Sub-Chronic Restraint Stress Suppresses Sexual Potency and Erection Efficiency by Targeting the Hypothalamic-Pituitary-Testicular Axis and the Nitric Oxide/Cyclic Guanosine Monophosphate/Phosphodiesterase 5α Pathway in Adult Rats.

INTRODUCTION: Male sexual potency and vigor are a complex neuroendocrine process and an important component of well-being. Psychological stress is one of the leading causes of male impotence worldwide. Therefore, to better understand the effects of psychological stress on male sexual potency, vigor, and the physiology of erection, we used the rat restraint stress (RS) model, which can most aptly simulate psychological stress. METHODS: Adult male SD rats were exposed to RS for 1.5 or 3 h/day for 30 days. Neuromodulators and hormones of sexual potency and penile erection were quantified using ELISA kit. The histoarchitecture of the penis was examined using Masson trichrome staining. Immunoblotting and immunofluorescence were used to assess the expression and immunolocalization patterns of penile erection markers. To assess sexual potency and vigor, a noncontact erection and a copulatory test were performed. RESULTS: RS exposure decreased the circulatory levels of gonadotropins and testosterone while increasing the serum corticosterone level. RS exposure altered the histomorphology of the penis by decreasing the smooth muscle/collagen ratio and increasing oxidative stress in penile tissue. Furthermore, RS adversely affected NO availability for penile erection by decreasing the neurotransmitter acetylcholine and other erection facilitatory markers such as p-Akt, nNOS, eNOS, and cGMP, while increasing the inhibitory marker PDE5α in the penis. RS exposure significantly reduced the frequencies of mount, intromission, and ejaculation, whereas it prolonged sexual exhaustion by increasing latencies of postejaculatory mount, intromission, and ejaculation. CONCLUSION: The current findings suggest that psychological stressors, such as RS, cause erectile dysfunction in adult male rats by modulating the hypothalamic-pituitary-testicular axis, oxidative balance, penile fibrosis, and the NO/cGMP/PDE5α pathway of penile erection.

Restoration of erectile function by a combination of antiapoptosis by JNK inhibitor and preservation of smooth muscle or endothelium by hepatocyte growth factor in a rat model of cavernous nerve injury.

BACKGROUND: Because of structural alterations in the corpus cavernosum after radical prostatectomy (RP), post-RP erectile dysfunction remains a very difficult condition to treat. We aimed to determine if the combined administration of a Jun-amino terminal kinase (JNK) inhibitor and hepatocyte growth factor (HGF) in the immediate post-injury period would restore erectile function by antiapoptotic and pro-regenerative effects through the rectification of molecular pathways related to the structural integrity of the penis in a rat model of bilateral cavernosal nerve crush injury (CNCI). METHODS: A total of 70 rats were divided into five groups: Sham surgery (S), CNCI (I), and once-daily intraperitoneal administration of 10.0 mg/kg JNK inhibitor + twice-weekly intracavernosal administration of low-dose (2.1 µg), medium-dose (4.2 µg), or high-dose (8.4 µg) HGF (I + J + LH or I + J + MH or I + J + HH, respectively) in the immediate post-injury period. Erectile responses to electrostimulation (1.0, 3.0, and 5.0 V), histological staining, caspase-3 activity, and Western blotting were evaluated 9 days after surgery. RESULTS: Group I showed lower intracavernosal pressure (ICP)/mean arterial pressure (MAP) after stimulation at each voltage, lower area under the curve (AUC)/MAP after stimulation at each voltage, less smooth muscle (SM) content, a lower SM/collagen ratio, higher caspase-3 activity, increased cJun phosphorylation, decreased protein expression of PECAM-1, decreased cMet phosphorylation, and decreased endothelial nitric oxide synthase (eNOS) phosphorylation compared to Group S. The SM content, SM/collagen ratio, protein expression of ICP/MAP, or AUC/MAP after stimulation at each voltage in Group I + J + LH were partially restored, despite the normalization of cJun phosphorylation and caspase-3 activity. The ICP/MAP, AUC/MAP, caspase-3 activity, SM content, protein expression of PECAM-1, cJun phosphorylation, cMet phosphorylation, and eNOS phosphorylation in both Groups I + J + MH and I + J + HH were restored to the levels observed in Group S, while the SM/collagen ratio was significantly improved but not completely normalized. CONCLUSIONS: Our data indicated that the combined administration of a JNK inhibitor and medium or high-dose HGF to nerve-injured rats in the immediate post-injury period after CNCI may restore erectile function to a level comparable to the normal level by suppressing cavernosal apoptosis and preserving the integrity of SM or endothelium via rectification of the cJun and cMet/eNOS pathways.

NOX1/4 Inhibitor GKT-137831 Improves Erectile Function in Diabetic Rats by ROS Reduction and Endothelial Nitric Oxide Synthase Reconstitution.

