背景:左归丸(ZGP)是一种传统的中药配方,在缓解卵巢衰老方面有着悠久的历史。
目的:研究ZGP对环磷酰胺(CTX)诱导的卵巢衰老过程中氧化应激和卵原干细胞(OSC)干性的影响,以及其涉及核因子红系2相关因子2(Nrf2,NFE2L2)/血红素加氧酶-1(HO-1,Hmox1)途径的分子机制。
方法:雌性SD大鼠随机分为7组:对照组,型号(CTX),戊酸雌二醇(EV,0.103mg/kg),ZGP-L(低剂量左归丸,1.851g/kg),ZGP-H(高剂量左归丸,3.702g/kg),ML385(30mg/kg),和ML385+ZGP-LCTX建模后,EV,ZGP-L,ZGP-H,ML385+ZGP-L组灌胃8周,而ML385和ML385+ZGP-L组每周两次给予Nrf2拮抗剂ML385。在建模后分离OSC,然后用含有10%ZGP或10μML385的药物血清处理。老鼠的一般情况,包括体重,卵巢重量/体重比,和发情周期,被观察到。卵巢超微结构,通过苏木精和曙红(H&E)染色评估卵泡和黄体计数。采用酶联免疫吸附试验(ELISA)测定血清激素水平。Nrf2/HO-1通路,干细胞,生殖细胞,通过qPCR和Westernblot分析细胞周期生物标志物。通过细胞计数试剂盒-8(CCK-8)测定评估细胞活力。使用流式细胞术和测定试剂盒评估氧化应激生物标志物。采用免疫荧光法检测并定位卵巢中的OSCs,量化平均荧光强度,并鉴定OSC。
结果:ZGP治疗后,CTX诱导的卵巢老化大鼠表现出改善的一般状况,体重增加,卵巢总重量与体重的比率更高,和类似于对照组的发情周期的恢复。血清雌二醇(E2)和卵泡刺激素(FSH)水平,两种性激素,也得到了改善。各阶段卵巢超微结构和卵泡计数均有改善。此外,ZGP干预后OSCs的活力和增殖能力增强.发现Nrf2/HO-1通路在CTX诱导的衰老卵巢OSC中下调。然而,ZGP通过激活Nrf2,HO-1和NAD(P)H氧化还原酶1(NQO1)的表达来逆转这种作用,增加抗氧化酶超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)的活性,减少丙二醛(MDA)和活性氧(ROS)的积累,从而恢复对氧化应激的抵抗力。此外,ZGP改善了OSCs的细胞周期,上调CyclinD1和CyclinE1的表达,恢复细胞干性,促进扩散,增强了细胞干细胞标记八聚体结合转录因子4(Oct4)和小鼠VASA同源物(MVH)的表达,下调P21的表达,从而抑制细胞凋亡。在使用ML385抑制Nrf2信号通路后,ZGP抗氧化应激和恢复细胞干性的治疗作用减弱。
结论:ZGP通过恢复正常的卵巢功能保护CTX诱导的卵巢衰老,减轻衰老OSC的氧化应激,促进OSC增殖,恢复老鼠的干性,可能通过调节Nrf2/HO-1途径。
BACKGROUND: Zuogui Pill (ZGP) is a traditional herbal formula of Chinese Medicine with a long history of use in alleviating ovarian aging.
OBJECTIVE: To examine the impact of ZGP on oxidative stress and the stemness of oogonial stem cells (OSCs) in cyclophosphamide (CTX)-induced ovarian aging, as well as its molecular mechanisms involving the nuclear factor erythroid 2-related factor 2 (Nrf2, NFE2L2)/heme oxygenase-1 (HO-1, Hmox1) pathway.
METHODS: Female Sprague-Dawley (SD) rats were randomly divided into seven groups: control, model (CTX), estradiol valerate (EV, 0.103 mg/kg), ZGP-L (low dose Zuogui Pill, 1.851 g/kg), ZGP-H (high dose Zuogui Pill, 3.702 g/kg), ML385 (30 mg/kg), and ML385+ZGP-L. After CTX modeling, the EV, ZGP-L, ZGP-H, and ML385+ZGP-L groups were treated by gavage for 8 weeks, while the ML385 and ML385+ZGP-L groups were administered the Nrf2 antagonist ML385 twice a week. OSCs were isolated after modeling and then treated with drug serum containing 10% ZGP or 10 μM ML385. The general conditions of the rats, including body weight, ovarian weight/body weight ratio, and estrous cycle, were observed. Ovarian ultrastructure, follicle and corpus luteum counts were assessed via hematoxylin and eosin (H&E) staining. Serum hormone levels were measured using enzyme-linked immunosorbent assay (ELISA). Nrf2/HO-1 pathway, stem cell, germ cell, and cell cycle biomarkers were analyzed by qPCR and Western blot. Cell viability was assessed by cell counting kit-8 (CCK-8) assay. Oxidative stress biomarkers were evaluated using flow cytometry and assay kits. Immunofluorescence was employed to detect and locate OSCs in the ovary, quantify the average fluorescence intensity, and identify OSCs.
RESULTS: After ZGP treatment, rats with CTX-induced ovarian aging exhibited improved general condition, increased body weight, higher total ovarian weight to body weight ratio, and a restoration of the estrous cycle similar to the control group. Serum levels of estradiol (E2) and follicle stimulating hormone (FSH), two sex hormones, were also improved. Ovarian ultrastructure and follicle count at all stages showed improvement. Moreover, the viability and proliferation capacity of OSCs were enhanced following ZGP intervention. The Nrf2/HO-1 pathway was found to be down-regulated in CTX-induced aging ovarian OSCs. However, ZGP reversed this effect by activating the expression of Nrf2, HO-1, and NAD(P)H oxidoreductase 1 (NQO1), increasing the activity of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), and reducing the accumulation of malonaldehyde (MDA) and reactive oxygen species (ROS), thus restoring resistance to oxidative stress. Additionally, ZGP improved the cell cycle of OSCs, up-regulated the expression of Cyclin D1 and Cyclin E1, restored cell stemness, promoted proliferation, enhanced the expression of cell stemness markers octamer-binding transcription factor 4 (Oct4) and mouse VASA homolog (MVH), and down-regulated the expression of P21, thereby inhibiting apoptosis. The therapeutic effects of ZGP against oxidative stress and restoration of cell stemness were attenuated following inhibition of the Nrf2 signaling pathway using ML385.
CONCLUSIONS: ZGP protected against CTX-induced ovarian aging by restoring normal ovarian function, alleviating oxidative stress in aging OSCs, promoting OSCs proliferation, and restoring their stemness in rats, possibly through regulating the Nrf2/HO-1 pathway.