A Chinese herbal formula, Shuganyiyang capsule, improves erectile function in male rats by modulating Nos-CGMP mediators

Rubus occidentalis and Ellagic Acid Affect the Contractility of Penile Corpus Cavernosum Smooth Muscle through the Nitric Oxide-Cyclic Guanosine Monophosphate and Cyclic Adenosine 3',5'-Monophosphate Signaling Pathway

The present study was designed to evaluate the relaxation effect of Rubus occidentalis (RO) and ellagic acid (EA) on rabbit penile corpus cavernosum smooth muscle (PCCSM). Rabbit PCCSM was treated with ROE or EA after preincubation with nitric oxide synthase (NOS), guanylate cyclase (GC), adenylyl cyclase (AC) or protein kinase A (PKA) blocker. Cyclic nucleotides in the perfusate were analyzed using radioimmunoassay (RIA). Subsequently, perfused PCCSMs were subjected to analysis to evaluate the expression level of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS). The interaction of ROE or EA with phosphodiesterase (PDE) 5 and PDE4 inhibitors, such as udenafil (UDE) and rolipram (ROL), were also evaluated. Both ROE and EA relaxed the PCCSM in a concentration-dependent manner. Coincubation of ROE or EA with NOS, GC, AC, or PKA blocker significantly decreased the ROE- and EA-induced relaxation. Pretreatment of ROE and EA significantly upregulated the cyclic guanosine monophosphate (cGMP), cyclic adenosine 3′,5′-monophosphate (cAMP), and eNOS levels in the perfused PCCSM. Furthermore, the treatment of ROE and EA markedly increased the UDE- and ROL-induced relaxation of the PCCSM. In conclusion, ROE and EA induced PCCSM relaxation by activating the nitric oxide (NO)-cGMp and cAMp signaling pathways and may have a synergistic action to improve erectile function.

Enzymatic preparation of Crassostrea oyster peptides and their promoting effect on male hormone production

ETHNOPHARMACOLOGICAL RELEVANCE

Crassostrea gigas Thunberg and other oysters have been traditionally used in China as folk remedies to invigorate the kidney and as natural aphrodisiacs to combat male impotence.

AIM OF THE STUDY

Erectile dysfunction (ED) has become a major health problem for the global ageing population. The aim of this study is therefore to evaluate the effect of peptide-rich preparations from C. gigas oysters on ED and related conditions as increasing evidence suggests that peptides are important bioactive components of marine remedies and seafood.

MATERIALS AND METHODS

Crassostrea oyster peptide (COP) preparations COP1, COP2 and COP3 were obtained from C. gigas oysters by trypsin, papain or sequential trypsin-papain digestion, respectively. The contents of testosterone, cyclic adenosine monophosphate (cAMP) and nitric oxide (NO) and the activity of nitric oxide synthase (NOS) in mice and/or cells were measured by enzyme-linked immunosorbent assays. Real-time PCR was used to assess the expression of genes associated with sex hormone secretion pathways. The model animal Caenorhabditis elegans was also used to analyze the gene expression of a conserved steroidogenic enzyme. In silico analysis of constituent peptides was performed using bioinformatic tools based on public databases.

RESULTS

The peptide-rich preparation COP3, in which >95% peptides were <3000 Da, was found to increase the contents of male mouse serum testosterone and cAMP, both of which are known to play important roles in erectile function, and to increase the activity of mouse penile NOS, which is closely associated with ED. Further investigation using mouse Leydig-derived TM3 cells demonstrates that COP3 was able to stimulate the production of testosterone as well as NO, a pivotal mediator of penile erection. Real-time PCR analysis reveals that COP3 up-regulated the expression of Areg and Acvr2b, the genes known to promote sex hormone secretion, but not Fst, a gene involved in suppressing follicle-stimulating hormone release. Furthermore, COP3 was also shown to up-regulate the expression of let-767, a well-conserved C. elegans gene encoding a protein homologous to human 17-β-hydroxysteroid dehydrogenases. Preliminary bioinformatic analysis using the peptide sequences in COP3 cryptome identified 19 prospective motifs, each of which occurred in more than 10 peptides.

