Impact of collagen-containing drug on the number and proliferative activity of dermal fibroblasts in the experiment

Background. Skin changes in ageing and exposure to a number of negative environmental factors, including tobacco smoke, are associated with connective tissue disorganization. The search for drugs that help to normalize the condition of skin cells and components of the extracellular matrix is an urgent task of modern medicine. Objective. Assessment of changes in the number of fibroblasts and their proliferative activity in the skin of experimental animals under prolonged exposure to cigarette smoke and subsequent application of collagen-containing drug. Material and methods. Experiments were carried out on 95 male rats of the Wistar line. The experimental group consisted of 75 animals, which were kept under conditions of exposure to cigarette smoke for 4 months, whereafter they were administered orally with collagen-containing drug. The experimental group was divided into 3 subgroups (25 animals in each), which received the drug during 1, 2 and 3 months, respectively. The control group included 20 animals not exposed to tobacco smoke. In order to assess the condition of dermal fibroblasts, skin biopsies were taken from animals in which histopathological and immunohistochemical methods were used to determine the number of fibroblasts, as well as the proportion of proliferating Ki-67+ fibroblasts. Results. A decrease in the number of fibroblasts (by 26.5%), as well as the proportion of proliferating Ki-67+ fibroblasts (2.3 times) has been revealed in skin biopsies in the group of experimental animals after four months of exposure to cigarette smoke compared to the control group indicators (p<0.05). Application of collagen-containing drug during 1, 2 and 3 months resulted in a significant increase in the number of fibroblasts and the proportion of proliferating Ki-67+ fibroblasts in the skin of animals. Conclusion. Exposure to cigarette smoke leads to a decrease in the number of fibroblasts and their proliferation in the skin of animals. The use of collagen-containing drug contributes to an increase in both the number of fibroblast population and their proliferative activity.