BACKGROUND: Previous studies have shown that oxidative stress contributes to hyperglycemia-induced erectile dysfunction. A preferential direct inhibitor of NOX1 and NOX4, GKT-137831, exhibited a strong anti­oxidative role via blockade of reactive oxygen species (ROS) generation in endothelial cells, but whether GKT-137831 could improve erectile function was not clear. AIM: Our study was designed to investigate the effect of NOX1/4 inhibition on improving diabetic erectile dysfunction (ED) in rats. METHODS: We used streptozotocin to induce type 1 diabetes mellitus (DM) in 32 male Sprague Dawley (SD) rats (8 weeks old). Eight weeks later, type 1 diabetes mellitus-induced erectile dysfunction (DMED) in rats was confirmed using an apomorphine test. Our study consisted of 3 groups: (i) nondiabetic control group (n = 8), (ii) DMED + vehicle group (DMED group; n = 8), and (iii) DMED + GKT-137831 group (n = 9); GKT-137831 was given as a once-daily intraperitoneal injection for 4 weeks. Cavernous nerve electrostimulation was used to evaluate erectile function. Western blot, ELISA, immunohistochemistry, and immunofluorescence were used to measure expression of specific proteins, and DHE fluorescent probe was performed to detect ROS level. OUTCOMES: Intracavernous pressure (ICP), nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway, oxidative stress level, inflammatory response, corporal autophagy, and apoptosis were measured. RESULTS: Erectile function in the DMED group was significantly impaired compared to the nondiabetic control group, whereas this impairment was improved with GKT-137831 treatment by 70%. Similarly, endothelial function and overactivated oxidative stress in the corpus cavernosum (CC) of the DMED + GKT-137831 group were improved. The DMED group showed serious inflammatory responses and excessive autophagy, which were inhibited by GKT-137831 treatment in the DMED + GKT-137831 group. CLINICAL TRANSLATION: Our study showed improvement in erectile function with GKT-137831 in a diabetic rat ED model. STRENGTH AND LIMITATIONS: This study suggested for the first time that GKT-137831, an NOX1/4 inhibitor undergoing clinical trials, is effective in improving erectile function in rats with type 1 DMED. However, we only investigated GKT-137831 treatment of streptozotocin-induced type 1 diabetic rats, and therapeutic evidence in other types of diabetes is lacking. CONCLUSION: GKT-137831 improves erectile function by 70% in type 1 DMED rats and constitutes a promising compound for the treatment of type 1 DMED, likely by inhibition of overactivated oxidative stress, down-regulation of proinflammatory factors, and amelioration of excessive autophagy and endothelial function. B Zhou, Y Chen, H Yuan, et al. NOX1/4 Inhibitor GKT-137831 Improves Erectile Function in Diabetic Rats by ROS Reduction and Endothelial Nitric Oxide Synthase Reconstitution. J Sex Med 2021;18:1970-1983.

Artificial intelligence based identification of the functional role of hirudin in diabetic erectile dysfunction treatment.

Diabetic erectile dysfunction (DED) hugely affected the patients' sexual life quality. However, there are no satisfactory therapeutic methods and intervention targets for this subtype of erectile dysfunction (ED). Inspired by the clinical practice of traditional Chinese medicine (TCM), we found that hirudin, the main active ingredient in the leech, could ameliorate the ED symptoms of the DED mouse model. To further reveal the underlying mechanism of hirudin, we designed a novel strategy to discover potential targets based on the diagnostic system of TCM, and found that myeloperoxidase (MPO) was a promising target of hirudin. Hirudin directly interacts with MPO and inhibits its activity, thus further decreases the content of oxidized low-density lipoprotein (ox-LDL) in serum. Our results demonstrated that the hirudin could ameliorate the symptoms of DED, and revealed the underlying mechanism of hirudin in regulating the activity of MPO.

[Regulatory effect of the lipid metabolic pathways of TMAO, FMO3 and FXR on compound stress-induced ED in rats and mechanisms of Yimusake intervention].