CONCLUSIONS

In this paper, Crassostrea oyster peptides were prepared by enzymatic hydrolysis and were found for the first time to increase ED-associated biochemical as well as molecular biology parameters. These results may help to explain the ethnopharmacological use of oysters and provide an important insight into the potentials of oyster peptides in overcoming ED-related health issues.

Research of stroke combined hyperlipidemia-induced erectile dysfunction in rat model

Objective: The study was aimed to evaluate the influences of erectile dysfunction (ED) in a rat model of stroke combined with hyperlipidemia (HLP). Methods: Male Sprague-Dawley rats were divided into control and hyperlipidemia (HLP) groups. HLP model was constructed by feeding with high-fat and cholesterol diets. Serum levels of total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), triglyceride (TG), and non-HDL were identified to check the model was success. Stroke model was established by FeCl₃. ICP/MAP value was detected to evaluate the erectile function of rats. Serum level of lipoproteins and the expressions of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) were detected by ELISA. Hematoxylin-eosin (HE) staining of corpus cavernosum and measurement of penis length were utilized to assessment erectile function. Western blot was used. Results: TC, TG, LDL, and non-HDL-C in serum were up-regulated, while HDL level was attenuated. After treatment, the serum lipid level recovered. From the ICP/MAP values, the erectile function of both two treatment groups recovered. The expression of PDE5A was up-regulated, while the levels of eNOS and cGMP were suppressed after surgery. The length of penis was decreased, and corpus cavernosum was damaged following HLP and stroke. However, the erectile function was recovered after treatment. Conclusion: Stroke combined HLP caused ED through NO-cGMP-PDE5 pathway.

Shugan Yiyang capsule for the treatment of erectile dysfunction: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Erectile dysfunction (ED) is a common disease. It affects the quality of life of both husband and wife and becomes an independent risk factor for cardiovascular events. In China, Shugan Yiyang (SGYY) capsule has been increasingly reported in clinical trials for the treatment of ED and reported inconsistent findings. Therefore, it is necessary to conduct a systematic review to evaluate the efficacy and safety of this drug for the treatment of ED.

METHODS

Chinese and English literature of SGYY capsule for ED published before August 31, 2019 will be comprehensive searched in PubMed, Cochrane Library, EMBASE, WANFANG, China National Knowledge Infrastructure, VIP Chinese Science and Technology Journal Database, Chinese biomedical document service system, and Clinicaltrials.gov. All randomized controlled trials that meet the eligibility criteria will be included and other studies will be excluded. Two investigators will conduct literature screening, data extraction and assess risk of bias alone, and the third investigator will handle disagreements. Two outcomes involving the international index of erectile function 5 score and adverse events will be evaluated. RevMan 5.3 and Stata 14.0 will be used to conduct this systematic review. The preferred reporting items for systematic reviews and meta-analysis protocols (PRISMA-P) statement is followed in this protocol and the the PRISMA statement will be followed in the completed systematic review.

CONCLUSION AND DISSEMINATION

The efficacy and safety of SGYY capsule for ED will be evaluated. We will publish the results of this systematic review in peer-reviewed journals to provide new evidence to clinicians.Registration information: PROSPERO CRD42019140903.

Traditional Chinese medical therapy for erectile dysfunction

Traditional Chinese medicine (TCM), including acupuncture and Chinese herbs, is used as an alternative therapy to increase the curative effect for erectile dysfunction (ED). A large number of studies have been conducted to investigate the effect and mechanism of TCM for treating ED. The therapeutic effect of acupuncture on ED is still controversial at present. However, some Chinese herbs exhibited satisfying outcomes and they might improve erectile function by activating nitric oxide synthase (NOS)-cyclic guanosine monophosphate (cGMP) pathway, increasing cyclic adenosine monophosphate (cAMP) expression, elevating testosterone level, reducing intracellular Ca²⁺ concentration, down-regulating transforming growth factor β1 (TGFβ1)/Smad2 signaling pathway, or ameliorating the oxidative stress.

