Supplemental dietary phytosterin protects against 4-nitrophenol-induced oxidative stress and apoptosis in rat testes

Guilu-Erxian-Glue alleviates Tripterygium wilfordii polyglycoside-induced oligoasthenospermia in rats by resisting ferroptosis via the Keap1/Nrf2/GPX4 signaling pathway

CONTEXT

Guilu-Erxian-Glue (GLEXG) is a traditional Chinese formula used to improve male reproductive dysfunction.

OBJECTIVE

To investigate the ferroptosis resistance of GLEXG in the improvement of semen quality in the oligoasthenospermia (OAS) rat model.

MATERIALS AND METHODS

Male Sprague-Dawley (SD) rats were administered Tripterygium wilfordii polyglycoside, a compound extracted from Tripterygium wilfordii Hook F. (Celastraceae), at a dose of 40 mg/kg/day, to establish an OAS model. Fifty-four SD rats were randomly divided into six groups: sham, model, low-dose GLEXG (GLEXGL, 0.25 g/kg/day), moderate-dose GLEXG (GLEXGM, 0.50 g/kg/day), high-dose GLEXG (GLEXGH, 1.00 g/kg/day) and vitamin E (0.01 g/kg/day) group. The semen quality, structure and function of sperm mitochondria, histopathology, levels of oxidative stress and iron, and mRNA levels and protein expression in the Keap1/Nrf2/GPX4 pathway, were analyzed.

RESULTS

Compared with the model group, GLEXGH significantly improved sperm concentration (35.73 ± 15.42 vs. 17.40 ± 4.12, p < 0.05) and motility (58.59 ± 11.06 vs. 28.59 ± 9.42, p < 0.001), and mitigated testicular histopathology. Moreover, GLEXGH markedly reduced the ROS level (5684.28 ± 1345.47 vs. 15500.44 ± 2307.39, p < 0.001) and increased the GPX4 level (48.53 ± 10.78 vs. 23.14 ± 11.04, p < 0.01), decreased the ferrous iron level (36.31 ± 3.66 vs. 48.64 ± 7.74, p < 0.05), and rescued sperm mitochondrial morphology and potential via activating the Keap1/Nrf2/GPX4 pathway.

DISCUSSION AND CONCLUSIONS

Ferroptosis resistance from GLEXG might be driven by activation of the Keap1/Nrf2/GPX4 pathway. Targeting ferroptosis is a novel approach for OAS therapy.

Enhancing developmental and reproductive toxicity knowledge: A new AOP stemming from glutathione depletion

Integrated approaches to testing and assessments (IATAs) have been proposed as a method to organise new approach methodologies in order to replace traditional animal testing for chemical safety assessments. To capture the mechanistic aspects of toxicity assessments, IATAs can be framed around the adverse outcome pathway (AOP) concept. To utilise AOPs fully in this context, a sufficient number of pathways need to be present to develop fit for purpose IATAs. In silico approaches can support IATA through the provision of predictive models and also through data integration to derive conclusions using a weight-of-evidence approach. To examine the maturity of a developmental and reproductive toxicity (DART) AOP network derived from the literature, an assessment of its coverage was performed against a novel toxicity dataset. A dataset of diverse compounds, with data from studies performed according to OECD test guidelines TG-421 and TG-422, was curated to test the performance of an in silico model based on the AOP network - allowing for the identification of knowledge gaps within the network. One such gap in the knowledge was filled through the development of an AOP stemming from the molecular initiating event 'glutathione reaction with an electrophile' leading to male fertility toxicity. The creation of the AOP provided the mechanistic rationale for the curation of pre-existing structural alerts to relevant key events. Integrating this new knowledge and associated alerts into the DART AOP network will improve its coverage of DART-relevant chemical space. In addition, broadening the coverage of AOPs for a particular regulatory endpoint may facilitate the development of, and confidence in, robust IATAs.

Network Pharmacology-Based Strategy to Investigate Pharmacological Mechanisms of the Drug Pair Astragalus-Angelica for Treatment of Male Infertility

Background

The traditional Chinese medicines Astragalus and Angelica are often combined to treat male infertility, but the specific therapeutic mechanism is not clear. Therefore, this study applies a network pharmacology approach to investigate the possible mechanism of action of the drug pair Astragalus-Angelica (PAA) in the treatment of male infertility.

