Resveratrol, an activator of SIRT1, restores erectile function in streptozotocin-induced diabetic rats

Effects of Spirulina maxima on a Model of Sexual Dysfunction in Streptozotocin-Induced Diabetic Male Rats

Arthrospira (Spirulina) maxima (SM) is a cyanobacterium that has a long history of being used as human food. In recent years, several investigations have shown its beneficial biological effects, among which its antioxidant capacity has been highlighted. The purpose of this study was to evaluate the effects of SM on body weight, glycemia, sexual behavior, sperm quality, testosterone levels, sex organ weights, and the activity of antioxidant enzymes in diabetic male rats (a disease characterized by an increase in reactive oxygen species). The experiment consisted of six groups of sexually expert adult males (n = 6): (1) control (vehicle); (2) streptozotocin (STZ)-65 mg/kg; (3) SM-400 mg/kg; (4) STZ + SM-100 mg/kg; (5) STZ + SM-200 mg/kg; and (6) STZ + SM-400 mg/kg. Sexual behavior tests were performed during the first 3 h of the dark period under dim red illumination. Our results showed that SM significantly improved sexual behavior and sperm quality vs. diabetic animals. Likewise, while the enzymatic activities of SOD and GPx increased, TBARS lipoperoxidation decreased and testosterone levels increased. In view of the findings, it is suggested that SM may potentially be used as a nutraceutical for the treatment of diabetic male sexual dysfunction due to its antioxidant property.

Long-term administration of resveratrol and MitoQ stimulates cavernosum antioxidant gene expression in a mouse castration model of erectile dysfunction

AIMS

Erectile dysfunction is a common complication within many pathological conditions associated with low testosterone. Testosterone deficiency increases oxidative stress in the penile tissue that contributes to endothelial dysfunction and subsequent erectile dysfunction. Current therapies do not ameliorate oxidative stress so targeting oxidative stress may improve erectile dysfunction. Resveratrol and MitoQ are two prospective drugs that have antioxidant-like properties and may be useful to improve erectile dysfunction induced by androgen deprivation.

MATERIALS AND METHODS

We castrated 12-week-old male C57BL/6 mice and performed an eight-week intervention with oral delivery of resveratrol or MitoQ at low and high doses. We assessed vascular reactivity of the corpus cavernosum and internal pudendal arteries (IPA) through dose-dependent responses to vasodilatory, vasocontractile, and neurogenic stimuli in a myograph system. We performed qRT-PCR to measure expression changes of 18 antioxidant genes in the corpus cavernosum.

KEY FINDINGS

Castration significantly impaired erectile function via impaired endothelial-dependent and-independent relaxation, and increased constriction of the corpus cavernosum, and induced severe endothelial dysfunction of the IPA. Castration decreased expression of 8 of the antioxidant genes investigated. Resveratrol and MitoQ were ineffective in reversing the effects of androgen deprivation on vascular reactivity, however high-dose resveratrol treatment upregulated several key antioxidant genes, including Cat, Sod1, Gstm1, and Prdx3.

SIGNIFICANCE

Our findings suggest that oral resveratrol and MitoQ treatment may provide protection to the corpus cavernosum under androgen deprived conditions by stimulating endogenous antioxidant systems. However, they may need to be paired with vasoactive drugs to reverse erectile dysfunction under androgen deprived conditions.

Micro RNA 200a contributes to the smooth muscle cells growth in aged-related erectile dysfunction via regulating Rho/ROCK pathway

Aged-related erectile dysfunction (A-ED) is generally regarded as degeneration of penile erectile tissue due to age, male hormone deficiency and concomitant cardiovascular disease. Current pathological studies of A-ED are still limited. In this study, aged rats were divided into AE group (aged rats with ED) and YN group (young normal rats) for evaluating the roles of miRNA-200a and RhoA/ROCK signalling pathway in A-ED. Apo-morphine test, ICP measurement and pathological results were compared between these two groups. After transfection of miRNA-200a into Corpus cavernosum smooth muscle cells (CCSMCs), the expression of miRNA-200a, RhoA, ROCK1 and ROCK2 in the AE group were significantly increased. Additionally, miRNA-200a, RhoA, ROCK1 and ROCK2 were upregulated at a high level after transfecting the miRNA-200a mimics. Therefore, we speculated that miRNA-200a is a positive regulator, which may inhibit the growth of CCSMCs by activating the Rho/ROCK pathway in vitro.

Phytomedicinal therapeutics for male infertility: critical insights and scientific updates

Infertility is a significant cause of anxiety, depression, and social stigma among couples and families. In such cases, male reproductive factors contribute widely to the extent of 20-70%. Male infertility is a multifactorial disease with several complications contributing to its diagnosis. Although its management encompasses both modern and traditional medicine arenas, the first line of treatment, adopted by most males, focuses on the reasonably successful medicinal plant-based conventional therapies. Phyto-therapeutics, which relies on active ingredients from traditionally known herbs, influences sexual behavior and male fertility factors. The potency of these phyto-actives depends on their preparation methods and forms of consumption, including decoctions, extracts, semi-purified compounds, etc., as inferred from in vitro and in vivo (laboratory animal models and human) studies. The mechanisms of action therein involve the testosterone pathway for stimulation of spermatogenesis, reduction of oxidative stress, inhibition of inflammation, activation of signaling pathways in the testes [extracellular-regulated kinase (ERK)/protein kinase B(PKB)/transformation of growth factor-beta 1(TGF-β1)/nuclear factor kappa-light-chain-enhancer of activated B cells NF-kB signaling pathways] and mediation of sexual behavior. This review critically focuses on the medicinal plants and their potent actives, along with the biochemical and molecular mechanisms that modulate vital pathways associated with the successful management of male infertility. Such intrinsic knowledge will significantly further studies on medicinal plants that improve male reproductive health.

Salidroside attenuates cardiac dysfunction in a rat model of diabetes

AIM

This study aimed to investigate the therapeutic effects of salidroside on diabetes-induced cardiovascular disease.

METHODS

Sprague-Dawley rats treated with 65 mg/kg of streptozotocin (STZ) on a daily basis were used to establish the diabetic rat model (blood glucose levels >13.9 mmol/L). Cardiac functions of diabetic rats were evaluated by their haemodynamic alterations. Western blot assay was performed to evaluate the protein levels of multiple signalling pathway factors. Quantitative real-time PCR assay was performed to investigate the inflammation and oxidative stress of diabetic rats.

RESULTS

Salidroside treatment improved the cardiac functions of diabetic rats. In addition, salidroside therapy attenuated the cardiac oxidative stress induced by diabetes. Salidroside inhibited the diabetes-induced inflammation in diabetic rat hearts. The apoptosis of cardiomyocytes was also alleviated by the treatment of salidroside. Salidroside also upregulated the phosphorylation levels of AMPK, ACC, TSC2 and RAPTOR.

CONCLUSION

Salidroside exerts protective effects against diabetes-induced cardiac dysfunction by modulating the mTOR and AMPK signalling pathways.

