Parkinson's disease (PD) is associated not only with neurologi- cal problems, but also with significant changes in peripheral organs and peripheral metabolism. This study aimed to inves- tigate the locomotor and exploratory behavior as well as bile pigment content in rats subjected to a rotenone-induced model of parkinsonian syndrome (PS), and to evaluate the effect of a novel benzodiazepine derivative, metresdiazenone, on these parameters. Motor and exploratory activity was assessed using the “open field” test, while bile pigment levels were determined through thin-layer chromatography. Metresdiazenone admin- istration at a dose of 1 mg/kg restored bile pigment content to 85% of control levels. At a dose of 2 mg/kg, the content of bile pigments reached control values, and at 4 mg/kg, it exceeded this indicator by 12.7%. In the absence of treatment, the concentration of pigments was significantly lower than in the control. In PS model rats, both locomotor and exploratory behavior were markedly reduced, with a 67% decrease in the frequency of rearing and an 84% reduction in the number of squares crossed in the open field test. Metresdiazenone significantly improved motor activity. Thus, with 1, 2, and 4 mg/kg doses, both the frequency of rearing and the number of crossed squares in the respective groups did not differ from the control levels, whereas without application of metresdiazenon the indicators were not fully restored. These findings suggest that metresdiazenone, across all tested doses, significantly enhances both bile pigment content and behavior in rats with a rotenone-induced model of PS.