Well, Ginkgo Biloba is known to have some impacts on the effects of stress, though I cannot say that those properties necessarily translate to not feeling them. Just posting these out for reference on the effects of Ginkgo Biloba on the effects of stresses.
Anti-stress effects of Ginkgo biloba and Panax ginseng: a comparative study; J Pharmacol Sci. 2003 Dec;93(4):458-64.
Rai D, Bhatia G, Sen T, Palit G.
We explored the anti-stress potential of the Ginkgo biloba (G. biloba, 30 mg/kg, p.o.) and compared it with that of Panax ginseng (P. ginseng, 100 mg/kg, p.o.) against acute stress (AS) and chronic stress (CS) models in rats.
Immediately after AS and CS, the rats were sacrificed, and adrenal glands and stomach were dissected out for weight determination and scoring of the ulcer index (UI), respectively, as well as changes in biochemical parameters like plasma glucose (GL), triglycerides (TG), cholesterol (CL), creatine kinase (CK), and serum corticosterone (CORT) were also estimated. AS significantly increased UI, adrenal gland weight (AGW), GL, CK activity, and CORT, whereas G. biloba significantly reduced them.
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Reduction of rise in blood pressure and cortisol release during stress by Ginkgo biloba extract (EGb 761) in healthy volunteers; J Physiol Pharmacol. 2002 Sep;53(3):337-48.
Jezova D, Duncko R, Lassanova M, Kriska M, Moncek F.
Single treatment with EGb 761 (120 mg) reduced stress-induced rise in blood pressure without affecting the heart rate. [...]
Thus, this study provides evidence that EGb 761 has an inhibitory action on blood pressure and it may influence cortisol release in response to some stress stimuli.
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"Stress-Alleviating" and "Vigilance-Enhancing" Actions of Ginkgo biloba Extract (EGb 761); DRUG DEVELOPMENT RESEARCH 62:1–25 (2004).
Francis V. DeFeudis and Katy Drieu
In humans, EGb 761 has vigilance-enhancing effects that support its clinical use in treating disorders involving stress-induced brain dysfunction and those non-cognitive symptoms of dementia currently classified as ‘‘behavioral and psychological symptoms of dementia’’ (BPSD).
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These effects of Ginkgo Biloba on cortisols and other effects of stresses may be via these two mechanisms;
Ginkgolide B in Ginkgo Biloba may slow down the secretion of corticotropin releasing hormone (CRH) by the hypothalamus that directs the production of cortisol by the adrenal gland, though take it lightly as it is an animal study with chronic administration of Ginkgo Biloba;
Effect of chronic administration of Ginkgo biloba extract or Ginkgolide on the hypothalamic-pituitary-adrenal axis in the rat; Life Sci. 1998;62(25):2329-40.
Marcilhac A, Dakine N, Bourhim N, Guillaume V, Grino M, Drieu K, Oliver C.
[...]Chronic i.p. injection of Ginkgolide B reduced basal corticosterone secretion without alteration in the subsequent CRH and AVP increase. However, the stimulation of CRH gene expression by insulin-induced hypoglycemia was attenuated by Ginkgolide B. These data confirm that the administration of EGb 761 and Ginkgolide B reduces corticosterone secretion. In addition, these substances act also at the hypothalamic level and are able to reduce CRH expression and secretion.[...]
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Ginkgolide B in Ginkgo Biloba may also slow down the production of cortisol from cholesterol. I honestly do not get much about this study, though. Your theory about the inhibition of glucocorticoid production may be explained through this mechanism;
Use of ginkgolide B and a ginkgolide-activated response element to control gene transcription: example of the adrenocortical peripheral-type benzodiazepine receptor; Cell Mol Biol (Noisy-le-grand). 2002 Sep;48(6):633-9.
Amri H, Drieu K, Papadopoulos V.
[...]These data indicate that EGb 761-induced inhibition of glucocorticoid production is due to specific transcriptional suppression of the adrenal PBR gene by GKB, and suggest that EGb 761 and GKB might serve as pharmacological tools to control excess glucocorticoid formation.
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Edited by Jun Han, 21 November 2014 - 10:43 PM.
