Mohadeseh Poudineh ^1* Bita Amiri ² Maryam Yazdani Tabrizi ³ Mahdyieh Naziri ⁴ Farzaneh Moradi ⁵ Mohammadreza Arzaghi ⁶ Iman Archin ⁷ Fatemeh Behaein ⁸ Anahid Bagheri Pour ⁹ Parna Ghannadikhosh ¹⁰ Saba Imanparvar ¹¹ Ata Akhtari Kohneshahri ¹² Ali Sanaye Abbasi ¹³ Nasibeh Zerangian ¹⁴ Dorsa Alijanzadeh ¹⁵ Hani Ghayyem ¹⁵ Arash Azizinezhad ¹⁶

• ¹ Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
• ² Tabriz university of Medical sciences, Tabriz, Iran
• ³ School of medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
• ⁴ School of Public Health, Iran University of Medical Sciences, Tehran, Alborz, Iran
• ⁵ Islamic Azad University Central Tehran Branch, Tehran, Alborz, Iran
• ⁶ Shahid Beheshti University of Medical Sciences, Tehran, Tehran, Iran
• ⁷ Kazan Federal University, Kazan, Tatarstan, Russia
• ⁸ Birjand University of Medical Sciences, Birjand, South Khorasan, Iran
• ⁹ Iran University of Medical Sciences, Tehran, Tehran, Iran
• ¹⁰ Tabriz University of Medical Sciences, Tabriz, Iran
• ¹¹ Ardabil University of Medical Sciences, Ardabil, Ardabil, Iran
• ¹² Islamic Azad University, Tabriz, Tabriz, Iran
• ¹³ Faculty of Medicine, Gilan University of Medical Sciences, Rasht, Gilan, Iran
• ¹⁴ PhD Student in Health Education and Health Promotion, Department of Health Education and Health Promotion, School of Health, Mashhad University of Medical Sciences, Mashhad, Iran., Mashhad, Iran
• ¹⁵ Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Alborz, Iran
• ¹⁶ Universal Scientific Education and Research Network, Tehran, Tehran, Iran

The incidence of neurological disorders, particularly age-related neurodegenerative pathologies, exhibits an alarming upward trend, while current pharmacological interventions seldom achieve curative outcomes. Despite their diverse clinical presentations, neurological diseases often share a common pathological thread: the aberrant accumulation of misfolded proteins within the endoplasmic reticulum (ER). This phenomenon, known as ER stress, arises when the cell's intrinsic quality control mechanisms fail to cope with the protein-folding burden. Consequently, misfolded proteins accumulate in the ER lumen, triggering a cascade of cellular stress responses. Recognizing this challenge, researchers have intensified their efforts over the past two decades to explore natural compounds that could potentially slow or even reverse these devastating pathologies. Flavonoids constitute a vast and heterogeneous class of plant polyphenols, with over 10,000 identified from diverse natural sources such as wines, vegetables, medicinal plants, and organic products. Flavonoids are generally divided into six different subclasses: anthocyanidins, flavanones, flavones, flavonols, isoflavones, and flavonols. The diverse family of flavonoids, featuring a common phenolic ring backbone adorned with varying hydroxyl groups and additional modifications, exerts its antioxidant activity by inhibiting the formation of ROS, as evidenced by research. Also, studies suggest that polyphenols such as flavonoids can regulate ER stress through apoptosis and autophagy. By understanding these mechanisms, we can unlock the potential of flavonoids as novel therapeutic agents for neurodegenerative disorders. Therefore, this review critically examines the literature exploring the modulatory effects of flavonoids on various steps of the ER stress in neurological disorders.