Clinical and epidemiological data evidence the need to search for new substances for treatment and prevention of increased anxiety associated with emotional and neurotic breakdown and worsening clinical prognosis of psychosomatic diseases. Of particular interest are the drugs of plant origin, which are generally well tolerated under prolonged use, and treat- ment is cheaper as compared with modem anxiolytics. The purpose of this study was to investigate the effects of course taking a flavonoid-containing plant preparation Extralife (water-soluble extract Pentaphylloides fruticosa, 40 mg/kg per day for 1 month) in <<anxious>> and <<non-anxious>> inbred albino rats sampled in the population using a multi-parameter method for evaluating anxiety-phobic states. This method was also used for evaluating the severity of anxiety (state anxiety) in rats in the dynamics of the survey. Sensorimotor reactivity (emotionality) was assessed by the parameters of the acoustic startle response. Extralife did not prevent the increase in state anxiety in <<non-anxious>> rats and did not change the level of anxiety in the <<anxious>> animals. However, the drug reduced the amplitude of the acoustic startle response in the <<anxious>> animals and increased startle response latency in both <<anxious>> and <<non-anxious>> rats, that is reduced the symptoms of anxiety caused by alarm sound stimuli in terms of sensorimotor reactivity. The data testify to the anxiolytic and sedative effects of Extralife more pronounced in the <<anxious>> animals. In a course intake of Extralife <<non-anxious>> rats demonstrated transient decrease in the pre-pulse inhibition of the acoustic startle response, probably associated with the occurrence of transient disturbances in the psycho-emotional sphere. The findings suggest that Extralife in a course taking may have negative side effects on the emotionality of <non-anxious> animals that determines the need to incorporate the features of mental and emotional status of the individual in the development of therapeutic approaches to the correction of high anxiety with the inclusion of the drug.