Аннотация:Abstracts of the XXth International Congress «Phytopharm-2016». Breaking of an organism's homeostasis by stress can trigger biological or behavioral adaptation and accelerate onset. Furthermore stress plays a role in a variety of human diseases including cancer. The stress-associated hormone Cortisol (or corticosterone) exerts a wide range of negative effects including the suppression of the immunity. The purpose of this investigation was to evaluate the effect of correcting the stress-associated hormone corticosterone serum level in CBA mice males genetically predisposal to hepatocarcinomas using multiphytoadaptogene dry powder extract (MPAC) in early postnatal ontogenesis (preventive administration). MPAC was produced by a special desiccation technology of forty medical herbs water-ethanol extracts mixture. MPAC has wide spectrum of activities including immunomodifying and antitumor effects. The control mice (n = 100) received drinking water. The experimental mice (n = 100) received 0,3% MPAC solution in drinking water during the first month of a mouse's life which is the final differentiation period of the normal liver. Serum corticosterone concentration was analyzed by enzyme-linked immunosorbent assay at the age of 4, 8 and 22 months. Corticosterone level in control animals was elevated from 75,6 ±1,7 pg/ml (at the age of 4 months) to 96,5 ±7,2 pg/ml (at the age of 8 months, p4-8 = 0,01) and to 140,0±4,5 pg/ml (at the age of 22 months, p8-22 = 0,0002). However the parameter in the experimental mice was lower when compared to the control animals (105,0 ±1,9 pg/ml, p1-2 = 0,0002) at the age of 22 months. Thus, MPAC in the preventive administration can suppress serum corticosterone level elevation during spontaneous hepatocarcinogenesis in mice.