Hongyang Jiang, Ziting Zhou, Nannan Xue, Jiasi Deng, Yuanyuan Zhou, Xinying Lv, Yuxuan Wang, Yi Zhang, Haotian Pan, Geyan Xu, Yinkun Tao, Mengran Li, Xin Cui, Hongyue Ma, Qian Wang, Zhigang Lu
Morphine-associated contextual reward learning promotes maladaptive drug-context associations during opioid exposure. Hederagenin (HE), a bioactive compound from traditional Chinese medicine, has neuroprotective potential, but its role in contextual reward learning remains unclear. Here, we investigated the effects of HE on morphine-induced conditioned place preference (CPP) acquisition and explored its target, downstream signaling, and brain-delivery strategy. HE attenuated morphine CPP acquisition in both sexes and reduced established CPP expression. Chemical proteomics identified the GABAA receptor α1 subunit (GABAA1, encoded by GABRA1) as a prioritized HE-associated target, supported by competitive pull-down, non-permeabilized HE-biotin labeling, microscale thermophoresis, cellular thermal shift assay, and molecular docking. Mechanistically, HE reduced c-Fos activation in ventral tegmental area (VTA) TH-positive dopaminergic neurons, attenuated reward-context-associated VTA calcium responses, suppressed intracellular Ca2 + elevation in SH-SY5Y cells, and reduced VTA CaMKII, PKA, and CREB phosphorylation. Animal-level analyses linked CPP scores to compartment-selective VTA calcium responses and p-CREB/CREB ratios, whereas TH+/c-Fos+ associations varied by treatment. Compared with non-targeted liposomes, RVG29-modified HE-loaded liposomes showed greater brain- and VTA-associated distribution and suppressed established CPP after a single administration. Together, these findings identify HE as a candidate modulator of morphine CPP through a GABAA1-related VTA Ca2 +-CaMK-cAMP-CREB mechanism and support RVG29 liposomes as an exploratory delivery strategy.