OBJECTIVE: To study of the regulatory effects of the lipid metabolic pathways of trimethylamine-N-oxide (TMAO), flavin-containingmonooxidase 3 (FMO3) and farnesoid X receptor (FXR) on compound stress-induced ED (CSED) rats and the mechanisms of Yimusake Tablets (YMSK) intervention. METHODS: Based on the results of metabonomics analysis, we determined the concentration of TMAO in the serum of the rats in the normal control (n = 30), the CSED model control (n = 30) and the YMSK intervention group (intragastrical administration of YMSK at 250 mg/kg once daily for 2－3 weeks after modeling, n = 30) by nuclear magnetic resonance (NMR) spectroscopy test. We also detected the expressions of the FMO3, FXR1 and FXR2 proteins in the liver tissue of the three groups of rats by Western blot. RESULTS: The serum TMAO level was significantly elevated in the CSED model control compared with that in the normal control group (ï¼»46.64 ± 5.16ï¼½ vs ï¼»34.98 ± 3.69ï¼½ µg/mL, P < 0.01) but remarkably decreased after YMSK intervention (ï¼»39.63 ± 4.81ï¼½ µg/mL) in comparison with that in the CSED model control group (P < 0.01). The rats in the CSED model control group, compared with the normal controls, showed significantly upregulated expressions of FMO3 (1.75 ± 0.90 vs 0.86 ± 0.62, P < 0.01),FXR1 (1.29 ± 0.38 vs 0.78 ± 0.25, P < 0.01) and FXR2 in the liver tissue (1.90 ± 0.63 vs 0.42 ± 0.27, P < 0.01), but all the three expressions were markedly decreased after YMSK intervention (FMO3: 1.05 ± 0.38, P < 0.05; FXR1: 1.07 ± 0.42, P < 0.05; FXR2: 1.04 ± 0.46, P < 0.01) as compared with those in the CSED model control group. CONCLUSIONS: The lipid metabolic pathways of TMAO, FMO3 and FXR underwent significant changes in the rat model of compound stress-induced ED, which could be improved by YMSK intervention, suggesting that YMSK may play an important role in protecting erectile function by regulating the lipid metabolic pathways of TMAO, FMO3 and FXR.

Upregulation of the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor axis by a combination of Yinyanghuo (Herba Epimedii Brevicornus) and Cheqianzi (Semen Plantaginis) improves erectile function in spontaneously hypertensive rats.

OBJECTIVE: To evaluate the effects of a combination of Yinyanghuo (Herba Epimedii Brevicornus) (HEB) and Cheqianzi (Semen Plantaginis) (SP) on erectile dysfunction caused by essential hypertension in spontaneously hypertensive rats (SHRs), and to elucidate the role of the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor (ACE2/Ang [1-7]/Mas receptor) axis in this process. METHODS: A total of 24 SHRs were randomly assigned to three groups: SHR-control, low-dose (12.5 g/kg) and high-dose (25 g/kg) HEB+SP (HEBSP). Eight Wistar-Kyoto rats were used as normal controls. HEBSP was administered by oral gavage for 28 d. Erectile function was measured once a week using the Heaton test. After 4 weeks of treatment, the corpus cavernosum was harvested from each rat to measure nitric oxide (NO), nitric oxide synthase (eNOS) and Ang (1-7) levels, as well as ACE2, Mas receptor and neuronal nitric oxide synthase (nNOS) protein expression. RESULTS: After 4 weeks of treatment, HEBSP significantly increased erectile function in the treated group compared with SHR-control group (P < 0.01). Additionally, HEBSP treatment significantly increased cavernosal levels of Ang (1-7), eNOS and NO. Moreover, HEBSP significantly elevated the expression levels of ACE2, Mas receptor and nNOS. These beneficial effects were elevated in the high-dose HEBSP group. CONCLUSION: HEBSP improved erectile function in SHRs by upregulating the ACE2/Ang (1-7)/Mas receptor axis, eNOS and nNOS pathways.

The cold-soaking extract of Chinese yam (Dioscorea opposita Thunb.) protects against erectile dysfunction by ameliorating testicular function in hydrocortisone-induced KDS-Yang rats and in oxidatively damaged TM3 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Clinical applications and pharmacological research suggest that Dioscorea opposita Thunb. (Chinese yam), a well-known traditional Chinese medicine which has been used for more than 2000 years to nourish kidney-yang and protect the male reproductive system, might be efficacious for the treatment of erectile dysfunction (ED). AIM OF THE STUDY: This study aimed to investigate the active component extract of Chinese yam, determine its effectiveness in hydrocortisone-induced "kidney-yang deficiency syndrome" (KDS-Yang) rats and in oxidatively damaged TM3 cells and explore the underlying mechanism on restoring erectile function. MATERIALS AND METHODS: We clarified the Chinese yam cold-soaking extract (CYCSE) as the main active extract of Chinese yam by a CCK8 assay and further identified its composition. The KDS-Yang rats were induced by intragastric administration of hydrocortisone. After 10 d of CYCSE intervention, cavernous and testis morphology were stained with hematoxylin and eosin. Inducible nitric oxide synthase (iNOS), cyclic guanosine monophosphate (cGMP), testosterone, 8-hydroxy-2-deoxyguanosine (8-OHdG) and superoxide dismutase (SOD) levels were detected by enzyme-linked immunosorbent assay kits. Leydig cells were performed using immunohistochemistry. Reactive oxygen species were measured using a DCFH-DA fluorescent probe, and testicular collagenous fibers were stained with a Masson kit. Detection of testicular apoptosis was performed by a TUNEL assay. Nrf2 and NQO1 mRNA expression levels were measured by qRT-PCR. The protein expression levels of Nrf2, HO-1, TGF-ß1 and SMAD2/3 were analyzed by Western blot. RESULTS: We demonstrated in KDS-Yang rats and oxidatively damaged TM3 cells that CYCSE successfully restored erectile function through ameliorating testicular function. Our data suggested that CYCSE can stimulate the NO/cGMP pathway and restore the cavernous morphology to protect against KDS-Yang-induced ED. It also protected testis morphology, increased Leydig cell proliferation and stimulated testosterone secretion. In the damaged testes, excessive increases in 8-OHdG and inhibition of SOD activity were ameliorated, and the Nrf2/HO-1 signaling pathway was enhanced after treatment with CYCSE, indicating that the antioxidant defense system was activated. These findings were also validated in vitro. Additionally, fibrosis of the testes and TM3 cells was reversed by CYCSE through the TGF-ß1/SMAD2/3 pathway. CONCLUSION: CYCSE has a therapeutic effect on KDS-Yang-induced ED, and the mechanism includes stimulation of testosterone secretion, resistance to oxidative stress and prevention of fibrosis. These findings provide a new scientific verification for the application of Chinese yam in the treatment of KDS-Yang-induced ED.

