Histopathological and immunohistochemical evaluation of the impact of coconut shell-derived liquid smoke hydrogel on diabetic wound healing

This study aimed to evaluate the therapeutic efficacy of hydrogel derived from distilled liquid smoke of coconut (Cocos nucifera L.) shell as a topical treatment to enhance wound healing in diabetic rat models, specifically Wistar rats, employing immunohistochemical and histopathological analyses. A total of 72 male Wistar rats were rendered diabetic through the administration of nicotinamide in conjunction with streptozotocin. Incisive wounds measuring 2 cm × 2 mm were subsequently created on 18 diabetic rats to assess the percentage of wound healing. Additional wounds measuring 1 cm × 2 mm were generated to evaluate angiogenesis, fibroblast proliferation, collagen deposition, neutrophil infiltration, lymphocytic response, and nuclear factor kappa beta (NF-κB) and tumor necrosis factor-alpha (TNF-α) expression levels. The wounds were treated topically with a hydrogel base, Bioplacenton gel, and hydrogel formulated with distilled coconut shell liquid smoke at 25%, 50%, and 75%. The percentage of wound healing was monitored over 21 days, while other parameters were evaluated over 14 days. The distilled liquid smoke (DLS) hydrogel exhibited significant wound healing potential in the diabetic rat model, with the 25% hydrogel concentration demonstrating the highest percentage of wound healing. Treated groups exhibited a notable reduction in the expression of NF-κB and TNF-α, alongside decreased levels of macrophages, neutrophils, and lymphocytes. Furthermore, re-epithelialization, fibroblast activity, and collagen synthesis were enhanced. The 25% hydrogel concentration was identified as the most effective formulation, attributed to its optimal concentration of acids and phenols, which minimized skin irritation and mitigated prolonged inflammation. In conclusion, the distilled coconut shell liquid smoke hydrogel, particularly at a 25% concentration, effectively facilitates wound healing under diabetic conditions by alleviating inflammation and supporting tissue regeneration. This hydrogel presents itself as a promising topical treatment for the management of diabetic wounds.