Excisional Wound Morphological Characteristics Under the Influence of Medicinal Leech Biologically Active Substances

Background. The stages of wound healing following surgery are generally consistent, but immune responses and increased inflammation can delay the normal healing process. As a result, additional support is crucial. Perfusion plays an important role in accelerating skin wound healing, and the saliva of medicinal leeches has been shown to enhance this process. Objective. To evaluate the effect of the medicinal leech Hirudo verbana on the morphological changes in an excisional wound. Methods. An excisional wound was created in the interscapular region of animals in both the control and experimental groups. In the experimental groups, one medicinal leech was applied on days 1, 3, 7, and 14. Tissue samples from the wound edge were collected immediately after leech application, and then at days 3, 7, 14, and 30 during the healing process. These samples were processed using standard histological techniques. Results. In the experimental group, intensive formation of granulation tissue was observed as early as day 3, compared to the control group. An increase in the thickness of the papillary layer, which was vascularized and supported epidermal nutrition, was noted in the experimental group at almost all time points. This may have contributed to enhanced proliferation processes, an increase in the number of hair follicles and sebaceous glands, and a reduction in scar size. On day 3, the number of leukocytes decreased, signaling a reduction in inflammation compared to the control group. By day 7, a significant reduction in subcutaneous tissue and the areas of hair follicles and sebaceous glands was observed, suggesting an increase in basal metabolic activity. Conclusions. The complex of biologically active substances from the medicinal leech Hirudo verbana positively affects the processes of reparative regeneration in excisional wounds, accelerating all stages of wound healing. It significantly increases the number of newly formed hair follicles and blood vessels, directly indicating the regenerative properties of these substances.