Modulation of SIRT1 expression improves erectile function in aged rats

Silent information regulator 2-related enzyme 1 (SIRT1) is an aging-related protein activated with aging. Herein, we evaluated the role of SIRT1 in aging-related erectile dysfunction. The expression of SIRT1 was modulated in aged Sprague-Dawley rats following intragastric administration of resveratrol (Res; 5 mg kg^-1), niacinamide (NAM; 500 mg kg^-1) or Res (5 mg kg^-1) + tadalafil (Tad; phosphodiesterase-5 [PDE5] inhibitor; 5 mg kg^-1) for 8 weeks. Then, we determined erectile function by the ratio of intracavernosal pressure (ICP)/mean systemic arterial pressure (MAP). Cavernosal tissues were extracted to evaluate histological changes, cell apoptosis, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP), the superoxide dismutase (SOD)/3,4-methylenedioxyamphetamine (MDA) level, and the expression of SIRT1, p53, and forkhead box O3 (FOXO3a) using immunohistochemistry, terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine 5'-triphosphate (dUTP) nick-end labeling (TUNEL), enzyme-linked immunosorbent assays, and western blot analysis. Compared with the control, Res treatment significantly improved erectile function, reflected by an increased content of smooth muscle and endothelium, NO/cGMP and SOD activity, and reduced cell apoptosis and MDA levels. The effect of Res was improved by adding Tad. In addition, the protein expression of SIRT1 was increased in the Res group, accompanied by decreased p53 and FOXO3a levels. In addition, inhibition of SIRT1 by NAM treatment resulted in adverse results compared with Res treatment. SIRT1 activation ameliorated aging-related erectile dysfunction, supporting the potential of SIRT1 as a target for erectile dysfunction treatment.

Efficacy of resveratrol in male urogenital tract dysfunctions: an evaluation of pre-clinical data

Resveratrol is a polyphenol found naturally in fruits and plants. Recently, studies in humans and animal models have suggested beneficial properties of this polyphenol, such as improvements to metabolic and lipid profiles, along with antioxidant, anti-inflammatory and anti-proliferative effects. In the urogenital tract (UGT), resveratrol has also been tested clinically and experimentally as a therapeutic drug in several diseases; however, the translational efficacy of resveratrol, especially in UGT, is still a matter of debate. In the present review, we address the pre-clinical efficacy of resveratrol in UGT-related dysfunctions, focusing on lower urinary tract symptoms, non-cancerous prostatic disease (benign prostatic hyperplasia and prostatitis) and erectile dysfunction. In vitro studies indicate that resveratrol reduces inflammatory markers and oxidative stress, and improves endothelial function in UGT organs and cells isolated from humans and animals. Despite displaying low oral bioavailability, in vivo administration of resveratrol largely improves erectile dysfunction, benign prostatic hyperplasia, prostatitis and voiding impairments, as evidenced in different animal models. Resveratrol also acts as a microbiota modulator, which may explain some of its beneficial effects in vivo. In contrast to the large amount of pre-clinical data, there are insufficient clinical trials to establish resveratrol treatment efficacy in human UGT-related diseases. In summary, we provide an overview of the in vivo and in vitro efficacy of resveratrol in animal and human UGT dysfunctions, which may support future clinical trials.

The near-infrared dye IR-61 restores erectile function in a streptozotocin-induced diabetes model via mitochondrial protection

This study aimed to evaluate the therapeutic effect of IR-61, a novel mitochondrial heptamethine cyanine dye with antioxidant effects, on diabetes mellitus-induced erectile dysfunction (DMED). Eight-week-old male Sprague-Dawley rats were intraperitoneally injected with streptozotocin (STZ) to induce type 1 diabetes. Eight weeks after STZ injection, all rats were divided into three groups: the control group, DM group, and DM + IR-61 group. In the DM + IR-61 group, the rats were administered IR-61 (1.6 mg kg^-1) twice a week by intravenous injection. At week 13, erectile function was evaluated by determining the ratio of the maximal intracavernous pressure to mean arterial pressure, and the penises were then harvested for fluorescent imaging, transmission electron microscopy, histological examinations, and Western blot analysis. Whole-body imaging suggested that IR-61 was highly accumulated in the penis after intravenous injection. IR-61 treatment significantly improved the maximal ICP of diabetic rats. Additionally, IR-61 ameliorated diabetes-induced inflammation, apoptosis, and phenotypic transition of corpus cavernosum smooth muscle cells (CCSMCs) in penile tissue. IR-61 also attenuated mitochondrial damage, reduced reactive oxygen species production in the corpus cavernosum and upregulated sirtuin1 (SIRT1), sirtuin3 (SIRT3), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and heme oxygenase expression in penile tissue. In conclusion, IR-61 represents a potential therapeutic option for DMED by protecting the mitochondria of CCSMCs, which may be mediated by activation of the SIRT1, SIRT3, and Nrf2 pathways.

Dietary natural products as epigenetic modifiers in aging-associated inflammation and disease

Covering: up to 2020Chronic, low-grade inflammation is linked to aging and has been termed "inflammaging". Inflammaging is considered a key contributor to the development of metabolic dysfunction and a broad spectrum of diseases or disorders including declines in brain and heart function. Genome-wide association studies (GWAS) coupled with epigenome-wide association studies (EWAS) have shown the importance of diet in the development of chronic and age-related diseases. Moreover, dietary interventions e.g. caloric restriction can attenuate inflammation to delay and/or prevent these diseases. Common themes in these studies entail the use of phytochemicals (plant-derived compounds) or the production of short chain fatty acids (SCFAs) as epigenetic modifiers of DNA and histone proteins. Epigenetic modifications are dynamically regulated and as such, serve as potential therapeutic targets for the treatment or prevention of age-related disease. In this review, we will focus on the role for natural products that include phytochemicals and short chain fatty acids (SCFAs) as regulators of these epigenetic adaptations. Specifically, we discuss regulators of methylation, acetylation and acylation, in the protection from chronic inflammation driven metabolic dysfunction and deterioration of neurocognitive and cardiac function.

Corpus cavernosum smooth muscle cell dysfunction and phenotype transformation are related to erectile dysfunction in prostatitis rats with chronic prostatitis/chronic pelvic pain syndrome

Background

The relationship between chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and erectile dysfunction (ED) has been shown in many studies. However, the specific mechanism remains unclear. This study was to investigate the corpus cavernosum smooth muscle cell function and phenotype transformation in Experimental autoimmune prostatitis (EAP) rats.

Methods

EAP was induced in rats by using prostate protein supplemented with immuneadjuvant extraction, and the max-ICP and MAP were measured. IHC and Masson staining were done to assess inflammatory infiltration and collagen deposition in the corpus cavernosum, respectively. Subsequently, normal rat and EAP rat CCSMCs were purified by tissue block implantation and differential adherence method. The oxidative stress, smooth muscle phenotype transformation, cell cycle and intracellular calcium ion transport were also evaluated.

