processed to a paraffin-embedded state. Serial sections, 4 μm thick, were obtained from each block and stained to enable accurate evaluation of the wound healing process [ 11 14 ]. Thus, haematoxylin and eosin (HE) stain was used to evaluate microscopic features; methenamine silver (Gomori PAMS) to stain the basement membrane zone (BMZ); Masson's trichrome (TM) to evaluate the collagen fibres and extracellular matrix during the proliferative and remodelling phases; routine Gram stain was applied to evaluate bacterial proliferation.…”

<p>Effects of Topical Insulin on Wound Healing: A Review of Animal and Human Evidences</p>

“…26 Negrini et al (2017) also showed that insulin solution promotes healing in Trachemys scripta elegans with secondintention wounds. 27 In addition, Chen et al (2012) reported that closure time of excision wound was reduced from 7 to 5 days in insulin solution-treated animals, and this finding is associated with improved inflammatory response, reepithelization, and collagen remodeling in the wounds of the insulin-treated group. 17 Likewise, Lima et al (2012) reported that insulin cream (0.5 U/100 g) applied daily for 8 days reduces wound healing time in diabetic rats by reversing defective AKT and ERK signal transduction.…”

Effects of topical insulin on wound healing: a meta-analysis of animal and clinical studies

“…A total of 6,363 articles were obtained through the above search strategy. After evaluating the qualification of the accredited research, a total of 13 studies, including four [16][17][18][19] clinical studies and nine [11,16,[20][21][22][23][24][25][26] animal studies, were found suitable to be involved in this review. The study flow chart is presented in Fig.…”