Methods

Relevant targets for PAA treatment of male infertility are obtained through databases. Protein-protein interactions (PPIs) are constructed through STRING database and screen core targets, and an enrichment analysis is conducted through the Metascape platform. Finally, molecular docking experiments were carried out to evaluate the affinity between the target protein and the ligand of PAA.

Results

The active ingredients of 112 PAA, 980 corresponding targets, and 374 effective targets of PAA for the treatment of male infertility were obtained, which are related to PI3K-Akt signaling pathway, HIF-1 signaling pathway, AGE-RAGE signaling pathway, IL-17 signaling pathway, and thyroid hormone signaling pathway.

Conclusion

In this study, using a network pharmacology method, we preliminarily analyzed the effective components and action targets of the PAA. We also explored the possible mechanism of action of PAA in treating male infertility. They also lay a foundation for expanding the clinical application of PAA and provide new ideas and directions for further research on the mechanisms of action of the PAA and its components for male infertility treatment.

Gene expression profiles of two testicular somatic cell lines respond differently to 4-nitrophenol mediating vary reproductive toxicity

4-Nitrophenol (PNP) has been extensively used in manufacturing for several decades. Its toxic effects on the male reproductive system have been reported, but the underlying mechanisms remain unclear. In this study, we utilized two testicular somatic cell lines (TM3 and TM4 cells) to explore the possible toxic effects of PNP on the male reproductive system. The activity of the cells after exposure to different doses of PNP (0.01, 0.1, 1, 10 and 100 μM) was evaluated. PNP treatment at 10 μM significantly inhibited cell viability, and 10 μM PNP was thus selected for subsequent experiments. Although PNP (10 μM) inhibited cell proliferation, promoted cell apoptosis, and changed the cell cycle distribution and ultrastructure in both types of cells, these effects were more significant in the TM4 cells. In addition, an Agilent mouse mRNA array was used to identify the gene expression differences between the control and PNP (10 μM) exposed TM3 and TM4 cells. The microarray analysis identified 67 and 1372 differentially expressed genes mainly concentrated in endothelial cell morphogenesis and anatomical structure development in TM3 cells and associated with cardiovascular system development and circulatory system development in TM4 cells. Moreover, a pathway analysis revealed that PNP not only predominately affected meiotic recombination and meiosis in TM3 cells, but also influenced axon guidance and developmental biology in TM4 cells. These results suggest that TM3 and TM4 cells exhibit different responses to PNP, which might mediate different toxic mechanisms.

Protective effect of pyrrolidine dithiocarbamate against methotrexate-induced testicular damage

The aim of the study was to investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) against methotrexate (MTX)-induced testicular damage in rats. Forty Wistar albino male rats were divided into equally four groups: Control group (saline solution, IP), PDTC group (100 mg/kg PDTC,IP, 10 days), MTX group (20 mg/kg MTX, IP, single dose, on the 6th day) and MTX + PDTC group (100 mg/kg PDTC, IP, 10 days and 20 mg/kg MTX, IP, single dose, on the 6th day). After 10 days, testicular tissues were excised for morphometric, histological and immunohistochemical evaluations. Serum testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH) and prokineticin 2 (PK2) levels were determined. Body and testicular weights were measured. Testicular damage was assessed by histological evaluation. Nuclear factor kappa B (NFkB), nuclear factor erythroid 2 related factor 2 (Nrf2) and PK2 immunoreactivities were evaluated by HSCORE. Body and testicular weights, serum FSH, LH, testosterone levels, seminiferous tubule diameter and germinal epithelial thickness were significantly decreased in the MTX group. However, serum PK2 level, histologically damaged seminiferous tubules and interstitial field width were significantly increased. Additionally, there was an increase in NFkB and PK2 immunoreactivity, whereas there was a significant decrease in Nrf2 immunoreactivity. PDTC significantly improved hormonal, morphometric, histological and immunohistochemical findings. Taken together, we conclude that PDTC may reduce MTX-induced testicular damage via NFkB, Nrf2 and PK2 signaling pathways.