Results

The ratio of max ICP/MAP in EAP rats significantly reduced, and the TNF-α content and collagen deposition in the corpus cavernosum markedly increased as compared to healthy rats. High-purity rat CCSMCs were obtained. Oxidative stress was evident and the cGMP content decreased in the EAP rat CCSMCs. The expression of Cav1.2, IP3R1 and RyR2 increased, but the SERCA2 expression decreased in EAP rat CCSMCs, which was accompanied by increased intracellular calcium. Increased expression of OPN, collagen and KCa3.1, decreased Calponin expression and increased proportion of cells in the S phase were also observed in the EAP rat CCSMCs.

Conclusion

CP causes oxidative stress and imbalance of intracellular calcium in CCSMCs and promotes CCSMCs transformation from contractile to synthetic state, which may be involved in the pathogenesis of ED.

Swimming training by affecting the pancreatic Sirtuin1 (SIRT1) and oxidative stress, improves insulin sensitivity in diabetic male rats

Background

Sirtuin1 is a regulator of oxidative stress involved in the management of diabetes complications. Due to the beneficial effects of swimming training in diabetes, this study aimed to investigate the effects of swimming training on pancreatic Sirtuin1, oxidative stress and metabolic parameters in type 2 diabetic male rats.

Materials and methods

Twenty-eight male Wistar rats (200–250 g) were randomly divided into four groups: control, diabetic, swim trained and swim trained diabetic rats (n = 7). Diabetes was induced by a high-fat diet and streptozotocin injection [35/kg intraperitoneally]. After 72 hours, animals with blood glucose levels ≥300 mg/dL were considered diabetic. Seven days after the induction of diabetes, animals in the exercise groups were subjected to swimming training (60 min/daily, 5 days/week) for 12 weeks. At the end of the intervention, the animals were anesthetized, and tissue/blood samples were prepared for measurements of metabolic parameters, albumin, the Sitruin1 gene and its protein expression levels, oxidative stress and histological study.

Results

This study indicated that the diabetic rats had a significant decrease (p < 0.01, p < 0.05) in pancreatic Sitruin1 gene and its protein expression levels, antioxidant enzymes, serum albumin, and the quantitative insulin sensitivity check index, but a significant increase (p < 0.01) in malondialdehyde level. Swimming training resulted in a considerable improvement (p < 0.01, p < 0.05) in pancreatic Sitruin1 gene and its protein expression levels, antioxidant enzymes, serum levels of albumin and metabolic parameters. In addition, histological findings indicated the beta-cells conservation.

Conclusions

This study suggested that pancreatic Sitruin1 may be a promising therapeutic target for diabetic complications.

Structural and functional abnormalities of penile cavernous endothelial cells result in erectile dysfunction at experimental autoimmune prostatitis rat

Background

There is growing recognition of the association of CP/CPPS accompany with ED. However, the specific mechanism of action remains unclear. The aim of this study was to investigate structural and functional abnormalities of cavernous endothelial cells in EAP rat, which may result in the ED.

Methods

we use rat prostate protein extract supplemented with immunoadjuvant to induce EAP rat, ICP and MAP were measured and inflammatory factor infiltration, Akt, eNOS, AR, nNOS and iNOS in the corpus cavernosum were tested. Subsequently, the normal rat and EAP rat cavernosum endothelial cells were purified by MACS, and the metabolism, oxidative stress, MMP, Akt, eNOS, AR and iNOS were evaluated.

Results

The EAP rat model was successfully constructed. The ratio of max ICP/MAP in EAP rat was significantly lower and TNF-α infiltration in corpus cavernosum was significantly higher than normal rats. Besides, Akt, eNOS and AR were decreased, iNOS was significantly increased. The growth and metabolism of endothelial cells in the EAP rats corpus cavernosum decreased and inflammatory factor mRNA was increased and intracellular oxidative stress was also increased significantly. The MMP of EAP rats cavernosum endothelial cells decreased and the expression of Akt, eNOS and AR were also significantly decreased, iNOS was significantly increased.

Conclusion

The prostate suffer local inflammatory infiltrate and promotes cytokines infiltrated into corpus cavernosum caused the oxidative stress increases and the metabolism or MMP decreases. In addition, AR, Akt and eNOS expression and phosphorylation are also reduced, thereby inhibiting the diastolic function of the corpus cavernosum, resulting in decreased erectile function.

Trends in erectile dysfunction research from 2008 to 2018: a bibliometric analysis

Insufficient penile erection to facilitate vaginal penetration is a medical condition referred to as erectile dysfunction (ED). By the year 2025, the number of ED cases across the world is expected to reach 322 million. There are numerous publications and studies in the field of ED over the past decades. Our aim is to comprehensively analyze the global scientific outputs of ED research and show the trends and hotspots in ED research. Data of publications were downloaded from the Web of Science Core Collection. We used CiteSpace IV and Excel 2016 to analyze literature information, including journals, countries/regions, institutes, authors, citation reports, and research frontiers. Until October 26, 2018, a total of 8880 papers in ED research were identified as published between 2008 and 2018. Journal of Sexual Medicine published the most articles. The United States contributed the most publications and occupied leading positions in H-index value and the number of ESI top papers. Maggi M owned the highest co-citations. The keyword "Oxidative stress" ranked first in the research front-line. The amount of articles published in ED research has been stable from 2008 to 2018. The United States showed enormous progress in ED research, and is still the dominant country. Oxidative stress, vardenafil, and late-onset hypogonadism were the latest research frontiers and should be paid more attention.

Cavernosal hydrogen sulfide levels are associated with nitric oxide and hemeoxygenase levels in diabetic rats

Penile erection is a neuromuscular event modulated by psyche, hormones as well as neurotransmitters. This pre-clinical study aimed to assess hydrogen sulfide (H₂S) relationship with nitric oxide (NO) and hemeoxygenase (HO) in the cavernous tissues of diabetic rats. Overall, 90 adult male rats were investigated (6 groups, n = 15 each). They were subdivided into the following groups; untreated rats, rats treated with H₂S donor/inhibitor, induced diabetic rats, diabetic rats treated with H₂S donor/inhibitor. At the 6th week, the rats were killed to assess cavernous tissue cGMP, NO, H₂S, HO enzyme activity levels. The rats treated with H₂S donor showed increased mean cavernous tissue cGMP, NO, H₂S, and HO enzyme activity levels whereas induced diabetic rats and rats treated with H₂S inhibitor showed significant decreases in these parameters compared with the untreated rats. On the other hands, diabetic rats treated with H₂S donor showed elevated mean cavernous tissue cGMP, NO, H₂S, and HO enzyme activity levels whereas diabetic rats treated with H₂S inhibitor showed significant decreases in these parameters compared with diabetic rats. Cavernous tissue H₂S levels exhibited significant positive correlations with the cavernous tissue levels cGMP, NO, and HO enzyme activity levels. From these results, it could be concluded that cavernous tissues H₂S plays a role of male sexual health by affecting cavernous tissues NO and HO enzyme activity in general and in diabetics in particular.

