OBJECTIVE: To investigate the underlying mechanism of "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture technique for improving reproductive function in mice with asthenospermia by regulating ferroptosis pathway. METHODS: Sixty male C57BL/6 mice were randomly divided into a blank group, a model group, an acupuncture group and a Fer-1 group, 15 mice in each one. Except the blank group, the intraperitoneal injection with cyclophosphamide (50·kg^-1·d^-1) was administered to establish the asthenospermia model in the mice of the rest 3 groups for 5 consecutive days. In the acupuncture group, "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture technique was operated in the mice, for 20 min each time; and in the Fer-1 group, Fer-1 solution (1 mg/kg) was injected intraperitoneally. The interventions of these two groups were delivered once daily and for 2 consecutive weeks. The testicular wet weight was measured and the testicular coefficient was calculated. Using sperm quality detection system, the sperm quality was detected. With ELISA used, the contents of testosterone (T), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the serum were detected. With HE staining, testicular and epididymal morphology was observed. Immunofluorescence was used to detect the expression of reactive oxygen species (ROS) in the testes. Biochemical assay was conducted to determine the contents of malondialdehyde (MDA), reduced glutathione (GSH), and total iron ion (TFe) in the testicular tissue. Transmission electron microscopy was used to examine mitochondrial structure of the testis, while JC-1 staining was used to assess mitochondrial membrane potential in the testicular tissue. Fluorescence quantitative PCR and Western blot analyses were employed to measure the mRNA and protein expression of solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), and acyl-CoA synthetase long-chain family member 4 (ACSL4) in the testicular tissue. RESULTS: Compared with the blank group, in the model group, the testicular wet weight and testicular coefficient decreased (P<0.01); the sperm concentration and sperm motility reduced (P<0.01), and the contents of T, FSH, and LH decreased in the serum (P<0.01); and the seminiferous tubules in the testis showed loose structure and deformed lumen, sperm cells were disorganized and the sperm numbers reduced; the tubular walls became thinner, and sperm numbers in the lumen less; the expression of ROS in testicular tissue, as well as the contents of MDA and TFe increased (P<0.01), and the content of GSH decreased (P<0.01); and the numbers of mitochondria reduced, the structure of cristae was serious damaged, and mitochondrial membrane potential level declined (P<0.01); the mRNA and protein expression of SLC7A11, GPX4, and FTH1 decreased (P<0.01), while the mRNA and protein expression of ACSL4 increased (P<0.01). In comparison with the model group, the acupuncture and Fer-1 groups showed the increase of testicular wet weight and coefficient (P<0.01), sperm concentration and motility (P<0.01), and the serum contents of T, FSH, and LH (P<0.01); and the improvements in testicular and epididymal histopathology; ROS expression and the contents of MDA and TFe decreased (P<0.01), and the content of GSH elevated (P<0.05); the mitochondrial structure and numbers were ameliorated and mitochondrial membrane potential rose (P<0.01). Besides, in comparison with the model group, the mRNA expression of SLC7A11 was higher (P<0.05, P<0.01), the mRNA and protein expression of GPX4 and FTH1 increased (P<0.01, P<0.05), and the mRNA and protein expression of ACSL4 decreased (P<0.01) in the acupuncture and the Fer-1 groups; and the protein expression of SLC7A11 was higher in the Fer-1 group (P<0.05). CONCLUSION "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture technique may improve the reproductive capacity in the mice with asthenospermia by alleviating ferroptosis-induced cellular damage and ameliorating testicular function.
