Rhodiola
Rhodiola (“arctic root”) is in the plant family Crassulaceae. It grows in the high altitudes in the Arctic, mountainous regions of Europe and Asia. This plant has been used in Russian and Chinese folk medicine. The Soviet Ministry of Health approved it as a medicine and stimulant in 1969 and has been described as an anti-fatigue agent in the Textbook of Phytomedicine for Pharmacists. It has been used in Europe for medical conditions ranging from anxiety to headache. As a stimulant it has been used to enhance physical endurance, manage stress, and improve attention and memory. It is classified as an adaptogen – a medicinal plant that can strengthen resistance to stress, as well as improve concentration, performance, and endurance during fatigue. Based on their efficacy in clinical studies, adaptogens can increase tolerance to mental exhaustion and endurance in situations of decreased performance. Studies on animals and isolated cells have found adaptogens to possess neuroprotective, anti-fatigue, anti-depressive, ant-anxiety, and CNS stimulating and tonic effects. Adaptogens are generally thought to contribute to cellular protection. Unlike conventional stimulants such as sympathomimetics (a class of chemicals that includes ephedrine and phentermine), adaptogens are not addictive, do not result in tolerance, and will not impair mental function or cause psychosis with extended use. Both pharmacological and clinical research on this extract have provided evidence that this adaptogen has positive biological implications without detectable levels of toxicity.
In brief, rhodiola indirectly extends the actions of neurotransmitters (brain cell chemical messengers), including epinephrine (adrenaline), dopamine, serotonin, and acetylcholine in the central nervous system through inhibition of the enzymes that degrade them. Rhodiola rosea contains roughly 140 compounds of which rosavin, salidroside, syringin, triandrin, and tyrosol are the primary active adaptogenic components.[1] The adaptogenic benefit of rhodiola is believed to feature a reduction in muscle damage following strenuous exercise. One study reported that rhodiola supplementation decreased exercise-induced muscle damage during 6 days of intensified exercise in untrained subjects. Another study found that it was able to prevent a decrease in energy from the “power plant” of the cell following exhaustive exercise.
Delving deeper into the science…
Evidence supports rhodiola’s impressive ability to improve attention, cognition, and mental performance in fatigue. This stress protective effect of adaptogens is believed top be the downstream effect of regulating homeostasis through mechanisms of action involving the hypothalamic-pituitary-adrenal axis along with mediators of the stress. [2] The main function of this adaptogen is thought to be their up-regulating and stress-mimetic effects on the “stress-sensor” heat shock protein – involved in cell survival and apoptosis. Heat shock protein inhibits gene expression responsible for the levels of circulating cortisol (stress hormone) and nitric oxide (causing vasodilation to increase blood flow). By preventing an increase in nitric oxide from stress and the downstream decrease in adenosine triphosphate (ATP) production, rhodiola imparts an increase in performance and endurance. Adaptogen-induced up-regulation of heat shock protein triggers two particular stress-induced pathways: stress-activated c-Jun n-terminal protein kinase-1 (JNK-1, required for normal coordinated movement, lifespan, and response to heat and oxidative stress) and DAF-16 (factor that acts in the insulin pathway that regulates longevity, fat metabolism, stress response). These pathways regulate resistance to stress, which benefits both mental and physical performance. It may even have positive implications for increased longevity.
Heat shock protein is a stress induced protein that is universally expressed and serves as a molecular chaperone. As a chaperone, this heat shock protein binds to protein substrates to protect them from breaking down or aggregating until stressful conditions have resolved. This chaperon is additionally involved in normal growth, protein transport, degradation of unwanted proteins, and many other important aspects of maintaining protein stability. More specifically, on exposure to stressors such as increased heat, decreased oxygen, inflammation, increased stress hormones, etc., both intracellular (iHSP72) expression and extracellular (eHSP72) levels increase. During exercise, eHSP72 is released into circulation from locations including the liver and brain. However, it is not release from the skeletal muscle. On the other hand, iHSP72 is increased in skeletal muscle during exercise. This provides cells with protection from ensuing stressors. While eHSP72 causes an inflammatory immune response, iHSP72 actually functions in an anti-inflammatory capacity by reducing damage to cells that do not have an active role in the inflammatory response. Animal studies found evidence of this protective benefit provided by iHSP72. Mice that were genetically manipulated to overexpress iHSP72 in their skeletal muscle were found to have incurred less damage than the non-genetically manipulated mice they were compared to. The mice expressing iHSP72 also recovered more rapidly from harmful muscle contractions than the other mice.
In addition to heat shock protein, research has additionally suggested the contribution of the stress hormone neuropeptide Y (NPY) as a target for this adaptogen. NPY influences many physiological processes, including the stress response, food intake, as well as circadian rhythms. A study conducted on brain support cells found significant suppression of adaptogen-induced NPY and Hsp72 release. This study suggests that the stimulation and release of both stress hormones NPY and Hsp72 into the body’s circulation is an innate defense mechanism against mild stressors. This response is to increase tolerance and ultimately be equipped to adapt to that stress.
Putting all of the pieces of this scientific puzzle back together, rhodiola shows promise as supplement that can benefit exercise, mental and physical performance, stress, and fatigue. On the molecular level, this adaptogen functions as a metabolic regulator that can increase your ability to adapt to environmental stressors and avoid preventable damage. It exerts clear anti-fatigue effects that can increase your capacity to function in stressful circumstances. These adaptogenic properties of rhodiola appear centered around the regulation of intracellular signaling and increasing the amount of the heat shock protein. Rhodiola can help to improve your threshold for mental exhaustion while enhancing your attention span. The myriad possible benefits of rhodiola are exceptional and provide strong support for this natural ingredient’s role as a supplement.
[1] SH Hung et al.The effectiveness and efficacy of Rhodiola rosea L.: A systematic review of randomized clinical trials Phytomedicine 18 (2011) 235–244.
[2] Khanum, F., Bawa, A.S., Singh, B., 2005. Rhodiola rosea: a versatile adaptogen. Comprehensive Reviews in Food Science and Food Safety 4 (2005) 55–62.
