Sulforaphane reduction of testicular apoptotic cell death in diabetic mice is associated with the upregulation of Nrf2 expression and function (original) (raw)

Sulforaphane prevention of diabetes-induced aortic damage was associated with the up-regulation of Nrf2 and its down-stream antioxidants

Nutrition & Metabolism, 2012

Background Oxidative stress plays an important role in diabetes-induced vascular inflammation and pathogenesis. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor orchestrating antioxidant and cyto-protective responses to oxidative stress. In the present study, we tested whether sulforaphane (SFN) can protect the aorta from diabetes and, if so, whether the aortic protection is associated with up-regulation of Nrf2 and its down-stream antioxidants. Methods Type 1 diabetes was induced in FVB mice by multiple low-dose streptozotocin. Diabetic and age-matched control mice were treated with or without SFN at 0.5 mg/kg daily in five days of each week for three months. At the end of 3 months treatment of SFN one set of mice were sacrificed to perform the experimental measurements. The second set of both diabetic and control mice were aged for additional 3 months without further SFN treatment and then sacrificed to perform the experimental measurements. Aortas from these mi...

Sulforaphane attenuation of type 2 diabetes-induced aortic damage was associated with the upregulation of Nrf2 expression and function

Oxidative medicine and cellular longevity, 2014

Type 2 diabetes mellitus (T2DM) significantly increases risk for vascular complications. Diabetes-induced aorta pathological changes are predominantly attributed to oxidative stress. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor orchestrating antioxidant and cytoprotective responses to oxidative stress. Sulforaphane protects against oxidative damage by increasing Nrf2 expression and its downstream target genes. Here we explored the protective effect of sulforaphane on T2DM-induced aortic pathogenic changes in C57BL/6J mice which were fed with high-fat diet for 3 months, followed by a treatment with streptozotocin at 100 mg/kg body weight. Diabetic and nondiabetic mice were randomly divided into groups with and without 4-month sulforaphane treatment. Aorta of T2DM mice exhibited significant increases in the wall thickness and structural derangement, along with significant increases in fibrosis (connective tissue growth factor and transforming growth factor), inf...

Testicular oxidative damage and role of combined antioxidant supplementation in experimental diabetic rats

The present study was designated to assess oxidative damage and its effect on germ cell apoptosis in testes of streptozotocin (STZ)-induced diabetic rats. The role of antioxidant supplementation with a mixture of vitamins E and C and alpha lipoic acid for protection against such damage was also evaluated. Forty-five adult male rats were randomly divided into three groups: group I, control, non-diabetic rats; group II, STZ-induced, untreated diabetic rats; group III, STZ-induced diabetic rats supplemented with a mixture of vitamins E and C and alpha lipoic acid. Glycated hemoglobin (HbA 1C), glucose, and insulin levels were estimated in blood samples. Malondialdehyde (MDA), the activities of the enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), and caspase-3 in addition to testosterone (T) level were all determined in testicular tissues. Histo-pathological studies using H&E stain, as well as, immunohistochemical detection of apoptosis using (TUNEL) method were also performed. Blood glucose and HbA 1c were significantly increased while insulin was significantly decreased in STZ-induced diabetic rats as compared with controls. In rat testicular tissues, MDA, and caspase-3 activity were significantly elevated while SOD and GPx enzymatic activities as well as T level were significantly decreased in diabetic rats as compared with control group. Antioxidant supple-mentation to diabetic rats restored the testicular enzymatic activities of SOD and GPx to almost control levels, in addition, MDA and caspase-3 activity decrease while T increase significantly as compared with untreated diabetic group. Prominent reduction of germ cell apoptosis was found in diabetic rats supplemented with antioxidants. An important role of testicular oxidative damage and germ cell apoptosis in diabetes-induced infertility could be suggested, treatment with antioxidants has a protective effect by restoring SOD and GPx antioxidant enzymatic activity.

