A Vortioxetine-Glycyrrhizic Acid Supramolecular Complex: Synthesis and Cellular Effects on Microglial and Blood Cells...

Background: Depression is a severe disorder associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation and neuroinflammation, and which restrains the efficacy of conventional antidepressants. Vortioxetine is a multimodal antidepressant with potential immunomodulatory properties. Glycyrrhizic acid (GA) is a natural compound derived from licorice root that exhibits anti-inflammatory activity and modulates glucocorticoid signaling. We hypothesized that a supramolecular complex of vortioxetine with GA (Vort:Na₂GA) would exert synergistic effects on inflammatory and glucocorticoid pathways. Methods: Vortioxetine compositions with Na₂GA were prepared using a mechanochemical method. Cytotoxicity, anti-inflammatory property, and glucocorticoid receptor (GR) signaling pathway modulation of the complex were evaluated in vitro using SIM-A9 microglial cells. Additionally, a 7-day oral administration study in intact female C57BL/6 mice was conducted to evaluate the effects on peripheral blood cells. Results: The Vort:Na₂GA complex improves the solubility of the parent drug while increasing its stability and permeability. Furthermore, the resulting complex exhibits reduced cytotoxicity, particularly under glucocorticoid challenge. In SIM-A9 microglial cells, the Vort:Na₂GA complex upregulated expression of Nr3c1 and Nr1d1 genes without activating canonical GR target genes (Fkbp5 and Gilz) and partially reversed dexamethasone-induced glucocorticoid resistance. In vivo, the complex reduced the percentage of inflammatory Ly6C^high monocytes and preserved dexamethasone-induced Gilz expression in peripheral blood cells, indicating protection against stress-induced glucocorticoid resistance. Conclusions: The Vort:Na₂GA supramolecular complex enhances the physicochemical and pharmacological profile of vortioxetine, reduces inflammation-associated myeloid cell populations, and preserves glucocorticoid sensitivity. These findings support its further evaluation as a potential therapeutic agent for depressive disorders with inflammatory and HPA axis-related components.