Small organism models for mode of action research on anti-ageing and nootropic herbs, foods, and formulations.

With global increase in ageing population along with increasing age-related neurodegenerative diseases (NDs), development of sustainable, safe and effective solutions for promoting healthy ageing and preventing diseases has become a priority. Traditional healthcare systems/medicines prescribe several herbs, foods and formulations to promote healthy ageing and prevent and/or treat age-related diseases. However, the scientific data elucidating their mechanism of action is very limited and deeper research using different models is warranted for timely and wider use. The clinical studies and research with higher model organisms, although useful, have several practical, technical, and financial limitations. Conversely, small organism models like Yeast, Roundworm, Fruit fly, and Zebrafish, which have genetic similarities to humans, can replicate the disease features and provide behavioural, cellular and molecular insights. The common features of ageing and NDs, like amyloid protein aggregations, oxidative stress, energy dysregulation, inflammation and neurodegeneration can be mimicked in the small organism models for Alzheimer's, Parkinson's, Huntington's diseases, and Amyotrophic Lateral Sclerosis. This review focuses on small organism model- based research unveiling interesting modes of action and synergistic effects of herbal extracts, foods, and formulations, which are indicated especially for healthy ageing and management of NDs. This will provide leads for the quick and sustainable development of scientifically evaluated solutions for clinically relevant, age-related conditions.