Eleuthero: benefits, dosage, contraindications

Adaptogen

Siberian ginseng seems to modify the levels of various neurotransmitters and hormones involved in the stress response, mainly at the HPA axis (hypothalamic-pituitary-adrenal axis). Various mechanisms have been proposed, including the inhibition of catechol-O-methyltransferase, which inactivates catecholamines. Consequently, catecholamine levels do not deplete, and the release of new catecholamines by nerve synapses decreases. Theoretically, this effect reduces the risk of exhausting the body's adaptive responses to stress. Moreover, it has been shown that eleutherosides enhance carbohydrate metabolism and energy supply and increase the synthesis of proteins and nucleic acids, although the direct molecular targets responsible for this adaptive response remain unknown. It has also been reported in vitro that eleutherosides bind to sites of progestogenic, estrogenic, mineralocorticoid, and glucocorticoid receptors and could therefore theoretically exert numerous important pharmacological actions in the body's response to stress. Thus, the herb's overall action has been described as "adaptogenic." Although the responsible mechanism of action remains unclear, several theories have been proposed to explain the effect of Siberian ginseng on allostatic systems. Indeed, research has shown that Siberian ginseng can act in various ways according to the stage of the stress response to support the "stress system." Research suggests there is a threshold of stress below which the herb increases the stress response and above which it decreases the stress response.

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Neurological

Eleuthero protects neurons and inhibits apoptosis of brain cells. In animal research, an aqueous extract of eleuthero inhibited inflammation and microglial activation in cerebral ischemia. In cultured rat cortical neurons, eleuthero extracts have been shown to have protective effects on neurite regeneration and synapse reconstruction in cultured rat cortical neurons damaged by beta-amyloid. This effect is thought to be due, at least in part, to eleutheroside B. In mice, eleutheroside E prevented sleep deprivation-induced behavioral disorders, including reduced latency to enter a dark chamber and locomotion, as well as increased monoamines (serotonin and dopamine) in the hippocampus, suggesting that this component of eleuthero could be valuable for stress experienced due to chronic insomnia.

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Cardiovascular

Eleuthero, when administered orally to rats (at 1 ml/kg for 8 days), showed protective effects on the heart. These benefits, which include protection against cardiac rhythm disorders (antiarrhythmics), appear to be due to an increase in levels of natural opioid peptides in the body. In the laboratory, eleuthero also shows a blood vessel relaxation effect. This effect could be caused by several mechanisms, such as increased nitric oxide production (a gas that relaxes blood vessels), activation of muscarinic receptors (receptors involved in nervous system control), or by influencing certain channels in cells that regulate the passage of potassium ions. In a study conducted on cultured neonatal rat heart cells, a specific component of eleuthero, acanthopanax senticoside B (part of the plant's saponins), protected these cells against damage caused by oxidative stress. It accomplished this by reducing lipid peroxidation (a type of cellular damage) and increasing the activity of the body's antioxidant defense mechanisms.

Hypoglycemic

Eleuthero possesses hypoglycemic properties observed in studies conducted in the laboratory (in vitro) and on animals (in vivo). - It reduces glucose absorption by inhibiting an enzyme called alpha-glucosidase, thus limiting the amount of glucose entering the bloodstream. - Eleutherosides, components of eleuthero, particularly eleutherosides E and B, allow glucose to enter cells without depending on insulin, the hormone usually required for this process. - Eleuthero may counter obstacles to glucose transfer caused by certain proteins (β-lipoproteins) in cell membranes. - Syringin, a component, improves glucose utilization and can lower blood glucose levels. This may be due to increased acetylcholine release, which stimulates insulin release, or to the promotion of β-endorphin secretion, leading to a decrease in blood glucose.

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Immunomodulator

Eleutherococcus extract has shown immunomodulatory effects, including increased cellular and humoral activity, activation and proliferation of immunocompetent cells, and stimulation and inhibition of cytokine synthesis, in human, animal, and in vitro research. According to a review, immunomodulatory polysaccharides or saponins isolated from eleutherococcus stimulated macrophages, promoted antibody formation, activated the complement, and increased T lymphocyte proliferation. In rabbits, eleutherococcus extract had a sustained immunostimulant effect and increased phagocytic activity. In vitro, syringin, a constituent of eleutherococcus root, stimulated the phagocytosis of rat blood macrophages (immune system cells that help fight infections). Also, eleutherococcus reduced the occurrence of allergic reactions. Histamine release from rat peritoneal mast cells, as well as TNF-alpha and IL-6 secretion, was also inhibited. Similar results have been observed in other animal studies, suggesting an anti-allergic effect of eleutherococcus.

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Antiviral

In vitro, a liquid extract of eleutherococcus inhibited the productive replication of RNA viruses, human rhinovirus, respiratory syncytial virus, and influenza A virus. However, it does not seem to affect DNA viruses such as adenovirus or herpes simplex type 1 virus.

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Anticancer

In animal research, eleutherococcus or its components have shown antitumor effects. The cytotoxic and antiproliferative effects of eleutherococcus have been demonstrated in various in vitro studies. Eleutherococcus extract has demonstrated antineoplastic activity against leukemia, hepatoma, and prostate cancer cells.