OBJECTIVE: To examine, dissect, and understand the molecular mechanisms and combinatorial effects of Zuogui (左归丸, ZGP) and Yougui pills (右归丸, YGP) in 4-vinyl cyclohexene diepoxide (4-VCD)-induced Perimenopausal syndrome (PMS).

METHODS: Using the 4-VCD-induced PMS mouse model, uterine and ovary index were measured, and serum sex steroidal hormone levels were evaluated after treatment with ZGP, YGP, ZGP + YGP, estradiol valerate (EV), and Gengnian An (gengnianan, GNA). Histopathological examinations, ingredient-target network predictions, western blotting, and real-time quantitative polymerase chain reaction (RT-qPCR) analyses were performed to ascertain the possible pharmacological effects and molecular mechanisms of ZYP and YGP.

RESULTS: Treatment with ZGP and YGP remarkably improves estrous cyclicity and prevents pathological damage to the uterus. Also, altered sex hormones, including AMH, E2, FSH, LH, P, and T, were restored to normal levels after ZGP and YGP administration. Ingredient-target network analysis showed that the 5 ingredients common to the ZGP and YGP formula modulate 53 targets shared with PMS. Pathway-enrichment analysis further predicted that ZGY and YGP likely regulate of apoptosis and other essential pathways during PMS. In-vivo studies showed that ZGP and YGP suppress PMS via modulating apoptosis through decreasing Caspase-3 and Bcl-2-associated X (Bax) levels and increasing B-cell lymphoma-2 (Bcl-2)/Bax and Bcl-2 levels. Importantly, ZGP + YGP treatment modulation effects were somewhat or significantly better compared to ZGP or YGP alone treatment.

CONCLUSION: ZGP and YGP represent novel anti-PMS agents whose effects involve restoring altered hormonal levels, protecting the uterus, and regulating apoptosis.