Animals ; Male ; Ferroptosis ; Mice ; Acupuncture Therapy ; Mice, Inbred C57BL ; Asthenozoospermia/metabolism* ; Humans ; Acupuncture Points ; Testis/metabolism* ; Luteinizing Hormone/metabolism* ; Malondialdehyde/metabolism* ; Reproduction ; Testosterone/metabolism*

OBJECTIVE: To observe the effects of electroacupuncture (EA) with different frequencies on spermatogenic function, testicular morphology and oxidative stress in oligoasthenospermia (OAT) rats, and to explore the mechanism and the optimal parameters of EA for OAT. METHODS: Sixty SPF-grade male SD rats were randomly divided into a solvent control group, a model group, a 2 Hz EA group, a 100 Hz EA group and a 2 Hz/100 Hz EA group, with 12 rats in each group. Except for the solvent control group, the other 4 groups were administered ornidazole suspension (800 mg·kg^-1·d^-1) by gavage for 28 d to establish the OAT model. Starting from the 1st of modeling, EA was applied at "Guanyuan" (CV4), "Qihai" (CV6) and bilateral "Sanyinjiao" (SP6) and "Zusanli" (ST36) in the 3 EA groups, continuous wave of 2 Hz, continuous wave of 100 Hz, and disperse-dense wave of 2 Hz/100 Hz were used in the 2 Hz EA group, the 100 Hz EA group, and the 2 Hz/100 Hz EA group, respectively, with current intensity of 1-3 mA, 30 min a time, once every other day, for 28 consecutive days. After intervention, the testicular index was calculated, epididymal sperm quality was assessed, and the fertility ability was observed; morphology of testicular tissue was observed by HE staining, and the Johnson score was calculated; the positive expression of reactive oxygen species (ROS) in testicular tissue was detected by immunofluorescence; the activity of superoxide dismutase (SOD) and catalase (CAT), as well as the level of malondialdehyde (MDA) in testicular tissue were measured by ELISA; the protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in testicular tissue was detected by Western blot. RESULTS: Compared with the solvent control group, in the model group, the testicular index, sperm concentration, sperm motility and the number of offspring were decreased (P<0.01), the seminiferous tubules atrophied and the Johnson score decreased (P<0.01); the activity of SOD and CAT, as well as the protein expression of Nrf2 and HO-1 in testicular tissue were decreased (P<0.01); the sperm deformity rate, the positive expression of ROS and the MDA level in testicular tissue were increased (P<0.01). Compared with the model group, in the 2 Hz EA group, the 100 Hz EA group and the 2 Hz/100 Hz EA group, the testicular index, sperm concentration, sperm motility and the number of offspring were increased (P<0.05, P<0.01), the pathological morphology of testicular tissue improved and the Johnson scores increased (P<0.01); the activity of SOD and CAT, as well as the protein expression of Nrf2 and HO-1 in testicular tissue were increased (P<0.05, P<0.01); the sperm deformity rate, the positive expression of ROS and the MDA level in testicular tissue were decreased (P<0.05, P<0.01). Compared with the 2 Hz EA group, in the 2 Hz/100 Hz EA group, the testicular index, sperm concentration, sperm motility, as well as the CAT activity and HO-1 protein expression in testicular tissue were increased (P<0.01, P<0.05); the positive expression of ROS was decreased (P<0.01). Compared with the 100 Hz EA group, in the 2 Hz/100 Hz EA group, the testicular index was increased (P<0.01), the positive expression of ROS in testicular tissue was decreased (P<0.01). CONCLUSION EA with 2 Hz continuous wave, 100 Hz continuous wave, and 2 Hz/100 Hz disperse-dense wave can all improve the spermatogenic arrest and reduce the level of oxidative stress in testicular tissue in OAT rats, the mechanism may be related to up-regulating the protein expression of Nrf2 and HO-1 and improving oxidative stress. EA with disperse-dense wave of 2 Hz/100 Hz shows the optimal effect.
Male ; Animals ; Electroacupuncture ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Spermatogenesis ; Oligospermia/genetics* ; Humans ; Testis/metabolism* ; Superoxide Dismutase/metabolism* ; Asthenozoospermia/genetics* ; Acupuncture Points ; Malondialdehyde/metabolism*

OBJECTIVE: To observe the effects of the "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture on key regulatory factors during mitochondrial apoptosis of testicular tissue in asthenozoospermia mice, and explore the potential mechanism of the protective effect of acupuncture on reproductive function. METHODS: Thirty C57BL/6 male mice were randomly divided into a blank group, a model group and an acupuncture group, 10 mice in each group. In the model and the acupuncture groups, the intraperitoneal injection of cyclophosphamide (30 mg•kg^-1•d^-1) was delivered for 7 days to prepare the asthenozoospermia model. After the success of modeling, the modeled mice in the acupuncture group were intervened with "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture, once daily and the needles were retained for 20 min. The duration of the intervention was 2 weeks. The general condition of each mouse was observed, and the body mass