Long-term exposure to p-Nitrophenol induces hepatotoxicity via accelerating apoptosis and glycogen accumulation in male Japanese quails

p-Nitrophenol (PNP) is the main end product of organophosphorus insecticides and a derivative of diesel exhaust particles. In addition to its unfavorable impact on reproductive functions in both genders, it also has various harmful physiological effects including lung cancer and allergic rhinitis. The identification of the cellular readout that functions in metabolic pathway perpetuation is still far from clear. This research aimed to study the impact of chronic PNP exposure on the health condition of the liver in Japanese quails. Quails were exposed to different concentrations of PNP as follows: 0.0 (control), 0.01mg (PNP/0.01), 0.1mg (PNP/0.1), and 1mg (PNP/1) per kg of body weight for 2.5 months through oral administration. Liver and plasma samples were collected at 1.5, 2, and 2.5 months post-treatment for biochemical, histopathology, and immunohistochemistry assessment. The plasma aspartate aminotransferase (AST) level was assessed enzymatically. The livers were collected for histopathology, glycogen accumulation, proliferating cell nuclear antigen (PCNA), and apoptosis assessment. Our results revealed an irregularity in body weight due to the long-term exposure of PNP with a significant reduction in liver weight. PNP treatment caused histopathological alterations in the hepatic tissues which increased in severity by the long-term exposure. The low dose led to mild degeneration with lymphocytic infiltration, while the moderate dose has a congestion effect with some necrosis; meanwhile severe hepatocyte degeneration and RBCs hemolysis were noticed due to high dose of PNP. Glycogen accumulation increased in hepatocytes by prolonged exposure to p-Nitrophenol with the highest intensity in the group treated by the high dose. Moderate and high doses of PNP resulted in a significant increase in apoptosis and hepatocytes' proliferation at the different time points after treatment. This increase is markedly notable and maximized at 2.5 months post-treatment. The damage occurred in a time-dependent manner. These changes reflected on the plasma hepatic enzyme AST that was clearly increased at 2.5 months of exposure. Therefore, it could be concluded that PNP has profound toxic effects on the liver in cellular level. Taking into consideration the time and dose factors, both have a synergistic effect on the accumulation of glycogen, apoptosis, and cellular proliferation, highlighting the power of cellular investigation which will potentially open the door for earlier medical intervention to counteract this toxicity. Collectively, PNP could have critical hurtful effects on the health of human beings, wild animals as well as livestock.

Red Ginseng Oil Attenuates Oxidative Stress and Offers Protection against Ultraviolet-Induced Photo Toxicity

Ginseng (Panax ginseng Meyer) is a well-known herbal medicine that has been used for a long time in Korea to treat various diseases. This study investigated the in vitro and in vivo protective effects of red ginseng extract (RGE) and red ginseng oil (RGO). Liver injury was produced in BALB/c mice by 400 mg/kg of acetaminophen intraperitoneal injection. The antioxidant effects of RGE and RGO on the free radicals 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) were measured. In addition, the hepatoprotective activities of RGE and RGO on liver markers, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and oxidative stress markers, including superoxide dismutase (SOD), catalase (CAT) enzyme activity, and 8-hydroxy-2-deoxyguanosine (8-OHdG) in serum and histopathological analysis, were evaluated. The protective effect of RGO on UV-induced phototoxicity was also evaluated in Balb/c 3T3 mouse fibroblast cell line. RGE and RGO effectively inhibited the radicals DPPH and ABTS compared with ascorbic acid and trolox, respectively. Moreover, RGE and RGO significantly decreased the liver enzyme (ALT and AST) levels, increased the antioxidant enzyme (SOD and CAT) levels, and decreased the DNA oxidation product (8-OHdG) content in mice serum. RGO also exhibited protective effect against UV irradiation compared with chlorpromazine hydrochloride, a known phototoxic drug, in Balb/c 3T3 cell line. RGE and RGO possess antioxidant and hepatoprotective properties in mice, and RGO exerts nonphototoxic activity in Balb/c 3T3 cells.