Effect of Resveratrol, a Dietary-Derived Polyphenol, on the Oxidative Stress and Polyol Pathway in the Lens of Rats with Streptozotocin-Induced Diabetes

Resveratrol is found in grapes, apples, blueberries, mulberries, peanuts, pistachios, plums and red wine. Resveratrol has been shown to possess antioxidative activity and a variety of preventive effects in models of many diseases. The aim of the study was to investigate if this substance may counteract the oxidative stress and polyol pathway in the lens of diabetic rats. The study was conducted on the rats with streptozotocin-induced type 1 diabetes. After the administration of resveratrol (10 and 20 mg/kg po for 4 weeks), the oxidative stress markers in the lens were evaluated: activity of superoxide dismutase, catalase and glutathione peroxidase, as well as levels of total and soluble protein, level of glutathione, vitamin C, calcium, sulfhydryl group, advanced oxidation protein products, malonyldialdehyde, Total Oxidant Status and Total Antioxidant Reactivity. The obtained results indicate that the administration of resveratrol to the diabetic rats shows antioxidative properties. It is not a result of antiglycaemic activity but resveratrol probably directly affects the antioxidative system. Resveratrol did not affect the polyol pathway in the lens of diabetic rats. Our results may indirectly indicate benefits of consumption of foods as well as dietary supplements containing resveratrol in diminishing oxidative stress in lenses of individuals suffering from diabetes mellitus.

Pharmacotherapy for erectile dysfunction in diabetic males

INTRODUCTION

Numerous studies have highlighted the intimate association between erectile dysfunction (ED) and diabetes mellitus (DM). However, the true pathogenesis of ED among diabetic men has not yet been fully discovered. The treatment of ED in diabetic patients remains an interesting area of research. The last two decades have witnessed phenomenal advances in the management of ED with the efficacy of pharmacotherapy for ED in diabetic patients encouraging, especially with introduction of innovative conservative tools for treatment.

AREAS COVERED

The aim of this review is to discuss the currently available information on ED pharmacotherapy in diabetic males and provide an expert perspective on the current treatment strategies.

EXPERT OPINION

Conservative treatment remains the initial step for the treatment of ED in diabetic patients. This kind of therapy consists of different modalities including: oral treatments, intracavernosal pharmacotherapy, and evolving modalities such as soluble guanylate cyclase activators, stem cells (SCs), and alternative treatments such as herbal treatment and transdermal/topical pharmacotherapy. However, it should be noted that the currently available pharmacotherapy is still far from ideal. One hopes to witness new drugs and technologies that may revolutionize ED treatment in the future, especially in such complex cases as DM.

Superparamagnetic iron oxide nanoparticle targeting of adipose tissue-derived stem cells in diabetes-associated erectile dysfunction

Erectile dysfunction (ED) is a major complication of diabetes, and many diabetic men with ED are refractory to common ED therapies. Adipose tissue-derived stem cells (ADSCs) have been shown to improve erectile function in diabetic animal models. However, inadequate cell homing to damaged sites has limited their efficacy. Therefore, we explored the effect of ADSCs labeled with superparamagnetic iron oxide nanoparticles (SPIONs) on improving the erectile function of streptozotocin-induced diabetic rats with an external magnetic field. We found that SPIONs effectively incorporated into ADSCs and did not exert any negative effects on stem cell properties. Magnetic targeting of ADSCs contributed to long-term cell retention in the corpus cavernosum and improved the erectile function of diabetic rats compared with ADSC injection alone. In addition, the paracrine effect of ADSCs appeared to play the major role in functional and structural recovery. Accordingly, magnetic field-guided ADSC therapy is an effective approach for diabetes-associated ED therapy.

Sulforaphane, a Natural Isothiocyanate Compound, Improves Cardiac Function and Remodeling by Inhibiting Oxidative Stress and Inflammation in a Rabbit Model of Chronic Heart Failure

Background

The aim of this study was to investigate the effects of sulforaphane (SFN), a natural isothiocyanate compound, in a rabbit ascending aortic cerclage model of chronic heart failure (CHF).

Material/Methods

Thirty New Zealand White rabbits were divided into the sham operation group (n=10), the CHF group (n=10), and the CHF + SFN group (n=10) treated with subcutaneous SFN (0.5 mg/kg) for five days per week for 12 weeks. After 12 weeks, echocardiography and biometric analysis were performed, followed by the examination of the rabbit hearts. Enzyme-linked immunosorbent assay (ELISA) and Western blot were used to detect levels of inflammatory cytokines, superoxide dismutase (SOD), and malondialdehyde (MDA).

Results

In the CHF group, compared with the sham operation group, there was an increase in the heart weight to body weight ratio (HW/BW), the left ventricular weight to body weight ratio (LVW/BW), the left ventricular end diastolic diameter (LVEDD), the left ventricular end systolic diameter (LVESD), plasma brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) levels, the cardiac collagen volume fraction (CVF), apoptotic index, expression levels of collagen I, collagen III, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and malondialdehyde (MDA) in the myocardial tissue, and a decrease in the left ventricular shortening fraction (LVFS) and left ventricular ejection fraction (LVEF), and cardiac superoxide dismutase (SOD) activity. These changes were corrected in the SFN-treated group.

Conclusions

In a rabbit model of CHF, treatment with SFN improved cardiac function and remodeling by inhibiting oxidative stress and inflammation.

Epigallocatechin-3-gallate ameliorates erectile function in aged rats via regulation of PRMT1/DDAH/ADMA/NOS metabolism pathway

Aging-related ED is predominantly attributed to neurovascular dysfunction mediated by NO suppression and increased oxidative stress in penis. The alterations of protein arginine methyltransferases 1 (PRMT1)/dimethylarginine dimethylaminohydrolase (DDAH)/asymmetrical dimethylarginine (ADMA)/NO synthase (NOS) pathway regulate NO production in the vascular endothelium. Epigallocatechin-3-gallate (EGCG) is one of the most abundant and antioxidative ingredients isolated from green tea. In the present study, 40 Sprague-Dawley rats were randomly distributed into four groups: one young rat group and three aged rat groups treated with daily gavage feedings of EGCG at doses of 0, 10 mg kg⁻¹, and 100 mg kg⁻¹ for 12 weeks, respectively. Erectile function was assessed by electrical stimulation of the cavernous nerves with intracavernous pressure (ICP) measurement. After euthanasia, penile tissue was investigated using Western blot and ELISA to assess the PRMT1/DDAH/ADMA/NOS metabolism pathway. Superoxide dismutase (SOD) and malondialdehyde (MDA) levels were detected by colorimetry. We also evaluated smooth muscle contents. The ratio of maximal ICP and mean systemic arterial pressure (MAP) was markedly higher in EGCG-treated aged rats than in untreated aged rats. We found that DDAH1 and DDAH2 were expressed in cavernosal tissue, and they were downregulated in corpora of aged rats. The administration of EGCG upregulated the expression and activity of DDAH. In contrast, EGCG treatment downregulated the expression of PRMT1 and ADMA content. Moreover, EGCG-treated rats showed an improvement in smooth muscle expression, the ratio of smooth muscle cell/collagen fibril, SOD activity, and MDA levels when compared with untreated aged rats.