was recorded before modeling, after modeling and after intervention completion. After intervention, the testicular mass was recorded and the weight coefficient was calculated, and the mouse sperm quality was examined; the serum contents of testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were detected using ELISA, the morphology of testicular tissue was observed using HE, the mitochondrial ultra-microstructure of testicular tissue was observed under transmission electrone microscopy, the mitochondrial membrane potential level of testicular tissue was detected using JC-1 staining, the positive rate of apoptosis cell of testicular tissue was observed using TUNEL; and the mRNA and protein expression of b-cell lymphocytoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), cytochrome c (Cyt C), apoptotic protease-activating factor1 (Apaf-1), Caspase-9 and Caspase-3 of testicular tissue was detected using real-time quantitative fluorescence PCR and Western blot methods separately; and the positive expression of Cleaved Caspase-3 of the testicular tissue was detected using immunohistochemistry. RESULTS: Compared with the blank group, the mice were in listless spirits, had shaggy hairs, the reduced appetite and movement, and weight loss in the model group (P<0.01); the testicular mass and the weight coefficient decreased (P<0.01); the total number of sperms, sperm motility, and sperm viability were declined (P<0.01); while the levels of serum T, FSH, and LH were dropped (P<0.01). The morphology of seminiferous tubules in testicular tissue was abnormal, the number of spermatogenic cells and the number of mitochondria decreased, the inner mitochondrial crest was fractured and lost, and vacuoles appeared. The level of mitochondrial membrane potential was reduced (P<0.01); and the positive rate of apoptosis cell in testicular tissue increased (P<0.01). The mRNA and protein expression of Bax, Cyt C, Apaf-1, Caspase-9 and Caspase-3 was elevated (P<0.01, P<0.05), the mRNA and protein expression of Bcl-2 was dropped (P<0.01), and the average absorbance value of Cleaved Caspase-3 increased (P<0.01). When compared with the model group, in the acupuncture group, the general condition of mice was improved, the testicular mass and the weight coefficient elevated (P<0.01); the total number of sperms, sperm motility, and sperm viability increased (P<0.01); while the levels of serum T, FSH, and LH rose (P<0.01). The pathological morphology of testicular tissue and the inner mitochondrial ultra-microstructure were ameliorated, the level of mitochondrial membrane potential was elevated (P<0.01); the positive rate of apoptosis cell was reduced (P<0.01). The mRNA and protein expression of Bax, Cyt C, Apaf-1, Caspase-9 and Caspase-3 was dropped (P<0.01, P<0.05), the mRNA and protein expression of Bcl-2 elevated (P<0.05), and the average absorbance value of Cleaved Caspase-3 declined (P<0.01). CONCLUSION "Zhibian" (BL54)-toward- "Shuidao" (ST28) acupuncture may ameliorate mouse reproductive function by inhibiting mitochondrial apoptosis pathway, alleviating testicular tissue damage in the asthenospermia mice induced by cyclophosphamide.
Animals ; Male ; Mice ; Apoptosis ; Acupuncture Therapy ; Mitochondria/metabolism* ; Asthenozoospermia/genetics* ; Humans ; Testis/metabolism* ; Mice, Inbred C57BL ; Spermatozoa/metabolism* ; Acupuncture Points ; Sperm Motility ; Testosterone/blood* ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Caspase 3/genetics* ; Follicle Stimulating Hormone/blood* ; Reproduction ; Cytochromes c/genetics* ; bcl-2-Associated X Protein/genetics* ; Apoptotic Protease-Activating Factor 1/genetics*

This study investigates the reproductive protective effect and potential mechanism of Cistanches Herba extract(CHE) on a rat model of kidney-Yang deficiency induced by adenine. Rats were randomly divided into five groups: normal, model, low-dose CHE(0.6 g·kg~(-1)·d~(-1)), high-dose CHE(1.2 g·kg~(-1)·d~(-1)), and L-carnitine(100 mg·kg~(-1)·d~(-1)). The rats were administered adenine(200 mg·kg~(-1)·d~(-1)) by gavage for the first 14 days to induce kidney-Yang deficiency, while simultaneously receiving drug treatment. After 14 days, the modeling was discontinued, but drug treatment continued to 49 days. The content of components in CHE was analyzed by high-performance liquid chromatography. The adenine-induced kidney-Yang deficiency model was assessed through symptom characterization and measurement of testosterone(T) levels using an enzyme-linked immunosorbent assay kit. Pathological damage to the testis and epididymis was evaluated based on the wet weight and performing hematoxylin-eosin staining. Sperm density and motility were measured using computer-aided sperm analysis, and sperm viability was assessed using live/dead sperm staining kits, and sperm morphology was evaluated using eosin staining, thereby determining rat sperm quality. Metabolomics was used to analyze changes in serum metabolites, enrich related metabolic pathways, and explore the mechanism of CHE in improving reproductive function damage in rats with kidney-Yang deficiency