Characteristics of the hepatotropic activity of cell-free cryopreserved biological agents in the model of autoimmune hepatitis

Background. Autoimmune hepatitis (AIH) is a severe acute or chronic progressive and relapsing immune-mediated inflammatory liver disease with dynamic and heterogeneous manifestations, potentially leading to cirrhosis and liver failure. The annual global incidence and prevalence of AIH are 1.4 and 17.4 per 100,000 individuals, respectively. Although corticosteroids are a common treatment for AIH, some patients poorly respond to this therapy, and others may experience serious side effects or relapse after discontinuing steroids. Therefore, new treatment methods are needed. Purpose – to characterize the hepatotropic activity of cell-free cryopreserved biological agents – ACBAs (MSC conditioned medium (MSC-MSC), placenta cryoextract (СEP) and spleen cryoextract (СES)) according to indicators of pigment metabolism and antioxidant-prooxidant homeostasis in the model of autoimmune hepatitis in rats. Materials and Methods. The effectiveness of acellular cryopreserved biological agents (ACBAs) in AIH was investigated in 42 male rats weighing 200–220 g. AIH was modeled by administering a hepatotropic antigenic mixture consisting of Freund's complete adjuvant and an antigen solution derived from allogeneic liver homogenate. The content of reactants with thiobarbituric acid (TBA-RP) was determined spectrophotometrically using the method by Asakawa T. et al. Catalase activity was measured spectrophotometrically according to the method by Korolyuk M.A. et al. Superoxide dismutase (SOD) activity was assessed spectrophotometrically using the method by Chevari S. et al. Bilirubin concentrations (total, direct, and indirect) were determined spectrophotometrically through the diazophenylsulfonic acid reaction with direct bilirubin. Results. Assessment of pigment metabolism indicated that the increase in total bilirubin in the control group animals was primarily due to the direct bilirubin pool, with its concentration increasing statistically significantly (p < 0.001) by 240.0% to 17.0 mmol/L, while indirect bilirubin levels increased (p < 0.001) by only 98.3% compared to intact rats. Among the studied ACBAs, the administration of CES demonstrated a comparable ability to normalize total bilirubin levels in rats with AIH, showing a statistically significant decrease (p < 0.001) of 40.2% to 20.0 mmol/L. Activation of the processes of lipid peroxidation (LPO) and depletion of the antioxidant system (AOS) led to a statistically significant decrease (p = 0.002) of the integral indicator of LPO-AOS – the antioxidant-prooxidant index (API) by 71.0% compared to the indicators of intact rats. In terms of the ability to restore catalase activity in liver tissues against the background of AIH in rats, all studied BKBZ were inferior to the reference drug sylibor. Conclusions. During the development of AIH in rats, there was an increase (p < 0.001) in total bilirubin levels by 148.9%, an increase in TBA-RP content (p < 0.001) by 172.5%, a decrease (p = 0.004) in SOD activity by 40.0%, and a decrease of 20.0% (p = 0.4) in catalase activity. Based on the ability to normalize pigment metabolism in AIH, the studied ACBAs can be arranged in the following order: MSC-CM (52.6%; p < 0.001) > CEP (49.6%; p < 0.001) > CES (40.2%; p < 0.001). In terms of restoring balance in the LPO-AOS system, the studied ACBAs can be arranged as follows: MSC-CM (201.4%; p = 0.005) > CEP (85.3%; p = 0.002) > CES (57.5%; p = 0.1).