Tangeretin ameliorates erectile and testicular dysfunction in a rat model of hypertension.

Tangeretin is a polymethoxyflavone concentrated in citrus peels and has several biological activities. This study examined whether tangeretin improved reproductive dysfunction in Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced hypertensive rats. Male Sprague-Dawley rats received L-NAME to induce hypertension and reproductive dysfunction for 5 w and were treated with tangeretin (15 or 30 mg/kg) or sildenafil citrate (10 mg/kg) for the final two weeks. Mean arterial pressure (MAP), intracavernosal pressure (ICP) response to cavernous nerve stimulation, endothelial nitric oxide synthase (eNOS), Angiotensin II receptor type 1 (AT1R) and gp91phox protein expressions and malondialdehyde (MDA) level in penile tissues were measured. Sperm concentrations and motility, seminiferous tubule morphology, serum testosterone, testicular eNOS and steroidogenic acute regulatory protein (StAR) expression were evaluated. Aortic superoxide generation, plasma and testicular MDA and plasma nitrate/nitrite levels were determined. Tangeretin reduced blood pressure and increased the maximum ICP/MAP associated with suppression of AT1R/gp91phox and upregulation of eNOS expression in hypertensive rats (P < 0.05). Furthermore, improvement of sperm quality relevant to increased testicular eNOS and StAR expression was found in tangeretin treated rats (P < 0.05). Changes in seminiferous tubule morphology in hypertensive rats were recovered by tangeretin (P < 0.05). It increased testosterone levels and reduced oxidative stress biomarkers and raised plasma nitrate/nitrite levels in L-NAME rats (P < 0.05). In conclusion, tangeretin improved maximum ICP/MAP and testicular dysfunction and morphology in rats treated with L-NAME. The molecular mechanisms are mediated by modulations of penile eNOS and AT1R/gp91phox expressions and testicular eNOS and StAR expression.

The beneficial effect of clove essential oil and its major component, eugenol, on erectile function in diabetic rats.

Diabetic men are at a higher risk of erectile dysfunction (ED). A tropical plant, clove (Syn. Eugenia caryophyllata, Caryophyllus aromaticus L., Syzygium aromaticum (L.) Merr. & L.M. Perry) from the Myrtaceae family has displayed aphrodisiac activity. The present research aimed to investigate the impacts of clove essential oil (CEO) and the ingredient of CEO, eugenol (E) on ED in diabetic rats. We divided Sprague-Dawley rats into control and diabetic groups. Erectile function was evaluated before and after CEO and E intracavernosal injection. CEO- and E-induced relaxation responses were investigated in isolated corpus cavernosum (CC) using various inhibitors. The intracavernous administration of CEO and E restored erectile responses in diabetic rats. CEO and E induced remarkable relaxation in all groups. CEO- and E-induced relaxation responses were partially inhibited after pre-contraction with KCl. Tetraethylammonium and glibenclamide inhibited the relaxation response to CEO. Glibenclamide inhibited maximum relaxation to E. The inhibitors of nitric oxide synthase (NOS), soluble guanylyl cyclase and nifedipine did not change CEO- and E-induced relaxation responses. The current results suggest that CEO and the major compound of the essential oil, E improved diabetes-induced ED in rats, and CEO caused CC relaxation via K+ channels independently NO signalling pathway.

Simvastatin alleviated diabetes mellitus-induced erectile dysfunction in rats by enhancing AMPK pathway-induced autophagy.

