Морфофункціональна характеристика моделі термічного опіку у щурів після фармакологічної корекції водно-сольовим екстрактом медичної п’явки Hirudo verbana

Thermal skin burns are accompanied by pronounced morphofunctional disorders that lead to a prolonged wound-healing process and an increased risk of pathological scar formation. The search for effective agents capable of modulating inflammation and stimulating reparative regeneration remains a relevant task of experimental medicine. The aim of this study was to investigate the morphofunctional features of thermal skin burn healing in rats under conditions of pharmacological correction using an aqueous-saline extract of Hirudo verbana. The study was performed on 80 outbred white rats in which a grade II-III thermal burn was modeled. The animals were divided into 2 groups: a control group with spontaneous healing and an experimental group treated with applications of an aqueous-saline extract of Hirudo verbana. To induce burn injury, a copper plate measuring 1.6×5 cm heated to 100 C was used. The contact time between the plate and the skin was 10 s. Treatment was initiated 24 h after burn induction and was performed once daily until complete wound healing. Applications of the extract were applied directly to the affected skin surface. Tissue samples were collected from the burn wound bed and the adjacent intact skin area within 1 cm from the wound edge. Histological examinations were carried out on days 3, 7, 14, and 30 after injury using standard light microscopy techniques and morphometric analysis. It was established that the use of the extract contributed to a reduction in the severity of inflammatory infiltration in the early stages, earlier appearance of the epidermal regenerate, accelerated formation of the basement membrane, and development of the dermal capillary network. At later observation periods, a more orderly organization of collagen and elastic fibers as well as more active restoration of skin appendages, compared to the control group. Of particular importance is the increase in the number and area of hair follicles at the later observation periods, on days 14 and 30, in the experimental group, since the restoration of skin appendages is considered one of the criteria of complete regeneration rather than simple scar formation. Thus, the results of the present study confirm that the aqueous-saline extract of Hirudo verbana exerts a complex positive effect on the main phases of thermal wound healing and may be considered a promising agent for the pharmacological correction of burn skin injuries. The application of the extract is accompanied by a reduction in the intensity of the inflammatory response and cellular infiltration, which contributes to the faster restoration of the morphofunctional structure of the skin and its barrier properties.