A network pharmacology approach to determine the underlying mechanisms of action of Yishen Tongluo formula for the treatment of oligoasthenozoospermia

Oligoasthenozoospermia is a complex disease caused by a variety of factors, and its incidence is increasing yearly worldwide. Yishen Tongluo formula (YSTLF), created by Professor Sun Zixue, has been used to treat oligoasthenozoospermia in clinical practice for several decades with a good therapeutic effect. However, the chemical and pharmacological profiles of YSTLF remain unclear and need to be elucidated. In this study, a network pharmacology approach was applied to explore the potential mechanisms of YSTLF in oligoasthenozoospermia treatment. All of the compounds in YSTLF were retrieved from the corresponding databases, and the bioactive ingredients were screened according to their oral bioavailability (OB) and drug-likeness (DL). The potential proteins of YSTLF were obtained from the traditional Chinese medicine systems pharmacology (TCMSP) database and the Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM) database, while the potential genes of oligoasthenozoospermia were obtained from the GeneCards database and the DisGeNET database. The STRING database was used to construct an interaction network according to the common targets identified by the online tool Venny for YSTLF and oligoasthenozoospermia. The topological characteristics of nodes were visualized and analyzed through Cytoscape. Biological functions and significant pathways were determined and analyzed using the Gene Ontology (GO) knowledgebase, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Metascape. Finally, the disease-formula-compound-target-pathway network was constructed by Cytoscape. A total of 106 bioactive ingredients and 134 potential targets from YSTLF were associated with oligoasthenozoospermia or considered to be therapeutically relevant. Pathway analysis indicated that the PI3K/Akt, MAPK and apoptosis signaling pathways were significant pathways involved in oligoasthenozoospermia. In conclusion, the current study expounded the pharmacological actions and molecular mechanisms of YSTLF in treating oligoasthenozoospermia from a holistic viewpoint. The potential molecular mechanisms were closely related to antioxidative stress, antiapoptosis and anti-inflammation, with TNF, CCND1, ESR1, NFKBIA, NR3C1, MAPK8, and IL6 being possible targets. This network pharmacology prediction may offer a helpful tool to illustrate the molecular mechanisms of the Chinese herbal compound YSTLF in oligoasthenozoospermia treatment.

Comparison of Phytochemical Contents and Cytoprotective Effects of Different Rice Bran Extracts from Indica and Japonica Rice Cultivars

The present study was aimed to evaluate the phytochemical contents and hepatocyte protective effects of functional extracts from rice bran of indica and japonica rice cultivars, Dasan 1 and Ilpum, respectively. The highest vitamin E (23.51 mg/g) and phytosterol (390.25 mg/g) content was observed in the unsaponifiable matter (USM) of Dasan 1 cultivar. However, USM of Ilpum showed the highest content of total policosanol and squalene (232.73 mg/g and 99.31 mg/g, respectively). The methanolic extract from the defatted rice bran (MEDR) of Dasan 1 showed the highest total polyphenol content, reducing power, and radical scavenging capacity, while USM of Dasan 1 showed the highest cell viability (81.3%) against oxidative stress in HepG2 cells. USM significantly increased glutathione levels and suppressed the production of reactive oxygen species in hepatocytes compared with methanolic extracts of the rice bran oils and/or MEDR. These results provide useful information on the functional extracts of rice bran from indica and japonica rice cultivars, including their antioxidant properties and cytoprotection in HepG2 cells.

A Network Pharmacology Approach to Reveal the Underlying Mechanisms of Zuogui Yin in the Treatment of Male Infertility

BACKGROUND AND AIM

Traditional Chinese medicine (TCM), as a complementary and alternative therapy, has played increasingly important roles in clinical treatment and disease prevention. Zuogui Yin (ZGY) is one of the well-known TCM prescriptions used for the treatment of male infertility. To fully reveal the potential mechanisms underlying the therapeutic effects of ZGY on male infertility, a network pharmacology approach was conducted at the molecular level.

METHODS

Network pharmacology approach was used in this study, which mainly included active compound screening, target prediction, gene enrichment analysis, and network analysis.

RESULTS

The network analysis successfully identified 148 potential active ingredients of ZGY and 155 predicted targets that were associated with male infertility. ZGY might play a role in the treatment of male infertility by regulating ten hub targets (VEGFA, CASP3, TNF, AKT1, EGF, EGFR, IL-6, MAPK1, TP53, and PTGS2) and six pathways (TNF signaling pathway, PI3K-Akt signaling pathway, FoxO signaling pathway, Toll-like receptor signaling pathway, VEGF signaling pathway, and MAPK signaling pathway).