BACKGROUND: Diabetes mellitus-induced erectile dysfunction is a common diabetic complication, and new therapeutics and the pathogenesis of diabetes mellitus-induced erectile dysfunction need to be investigated. OBJECTIVES: The aim was to investigate the pathogenesis of diabetes mellitus-induced erectile dysfunction and the pharmacological mechanism of simvastatin treatment in diabetes mellitus-induced erectile dysfunction model rats. MATERIALS AND METHODS: A total of 86 male Sprague Dawley rats aged 8 weeks old were used in this study. The rats were divided into three groups: control (normal), diabetes mellitus-induced erectile dysfunction (streptozotocin-injected), and diabetes mellitus-induced erectile dysfunction + simvastatin (sim). Each group was subdivided into two subgroups for in vitro and in vivo analyses. A bioinformatics method was used to detect differences in gene expression in the corpus cavernosum between normal and diabetes mellitus-induced erectile dysfunction rats. Erectile function was measured by a cavernous nerve electrostimulation test. Corpus cavernosum fibrosis was assessed by Masson staining and Western blotting. Immunofluorescence and Western blotting were performed to explore the differential expression of autophagy-related genes and the AMPK-SKP2-CARM1 pathway genes in rat cavernous smooth muscle cells and the corpus cavernosum. The autophagosomes of the corpus cavernosum tissue were observed by transmission electron microscopy. RESULTS: Autophagy-related genes and pathways (the AMPK and FoxO pathway) were identified by bioinformatics analysis and confirmed at the protein level. Simvastatin, an AMPK agonist, was used to treat diabetes mellitus-induced erectile dysfunction rats for 8 weeks, demonstrating that erectile function was improved for 80.5% (P < .05) of rats. Corpus cavernosum fibrosis was alleviated (P < .05), and autophagy was further enhanced (P < .05); these results might be partially caused by AMPK-SKP2-CARM1 pathway activation (P < .05). DISCUSSION AND CONCLUSION: Simvastatin could enhance protective autophagy by activating the AMPK-SKP2-CARM1 pathway to improve erectile function in diabetes mellitus-induced erectile dysfunction rats.

Effects of Chaga Medicinal Mushroom Inonotus obliquus (Agaricomycetes) Extracts on NOS-cGMP-PDE5 Pathway in Rat Penile Smooth Muscle Cells.

Some medicinal mushrooms have effects on sexual dysfunctions. Nitric oxide synthase (NOS)-cyclic gua-nosine monophosphate (cGMP)-phosphodiesterase 5 enzyme (PDE5) pathway is one of the pathophysiological basis of erectile dysfunction (ED). The normal erectile function involves the synthesis of nitric oxide (NO), and the subsequent accumulation of cGMP, whereas cGMP degradation is specifically controlled by PDE5, which promotes corporal smooth muscle cell (SMC) tone and terminates erection. The antioxidant activities of Inonotus obliquus (chaga) water extracts (IO1) and water extraction and alcohol precipitation extracts (IO2) were compared using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay and oxygen radical absorbance capacity (ORAC) method. Three subtypes of NOS (nNOS, iNOS, and eNOS) and PDE5 protein expressions were tested by Western blotting, and cGMP was determined by ELISA on a rat corporal primary SMC. The results revealed that IO2, which had a significantly higher polysaccharide content than IO1, showed a significantly higher ORAC value and a significantly lower half inhibitory concentration for DPPH scavenging activity than IO1. We observed that both IO1 and IO2 increased the expression of eNOS and iNOS significantly compared with the control. Furthermore, when compared with the control, IO1 increased PDE5 expression significantly, while IO2 showed no effect. The different impacts on PDE5 might be the reason that IO2, not IO1, showed significant inducible effect on cGMP compared with the control. This is to our knowledge, the first study exploring the effect of I. obliquus on NOS-cGMP-PDE5 pathway on SMC. The results provide a possible selection of I. obliquus for the treatment of ED.

JTE-013 supplementation improves erectile dysfunction in rats with streptozotocin-induced type â diabetes through the inhibition of the rho-kinase pathway, fibrosis, and apoptosis.

BACKGROUND: Erectile dysfunction (ED) is a common complication in patients with diabetes mellitus (DM) that severely affects the patients' quality of life. However, the effectiveness of oral phosphodiesterase type 5 inhibitors in these patients is poor. Sphingosine-1-phosphate (S1P) and S1P receptor 2 (S1PR2) are important factors regulating the Rho-kinase pathway, and understanding these factors may provide ideas for new therapeutic strategies for ED. OBJECTIVES: To investigate whether the S1PR2 receptor antagonist JTE-013 could improve DM-induced ED (DMED) in rats and to explore the potential mechanisms. MATERIALS AND METHODS: We used 50 male Sprague Dawley rats (8 weeks old) for this experiment. Type Ⅰ DM was induced in forty-two rats via streptozotocin administration; the rest of the rats served as controls. Eight weeks after DM induction, rats with ED were selected via an apomorphine test. Eight of them were injected intraperitoneally with JTE-013 each day for 4 weeks. The rest were fed under the same conditions for 4 weeks. Erectile function was measured by cavernous nerve electrostimulation. The expression levels of related signaling pathways were evaluated using Western blotting, real-time PCR, and immunohistochemistry. RESULTS: Erectile function was significantly impaired in the DMED group compared with the control group and was partially improved in the DMED + JTE-013 group. The expression of S1PR2 and the activity of the RhoA/ROCK/phospho-myosin phosphatase target subunit 1 (p-MYPT1) pathway proteins were higher in the DMED group than in the other two groups, and JTE-013 treatment significantly reduced the expression/activity of these proteins. Furthermore, the DMED group showed severe corporal fibrosis, a higher apoptotic index and increased activity in the TGF-ß1/LIMK2/Cofilin pathway compared with the control group. JTE-013 supplementation significantly ameliorated these pathological changes. DISCUSSION AND CONCLUSION: JTE-013 supplementation partially improved erectile function in rats with DMED, likely by inhibiting smooth muscle contraction, corporal fibrosis, and apoptosis.

