The role of astroglial proteins in the brains of rats under the influence of doxorubicin and Humilid

Abstract

Doxorubicin causes toxic side effects which result in profound changes in various organs including the heart muscle, which leads to the development of cardiomyopathy, with further complications, as our earlier studies have shown. But there are complications in treatment by anthracycline chemotherapy. The reduction of toxicity of cytotoxic drugs without reduction of their antitumor action remains an important medical challenge. The S-100b and glial fibrillar acid protein (GFAP) are the key astroglial proteins which are widely used as biomarkers for neurotraumas and strokes. Thus the purpose of our work was to study the GFAP and S-100b levels under the experimental model of doxorubicin-induced cardiomyopathy and the effect of the cytostatic separately or combined with Humilid. The level of studied proteins was measured by ELISA using monospecific antibodies against GFAP and S-100b (Sigma, USA), secondary anti-IgG labeled with horseradish peroxidase (Sigma, USA) and GFAP and S-100b standards (Sigma, USA). The experiment was conducted on white Wistar male rats weighing 210 ±50 g, which were divided into 3 groups with 8 animals in each: 1 – control, rats received saline i/p, 2 – doxorubicin 1 mg/kg i/p once weekly during 4 weeks, 3 – doxorubicin by the same scheme plus 0.01% solution of Humilid during 4 weeks. Under impact of doxorubicin an increase of fibrillar GFAP content in the rats’ hippocampus was shown, which may have occurred as a result of the proliferation of astrocytes. An increase of concentration of S-100b to 20–26% compared with the control animals was also detected in the hippocampus, thalamus and the cerebral cortex of the studied animals. Concomitant administration of doxorubicin with Humilid partially prevented the increase in concentration of GFAP and S-100b in the rats’ hippocampus. The reciprocal change in the level of S-100b and GFAP in the peripheral nervous system of the heart tissue was defined with a high degree of correlation under impact of doxorubicin. Accordingly, we have proposed the hypothesis that the increase in of the filament GFAP in the hippocampus may occur due to the development of the ischemic state under the impact of doxorubicin-induced cardiomyopathy. Humilid with doxorubicin prevented changes in the researched astroglial proteins of the heart muscle and brain parts of rats.

Keywords

• cardiomyopathy
• GFAP
• S-100b
• hippocampus
• cerebellum
• cortex