[Mechanism of Danhong Injection in regulating endometrial breakdown during menstruation via HIF1A/CXCR4 pathway]

This paper aims to investigate the effects of Danhong Injection on endometrial breakdown in a menstrual-like mouse model and its underlying mechanisms.In this study,a menstrual-like mouse model was established,and uterine tissue morphology was observed at different time points after progesterone(P4) withdrawal.The menstrual-like mice were randomly divided into a sham group,a model group,low-(0.6 mL·kg~(-1)) and high-(1.2 mL·kg~(-1)) dose Danhong Injection groups,and a high-dose Danhong Injection plus hypoxia-inducible factor-lα(HIF1A) inhibitor(PX-478,40 mg·kg~(-1)) group.The results show that 24 hours after P4withdrawal,compared with those in the sham group,the mice in the model group exhibit decreased serum P4 and estradiol(E_2)levels,increased follicle-stimulating hormone(FSH) and luteinizing hormone(LH) levels,endometrial breakdown,and significantly increased apoptosis rate.The gene and protein expression of inflammatory cytokines,such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),interleukin-10(IL-10),and cluster of differentiation 45(CD45) were increased.The gene and protein expression of apoptosis-related proteins,such as activated cleaved caspase-3,HIF1A,and C-X-C chemokine receptor 4(CXCR4),were also increased.The B-cell lymphoma-2(Bcl-2)/Bcl-2-associated X protein(Bax) decreased.After Danhong Injection intervention,especially in the high-dose Danhong Injection group,serum P4 levels were increased,while E_2,FSH,and LH levels were decreased.Endometrial breakdown and apoptosis were alleviated;inflammatory cytokines and cleaved caspase-3 expression were downregulated;IL-10 levels,Bcl-2/Bax,and gene and protein expression of HIF1A and CXCR4 were unregulated.By 48 hours after P4 withdrawal,partial endometrial repair occurred in the mice from the model group,with increased protein expression of α-smooth muscle actin(α-SMA) and matrix metalloproteinase-9(MMP-9),while mRNA expression of HIF1A and CXCR4 showed no significant changes.Although Danhong Injection with different doses did not significantly alter serum hormone levels at this time point,it accelerated endometrial repair and reduced α-SMA and MMP-9 protein expression.The HIF1A inhibitor PX-478 reversed its positive effects during the repair phase.In summary,Danhong Injection may delay P4 withdrawal and improve the hormonal environment,thereby alleviating endometrial breakdown in menstrual-like mice.In the local endometrium,its mechanism of action may be related to activating the HIF1A/CXCR4 signaling pathway,inhibiting excessive stromal cell apoptosis,alleviating inflammatory responses,and promoting tissue homeostasis restoration.