Fluted pumpkin (Telfairia occidentalis) seed modulates some markers of erectile function in isolated rat's corpus cavernosum: Influence of polyphenol and amino acid constituents.

Pumpkin seeds are often used in traditional medicine in the management of erectile dysfunction. However, there is insufficient information about the possible biochemical rationale behind this practice. Hence, this study investigated the influence of fluted pumpkin seed on critical enzymes involved in erectile function in isolated rats' corpus cavernosum in vitro. The phenolics and amino acid contents of fluted pumpkin seed were determined using HPLC-DAD and GC-PFPD analyses respectively. The aqueous extract of the fluted pumpkin seed significantly (p < .05) scavenged free radicals and inhibited PDE-5, arginase, AChE, and ACE in rats' corpus cavernosum in a concentration-dependent pattern. Quercitrin and luteolin were the most dominant phenolics, while arginine, aspartate, and cysteine were the most aboundant amino acid constituents. The positive modulatory effect of the fluted pumpkin seed on these critical markers of erectile function could be attributed to its polyphenolics and amino acid constituents. PRACTICAL APPLICATIONS: This study brought to limelight the medicinal importance of fluted pumpkin seed in erectile functions. Therefore, this seed could be used as a functional food ingredient in the management of erectile dysfunctions and also in improving erectile functions in men. In addition, the dominant phenolics and amino acid constituents of this seed might be an effective nutraceutical in enhancing erections in men.

Phenolic analysis and erectogenic function of African Walnut (Tetracarpidium conophorum) seeds: The impact of the seed shell on biological activity.

This study investigated the erectogenic potential of African walnut seed (AWS). The extract from AWS cooked with/without shell interacted with phosphodiesterase-5 (PDE-5), arginase, angiotensin-I converting enzymes (ACE), and acetylcholinesterase (AChE); enzymes associated with erectile dysfunction (ED) and Fe2+ -induced malonaldehyde (MDA) production in the isolated penile tissue. The results showed that the extracts inhibited the enzymes and MDA production, but Walnut cooked with shell had the highest effect. This agreed with increased phenolic acids and flavonoids, found in the AWS cooked with the shell, compared with that cooked without shell. The inhibition of enzymes and antioxidative potentials could be among the possible mechanisms of actions of AWS in the management/treatment of ED. However, cooking walnut seed with the shell seem to be a contributing factor, as this could prevent possible leaching out of the phytochemicals that could be responsible for these biological effects. PRACTICAL APPLICATIONS: Walnut seed possesses a high content of phenolic compounds and inhibit enzymes relevant to the management of erectile dysfunction. Traditionally, Walnut seed is being cooked with/without the shell and consumed for the purpose of alternative medicine in folklore. Our investigation revealed the possible mechanism underlying the therapeutic effect Walnut seed in the management of ED, but the impact of the shell during cooking contributes to this effect. This result will inform the consumers and food scientist on the importance of cooking Walnut seed with the shell in order to maximize its nutraceutical values.

Anogeissus leiocarpus attenuates paroxetine-induced erectile dysfunction in male rats via enhanced sexual behavior, nitric oxide level and antioxidant status.

Sexual dysfunction is a side effect of the antidepressant drug paroxetine. Anogeissus leiocarpus is a medicinal plant with a wide range of biological activities which include antioxidant and antiulcer properties. With these in mind, we investigated the effect of Anogeissus leiocarpus stem bark extract on paroxetine-induced sexual dysfunction in male Wistar rats. Forty-two adult male Wistar rats were divided into seven experimental groups: normal control, PAR (10 mg/kg), PAR + sildenafil (5 mg/kg), ALE (50 and 100 mg/kg) and PAR + ALE (50 and 100 mg/kg). The experiment lasted for 21 days, after which the rats were subjected to sexual behavioral test. Various biochemical assays (phosphodiesterase-5, arginase, acetylcholinesterase, nitric oxide and MDA) were carried out on the penile tissue homogenate. From our findings, paroxetine significantly altered sexual behavior in male rats and increased phosphodiesterase-5, arginase and acetylcholinesterase activities with a concomitant decrease in nitric oxide level. Furthermore, paroxetine altered antioxidant status which revealed by increased MDA level and reduced thiol level. However, treatment with Anogeissus leiocarpus stem bark extract reversed the altered sexual behavior in male rats and boosted antioxidant status. In addition, administration of Anogeissus leiocarpus stem bark extract resulted in a significant attenuation of phosphodiesterase-5, arginase and acetylcholinesterase activities in paroxetine-induced rats. In view of the aforementioned findings, Anogeissus leiocarpus could be considered a promising natural agent in erectile dysfunction management.

