Therapeutic Effects of Scutellaria baicalensis Georgi Extract and Baicalein on Olfactory Dysfunction and Neurobehavioral Alterations in a Methimazole-Induced Injury Model

Background: Olfactory dysfunction is a pathology associated with viral infections, toxic damage, aging, and neurodegenerative diseases. Damage to the olfactory epithelium impairs olfactory function and related neurological behaviors. This study evaluated the restorative effects of Scutellaria baicalensis Georgi (SBG) extract and baicalein in a methimazole-induced olfactory dysfunction model. Methods: Olfactory epithelial damage was induced in mice with methimazole, followed by treatment with SBG extract or baicalein. Olfactory and neurobehavioral functions were assessed using odor-finding, novel object recognition (NOR), Morris water maze (MWM), open field (OFT), and elevated plus maze tests (EPM). Histological, immunohistochemical, and in vitro analyses were performed to evaluate epithelial regeneration, mature olfactory sensory neurons (OSNs) expressing olfactory marker protein (OMP), and proliferative activity. Results: Methimazole induced severe olfactory epithelial damage, impairing olfactory behavior and reducing learning and memory. Treatment with SBG extract and baicalein significantly improved olfactory and cognitive functions. Histological and immunohistochemical analyses confirmed restoration of epithelial structure and olfactory neurons. In vitro, SBG extract increased epithelial cell density and modulated proliferative activity. Conclusions: SBG extract and baicalein promote recovery of olfactory function and improve neurobehavioral outcomes, indicating their potential as therapies for olfactory dysfunction.