A literature review of the studies concerning selected plant-derived adaptogens and their general function in body with a focus on animal studies

Background: Adaptogens are generally referred to the substances, mostly found in plants, which non-specifically increase resilience and chances of survival by activation of signaling pathways in affected cells. Purpose: This literature review was conducted to summarize the investigation, until March 2021, on selected adaptogenic plants and plant-derived substances. Study Design: Electronic databases were searched (up to March 2021) for in vitro and animal studies, as well as clinical trials. Moreover, all modes of action connected with the adaptogenic effects of plants and phytochemicals were collected. Methods: The search of relevant studies was performed within electronic databases including Scopus, Science Direct, PubMed, and Cochrane library. The most important keywords were adaptogen, plant, phytochemical, and plant-derived. Results: The most investigated medicinal herbs for their adaptogenic activity are Eleutherococcus senticosus, Panax ginseng, Withania somnifera, Schisandra chinensis, and Rhodiola spp., salidroside, ginsenosides, andrographolide, methyl jasmonate, cucurbitacin R, dichotosin, and dichotosininare are phytochemicals that have shown a considerable adaptogenic activity. Phytochemicals that have been demonstrated adaptogenic properties mainly belong to flavonoids, terpenoids, and phenylpropanoid glycosides. Conclusion: It is concluded that the main modes of action of the selected adaptogenic plants are stress modulatory, antioxidant, anti-fatigue, and physical endurance enhancement. Other properties were nootropic, immunomodulatory, cardiovascular, and radioprotective activities.