[Differentially expressed proteins in the penile tissue of rats with compound stress-induced ED after intervention with Yimusake Tablets: A bioinformatics analysis].

OBJECTIVE: To search for specific protein makers and target proteins for intervention with Yimusake Tablets (YT) in the penile tissue of rats with ED induced by compound cold stress and explore the molecular mechanisms underlying the development and progression of ED. METHODS: Eighty adult male rats were screened and divided into three groups, normal control (n = 10), ED model control (n = 15) and YT intervention (n = 15). The model of compound cold stress-induced ED was established in the latter two groups, and meanwhile the animals in the YT intervention group were treated with oral YT for 2 weeks. After that, proteins were extracted from the penile tissues of the rats for screening and identification by iTRAQ labeling combined with LC-MS-MS proteomics, and the IPA bioinformatics software was used for analysis of differentially expressed proteins. RESULTS: A total of 48 differentially expressed proteins were identified from the penile tissue of the ED model controls, of which 18 were associated with endothelial function, 5 with smooth muscle activity and 4 with inflammation, involving the biological processes of glucose metabolism and alcohol catabolism and the signaling pathways of glucose metabolism, calcium and RXR activation. In comparison, 29 differentially expressed proteins were identified from the rats in the YT intervention group, of which 5 were associated with endothelial function, 1 with smooth muscle activity and 4 with inflammation, involving the biological processes of glucose metabolism, vasodilation and acute-phase response and the signaling pathways glucose metabolism, RXR activation and acute-phase response. Seven ED-associated candidate biomarkers were obtained from the differentially expressed proteins in the ED model control and YT intervention group, including Collagen alpha-1(III) chain（COL3α1）, Collagen alpha-1(I) chain（COL1α1）, Collagen alpha-2(I) chain（COL1α2）, Glyceraldehyde-3-phosphate dehydrogenase（GAPDH）, T-kininogen 1（MAP1）,Biglycan（BGN）, and Myosin-11（MYH11）. CONCLUSIONS: Changes of vascular endothelial and smooth muscle functions in the penile tissue are likely to be the key mechanisms underlying the development and progression of compound stress-induced ED, which is also associated with inflammation as well as the interaction of the identified differentially expressed proteins and their participation in the relevant signaling pathways. The 7 proteins obtained can be used as the markers of compound stress-induced ED in the rat penile tissue, of which MAP1, GAPDH, BGN and MYH11 may serve as target proteins for YT intervention.

Protective effects of Danshen injection against erectile dysfunction via suppression of endoplasmic reticulum stress activation in a streptozotocin-induced diabetic rat model.

BACKGROUND: Erectile dysfunction (ED) is a common complication of diabetes. This study aimed to explore the beneficial effect of Danshen injection on ED in a streptozotocin (STZ)-induced diabetic rat model and the underlying mechanism. METHODS: The diabetic rat model was established by an intraperitoneal injection of 60 mg/kg STZ in male Sprague-Dawley rats. The diabetic rats were intraperitoneally injected with Danshen solution (0.5 or 1 mL/kg/day) or the same volume of saline for 6 weeks. Age-matched rats served as controls. After 6 weeks, erectile function and histological morphology of the corpora cavernosum were assessed. Oxidative stress indicators, including superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and reactive oxygen species (ROS) levels, were measured in penile tissues. The expression levels of glucose-regulated protein 78 (Grp78), growth arrest and DNA damage-inducible gene 153 (GADD153/CHOP) were determined by immunohistochemistry, immunoblotting, and RT-PCR. Apoptosis was detected by a TUNEL assay. RESULTS: The erection times of diabetic rats were significantly less than those of control rats. Danshen injection could improve erectile function via increased erection times. Danshen injection was also found to ameliorate the morphological abnormalities of the corpora cavernosum, to reduce the number of apoptotic cells, and to suppress caspase-3 activation in penile tissue, accompanied by downregulation of the endoplasmic reticulum stress biomarkers Grp78 and CHOP. Danshen injection could increase SOD activity as well as reduce ROS and MDA levels in diabetic rats, indicating suppression of oxidative stress. CONCLUSION: Danshen injection could rescue diabetes-associated ED, possibly via suppressing the oxidative stress and endoplasmic reticulum (ER) stress-induced apoptosis pathways.