Evaluation of Prolidase Activity, Oxidative Stress, and Antioxidant Enzyme Levels in Testicular and Penile Tissues after Human Chorionic Gonadotropin Treatment in Rats by Predicting Infertility and Erectile Dysfunction

OBJECTIVES

Prolidase plays a vital role in collagen turnover, matrix remodeling, and cell growth. We aimed to evaluate the association between treatment with chorionic gonadotropin and infertility and erectile dysfunction by investigating tissue prolidase activity, oxidative stress, and levels of antioxidant enzymes.

MATERIALS AND METHODS

The 16 male Wistar albino rats used in this study were randomly divided into 2 groups: rats treated with human chorionic gonadotropin (hCG) and control rats (n = 8 in each group). The rats in the hCG group were subcutaneously injected with 50 IU hCG daily for 15 days, while the rats in the control group were subcutaneously injected isotonic saline. All of the rats were sacrificed by a lethal overdose of sodium pentobarbital at the first month after hCG administration. Prolidase activity and levels of malonyl aldehyde, glutathione reductase, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were estimated in the testicular and penile tissue. The testicles and penis were transversely dissected and placed in formalin.

RESULTS

Levels of prolidase and malonyl aldehyde in the testicular and penile tissues were significantly higher in the hCG group than in the control group (p < 0.001), while levels of glutathione reductase, SOD, GSH-Px, and CAT were significantly lower in the hCG group than in the control group (p < 0.001).

CONCLUSIONS

In this study, we observed that treatment with hCG increased prolidase activity and oxidative stress and decreased the antioxidant capacity of penile and testicular tissues; therefore, this may affect fertility and erectile function.

Resveratrol attenuates reproductive alterations in type 1 diabetes-induced rats

The progression of diabetes mellitus leads to several complications including overproduction of reactive oxygen species and reproductive alterations. As resveratrol (RES) is a powerful anti-oxidant and an anti-apoptotic compound, we hypothesized that side effects of type-1 diabetes (DM1) on male reproduction could be reduced by the RES treatment. Eighty-four prepubertal male rats were distributed into seven groups: sham-control (SC), RES-treated (R), resveratrol-vehicle-treated (RV), diabetic (D), diabetic-insulin-treated (DI), diabetic-RES-treated (DR), diabetic-insulin and RES-treated (DIR). DM1 was induced by a single intraperitoneal streptozotocin (STZ) injection (65 mg/kg) on the 30th day postpartum (dpp). Animals of DR, DIR and R groups received 150 mg/day of RES by gavage for 43 consecutive days (from the 33 to 75 dpp). DI and DIR rats received subcutaneous injections of insulin (1 U/100 g b.w./day) from 5th day after the DM1 induction. The blood glucose level was monitored. At 75 dpp, the euthanasia was performed for morphometric and biometric testicular analyses, spermatic evaluation and hormonal doses. In the D group, the blood glucose level was higher than in the DR, DI and DIR groups. Besides morphometric testicular measurements, testosterone and estradiol doses were lower in D group than in DR and DIR groups; LH dose was also lower than in DR. The preputial separation age was delayed in diabetes-induced groups. The DR and DIR groups showed an improvement in sperm mitochondrial activity, epididymal sperm counts and the frequency of morphologically normal sperms. RES treatment improved glycaemic level, sperm quantitative and qualitative parameters and the hormonal profile in DM1-induced rats and seems to be a good reproductive protector.

Natural antioxidants in the treatment and prevention of diabetic nephropathy; a potential approach that warrants clinical trials

Diabetic nephropathy is the major cause of end-stage renal disease and effective and new therapeutic approaches are needed in diabetic nephropathy and chronic kidney diseases. Oxidative stress and inflammatory process are important factors contributing to kidney damage by increasing production of oxidants. KEAP1/Nrf2/ARE pathway regulates the transcription of many antioxidant genes and modulation of the pathway up regulates antioxidants. NFB controls the expression of genes involved in the inflammatory response. Natural substances have antioxidant and anti-inflammatory activities and have an impact on NFB and KEAP1/Nrf2/ARE pathways. The preclinical studies explored the effectiveness of whole herbs, plants or seeds and their active ingredients in established diabetic nephropathy. They ameliorate oxidative stress induced kidney damage, enhance antioxidant system, and decrease inflammatory process and fibrosis; most likely by activating KEAP1/Nrf2/ARE pathway and by deactivating NFB pathway. Whole natural products contain balanced antioxidants that might work synergistically to induce beneficial therapeutic outcome. In this context, more clinical studies involving whole plants or herbal products or mixtures of different herbs and plants and their active ingredients might change our strategies for the management of diabetic nephropathy. The natural products might be useful as preventive interventions and studies are required in this field.

The role of dietary polyphenols in the management of erectile dysfunction-Mechanisms of action

The incidence of erectile dysfunction (ED) is on the increase and it is estimated that it will affect about 322 million men globally by the year 2025 if adequate measures are not taken to curb it. Natural polyphenols in plant based diets have gained public interest in recent times due to their roles in the prevention of various disease that implicate free radicals/reactive oxygen species and recently on ED. However, the role of polyphenols in the management of ED has not been explored due perhaps to limited data available. Hence this study which reviewed the role of dietary polyphenols in the management of ED and their mechanisms of action. Literature search was carried out in several electronic data bases such as Pubmed, Google Scholar, Medline, Agora and Hinari from1972 to 2016 to identify the current status of knowledge on the role of polyphenols in the management of erectile dysfunction. Progress made so far in this direction suggests inhibition of arginase, acetylcholinesterase, angiotensin converting enzyme, rho-kinase II; activation of endothelial and neuronal NO synthase; decreased synthesis of luteinizing hormone and testosterone reduction; activation of silent information regulator 2-related enzymes (sirtuin1) as well as free radical/reactive oxygen species inhibition as the mechanisms through which the polyphenols identified in this review exert beneficial roles in the management of ED.

Demethylation treatment restores erectile function in a rat model of hyperhomocysteinemia

Methylation modification is an important cellular mechanism of gene expression regulation. Dimethylarginine dimethylaminohydrolase-2 (DDAH-2) protein is a pivotal molecular for endothelium function. To explore the effects of 5-aza-deoxycytidine (5-aza), a demethylation agent, in hyperhomocysteinemia (hhcy)-related erectile dysfunction (ED) rats, 5-aza (1 mg kg⁻¹) was administrated to Sprague-Dawley hhcy-rats induced by supplemented methionine chow diet. Erectile function, nitric oxide-cyclic guanosine monophosphate (NO-cGMP) levels, expression of DDAH-2 protein and promoter methylation status of DDAH-2 were studied in the corpora cavernosa. We found that supplemented methionine diet induced a high homocysteine level after 6 weeks of treatment. DDAH-2 protein was down-regulated in the corpora cavernosa while the administration of 5-aza up-regulated DDAH-2 expression and restored erectile function. The methionine-fed rats showed high methylation levels of DDAH-2 promoter region while the group treated with 5-aza demonstrated lower-methylation levels when compared to the methionine-fed group. Besides, the administration of 5-aza improved NO and cGMP levels in methionine-fed rats. Therefore, the methylation mechanism involves in ED pathogenesis, and demethylation offers a potential new strategy for ED treatment.

