Enhancing effects of Salidroside, a bioactive compound of Rhodiola Rosea, on cognition and emotional behavior in adult mice

Rhodiola Rosea (R. Rosea) is an herbal medicine used in traditional popular medicine to increase work performances and improve cardiovascular function and cognition. R. Rosea properties have been mainly attributed to the glycoside salidroside, a bioactive compound present in R. Rosea extracts, which seems to act as an adaptogen, i.e. a substance able to increase the organism’s resistance to a variety of chemical, biological and physical stressors in a non-specific way. Moreover, salidroside has been shown to present a neuroprotective action against numerous stressful conditions in rodents. Therefore, here we aimed to investigate whether a single acute dose of salidroside was able to ameliorate memory and counteract anxiety and depression in adult wild type mice.We performed the following behavioral studies: fear conditioning to assess cued and contextual memory, elevated plus maze and open field to evaluate anxiety, and tail suspension test to evaluate depression. We showed that a single i.p. administration of salidroside (25 mg/kg) was able to enhance fear memory, both cued and contextual, thus involving both the amygdala and the hippocampus. Acute administration of salidroside also affected emotional behavior, acting as an anxiolytic and antidepressant substance.These results, together with the low spectrum of side effects, suggest that salidroside might represent an interesting pharmacological tool to treat neurodegenerative disorders, such as Alzheimer’s disease, characterized by memory impairment and affective symptoms.