Abstract
Aging is a process associated with distinctive changes in physiological
functions and physical appearance that result from progressive tissue degeneration,
harming the structure and function of vital organs. Illnesses that are particularly
frequent in people 65 years of age and older are generally grouped as age-related
diseases or aging-related diseases and include neurodegenerative diseases such as
Alzheimer's disease (AD) and Parkinson's disease (PD), which are caused by
progressive degeneration and/or neuronal death to produce debilitating conditions, and
they have no cure. For these illnesses, the most important risk factor is aging. Aging
involves changes in neuroendocrine and inflammatory responses and presents a stage
with chronic and low-grade inflammation, characterized by a general increase in the
production of proinflammatory cytokines, inflammatory markers, and cellular
senescence. Herbal medicine, as well as various components of the human diet,
including vegetables, cereals, and fruits, contain widely varied phytochemicals
including flavonoids, which are the most common polyphenolic compounds.
Epidemiological studies suggest that a higher intake of flavonoid-rich foods and
beverages is associated with better cognitive outcomes, lower dementia rates, and
reduced risk of neurodegenerative diseases. Moreover, numerous preclinical studies
have shown that these compounds have a therapeutic effect on animal models of human
degenerative diseases and highlight the anti-inflammatory effect of flavonoids by
decreasing the activated glial cells and several proinflammatory mediators. Much
modern scientific research has focused on establishing biological activities of purified
single compounds to provide an evidence base for the rationale of traditional practice,
and also to integrate these into modern medical practice.