Aurantii Fructus (AF)is a traditional Chinese medicine historically used to regulate Qi and alleviate emotional distress, suggesting potential psychotropic effects. This study investigates its therape Show more
Aurantii Fructus (AF)is a traditional Chinese medicine historically used to regulate Qi and alleviate emotional distress, suggesting potential psychotropic effects. This study investigates its therapeutic value for depression based on this traditional indication. To evaluate the rapid antidepressant-like effect of a single acute dose of AF extract in a chronic unpredictable mild stress (CUMS) mouse model and elucidate its underlying molecular mechanisms through integrated transcriptomic and metabolomic analyses. AF flavonoid content was quantified by HPLC. Male mice underwent a 4-week CUMS protocol. A single oral dose of AF was administered 2 h prior to behavioral testing (NSF, TST, SPT, and OFT), with ketamine serving as a positive control. Hippocampal transcriptome analysis was performed by RNA sequencing, and serum metabolites were profiled via LC-MS in both positive and negative ion modes. Pearson correlation analysis assessed relationships between key targets and behavioral outcomes. Pathway involvement was functionally validated in a separate experiment using a hypoxanthine synthesis inhibitor. AF contained narirutin (1.32 mg/g), hesperidin (3.19 mg/g), neohesperidin (22.89 mg/g), naringenin (0.03 mg/g), and nobiletin (0.08 mg/g). Acute AF administration rapidly reversed CUMS-induced depressive-like behaviors, significantly decreasing latency to feed and increasing food consumption in the NSF test, reducing immobility time in the TST, and elevating sucrose preference in the SPT, without altering locomotor activity. Transcriptomic analysis revealed specific downregulation of hippocampal caspase-4 expression by AF. Metabolomic profiling showed AF normalized elevated serum hypoxanthine levels. Serum hypoxanthine levels negatively correlated with hippocampal caspase-4 expression and behavioral improvements, whereas caspase-4 expression positively correlated with behavioral deficits. Pharmacological inhibition of hypoxanthine synthesis abolished AF's antidepressant effects and prevented its normalization of hippocampal caspase-4, NF-κB, GDNF, and BDNF expression. Acute AF produces rapid, ketamine-like antidepressant effects by targeting the hypoxanthine-caspase-4 pathway. This study reveals a novel purinergic mechanism underlying AF's traditional use for emotional disorders and offers a promising therapeutic strategy for rapid-acting antidepressant development. Show less