Improvement in erectile function in a rat model of high cholesterol diet-induced atherosclerosis by atorvastatin in a manner that is independent of its lipid-lowering property

The purpose of the present study is to explore the effects of a lipid-lowering drug atorvastatin, a three-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, in the treatment of erectile dysfunction (ED) in a rat model of atherosclerosis (AS) and the possible mechanisms underneath. A high-cholesterol diet was administrated to Sprague-Dawley rats in an attempt to induce an ASED model, which was later confirmed by abdominal aorta histopathology and erectile function evaluation. ASED rats were further assigned to non-treatment group, atorvastatin low-dose treatment group (5 mg kg^-1  day^-1 ), high-dose group (10 mg kg^-1  day^-1 ) and sildenafil (1.5 mg kg^-1  day^-1 ) treatment group. Lipid profile, erectile function, oxidative stress biochemical markers, endothelial nitric oxide synthase (eNOS) and extracellular superoxide dismutase (SOD_EX ) mRNA expression were evaluated after 8-week treatment duration. Erectile function was impaired in AS rat model, which was preserved in atorvastatin and sildenafil intervention groups. The oxidative stress biochemical markers were attenuated, while eNOS and SOD_EX mRNA expression were restored in atorvastatin and sildenafil groups, which were found to be involved in ED pathogenesis. However, the lipid profile remained unaltered in the treatment group, and it was elevated in ASED rats. This kind of lipid-lowering agent, or atorvastatin, has the utilisation potential in ASED treatment, even before lipid profiles altered. This effect on erectile function preservation of atorvastatin was attributed to its preservation of endothelial function, possibly through amelioration of oxidative stress and improvement in eNOS expression.

In vitro and in vivo investigation of natural compounds from seed extract of Mucuna pruriens lacking l-DOPA for the treatment of erectile dysfunction

OBJECTIVE

To investigate the biological effects of the Mucuna pruriens (M. pruriens) seed extracts that lacked l-DOPA, which was formerly reported as the active ingredient, on erectile dysfunction (ED) both in vitro and in vivo.

METHODS

Seed of M. pruriens plant that cultivated in Mae Taeng District, Chiang Mai Province, Thailand, was collected. Component of its seeds were extracted and isolated into 2 fractions using methanol, polar and nonpolar. Each fraction was investigated for phytochemicals using gas chromatography and mass spectroscopy and was screened for biological activity in vitro using three different cell lines. The most biological active fraction was used to treat both streptozotocin (STZ)-induced diabetes mellitus-erectile dysfunction (DM-ED) male Wistar rats and normal rats (n = 6 per groups) to compare the effect on sexual behavior parameters, including number of intromission, mounting and ejaculation, with that of rats given Sildenafil by individually pairing with their female counterparts. Penile tissues and serums were collected to determine histological structure, related gene expression and biomolecules.

RESULTS

The phytochemicals of the polar fraction were possibly catechol and its derivatives plus polyphenols, whereas the nonpolar fraction consisted of lipid derivatives. l-DOPA was not detected in either of the extracts. The polar fraction was able to up-regulate the expression of ED-related genes including eNOS and nNOS in vitro which subsequently promotes nitric oxide production and maintains intracellular cyclic guanosine monophosphate levels. When administrated to DM-ED rats, the polar extract significantly improved all sexual behavior parameters in DM-ED rats compared to untreated group (18.3 ± 1.8 to 10.8 ± 2.9 for intromission, 9.8 ± 2.2 to 5.7 ± 1.3 for mounting, and 1.8 ± 0.6 to 0.2 ± 0.4 for ejaculation). That effect might due to the ability of the extract to stimulate the expression of eNOS and nNOS which results in nitric oxide production and subsequently maintains cyclic guanosine monophosphate levels in penile tissue. Moreover, this extract may also prevent penile tissue deterioration due to diabetes.

CONCLUSIONS

The polar extract of M. pruriens seed can be used for ED therapy, especially in patients with metabolic diseases including diabetes. The action of the extract might be due to catechol and its derivatives and polyphenols.

A Variant in the Precursor of MicroRNA-146a is Responsible for Development of Erectile Dysfunction in Patients with Chronic Prostatitis via Targeting NOS1

Background

The morbidity of erectile dysfunction (ED) has been found to be substantially increased in patients with chronic prostatitis (CP). Accumulating evidence shows that single-nucleotide polymorphism (SNP) located in pre-miRNA or mature microRNA may affect the processing of microRNA (miRNA) and alter the expression of the miRNA, as well as its target gene. In this study we investigated the association between rs2910164 G/C polymorphism and risk of ED in patients with CP, as well as the underlying molecular mechanism.

Material/Methods

Computational analysis was used to search for the target of miR-146a, and the luciferase reporter assay system was used to validate NOS1 to be the target gene of miR-146a. We also treated PC-3 cells with miR-146a mimics/inhibitors to verify the negative regulatory relationship between miR-146a and NOS1, and real-time PCR and Western blot analysis were used to estimate the expression of the NOS1 mRNA and miR-146a.

Results

The binding site of miR-146a was found to be located within the 3′-UTR of the NOS1 by searching an online miRNA database (www.mirdb.org), and luciferase reporter assay was done to confirm that NOS1 is a direct target gene of miR-146a. We also found that mRNA and protein expression level of NOS1 in PC-3 cells treated with miR-146a mimics and NOS1 siRNA was substantially down-regulated compared with scramble control, while cells treated with miR-146a inhibitors showed increased expression of NOS1. In addition, 705 people were recruited for our research – 342 CP patients with ED and 363 CP patients without ED – and we found that the presence of minor allele of rs2910164 polymorphism is significantly associated with reduced risk of ED in patients with CP.

Conclusions

The findings indicate a decreased risk of ED in patients with CP who are carriers of miR-146a rs2910164 C allele, and this association might be due to its ability to compromise the expression of miR-146a, and thereby increase the expression of its target gene, NOS1.

MicroRNA-200a is up-regulated in aged rats with erectile dysfunction and could attenuate endothelial function via SIRT1 inhibition

MiR-200a was shown to be upregulated in the corpus cavernosum (CC) of rats with aging-related erectile dysfunction (A-ED) in our previous study. Among its target genes, SIRT1 was also reported as a protective factor in erectile function by our groups previously. Thus, miR-200a might attenuate the erectile function in A-ED via SIRT1 inhibition. In the present study, three animal groups were included: aged rats with ED (group AE, n = 8), aged rats with normal erectile function (group AN, n = 8), and young rats as normal controls (group YN, n = 8). CCs from each group were collected for histological and molecular measurements to validate the dysregulation of miR-200a and SIRT1. After that, the cavernous endothelial cells (CECs) from CC of aged rats with normal erectile function were transfected with miR-200a in vitro. Then the expression of SIRT1 and molecules within the eNOS/NO/PKG pathway were measured to investigate whether the transfection could imitate the attenuated process of erectile function in the aged. As a result, miR-200a was upregulated while the SIRT1, the levels of eNOS and cGMP were all downregulated in the CCs from AE group. After transfection in vitro, the miR-200a was upregulated while the SIRT1 and levels of eNOS and cGMP were obviously downregulated. Finally, based on the results of our previous study, we further verify that up-regulation of miR-200a could participate in the mechanisms of A-ED via SIRT1 inhibition, and mainly attenuate endothelial function via influencing the eNOS/NO/PKGpathway.