Divergent Effects of Sulforaphane on Basal and Glucose-Stimulated Insulin Secretion in β-Cells: Role of Reactive Oxygen Species and Induction of Endogenous Antioxidants

Pharmaceutical Research, 2013

Purpose Oxidative stress is implicated in pancreatic β-cell dysfunction, yet clinical outcomes of antioxidant therapies on diabetes are inconclusive. Since reactive oxygen species (ROS) can function as signaling intermediates for glucose-stimulated insulin secretion (GSIS), we hypothesize that exogenously boosting cellular antioxidant capacity dampens signaling ROS and GSIS. Methods To test the hypothesis, we formulated a mathematical model of redox homeostatic control circuit comprising known feedback and feedforward loops and validated model predictions with plant-derived antioxidant sulforaphane (SFN). Results SFN acutely (30-min treatment) stimulated basal insulin secretion in INS-1(832/13) cells and cultured mouse islets, which could be attributed to SFN-elicited ROS as Nacetylcysteine or glutathione ethyl ester suppressed SFNstimulated insulin secretion. The mathematical model predicted an adapted redox state characteristic of strong induction of endogenous antioxidants but marginally increased ROS under prolonged SFN exposure, a state that attenuates rather than facilitates glucose-stimulated ROS and GSIS. We validated the prediction by demonstrating that although 24-h treatment of INS-1(832/13) cells with low, non-cytotoxic concentrations of SFN (2-10 μM) protected the cells from cytotoxicity by oxidative insult, it markedly suppressed insulin secretion stimulated by 20 mM glucose. Conclusions Our study indicates that adaptive induction of endogenous antioxidants by exogenous antioxidants, albeit cytoprotective, inhibits GSIS in β-cells. KEY WORDS antioxidant . computational model . insulin secretion . Nrf2 . ROS . sulforaphane ABBREVIATIONS AC Antioxidant capacity ARE Antioxidant response element BSA Bovine serum albumin CM-H2DCFDA 5-(and-6)-chloromethyl-2' 7'dichlorodihydrofluorescein diacetate, acetyl ester DEM Diethylmaleate DMEM Dulbecco's modified Eagle's medium FBS Fetal bovine serum GCLC γ-glutamate cysteine ligase catalytic subunit GSH-EE Glutathione ethyl ester

Ellagic acid improved diabetes mellitus-induced testicular damage and sperm abnormalities by activation of Nrf2

Saudi Journal of Biological Sciences, 2021

Diabetes mellitus induces testicular damage, increases sperm abnormalities, and impairs reproductive dysfunction due to induction of endocrine disturbance and testicular oxidative stress. This study evaluated the reproductive protective effect of ellagic acid (EA) against testicular damage and abnormalities in sperm parameters in Streptozotocin (STZ)-induced diabetic rats (T1DM) and examined some possible mechanisms of protection. Adult male rats were segregated into 5 groups (n = 12 rat/each) as control, control + EA (50 mg/kg/day), T1DM, T1DM + EA, and T1DM + EA + brusatol (an Nrf-2 inhibitor) (2 mg/ twice/week). All treatments were conducted for 12 weeks, daily. EA preserved the structure of the seminiferous tubules, prevented the reduction in sperm count, motility, and viability, reduced sperm abnormalities, and downregulated testicular levels of cleaved caspase-3 and Bax in diabetic rats. In the control and diabetic rats, EA significantly increased the circulatory levels of testosterone, reduced serum levels of FSH and LH, and upregulated Bcl-2 and all steroidogenic genes (StAr, 3b-HSD1, and 11b-HSD1). Besides, it reduced levels of ROS and MDA but increased levels of GSH and MnSOD and the transactivation of Nrf2. All these biochemical alterations induced by EA were associated with increased activity and nuclear accumulation of Nrf2. However, all these effects afforded by EA were weakened in the presence of brusatol. In conclusion, EA could be an effective therapy to alleviated DM-induced reproductive toxicity and dysfunction in rats by a potent antioxidant potential mediated by the upregulation of Nrf2.