CONCLUSION

This study explored the pharmacological activity and molecular mechanisms of ZGY against male infertility from a holistic perspective. The underlying molecular mechanisms were closely related to the intervention of oxidative stress and apoptosis with CASP3, TP53, AKT1, and MAPK1 being possible targets.

Dietary β-sitosterol regulates serum lipid level and improves immune function, antioxidant status, and intestinal morphology in broilers

This research investigated effects of dietary β-sitosterol addition at different levels on serum lipid levels, immune function, oxidative status, and intestinal morphology in broilers. One-day-old broiler chicks were allocated to 5 groups of 6 replicates. Chickens in the 5 groups were fed a basal diet supplemented with 0 (control group), 40, 60, 80, and 100 mg/kg of β-sitosterol for 42 D, respectively. β-Sitosterol linearly decreased (P < 0.05) concentrations of serum total cholesterol, jejunal tumor necrosis factor α (TNF-α), and ileal interleukin 1β (IL-1β) and mRNA relative expressions levels of jejunal TLR4 and ileal MyD88, whereas it linearly increased (P < 0.05) contents of jejunal immunoglobulin G (IgG), ileal secreted IgA and glutathione, jejunal catalase activity and Nrf2 mRNA relative expression level, villus height (VH), and VH-to-crypt depth (CD) ratio (VH:CD) in the jejunum and ileum. Linear and quadratic increases (P < 0.05) in absolute and relative spleen weight were observed by dietary β-sitosterol, whereas malondialdehyde (MDA) concentration in the jejunum and ileum followed the opposite trend (P < 0.05). Compared with the control group, dietary β-sitosterol at higher than or equal to 60 mg/kg level decreased (P < 0.05) contents of serum total cholesterol, ileal MDA, and jejunal TLR4 mRNA relative expression level, whereas it increased (P < 0.05) absolute spleen weight and ileal glutathione content. Higher than or equal to 80 mg/kg level of β-sitosterol enhanced (P < 0.05) jejunal IgG concentration, VH, catalase activity, and Nrf2 relative expression level and ileal secreted IgA content, but reduced (P < 0.05) ileal IL-1β content and MyD88 mRNA relative expression level. β-Sitosterol addition at 60 and 80 mg/kg levels increased (P < 0.05) relative spleen weight, whereas it decreased (P < 0.05) jejunal MDA accumulation. Moreover, 100 mg/kg level of β-sitosterol reduced (P < 0.05) jejunal TNF-α level, but it increased (P < 0.05) VH in the jejunum and VH:CD in the jejunum and ileum. Accordingly, dietary β-sitosterol supplementation could regulate serum cholesterol level, promote immune function, and improve intestinal oxidative status and morphology in broilers.

4-nitrophenol exposure in T24 human bladder cancer cells promotes proliferation, motilities, and epithelial-to-mesenchymal transition

Although health hazards of 4-nitrophenol (PNP) exposure have been reported, the adverse effects of PNP exposure on cancer biological features are still unknown. We investigated the effects of administration of PNP in T24 human bladder cancer cells. The results showed that PNP exposure promoted cellular proliferation, migration and invasion, inhibited adhesion and apoptosis in vitro. Using quantitative real-time PCR, we found that (1) the mRNA expression levels of cell-cycle regulators PCNA, cyclin D1 and COX-2 were increased in PNP-treated cells compared to controls, however, that of pro-apoptotic gene Bax was decreased; (2) the expression level of EMT-associated gene E-cadherin was decreased in PNP-treated cells, whereas those of N-cadherin, vimentin, snail, and slug were increased; (3) the expression levels of cancer-promoting genes HIF-1, IL-1β, VEGFα and K-Ras were enhanced, but those of tumor suppressors p53, PTEN and BRCA were decreased. There was a positive association between PNP exposure times and the promotion effects. Finally, we found that the expression level of PPARγ (γ1 isoform) was increased in PNP-treated T24 cells. GW9662, a specific PPARγ antagonist, attenuated PNP-induced cell migration and invasion. These findings indicate that PNP exposure may promote bladder cancer growth and progression involving PPARγ signaling. PPARγ is a potential target for development of novel intervention study on environment pollution. Environ. Mol. Mutagen. 61:316-328, 2020. © 2019 Wiley Periodicals, Inc.