syndrome. Compared to the normal group, the model group exhibited significant kidney-Yang deficiency symptoms, reduced T levels, decreased testicular and epididymal wet weights, and significant pathological damage to the testis and epididymis. The sperm density, motility, and viability decreased, with an increased rate of sperm abnormalities. In contrast, rats treated with CHE showed marked improvements in kidney-Yang deficiency symptoms, restored T levels, alleviated pathological damage to the testis and epididymis, and improved various sperm parameters. Metabolomics results revealed 286 differential metabolites between the normal and model groups(191 upregulated and 95 downregulated). Seventy-five differential metabolites were identified between the model and low-dose CHE groups(21 upregulated and 54 downregulated). A total of 24 common differential metabolites were identified across the three groups, with 22 of these metabolites exhibiting opposite regulation trends between the two comparison groups. These metabolites were primarily involved in linoleic acid metabolism, ether lipid metabolism, and pantothenic acid and coenzyme A biosynthesis, as well as metabolites including 13-hydroperoxylinoleic acid, lysophosphatidylcholine, and pantethine. CHE can improve kidney-Yang deficiency symptoms in rats, alleviate reproductive organ damage, and enhance sperm quality. The regulation of lipid metabolism may be a potential mechanism through which CHE improves reproductive function in rats with kidney-Yang deficiency. The potential bioactive compounds of CHE include echinacoside, verbascoside, salidroside, betaine, and cistanoside A.
Animals ; Male ; Rats ; Yang Deficiency/physiopathology* ; Metabolomics ; Kidney/physiopathology* ; Rats, Sprague-Dawley ; Drugs, Chinese Herbal/administration & dosage* ; Cistanche/chemistry* ; Kidney Diseases/metabolism* ; Testis/metabolism* ; Humans ; Reproduction/drug effects* ; Testosterone/blood*

Testicular descent occurs in two consecutive stages: the transabdominal stage and the inguinoscrotal stage. Androgens play a crucial role in the second stage by influencing the development of the gubernaculum, a structure that pulls the testis into the scrotum. However, the mechanisms of androgen actions underlying many of the processes associated with gubernaculum development have not been fully elucidated. To identify the androgen-regulated genes, we conducted large-scale gene expression analyses on the gubernaculum harvested from luteinizing hormone/choriogonadotropin receptor knockout ( Lhcgr KO) mice, an animal model of inguinoscrotal testis maldescent resulting from androgen deficiency. We found that the expression of secreted protein acidic and rich in cysteine (SPARC)-related modular calcium binding 1 ( Smoc1 ) was the most severely suppressed at both the transcript and protein levels, while its expression was the most dramatically induced by testosterone administration in the gubernacula of Lhcgr KO mice. The upregulation of Smoc1 expression by testosterone was curtailed by the addition of an androgen receptor antagonist, flutamide. In addition, in vitro studies demonstrated that SMOC1 modestly but significantly promoted the proliferation of gubernacular cells. In the cultures of myogenic differentiation medium, both testosterone and SMOC1 enhanced the expression of myogenic regulatory factors such as paired box 7 ( Pax7 ) and myogenic factor 5 ( Myf5 ). After short-interfering RNA-mediated knocking down of Smoc1 , the expression of Pax7 and Myf5 diminished, and testosterone alone did not recover, but additional SMOC1 did. These observations indicate that SMOC1 is pivotal in mediating androgen action to regulate gubernaculum development during inguinoscrotal testicular descent.
Animals ; Male ; Mice ; Testis/growth & development* ; Mice, Knockout ; Androgens/pharmacology* ; Testosterone/pharmacology* ; Receptors, LH/metabolism* ; Calcium-Binding Proteins/metabolism*

Spermatogenesis is a fundamental process that requires a tightly controlled epigenetic event in spermatogonial stem cells (SSCs). The mechanisms underlying the transition from SSCs to sperm are largely unknown. Most studies utilize gene knockout mice to explain the mechanisms. However, the production of genetically engineered mice is costly and time-consuming. In this study, we presented a convenient research strategy using an RNA interference (RNAi) and testicular transplantation approach. Histone H3 lysine 9 (H3K9) methylation was dynamically regulated during spermatogenesis. As Jumonji domain-containing protein 1A (JMJD1A) and Jumonji domain-containing protein 2C (JMJD2C) demethylases catalyze histone H3 lysine 9 dimethylation (H3K9me2), we firstly analyzed the expression profile of the two demethylases and then investigated their function. Using the convenient research strategy, we showed that normal spermatogenesis is disrupted due to the downregulated expression of both demethylases. These results suggest that this strategy might be a simple and alternative approach for analyzing spermatogenesis relative to the gene knockout mice strategy.