Preventive effect of non-mitogenic acidic fibroblast growth factor on diabetes-induced testicular cell death

Reproductive toxicology (Elmsford, N.Y.), 2014

Fibroblast growth factor (FGF)-1 was found to protect the heart from oxidative damage, but clinically its long-term use was restricted for its undesirable proliferating activity on cells. Thus a cluster of amino acids responsible for the proliferation were deleted in the native FGF-1 to create a non-mitogenic FGF-1 (nmFGF-1). Whether the nmFGF-1 protects male germ cells from diabetes-induced apoptotic death was examined in diabetic mice induced with multiple low-doses of streptozotocin, followed by nmFGF-1 treatment for 6 months. Diabetic mice showed a decrease in testicular weight and an increase in apoptotic cell death. Treatment with nmFGF-1 alleviated the diabetic effects on testicular weight and apoptotic cell death. Mechanistically, nmFGF-1 may alleviate diabetes-induced germ cell death by decreasing the BAX/Bcl-2 ratio and endoplasmic reticulum stress as well as associated cell death, which is associated with Nrf-2 activation.

Cardamonin exerts a protective effect against autophagy and apoptosis in the testicles of diabetic male rats through the expression of Nrf2 via p62-mediated Keap-1 degradation

2021

Cardamonin (CARD) is a chalconoid with anti-inflammatory and antioxidant properties, and it is present in several plants. We sought to explore whether CARD exerts any positive effects against hyperglycemia-induced testicular dysfunction caused by type 2 diabetes and aimed to identify its possible intracellular pathways. Adult male rats were subdivided into six groups: control, CARD, diabetic (DM), DM + glibenclamide (GLIB), DM + CARD and DM + GLIB + CARD. Type 2 DM induced a significant increase in blood glucose and insulin resistance, along with diminished serum insulin, testosterone and gonadotropins levels, which were associated with the impairment of key testicular androgenic enzymes and cellular redox balance. Administration of CARD at a dose of 80 mg/kg for 4 weeks effectively normalized all of these alterations, and the improvement was confirmed by epididymal sperm analysis. After treatment with CARD, the pathological changes in spermatogenic tubules were markedly improved. S...

The Protective Effect of Sulforaphane against Oxidative Stress through Activation of NRF2/ARE Pathway in Human Granulosa Cells

Cell J, Vol 23, No 6, November 2021, 94

Objective: Sulforaphane (SFN) is a natural free radical scavenger that can reduce oxidative stress (OS) through mediating nuclear factor (erythroid-derived 2)-like 2 (NF-E2-related factor 2 or NRF2)/antioxidant response element (ARE) signaling pathway and the downstream antioxidant enzymes. Here, we intended to study the role of SFN in OSinduced human granulosa cells (GCs) by investigating the intracellular levels of reactive oxygen species (ROS), cell death, and NRF2-ARE pathway. Materials and Methods: This experimental study was conducted on GCs of 12 healthy women who had normal menstrual cycles with no history of polycystic ovary syndrome (PCOS), endometriosis, menstrual disorders, hyperprolactinemia, or hormonal therapy. After isolation of GCs, the MTT assay was performed to explore GCs viability after treatment with SFN in the presence or absence of H 2 O 2. Flow cytometry was utilized to determine the intracellular ROS production and the apoptosis rate. Evaluation of the mRNA and protein expression levels of NRF2 and phase II enzymes including superoxide dismutase (SOD) and catalase (CAT) was performed by quantitative real-time polymerase chain reaction (PCR) and western blotting. Finally, the data were analyzed by SPSS software using One-way ANOVA and the suitable post-hoc test. Significance level was considered as P<0.05. Results: Pretreatment of GCs with SFN attenuated intracellular ROS production and apoptosis rate in the H 2 O 2-exposed cells. Moreover, SFN treatment increased the mRNA expression level of NRF2, SOD, and CAT. Higher expression of NRF2 and SOD was also observed at the protein level. Conclusion: Our study demonstrated that SFN protects human GCs against H 2 O 2 induced-OS by reducing the intracellular ROS production and the following apoptosis through a mechanism by which NRF2 increases the antioxidant enzymes such as SOD and CAT. This result may have a potential application in assisted reproduction cycles by improving the quality of GCs and the embedded oocyte, especially in PCOS patients.

