Effect of melatonin include into original dermal film upon adaptive immunity in experimental thermal trauma

Abstract

Adaptive immunity changes in thermal trauma (TT) increase the risk of infectious complications and limit repair of the lesion. Hence, search and preclinical testing of effective and safe means to locally manage TT, containing bioregulators, is an urgent task of modern medicine. Dermal films (DF) are an innovative and popular variant of wound coatings for small-area burns, and pleiotropic properties of melatonin (MT) suggest its effectiveness in TT. The aim of the work is to investigate the effect of MT, as a component of original DF, upon the indexes of adaptive immunity in experimental TT. The experiment was performed on 115 male Wistar rats. Grade IIIA TT with area of 3.5% were produced by contact with boiling water for 12 s. DF with an area of 12 cm2 based on sodium carboxymethylcellulose contatning MT (5 mg/g) was applied daily for 5 days. Similar DF matrix, but without MT, was used in the control group, Amounts of CD3+ and CD45RA+ cells in blood, and lymphocyte subpolulations with early and late signs of apoptosis and partially necrotic cells were evaluated with flow cytofluorometer, as well as IgG and IgM concentrations were measured in blood serum using rat test systems. With TT, the amount of CD3+ in the blood decreases on days +5 and +10, CD45RA+, on days +5, +10 and +20, and the concentration of IgG in the serum, on days +5 and +10 of observation. On days +5 and +10 after TT, a relationship was established between CD3+ and the number of lymphocytes with signs of early apoptosis (R = -0.47; p 0.05; R = -0.51; p 0.05, respectively), and signs of late apoptosis and necrosis (R = -0.64; p 0.05; R = -0.42; p 0.05, respectively), between CD45RA+ and the number of lymphocytes with signs of early apoptosis (R = -0.47; p 0.05; R = -0.49; p 0.05, respectively), and signs of late apoptosis and necrosis (R = -0.57; p 0.05; R = -0.49; p 0.05, respectively). Usage of MT in DF composition leads to increase in blood CD3+ on the 5th and 20th days, CD45RA+, on the 5th day, and an increase in serum IgG concentration was observed on the 5th and 10th days following TT. Restriction of necrotic and apoptotic death of blood lymphocyte may be among the mechanisms of the immunotropic effect produced by MT which is, probably, due to its local antioxidant and anti-inflammatory action in the TT area.