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Adaptogens exert a stress protective effect by modulation of expression of molecular chaperons
Adaptogens are herbal preparations that enhance resistance to stress and increase concentration, performance and endurance during fatigue. We have shown that the stress protective effect of adaptogens is associated with the modulation of expression of heat shock proteins (HSP70 and HSP16), being molecular chaperons involved in stress-induced cytoprotection and in adaptation to repeated exposure to the initial stressor. Activation of a stress response results in increased expression of HSP. Physical exercise, for example, stimulates expression of inducible-HSP72 in the hippocampus of rats. Repeated administration of ADAPT-232 (a fixed combination of extracts of Eleutherococcus senticosus, Schisandra chinensis and Rhodiola rosea) to rats for 7 consecutive days (36mg/kg per day) similarly stimulated the expression of both inducible-HSP72 and constitutive HSC-73 and results in a significant protective effect on the stress-induced (forced swimming) expression of i-HSP72. In forced swimming test, rats treated with ADAPT-232 swam 1.5-times longer (p<0.05) than control animals. Treatment with ADAPT-232 increased expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a key enzyme involved in ATP production, in the hippocampus of rats by 2-fold. However, the forced swimming test produced a 5-fold increase in GAPDH expression in control rats but an increase of only 1.7-fold (p=0.012) in rats pre-treated with ADAPT-232. This effect of adaptogens is achieved by inhibition of stress-induced nitric oxide, which is known to inhibit GAPDH. Adaptogens thus act as challengers and mild stressors, and give rise to adaptive and stress-protective effects mainly associated with the hypothalamus-pituitary-adrenal axis, a part of the stress system that also contributes to the nervous, cardiovascular, immune, gastrointestinal and endocrine systems.