The anti-fungal β-sitosterol targets the yeast oxysterol-binding protein Osh4

BACKGROUND

β-Sitosterol is a plant metabolite with a broad range of anti-fungal activity, however, this compound is not toxic against a few fungal species. The target of β-sitosterol and the nature of its selective toxicity are not yet clear. Using a yeast model system and taking advantage of molecular biology and computational approaches, we identify the target and explain why β-sitosterol is not toxic against some fungal pathogens.

RESULTS

β-Sitosterol (200 μg mL^-1 ) is toxic against yeast cells expressing only Osh4 (an oxysterol-binding protein) and harbouring a upc2-1 mutation (which enables sterol uptake), but not against yeast strains expressing all seven Osh proteins and harbouring a upc2-1 mutation. Furthermore, β-sitosterol is not toxic against yeast strains without the upc2-1 mutation irrespective of the number of Osh proteins being expressed. The deletion of COQ1 (a gene known to be highly induced upon deletion of OSH4) enhances the toxicity of β-sitosterol in yeast cells expressing only Osh4 and harbouring the upc2-1 mutation. Molecular modelling suggests that β-sitosterol binds to Osh4 and the binding mode is similar to the binding of cholesterol to Osh4.

CONCLUSION

Our results indicate that the concentrations of β-sitosterol, and Osh4, as well as its homologues within cells, are most likely the main determinants of β-sitosterol toxicity. Furthermore, some fungal species do not take up sterols, e.g. Saccharomyces cerevisiae, under aerobic conditions. Therefore, sterol uptake may also contribute to the β-sitosterol anti-fungal effect. These findings enable predicting the toxicity of β-sitosterol against plant fungal pathogens. © 2019 Society of Chemical Industry.

Role of Autophagy in Zinc Oxide Nanoparticles-Induced Apoptosis of Mouse LEYDIG Cells

Zinc oxide nanoparticles (ZnO NPs) have shown adverse health impact on the human male reproductive system, with evidence of inducing apoptosis. However, whether or not ZnO NPs could promote autophagy, and the possible role of autophagy in the progress of apoptosis, remain unclear. In the current study, in vitro and in vivo toxicological responses of ZnO NPs were explored by using a mouse model and mouse Leydig cell line. It was found that intragastrical exposure of ZnO NPs to mice for 28 days at the concentrations of 100, 200, and 400 mg/kg/day disrupted the seminiferous epithelium of the testis and decreased the sperm density in the epididymis. Furthermore, serum testosterone levels were markedly reduced. The induction of apoptosis and autophagy in the testis tissues was disclosed by up-regulating the protein levels of cleaved Caspase-8, cleaved Caspase-3, Bax, LC3-II, Atg 5, and Beclin 1, accompanied by down-regulation of Bcl 2. In vitro tests showed that ZnO NPs could induce apoptosis and autophagy with the generation of oxidative stress. Specific inhibition of autophagy pathway significantly decreased the cell viability and up-regulated the apoptosis level in mouse Leydig TM3 cells. In summary, ZnO NPs can induce apoptosis and autophagy via oxidative stress, and autophagy might play a protective role in ZnO NPs-induced apoptosis of mouse Leydig cells.

Oxidative stress-induced alterations in seminal plasma antioxidants: Is there any association with keap1 gene methylation in human spermatozoa?

Kelch-like ECH-associated protein 1 (keap1)-nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway is one of the master regulators of cellular defence against oxidative stress. Epigenetic alterations like hypermethylation of keap1 gene impair keap1-Nrf2 system in several oxidative stress-associated diseases. The objective of this study was to evaluate the epigenetic status of keap1 in sperm DNA of normozoospermic subjects, having different levels of reactive oxygen species (ROS) in seminal plasma. Semen samples were obtained from 151 apparently healthy male partners of couples who attended the Avicenna infertility clinic. Samples were categorised into four groups according to their ROS levels: group A (n = 39, ROS < 20 RLU/s per 10⁶ spermatozoa), group B (n = 38, 20 ≤ ROS < 40 RLU/s per 10⁶ spermatozoa), group C (n = 31, 40 ≤ ROS < 60 RLU/s per 10⁶ spermatozoa) and group D; (n = 43, ROS ≥ 60 RLU/s per 10⁶ spermatozoa). Keap1 methylation status was assessed using methylation-specific PCR along with seminal total antioxidant capacity. The results showed no significant alterations in keap1 methylation in any groups, whereas the total antioxidant capacity enhanced with increasing levels of ROS exposure. These results indicate that keap1 was not methylated during ROS elevation and oxidative stress, suggesting that the cells have adopted other mechanisms to elevate antioxidant level.

