Efficacy and safety of letrozole or anastrozole in the treatment of male infertility with low testosterone-estradiol ratio: A meta-analysis and systematic review.

BACKGROUND: Aromatase inhibitors (AIs) have been used to treat male infertility for decades. However, due to the lack of large-scale randomized controlled studies and basic research, the efficacy and safety of AIs in the treatment of male infertility remain controversial. Therefore, it is necessary to conduct an evidence-based preliminary evaluation of the existing clinical trials of AIs in the treatment of male infertility. METHOD: A comprehensive literature search was performed in the PubMed, Embase, Cochrane, CNKI, VIP, CBM, and Wanfang databases through August 2021 for all studies. We conducted a systematic review with a meta-analysis of all available studies reporting sperm conventional parameters, gonadotropin and testosterone levels, and/or the pregnancy rate. RESULTS: A total of 10 studies involving 666 patients were included. Letrozole (LE) or anastrozole (AZ) administration significantly increased sperm concentration, total sperm count, serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T) levels, and the testosterone-to-estradiol ratio (T/E2), but E2 levels were significantly reduced compared with baseline values. Compared with the control group, which included selective estrogen receptor modulators (SEMRs) or human chorionic gonadotropin (HCG), LE, or AZ did not have any significant effect on sperm concentration, motility, and morphology, except that AIs had less effect on sperm motility than the control group (weighted mean difference [WMD]: -2.55; 95% CI: -4.11 to -1.00; p = 0.001). CONCLUSION: AIs may be effective in the treatment of male infertility. For infertile male patients planning assisted reproduction, discontinuation of AIs for 2-7 days prior to sperm retrieval may increase the success rate of fertilization. Further studies with larger sample sizes are needed to validate these findings.

[Bushen Huoxue Recipe reduces cyclophosphamide-induced apoptosis of spermatogenic cells in mice].

OBJECTIVE: To investigate the effect of Bushen Huoxue Recipe (BHR) on cyclophosphamide-induced apoptosis of testicular spermatogenic cells in mice and its possible action mechanisms. METHODS: Fifty male Babl/c mice aged 8－9 weeks were randomly divided into five groups of an equal number: blank control, model control, low-dose BHR, medium-dose BHR and high-dose BHR. The animals in the blank control group were intraperitoneally injected with normal saline, while those in the other four groups with cyclophosphamide at 50 mg/kg/d, all for 7 days. After modeling, the mice in the blank and model control groups were given distilled water via gavage once a day, and those in the low-, medium- and high-dose BHR groups treated intragastrically with BHR at 7.5, 15 and 30 g/kg/d qd for 30 successive days. Then, the apoptosis index of the testicular spermatogenic cells was obtained by TUNEL and the expressions of Bax and Bcl-2 mRNA and proteins determined by RT-PCR and Western blot, respectively. RESULTS: Compared with the mice in the blank control group, the BHR model controls showed dramatically increased apoptosis of testicular spermatogenic cells and up-regulated mRNA and protein expressions of Bax and Bcl-2 in the testis tissue (P < 0.01). In comparison with the model controls, the mice in the BHR treatment groups exhibited significantly reduced apoptosis of testicular spermatogenic cells and down-regulated mRNA and protein expressions of Bax and Bcl-2 in the testis tissue (P < 0.01). CONCLUSIONS: Bushen Huoxue Recipe can reduce cyclophosphamide-induced apoptosis of testicular spermatogenic cells in mice, which may be associated with its ability of regulating the expressions of Bax and Bcl-2 mRNA and proteins in the testis tissue.

AT1R knockdown confers cardioprotection against sepsis-induced myocardial injury by inhibiting the MAPK signaling pathway in rats.

Myocardial dysfunction is an important manifestation of sepsis. In addition, inactivation of the mitogen-activated protein kinase (MAPK) signaling pathway has been reported to be beneficial in sepsis. The current study used gene expression profiling to demonstrate the overexpression of angiotensin II type 1 receptor (AT1R) and activation of the MAPK signaling pathway in sepsis. In this study, we used a rat model of sepsis established by cecal ligation and puncture to explore the mechanism of AT1R silencing in relation to the MAPK signaling pathway on myocardial injury. Various parameters including blood pressure, heart rate, and cardiac function changes were observed. Enzyme-linked immunosorbent assay was used to measure the concentration of cardiac troponin T (TnT), cardiac troponin I (cTnI), and creatine kinase isoenzyme muscle/brain (CK-MB). Myocardial enzyme, tissue antioxidant capacity, mitochondria swelling, and membrane potential were also detected. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling staining was applied to measure cell apoptosis, and messenger RNA and protein levels of apoptosis-related proteins (Fas ligand [Fasl], B-cell CLL/lymphoma [Bcl-2], p53) were also detected. Initially, sepsis rats exhibited decreased survival rate, but increased ejection fraction (EF), heart rate, and concentrations of TnT, cTnI, and CK-MB. Furthermore, decreased AT1R expression inactivated the MAPK signaling pathway (shown as decreased extracellular signal-regulated kinase and cyclic adenosine 3',5'-monophosphate response element binding protein expression), decreased EF, heart rate, and concentrations of TnT, cTnI, and CK-MB, but increased sepsis rat survival rate. Eventually, decreased AT1R expression inhibited myocardial cell apoptosis (shown as decreased apoptosis rate and p53 and Fasl expression as well as increased Bcl-2 expression). These findings indicated that AT1R silencing plays an inhibitory role in sepsis-induced myocardial injury by inhibiting the MAPK signaling pathway.