Spermatogenesis/physiology* ; Animals ; Male ; Mice ; Epigenesis, Genetic ; Jumonji Domain-Containing Histone Demethylases/metabolism* ; Histones/metabolism* ; RNA Interference ; Testis/metabolism* ; Methylation ; Mice, Knockout ; Histone Demethylases

Researchers commonly use cyclization recombination enzyme/locus of X-over P1 (Cre/loxP) technology-based conditional gene knockouts of model mice to investigate the functional roles of genes of interest in Sertoli and Leydig cells within the testis. However, the shortcomings of these genetic tools include high costs, lengthy experimental periods, and limited accessibility for researchers. Therefore, exploring alternative gene silencing techniques is of great practical value. In this study, we employed adeno-associated virus (AAV) as a vector for gene silencing in Sertoli and Leydig cells. Our findings demonstrated that AAV serotypes 1, 8, and 9 exhibited high infection efficiency in both types of testis cells. Importantly, we discovered that all three AAV serotypes exhibited exquisite specificity in targeting Sertoli cells via tubular injection while demonstrating remarkable selectivity in targeting Leydig cells via interstitial injection. We achieved cell-specific knockouts of the steroidogenic acute regulatory ( Star ) and luteinizing hormone/human chorionic gonadotropin receptor (Lhcgr) genes in Leydig cells, but not in Sertoli cells, using AAV9-single guide RNA (sgRNA)-mediated gene editing in Rosa26-LSL-Cas9 mice. Knockdown of androgen receptor ( Ar ) gene expression in Sertoli cells of wild-type mice was achieved via tubular injection of AAV9-short hairpin RNA (shRNA)-mediated targeting. Our findings offer technical approaches for investigating gene function in Sertoli and Leydig cells through AAV9-mediated gene silencing.
Animals ; Male ; Leydig Cells/metabolism* ; Mice ; Dependovirus/genetics* ; Sertoli Cells/metabolism* ; Gene Silencing ; Genetic Vectors ; Testis/cytology*

OBJECTIVE: To explore the role of the CMTM2 gene in regulating testicular spermatogenesis in the mouse model of experimental autoimmune orchitis (EAO). METHODS: We constructed an EAO model in CMTM2 knockout and wild-type (WT) mice, studied the immunological reproductive phenotype and examined the number, morphology and activity of the sperm generated in the CMTM2 knockout mice. We assessed the infiltration of macrophages and lymphocytes in the testis tissue sections and Leydig cells, and determined the expression levels of CMTM2 in the homozygous knockout (KO), heterozygous and WT mice by RT-PCR, Western blot and Northern blot. RESULTS: Statistically significant differences were observed in the long testicular axis and the number of sperm generated between the KO and WT mice after reaching adulthood (P<0.05). The total numbers of macrophages and lymphocytes were markedly increased, while sperm motility and the percentage of morphologically normal sperm remarkably decreased in the testis of the KO mouse model compared with those in the WT mouse model of EAO. CONCLUSION The CMTM2 gene, as a regulator of spermatogenesis, is highly expressed in adult male mice and plays an important role in the maintenance of spermatogenesis. Moreover, decreased expression products of the CMTM2 gene may weaken spermatogenesis under chronic inflammation conditions.