Effects of CeO2 nanoparticles on the HO-1, NQO1, and GCLC expression in the testes of diabetic rats

CeO₂ nanoparticles (CNPs) as effective ROS scavengers exhibit potent antioxidant activity. In this study the effect of CNPs investigated was on HO-1, NQO1, and GCLC expression in the streptozotocin (STZ)-induced diabetic rats. Twenty-four male Wistar rats were divided into 4 groups: controls did not receive any treatment; diabetic rats received STZ (60 mg/kg daily); CNPs group received CNPs 30 mg/kg daily for 2 weeks; and rats in STZ + CNPs group received CNPs 30 mg/kg daily for 2 weeks following STZ injection. Oxidative stress was evaluated by measurement of total antioxidant capacity (TAC) and total oxidative status (TOS levels). HO-1, NQO1, and GCLC expression was measured using quantitative real-time PCR. Following STZ injection, significant lower levels of TAC and higher levels of TOS were observed. CNPs could alleviate deleterious effects of diabetes through the enhancement of TAC levels and a significant decline in TOS levels. HO-1, NQO1, and GCLC expression in the diabetic rats were lower than controls. HO-1, NQO1, and GCLC was upregulated in the diabetic rats treated with CNPs. There were significant correlations between NQO1 and GCLC, NQO1 and HO-1, and between HO-1 and GCLC expression. Moreover, Nrf2 was associated with NQO1, GCLC, and HO-1 expression. CNPs as Nrf2 upregulator confer protection against oxidative stress in the testes of STZ-induced diabetic rats by upregulating HO-1, GCLC, and NQO1 cytoprotective genes.

Standardized extract of Bacopa monnieri (CDRI-08): Effect on germ cell dynamics and possible mechanisms of its beneficial action on spermatogenesis and sperm quality in male mice

Bacopa monnieri (BM) is used in traditional medicine as nerve tonic. We have recently shown that CDRI-08, a standardized extract of BM, improves testicular functions and epididymal sperm quality in Parkes (P) mice. The aim of the present study was to investigate the effect of CDRI-08 on germ cell dynamics and mechanisms of its action on spermatogenesis and sperm quality in P mice, and to determine the chemical profile of the extract. CDRI-08 (40 and 80 mg/kg body weight) was orally administered to male mice for 28 days. Germ cell dynamics, oxidative stress parameters in testis and sperm, and expressions of nuclear factor-erythroid-2-related factor-2 (Nrf2), phosphorylated protein kinase B (p-Akt) and upstream kinases in mitogen-activated protein kinase (MAPK) pathway namely MAP2K1, MAP2K2 and MKK4 in the testis were evaluated. The treatment potentiated germ cell dynamics and improved sperm quality by enhancing antioxidant enzymes activities. The beneficial effects of CDRI-08 in the testis involve p-Akt-mediated activation of Nrf2, thereby enhancing antioxidant enzymes activities; upregulation of MAP2K1 and MAP2K2 and suppression of MKK4 are also implicated in this action. A total of 26 phytocomponents were identified in CDRI-08 by GC-MS. The results suggest that CDRI-08 also may prove useful in improving reproductive health in males.

Attenuation of perfluorooctanoic acid-induced testicular oxidative stress and apoptosis by quercetin in mice

Quercetin treatment attenuated PFOA-induced oxidative stress and apoptosis in the testes of mice.

Induction of Nrf2/ARE-mediated cytoprotective genes by red ginseng oil through ASK1-MKK4/7-JNK and p38 MAPK signaling pathways in HepG2 cells

BACKGROUND

The induction of cellular defensive genes such as phase II detoxifying and antioxidant enzymes is a highly effective strategy for protection against carcinogenesis as well as slowing cancer development. Transcription factor Nrf2 (nuclear factor E2-related factor 2) is responsible for activation of phase II enzymes induced by natural chemopreventive compounds.

METHODS

Red ginseng oil (RGO) was extracted using a supercritical CO₂ extraction system and chemical profile of RGO was investigated by GC/MS. Effects of RGO on regulation of the Nrf2/antioxidant response element (ARE) pathway were determined by ARE-luciferase assay, western blotting, and confocal microscopy.