Co-administration of Selenium Nanoparticles and Metformin Abrogate Testicular Oxidative Injury by Suppressing Redox Imbalance, Augmenting Sperm Quality and Nrf2 Protein Expression in Streptozotocin-Induced Diabetic Rats

Biological Trace Element Research, 2020

Selenium nanoparticles (SeNPs) and metformin (Met) elicit individually protective effects against testicular oxidative injury in diabetic rats. However, the combined effects of both compounds have not been investigated. We investigated the effects of SeNPs and Met individual/co-treatment on testicular oxidative injury in diabetic rats. Diabetes was induced by a single intraperitoneal administration of streptozotocin (STZ-40 mg/kg bwt). The rats were equally divided into 6 groups: Group one-non-diabetic; group two-diabetic untreated; and group six-non-diabetic received citrate buffer (2 mL/kg bwt), while group three, four, and five received SeNPs (0.1 mg/kg bwt), Met (50 mg/kg bwt), and SeNPs/Met combined respectively, for 42 days. Results revealed that SeNPs, as well as Met treatment significantly (p < 0.001), lowered blood glucose levels and improved relative organ weights in treated rats than those of the untreated group. Moreover, a synergistic effect was observed in the co-administration group. Additionally, combined treatment elicited better effect, in augmenting the pituitary and testicular hormone (LH, FSH, prolactin, and testosterone) levels, marker enzymes/protein associated with steroidogenesis (3-βHSD, 17-βHSD, and StAR protein), and sperm functional parameters than those of individual treatment groups, when compared with control. Furthermore, the combinatorial effects of SeNPs and Met surpassed their influence in attenuating testicular oxidative stress/inflammation and upregulation of Nrf2 protein expression in diabetic rats when compared with control. Overall, normal rats, co-treated with SeNPs and Met, did not reveal any deleterious effect. Therefore, SeNPs and Met combined treatment may better improve testes function in diabetic conditions than an individual regimen.

Naringenin attenuates testicular damage, germ cell death and oxidative stress in streptozotocin induced diabetic rats: naringenin prevents diabetic rat testicular damage

Journal of Applied Biomedicine, 2013

The aim of this study was to investigate the protective effect of naringenin on oxidative stress, on proinflammatory cytokines like TGF-β1, IL-1β and on programmed cell death in the testicular damage resulting from streptozotocin (STZ) induced diabetes in rats. Diabetes was induced by a single intraperitoneal injection of STZ (50 mg/kg), and the rats were treated with naringenin (5 mg/kg and 10 mg/kg) administered once a day orally for 10 weeks, starting 3 days after the STZ injection. At the end of the study, all animals were sacrificed. Testis tissue and blood samples were collected for the assessment of sperm parameters, and for biochemical and histopathological analysis. Naringenin treatment significantly decreased the levels of elevated tissue TBARS (thio-barbituric acid) and increased the superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) enzyme activities in the testis tissues. The naringenin-treated rats in the diabetic group showed an improved histological appearance, sperm parameters, and serum testosterone levels, along with a decrement of terminal dUTP nick end-labeling (TUNEL) detected program cell death and a reduced over expression of TGF-β1, IL-1β in Sertoli cells and Leydig cells. These results suggest that naringenin is a food supplement potentially beneficial in reducing testicular damage in diabetic rats by decreasing the oxidative stress related to programmed cell death.