CITRUS ESSENTIAL OILS AND FRUITS IN AROMATHERAPY AND NUTRITION: NEUROPHYSIOLOGICAL MECHANISMS AND THERAPEUTIC APPLICATIONS

Purpose: to summarize current scientific data on the chemical composition of citrus essential oils (CEOs) and bioactive components of citrus fruits, the neurophysiological mechanisms of the inhalational action of CEOs, and the systemic effects of alimentary consumption of citrus fruits, as well as their therapeutic potential in the prevention and dietary support of anxiety, depressive, insomnia-related, neurodegenerative, dermatological, cardiovascular, oncological, and metabolic conditions. Materials and Methods. An analytical review of scientific publications was conducted using the PubMed/MEDLINE, Scopus, Web of Science, ScienceDirect, and Google Scholar databases. A total of 21 sources (2001–2026) were reviewed, including randomized controlled clinical trials, cohort and observational studies, systematic reviews, and meta-analyses. Results. CEOs constitute a complex mixture (approximately 400 compounds), dominated by monoterpenes – primarily d-limonene. Upon inhalation, CEO molecules reach the brain via three pathways: activation of olfactory chemoreceptors, direct neuronal penetration, and absorption into alveolar circulation, thereby exerting anxiolytic, antidepressant, sedative, anti-inflammatory, antioxidant, and neuroprotective effects through modulation of gamma-aminobutyric acid (GABA), serotonergic and dopaminergic neurotransmission, inhibition of monoamine oxidase and acetylcholinesterase, reduction of cortisol levels, and increased hippocampal brain-derived neurotrophic factor (BDNF). Clinical studies from 2021–2026 confirm the efficacy of bergamot, bitter orange, and sweet orange oils in reducing anxiety and improving sleep quality and mood. Аlimentary consumption of citrus fruits – a source of flavonoids, vitamin C, carotenoids, and pectin – exerts an independent systemic effect: it reduces the risk of cardiovascular, oncological, and metabolic diseases, modulates the gut microbiota and systemic inflammation, has neuroprotective potential due to flavonoids’ ability to cross the blood-brain barrier, and supports collagen synthesis and tissue regeneration through vitamin C. Conclusions. Inhalational aromatherapy using CEOs is a scientifically substantiated, safe, and accessible adjunctive method for correcting anxiety-depressive disorders and sleep disturbances, while regular alimentary consumption of citrus fruits exerts an independent, preventive effect on cardiovascular, oncological, and metabolic conditions and supports connective tissue health.