RESULTS

The predominant components of RGO were 9,12-octadecadienoic acid (31.48%), bicyclo[10.1.0]tridec-1-ene (22.54%), and 22,23-dihydrostigmasterol (16.90%). RGO treatment significantly increased nuclear translocation of Nrf2 as well as ARE reporter gene activity, leading to upregulation of heme oxygenase-1 and NAD(P)H:quinone oxidoreductase 1. Phosphorylation of the upstream kinases such as apoptosis signal-regulating kinase (ASK)1, mitogen-activated protein kinase (MAPK) kinase (MKK)4/7, c-Jun N-terminal kinase (JNK), and p38 MAPK were enhanced by treatment with RGO. In addition, RGO-mediated Nrf2 expression and nuclear translocation was attenuated by JNK inhibitor SP600125 and p38 MAPK inhibitor SB202190.

CONCLUSION

RGO could be used as a potential chemopreventive agent, possibly by induction of Nrf2/ARE-mediated phase II enzymes via ASK1-MKK4/7-JNK and p38 MAPK signaling pathways.

4-Nitrophenol induces activation of Nrf2 antioxidant pathway and apoptosis of the germ cells in rat testes

The potential of 4-nitrophenol (PNP) to affect testicular function of rats was assessed by intratesticular injection (IT). The protective effects of phytosterin (PS) on PNP-induced injury were assessed. Rats were sacrificed on days 1, 3, and 7 after IT of PNP (0.1 M, 50 μl). PNP induced hemorrhage in intertubular areas and denudation of germinal epithelium. The expression of caspase-3 and sperm abnormalities were significantly increased (P < 0.05). The concentrations of testosterone in serum were significantly increased (P < 0.05) on the 1st and 3rd day. PNP induced oxidative stress in testes, which manifested increased SOD, CAT, GSH-Px activities, and increases in MDA, GSH, H2O2 concentrations (P < 0.05). The Nrf2 antioxidant pathway was activated as indicated by increased expression of Nrf2, HO-1, and GCLC mRNA (P < 0.05). Moreover, supplementation with PS resulted in an amelioration of PNP-induced oxidative damage. These results suggest that PNP induced activation of Nrf2 antioxidant pathway and apoptosis of the germ cells.

Involvement of oxidative stress in tri-ortho-cresyl phosphate-induced autophagy of mouse Leydig TM3 cells in vitro

BACKGROUND

As a plasticizer, plastic softener, and flame-retardant, tri-ortho-cresyl phosphate (TOCP) is and has been widely used in industry and reported to have a toxic effect on the male reproductive system in animals besides neurotoxicity and immunotoxicity. We have reported that TOCP inhibits spermatogenesis and induces autophagy of rat spermatogonial stem cells, but it is still unknown whether TOCP induces autophagy of mouse Leydig cells and its potential mechanism.

METHODS

Cell viability was observed by MTT assay. Level of testosterone was measured by radioimmunoassay. Apoptosis was observed by AnnexinV-FITC/PI assay. The contents of LC3, Atg5-Atg12, and Beclin 1 were detected by Western blotting analysis. Autophagosomes were investigated by transmission electron microscopy. The contents of MDA and GSH and the activities of SOD, GSH-PX, total antioxidant status (TAS) and total oxidant status (TOS) were measured by oxidative stress kits.

RESULTS

The present study shows that TOCP markedly inhibited viability and testosterone output of mouse Leydig TM3 cells but had no effect on apoptosis. However, TOCP significantly increased both LC3-II and the ratio of LC3-II to LC3-I and the contents of autophagy proteins Atg5 and Beclin 1. Transmission electron microscopy (TEM) showed that TOCP increased autophagic vacuoles of the cytoplasm, indicating that TOCP could induce autophagy of the cells. TOCP significantly induced oxidative stress of mouse Leydig TM3 cells. H2O2 also inhibited viability and induced autophagy of the cells; however, inhibition of oxidative stress by N-acetyl-L-cysteine (NAC) could rescue the inhibition of cell viability and induction of autophagy by TOCP.

CONCLUSIONS

The results show oxidative stress might be involved in TOCP-induced autophagy of mouse Leydig TM3 cells.