Resveratrol treatment may preserve the erectile function after radiotherapy by restoring antioxidant defence mechanisms, SIRT1 and NOS protein expressions.

Radiotherapy (RT) for prostate cancer (PC) can cause erectile dysfunction (ED) by damaging neurovascular structures with oxidative stress. In this study, we evaluated the effects of resveratrol, an antioxidant, on post-RT ED. Fifty rats in five groups were evaluated; control (C), prostate-confined radiotherapy with short- and long-term vehicle or resveratrol treatment. Cavernosal tissues were obtained to analyze glutathione (GSH), nitric oxide (NO), cyclic guanosine monophosphate (cGMP), 8-hydroxy-2'-deoxy-guanosine (8-OHdG) levels and superoxide dismutase (SOD), caspase-3 activities, sirtuin-1, Foxo-3, nNOS, and eNOS protein expressions. Intracavernosal pressures (ICP) were measured for the long-term treatment group. In the RT + long-term vehicle treatment group, tissue GSH, NO, cGMP, and SOD activity were decreased while 8-OHdg levels and caspase-3 activities were increased. Radiotherapy caused a decrease in sirtuin-1, nNOS, and eNOS protein expressions. These parameters were reversed by resveratrol treatment. Foxo-3 protein expressions were unaltered in the RT + short-term vehicle treatment group and started to increase as a defense mechanism in the RT + long-term vehicle group; however, resveratrol treatment caused a significant increase in Foxo-3 expressions. Resveratrol preserved the metabolic pathways involved in erectile function and provided functional protection. Resveratrol can be used as a supplementary agent in patients undergoing radiotherapy to preserve erectile function.

African crocus (Curculigo pilosa) and wonderful kola (Buchholzia coriacea) seeds modulate critical enzymes relevant to erectile dysfunction and oxidative stress.

Background The seeds of African crocus (AC) (Curculigo pilosa) and wonderful kola (WK) (Buchholzia coriacea) are commonly used in folklore medicine in managing erectile dysfunction (ED) without the full understanding of the possible mechanism of actions. This study investigated and compared the effects of aqueous extracts from the seeds of AC and WK on arginase and acetylcholinesterase (AChE) activities and some pro-oxidant [FeSO4 and sodium nitroprusside (SNP)]-induced lipid peroxidation in rat penile homogenate in vitro. Method Aqueous extracts of AC and WK were prepared, and their effects on arginase and AChE activities as well as FeSO4- and SNP-induced lipid peroxidation in rat penile homogenate were assessed. Furthermore, phenolic constituents of the extract were determined using high-performance liquid chromatography coupled with diode-array detector (HPLC-DAD). Results Both extracts exhibited concentration-dependent inhibition on arginase (AC, IC50=0.05 mg/mL; WK, IC50=0.22 mg/mL) and AChE (AC, IC50=0.68 mg/mL; WK, IC50=0.28 mg/mL) activities. The extracts also inhibited FeSO4- and SNP-induced lipid peroxidation in rat penile homogenate. HPLC-DAD analysis revealed the presence of phenolic acids (gallic, caffeic, ellagic and coumaric acids) and flavonoids (catechin, quercetin and apigenin) in AC and WK. AC had higher arginase inhibitory and antioxidative activities but lower AChE inhibitory properties when compared with WK. Conclusions These effects could explain the possible mechanistic actions of the seeds in the management/treatment of ED and could be as a result of individual and/or synergistic effect of the constituent phenolic compounds of the seeds.

Dietary supplementation of tiger nut alters biochemical parameters relevant to erectile function in l-NAME treated rats.

Tiger nut tubers have been reportedly used for the treatment of erectile dysfunction (ED) in folk medicine without scientific basis. Hence, this study evaluated the effect of tiger nut on erectile dysfunction by assessing biochemical parameters relevant to ED in male rats by nitric oxide synthase (NOS) inhibitor, Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME) treatment. Rats were divided into five groups (n = 10) each: Control group; l-NAME plus basal diet; l-NAME plus Sildenafil citrate; diet supplemented processed tiger nut (20%) plus l-NAME;diet supplemented raw tiger nut (20%) plus l-NAME. l-NAME pre-treatment (40 mg/kg/day) lasted for 14 days. Arginase, acetycholinesterase (AChE) and adenosine deaminase (ADA) activities as well as nitric oxide levels (NO) in serum, brain and penile tissue were measured. l-NAME increased the activity of arginase, AChE and ADA and reduced NO levels. However, dietary supplementation with tiger nut caused a reduction on the activities of the above enzymes and up regulated nitric oxide levels when compared to the control group. The effect of tiger nut supplemented diet may be said to prevent alterations of the activities of the enzymes relevant in erectile function. Quercetin was revealed to be the most active component of tiger nut tuber by HPLC finger printing.