Rhodiola: benefits, dosage, contraindications

Adaptogenic

The adaptogenic properties of Rhodiola show protection against stress, increased work capacity and learning, and memory. Animal studies have shown that chronic intake of Rhodiola extract, standardized to 3% rosavins and 1% salidroside, effectively inhibits behavioral and physiological changes induced by prolonged exposure to mild stressors. This action is comparable to that of fluoxetine, a medication commonly used to treat depression. The beneficial effects of Rhodiola, when administered in several doses, are mainly related to its action on the hypothalamic-pituitary-adrenal (HPA) axis, a central system in the body's stress response. A single dose of Rhodiola can be useful in situations requiring a rapid stress response, by acting on the sympathoadrenal system. Rhodiola begins to act within 30 minutes of administration and its stimulating effect can last between 4 and 6 hours. This rapid action is attributed to the plant's active compounds, salidroside and rosavins. These effects have been observed in humans, with a recent double-blind, placebo-controlled clinical study on young volunteers showing that standardized Rhodiola extracts increase endurance.

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Antidepressant

The components of Rhodiola: rhodioloside, salidroside, and tyrosol are associated with its antidepressant activity. They inhibit the activity of monoamine oxidase A, an enzyme linked to a number of psychiatric disorders such as depression, aggression, and antisocial behavior. They would also stimulate cognitive functions such as memory and learning. However, the mechanism is not documented. The effect of Rhodiola was tested in a double-blind, placebo-controlled clinical study in patients with mild to moderate depression with recurrent episodes. Results indicate that after 6 weeks of treatment with Rhodiola extract, there is a significant improvement, particularly in global depression and insomnia.

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Antioxidant

Rhodiola has antioxidant properties and protects cells against oxidative stress and aging, especially liver cells thanks to the action of salidroside. Its antioxidant effects are potentially superior to those of other adaptogens such as eleuthero.

Bioenergizing

Rhodiola extracts would increase ATP production in muscles, thereby promoting endurance in physical activity.

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Hepatoprotector

Rhodiola produces a hepatoprotective effect manifested by normalizing the activity of aspartate-aminotransferase and alkaline phosphatase and returning urea and bilirubin levels to normal. Rhodiola also reduces the activity of alanine aminotransferase and glutathione-S-transferase in the plasma of rats in a toxic hepatic model.

Cardiovascular

Rhodiola extracts might prevent stress-induced cardiac damage by preventing the increase of cardiac catecholamines and cyclic AMP. In animals, administration of Rhodiola extract prevents the reduction of contractile force after exposure to cold. Another study shows a marked preventive effect on adrenaline and calcium chloride (CaCl2)-induced arrhythmias. Salidroside appears responsible for these effects.

Neurological

Rhodiola, and particularly one of its components called salidroside, has demonstrated neuroprotective effects in animal studies. Salidroside acts in a dose-dependent manner to protect brain cells against different types of damage. One of the main ways salidroside protects the brain is by fighting oxidative stress, a process that can damage cells and is involved in many neurodegenerative diseases. Salidroside prevents apoptosis, which is programmed cell death often triggered by excessive oxidative stress. It also inhibits the production of reactive oxygen species (ROS), which are harmful byproducts of cellular metabolism that can cause significant damage to cells. Other studies have shown that Rhodiola inhibits monoamine oxidase B activity and therefore offers protection against neurodegenerative diseases associated with this enzyme such as Alzheimer's and Parkinson's. In addition, salidroside helps restore the mitochondrial membrane potential, essential for proper cell function, and reduces the concentration of free calcium inside cells, a factor that can contribute to cellular damage if excessive. Thanks to these properties, salidroside from Rhodiola could play an important role in the prevention and treatment of diseases related to brain injuries, such as ischemic strokes and neurodegenerative diseases.

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Cognitive function

A clinical study measured the effect of Rhodiola on the mental performance of young doctors. A significant increase in cognitive functions was observed in the group treated with Rhodiola. The beneficial effects of Rhodiola on mental performance may be partly explained by its anti-cholinesterase action. The anti-cholinesterase action is Rhodiola's ability to inhibit the activity of the enzyme cholinesterase. This enzyme is crucial in the functioning of the nervous system as it breaks down acetylcholine, an essential neurotransmitter involved in many functions, including memory, concentration, and the learning process. Its inhibition leads to an increased concentration of acetylcholine in the brain, potentially positively impacting cognitive functions.

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Anti-ageing

Preliminary evidence from animal research suggests that rhodiola could increase lifespan by reducing oxidative stress. Moreover, salidroside, a constituent of rhodiola, protects human fibroblast cells from premature aging by modulating oxidative status.

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Anxiolytic

In mice, Rhodiola extract produced significant anxiolytic effects.

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Antiviral

Laboratory research suggests that salidroside possesses antiviral activities against coxsackievirus B3 (a human pathogen linked to cardiac arrhythmias and acute heart failure) in vitro and in vivo. Additionally, flavonols isolated from Rhodiola appear to have anti-influenza viral activity in vitro.

Anti-inflammatory

Rhodiola has anti-inflammatory properties by reducing C-reactive protein levels and inhibiting enzymes involved in the inflammation cascade.