Animals ; Male ; Mice ; Orchitis/genetics* ; Spermatogenesis/genetics* ; Disease Models, Animal ; Testis/metabolism* ; Autoimmune Diseases/genetics* ; Mice, Knockout ; MARVEL Domain-Containing Proteins/genetics*

Objective: To study the effects of cadmium chloride (CdCl(2)) exposure on testicular autophagy levels and blood-testis barrier integrity in prepubertal male SD rats and testicular sertoli (TM4) cells. Methods: In July 2021, 9 4-week-old male SD rats were randomly divided into 3 groups: control group (normal saline), low dose group (1 mg/kg·bw CdCl(2)) and high dose group (2 mg/kg·bw CdCl(2)), and were exposed with CdCl(2) by intrabitoneal injection. 24 h later, HE staining was used to observe the morphological changes of testis of rats, biological tracer was used to observe the integrity of blood-testis barrier, and the expression levels of microtubule-associated protein light chain 3 (LC3) -Ⅰ and LC3-Ⅱ in testicular tissue were detected. TM4 cells were treated with 0, 2.5, 5.0 and 10.0 μmol/L CdCl(2) for 24 h to detect the toxic effect of cadmium. The cells were divided into blank group (no exposure), exposure group (10.0 μmol/L CdCl(2)), experimental group[10.0 μmol/L CdCl(2)+60.0 μmol/L 3-methyladenine (3-MA) ] and inhibitor group (60.0 μmol/L 3-MA). After 24 h of treatment, Western blot analysis was used to detect the expression levels of LC3-Ⅱ, ubiquitin binding protein p62, tight junction protein ZO-1 and adhesion junction protein N-cadherin. Results: The morphology and structure of testicular tissue in the high dose group were obvious changed, including uneven distribution of seminiferous tubules, irregular shape, thinning of seminiferous epithelium, loose structure, disordered arrangement of cells, abnormal deep staining of nuclei and vacuoles of Sertoli cells. The results of biological tracer method showed that the integrity of blood-testis barrier was damaged in the low and high dose group. Western blot results showed that compared with control group, the expression levels of LC3-Ⅱ in testicular tissue of rats in low and high dose groups were increased, the differences were statistically significant (P<0.05). Compared with the 0 μmol/L, after exposure to 5.0, 10.0 μmol/L CdCl(2), the expression levels of ZO-1 and N-cadherin in TM4 cells were significantly decreased, and the expression level of p62 and LC3-Ⅱ/LC3-Ⅰ were significantly increased, the differences were statistically significant (P<0.05). Compared with the exposure group, the relative expression level of p62 and LC3-Ⅱ/LC3-Ⅰ in TM4 cells of the experimental group were significantly decreased, while the relative expression levels of ZO-1 and N-cadherin were significantly increased, the differences were statistically significant (P<0.05) . Conclusion: The mechanism of the toxic effect of cadmium on the reproductive system of male SD rats may be related to the effect of the autophagy level of testicular tissue and the destruction of the blood-testis barrier integrity.
Rats ; Male ; Animals ; Testis ; Cadmium Chloride/metabolism* ; Cadmium ; Blood-Testis Barrier/metabolism* ; Rats, Sprague-Dawley ; Cadherins/metabolism* ; Autophagy

OBJECTIVE: To explore the mechanism underlying the inhibitory effect of quercetin against testicular oxidative damage induced by a mixture of 3 commonly used phthalates (MPEs) in rats. METHODS: Forty male Sprague-Dawley rats were randomly divided into control group, MPEs exposure group, and MPEs with low-, median- and high-dose quercetin treatment groups. For MPEs exposure, the rats were subjected to intragastric administration of MPEs at the daily dose of 900 mg/kg for 30 consecutive days; Quercetin treatments were administered in the same manner at the daily dose of 10, 30, and 90 mg/kg. After the treatments, serum levels of testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), and testicular malondialdeyhde (MDA), catalase (CAT) and superoxide dismutase (SOD) were detected, and testicular pathologies of the rats were observed with HE staining. The expressions of nuclear factor-E2-related factor 2 (Nrf2), Kelch-like ECH2 associated protein 1 (Keap1) and heme oxygenase 1 (HO-1) in the testis were detected using immunofluorescence assay and Western blotting. RESULTS: Compared with the control group, the rats with MPEs exposure showed significant reductions of the anogenital distance, weight of the testis and epididymis, and the coefficients of the testis and epididymis with lowered serum testosterone, LH and FSH levels (P < 0.05). Testicular histological examination revealed atrophy of the seminiferous tubules, spermatogenic arrest, and hyperplasia of the Leydig cells in MPEs-exposed rats. MPEs exposure also caused significant increments of testicular Nrf2, MDA, SOD, CAT and HO-1 expressions and lowered testicular Keap1 expression (P < 0.05). Treatment with quercetin at the median and high doses significantly ameliorated the pathological changes induced by MPEs exposure (P < 0.05). CONCLUSION Quercetin treatment inhibits MPEs-induced oxidative testicular damage in rats possibly by direct scavenging of free radicals to lower testicular oxidative stress and restore the regulation of the Nrf2 signaling pathway.
Rats ; Male ; Animals ; Testis ; Quercetin/pharmacology* ; Rats, Sprague-Dawley ; NF-E2-Related Factor 2/metabolism* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Oxidative Stress ; Testosterone/pharmacology* ; Superoxide Dismutase/metabolism* ; Follicle Stimulating Hormone ; Luteinizing Hormone