Herba Sideritis: Insights from a Herbal Monograph with Particular Reference to Adaptogenic Potential in Neurodegenerative Disorders and Aging-related Cognitive Decline, Edition 1

Abstract

Background: Greek mountain tea (GMT), Herba Sideritis (Sideritis scardica Griseb.), is traditionally used to treat the common cold and mild gastrointestinal disorders. Sideritis spp. has been characterized as a genus with more than 150 perennial species widely distributed in the Mediterranean and the Canary and Madeira Islands. GMT was adopted in 2015 in the European Union as a traditional herbal medicine. Recent studies suggest its potential efficacy for reducing the risk of age-related cognitive decline and neurodegenerative diseases, which could be associated with the common mechanisms of action.

Aims and Hypothesis: The aims of this monograph were: (i) to systematically update new evidence of the quality, efficacy, and safety of GMT preparations and validate their potential health benefits, and (ii) to elaborate a rationale for a mode of polyvalent pharmacological action, which is likely associated with a regulation of the neuroendocrine-immune complex (stress system).

Methods: Literature screening using the Pubmed database and original publications were assessed according to WHO criteria for monographs of herbal medicines.

Results: Sideritis scardica extracts and its ingredient phenylethyl-phenylpropanoid glycoside acteoside (AC, syn. verbascoside) exhibited cognitive improvement, stress-protective, neuroprotective, neurogenesis, anxiolytic, anti-aging, anti-inflammatory, antimicrobial, gastroprotective, glycemic, anti-obesity, antioxidant, and anti-tumor activity. According to the findings, the combination of Sideritis scardica with vitamin B may be relevant for persons solving cognitive tasks under conflict and/or noise (e.g., open-plan offices or car-driving) and support that the tested product alleviates stress-induced impairment of executive functioning (working memory, cognitive flexibility, controlled behavioral inhibition). The recent findings supported by preclinical and clinical data suggest using Herba Sideritis extracts to improve cognitive functions and mental disorders in aging.

Conclusion: This monograph provides systematic information on the safety, efficacy, and quality of Herba Sideritis, paving the way for its potential use in reducing the risk of age-related cognitive decline and neurodegenerative disorders. It includes details of botanical descriptions, chemical constituents, dosage recommendations, adverse effects, and interactions for health professionals, researchers, and policymakers aiding in evidence-based practices and ensuring the safe use of medicinal products. Further preclinical and clinical research is crucial to fully validate GMT's health benefits and unravel the mechanisms underlying its adaptogenic effects.