Effects of resveratrol on the alterations of cavernosal eNOS and LOX-1 expression in the hypercholesterolemic condition: a preliminary study

BACKGROUND/AIM

The aim of this study was to determine the effects of resveratrol on the alterations of cavernosal eNOS and LOX-1 mRNA expression in the hypercholesterolemic condition.

MATERIALS AND METHODS

Twenty-one New Zealand white male rabbits were separated into three groups. Rabbits were fed with a normal dietary intake for the control group and a 2% cholesterol diet for the hypercholesterolemia and resveratrol groups for 6 weeks. Resveratrol 4 mg/kg daily was administered for the resveratrol group. Cavernosal LOX-1 and eNOS mRNA expressions were determined with real-time RT-PCR in all groups. The statistical analysis was performed with the Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

We found no difference between mean LOX-1 mRNA expression levels in the three groups. Lower mean eNOS mRNA expression level was determined in the hypercholesterolemia group when compared with the control group (P = 0.011). Mean eNOS mRNA expression level in the resveratrol group was similar to that in the control group but significantly higher than that in the hypercholesterolemia group (P < 0.001).

CONCLUSION

This preliminary study demonstrates the beneficial effects of resveratrol on cavernosal eNOS expression. The presence of cavernosal LOX-1 expression was also shown for the first time. Resveratrol may be an alternative option in hypercholesterolemic erectile dysfunction with further studies supporting its beneficial effects on the corpus cavernosum.

Protective effect of resveratrol and quercetin on in vitro-induced diabetic mouse corpus cavernosum

BACKGROUND

Hyperglycemia and increased levels of methylglyoxal (MGO) can trigger the development of vascular complications in diabetes. Resveratrol and quercetin are red wine polyphenols with known beneficial cardiovascular properties, including an antioxidant capacity. This study evaluated whether resveratrol and/or quercetin could prevent in vitro-induced diabetic changes in neurogenic and vascular relaxant responses of mouse arteries and corpora cavernosa.

METHODS

Isometric tension of isolated aorta, mesenteric arteries and corpora cavernosa was measured using organ bath systems. Diabetic conditions were mimicked in vitro by co-incubating the tissues for 2 h with high glucose (HG, 30 mM) and MGO (120 µM).

RESULTS

The presence of HG and MGO significantly blunted acetylcholine (Ach)-induced relaxations in corpora cavernosa and mesenteric arteries but not in aorta. Electrical field stimulated (EFS) responses of corpora cavernosa were also significantly inhibited by these diabetic conditions. In corpora cavernosa 2 h co-incubation with resveratrol (30 µM) or quercetin (30 µM) significantly attenuated HG and MGO-induced deficits in Ach- and EFS-responses.

CONCLUSIONS

Our study demonstrates that in mouse arteries, HG and MGO rather affect endothelium derived hyperpolarizing factor-mediated than nitric oxide (NO)-mediated relaxations. In corpora cavernosa HG and MGO interfere with NO release. Resveratrol and quercetin protect mouse corpora cavernosa from diabetic-induced damage to NO-mediated relaxant responses. This might rely on their antioxidant capacity.

Assessing Colonic Exposure, Safety, and Clinical Activity of SRT2104, a Novel Oral SIRT1 Activator, in Patients with Mild to Moderate Ulcerative Colitis

BACKGROUND

Sirtuins are a class of proteins with important physiologic roles in metabolism and inflammation. Sirtuin (silent mating type information regulation 2 homolog) 1, or SIRT1, activation is an unexplored therapeutic approach for the treatment of ulcerative colitis (UC).

METHODS

Patients with mild to moderately active UC were blindly randomized to 50 mg or 500 mg daily of SRT2104, a selective activator of SIRT1, for 8 weeks. Colonic exposure and safety were assessed, as well as blinded endoscopic scoring and disease activity by Mayo score, Simple Clinical Colitis Activity Index and fecal calprotectin.

RESULTS

Across both SRT2104 groups, only 3 of 26 evaluable subjects achieved remission on blinded endoscopic assessment. Clinical remission (Mayo score ≤2, no subscore >1) was achieved in 4 patients (2 of 13 evaluable patients in each dose group). Fecal calprotectin levels declined with treatment in both groups, but after 56 days of treatment subjects were still found to have levels approximately 4-fold elevated above normal. One subject experienced an SAE requiring study withdrawal and another was withdrawn for a severe UC flare; 19 subjects (61%) across both treatment groups experienced at least 1 treatment emergent adverse event. Average drug exposure increased in a dose-dependent manner for escalating doses of SRT2104, and colonic exposure was 140 to 160 times higher than plasma exposures.

CONCLUSIONS

SRT2104 did not demonstrate significant clinical activity in mild to moderately active UC. This suggests that further evaluation of SRT2104 as a therapeutic strategy for the treatment of UC is not warranted.

Molecular mechanisms associated with diabetic endothelial-erectile dysfunction

Erectile dysfunction (ED) is a common complication of diabetes, affecting up to 75% of all diabetic men. Although the aetiology of diabetic ED is multifactorial, endothelial dysfunction is recognized as a mainstay in the pathophysiology of the disease. Endothelial dysfunction is induced by the detrimental actions of high glucose levels and increased oxidative stress on endothelial cells that make up the vascular lining. Besides directly injuring the endothelium, diabetes might also hamper vascular repair mechanisms of angiogenesis and vasculogenesis. These states exacerbate and maintain endothelial dysfunction, impairing vasorelaxation events and cavernosal blood perfusion, which are crucial for normal erectile function.

Resveratrol and sildenafil synergistically improve diabetes-associated erectile dysfunction in streptozotocin-induced diabetic rats

AIMS

Despite effective control of blood glucose levels in diabetic patients, complaints of diabetes-associated erectile dysfunction (ED) persist. Resveratrol has been indicated to possess anti-diabetic effects and therapeutic potential for ED. This study was conducted to observe the effect of resveratrol alone or in combination with sildenafil on ED in streptozotocin (STZ)-induced diabetic rats.

MAIN METHOD

Among 58 adult male STZ-induced (60 mg/kg) diabetic Sprague-Dawley rats, 48 STZ-induced diabetic rats were randomized equally to four groups: untreated diabetic rats, resveratrol (25mg/kg), sildenafil (5mg/kg) or resveratrol (25mg/kg) plus sildenafil (5mg/kg) through oral gavage for 8 weeks. Additionally, 12 age-matched rats were chosen as controls. Intracavernous pressure (ICP) and mean arterial blood pressure (MAP) were used to measure erectile function. The cavernous level of cyclic guanosine monophosphate (cGMP), protein and mRNA of endothelial NO synthase (eNOS), neuronal NOS (nNOS), and phosphodiesterase-5 (PDE5) was measured.

