Banxia Houpo Decoction reduces lysosomal leakage of prefrontal astrocytes through the OGT-CTSB-NLRP3 pathway to improve depressive-like behaviors

Abstract

Ethnopharmacological relevance: Depression in traditional Chinese medicine is mechanistically linked to neuroinflammation-a key pathogenesis driving depressive disorders. Baixian Houpo Decoction (BXHPD), originating from the classical TCM text Jinkui Yaolue, is prescribed for depression attributable to "phlegm-qi stagnation". While modern pharmacological studies confirm its potent anti-inflammatory properties, the molecular pathways underpinning BXHPD's therapeutic effects against neuroinflammation remain undefined.

Objective: We aimed to evaluate the antidepressant effect of BXHPD in a cortical corticosterone (CORT)-induced mouse model of depression and its potential molecular mechanisms.

Materials and methods: Male C57BL/6 wild-type and Aldh1l1-Cre/ERT2 mice received CORT injetions to induce depression. Behavioral tests included sucrose preference (SPT), tail suspension (TST), forced swim (FST), and open field (OFT) tests. Hippocampal neuropathology was assessed via Nissl staining for neuronal damage and ELISA for pro-inflammatory (IL-1β, IL-6, TNF-α) and anti-inflammatory (IL-10, IL-4) cytokines. Molecular analyses involved CO-IP for O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT)-Cathepsin B (CTSB) interaction, O-GlcNAcylation, and NLRP3 inflammasome activation; western blotting for protein expression; immunofluorescence for OGT/S100β and CTSB/LAMP1 colocalization; and DHE staining for ROS detection.

Results: BXHPD alleviated depressive-like behaviors, reduced neuronal damage, and inhibited pro-inflammatory cytokine release in depressed mice. Mechanistically, BXHPD downregulated OGT, thereby reducing CTSB O-GlcNAcylation to promote its maturation. This decrease in O-GlcNAcylation lowered ROS levels, attenuated lysosomal membrane permeabilization (LMP), limited cytoplasmic CTSB leakage, and ultimately suppressed NLRP3 inflammasome activation.

Conclusion: BXHPD targets astrocytes in the medial prefrontal cortex via the OGT/CTSB/NLRP3 pathway to alleviate neuroinflammation and improve depressive-like behaviors.

Keywords: Astrocytes; BXHPD; Depression; Glycosylation modification; Neuroinflammation; OGT.