KEY FINDINGS

Treatment with either resveratrol or sildenafil improved ICP/MAP compared to the untreated diabetic rats (P<0.05). Treatment with resveratrol increased nNOS and eNOS expression, inhibited PDE5 expression, and increased the cavernous cGMP level compared to the untreated diabetic rats. Resveratrol significantly decreased superoxide anion and ROS production. Two-way ANOVA indicated that resveratrol in combination with sildenafil therapy had a significant synergistic effect in improving ICP/MAP and cavernous cGMP levels.

SIGNIFICANCE

Resveratrol improves diabetes-associated ED in rats. Combination therapies with resveratrol and sildenafil have a synergistic effect in improving ED. The mechanisms might be attributed to its anti-oxidative properties and NO-cGMP signaling pathway upregulation.

Role of oxidative stress-induced systemic and cavernosal molecular alterations in the progression of diabetic erectile dysfunction

BACKGROUND

Erectile dysfunction (ED) is a prevalent complication of diabetes, and oxidative stress is an important feature of diabetic ED. Oxidative stress-induced damage plays a pivotal role in the development of tissue alterations. However, the deleterious effects of oxidative stress in the corpus cavernosum with the progression of diabetes remain unclear. The aim of this study was to evaluate systemic and penile oxidative stress status in the early and late stages of diabetes.

METHODS

Male Wistar streptozotocin-diabetic rats (and age-matched controls) were examined 2 (early) and 8 weeks (late) after the induction of diabetes. Systemic oxidative stress was evaluated by urinary H2 O2 and the ratio of circulating reduced/oxidized glutathione (GSH/GSSG). Penile oxidative status was assessed by H2 O2 production and 3-nitrotyrosine (3-NT) formation. Cavernosal endothelial nitric oxide synthase (eNOS) was analyzed by quantitative immunohistochemistry. Dual immunofluorescence was also performed for 3-NT and α-smooth muscle actin (α-SMA) and eNOS-α-SMA.

RESULTS

There was a significant increase in urinary H2 O2 levels in both diabetic groups. The plasma GSH/GSSG ratio was significantly augmented in late diabetes. In cavernosal tissue, H2 O2 production was significantly increased in late diabetes. Reactivity for 3-NT was located predominantly in cavernosal smooth muscle (SM) and was significantly reduced in late diabetes. Quantitative immunohistochemistry revealed a significant decrease in eNOS levels in cavernosal SM and endothelium in late diabetes.

CONCLUSIONS

The findings indicate that the noxious effects of oxidative stress are more prominent in late diabetes. Increased penile protein oxidative modifications and decreased eNOS expression may be responsible for structural and/or functional deregulation, contributing to the progression of diabetes-associated ED.

The pharmacology of resveratrol in animals and humans

In addition to thousands of research papers related to resveratrol (RSV), approximately 300 review articles have been published. Earlier research tended to focus on pharmacological activities of RSV related to cardiovascular systems, inflammation, and carcinogenesis/cancer development. More recently, the horizon has been broadened by exploring the potential effect of RSV on the aging process, diabetes, neurological dysfunction, etc. Herein, we primarily focus on the in vivo pharmacological effects of RSV reported over the past 5 years (2009-2014). In addition, recent clinical intervention studies performed with resveratrol are summarized. Some discrepancies exist between in vivo studies with animals and clinical studies, or between clinical studies, which are likely due to disparate doses of RSV, experimental settings, and subject variation. Nevertheless, many positive indications have been reported with mammals, so it is reasonable to advocate for the conduct of more definitive clinical studies. Since the safety profile is pristine, an added advantage is the use of RSV as a dietary supplement. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.

Effect of HGF on the apoptosis of rat corpus cavernosum smooth muscle cells induced by TGFβ1

Corpus cavernosum smooth muscle cells (CCSMCs) are important functional cells for penile erection. We evaluated the effect of transforming growth factor β1 (TGFβ1) and hepatocyte growth factor (HGF) on the viability and apoptosis of CCSMCs in vitro. CCSMCs from healthy male Sprague Dawley rats were randomly divided into four groups: a negative control group, a TGFβ1 group, a HGF group and a HGF+ TGFβ1 group. Differences in cell viability and apoptosis among groups were observed by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and flow cytometry. Western blot was used to detect the change of apoptosis-related proteins. The level of reactive oxygen species (ROS) was detected by colorimetry. In the TGFβ1 group, the MTT values were obviously decreased at 12 h, 24 h, 48 h-0.320, 0.383 and 0.432 respectively. However, compared with the normal group, the apoptosis index was markedly increased, reaching 26.86% at the 48-h time point. After TGFβ1 treatment, the levels of cleaved caspase-3 and p-Smad2 were increased in the cells, but the levels of Bcl-xL, Bcl-2 and p-Akt were significantly lower. However, HGF co-treatment partially reversed these changes and could decrease the intracellular ROS level while increasing the Akt phosphorylation level. These results indicate that TGFβ1 might induce apoptosis of CCSMCs in vitro and that HGF could interfere with the above process through downregulation of apoptosis signalling and oxidative stress reaction.

Gas what: NO is not the only answer to sexual function

The ability to get and keep an erection is important to men for several reasons and the inability is known as erectile dysfunction (ED). ED has started to be accepted as an early indicator of systemic endothelial dysfunction and subsequently of cardiovascular diseases. The role of NO in endothelial relaxation and erectile function is well accepted. The discovery of NO as a small signalling gasotransmitter led to the investigation of the role of other endogenously derived gases, carbon monoxide (CO) and hydrogen sulphide (H2 S) in physiological and pathophysiological conditions. The role of NO and CO in sexual function and dysfunction has been investigated more extensively and, recently, the involvement of H2 S in erectile function has also been confirmed. In this review, we focus on the role of these three sister gasotransmitters in the physiology, pharmacology and pathophysiology of sexual function in man, specifically erectile function. We have also reviewed the role of soluble guanylyl cyclase/cGMP pathway as a common target of these gasotransmitters. Several studies have proposed alternative therapies targeting different mechanisms in addition to PDE-5 inhibition for ED treatment, since some patients do not respond to these drugs. This review highlights complementary and possible coordinated roles for these mediators and treatments targeting these gasotransmitters in erectile function/ED.

Treatment of erectile dysfunction: new targets and strategies from recent research

In recent years, research on penile erection has increasingly been centered on the molecular mechanisms involved. Major progress has been made in the field and at present a whole number of neurotransmitters, chemical effectors, growth factors, second-messenger molecules, ions, intercellular proteins, and hormones have been characterized as components of the complex process of erection. This knowledge has led to the discovery of several new therapeutic targets and multiple medical approaches for the treatment of erectile dysfunction (ED). This review focuses on the progress made in this field within the last few years.