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.

Shengjing Capsule Improves Erectile Function Through Regulation of Nitric Oxide-induced Relaxation in Corpus Cavernosum Smooth Muscle in a Castrated Rat Model

OBJECTIVE

To evaluate the effects of Shengjing capsule on erectile function in a castrated rat model, and further to investigate the underlying molecular mechanism.

MATERIALS AND METHODS

Thirty male Sprague-Dawley rats were randomly divided into six groups (n = 5 per group), including sham group, castration group, testosterone replacement group, high-dose Shengjing capsule group, medium-dose Shengjing capsule group, and low-dose Shengjing capsule group. The weight of the body and androgen-sensitive organs, and the serum level of testosterone were assessed. Erectile function was evaluated using cavernous nerve electrical stimulation after treatment. Corpus cavernosum tissue was examined by Masson's trichrome staining, immunohistochemistry, quantitative reverse transcriptase-polymerase chain reaction, and Western blot.

RESULTS

Serum testosterone level, mean weights of body, and accessory sexual organs were not significantly different between Shengjing capsule treatment and the castration groups (P > .05 for all). Significant recovery of erectile function and the increased smooth muscle components were observed in the Shengjing capsule treatment group as compared with the castration group (P < .01 and P < .01, respectively). The gene and protein expression of 3 subtypes of nitric oxide synthase (NOS)-neuronal (nNOS), inducible (iNOS), and endothelial (eNOS) -in cavernous tissue in Shengjing capsule-treated rats were significantly higher than in the castration group (P < .05 for all). Phosphodiesterase type 5 messenger ribonucleic acid and protein expression in each group followed a trend similar to that of smooth muscle content.

CONCLUSION

These results show that Shengjing capsule improves the erectile function by protecting the smooth muscle content and enhancing NOS activity in penile tissues of castrated male rats.

Penile erectile dysfunction after brachial plexus root avulsion injury in rats

Our previous studies have demonstrated that some male patients suffering from brachial plexus injury, particularly brachial plexus root avulsion, show erectile dysfunction to varying degrees. However, the underlying mechanism remains poorly understood. In this study, we evaluated the erectile function after establishing brachial plexus root avulsion models with or without spinal cord injury in rats. After these models were established, we administered apomorphine (via a subcutaneous injection in the neck) to observe changes in erectile function. Rats subjected to simple brachial plexus root avulsion or those subjected to brachial plexus root avulsion combined with spinal cord injury had significantly fewer erections than those subjected to the sham operation. Expression of neuronal nitric oxide synthase did not change in brachial plexus root avulsion rats. However, neuronal nitric oxide synthase expression was significantly decreased in brachial plexus root avulsion + spinal cord injury rats. These findings suggest that a decrease in neuronal nitric oxide synthase expression in the penis may play a role in erectile dysfunction caused by the combination of brachial plexus root avulsion and spinal cord injury.

A novel method to establish a rat ED model using internal iliac artery ligation combined with hyperlipidemia

Objective

To investigate a novel method, namely using bilateral internal iliac artery ligation combined with a high-fat diet (BCH), for establishing a rat model of erectile dysfunction (ED) that, compared to classical approaches, more closely mimics the chronic pathophysiology of human ED after acute ischemic insult.

Materials and Methods

Forty 4-month-old male Sprague Dawley rats were randomly placed into five groups (n = 8 per group): normal control (NC), bilateral internal iliac artery ligation (BIIAL), high-fat diet (HFD), BCH, and mock surgery (MS). All rats were induced for 12 weeks. Copulatory behavior, intracavernosal pressure (ICP), ICP/mean arterial pressure, hematoxylin-eosin staining, Masson's trichrome staining, serum lipid levels, and endothelial and neuronal nitric oxide synthase immunohistochemical staining of the cavernous smooth muscle and endothelium were assessed. Data were analyzed by SAS 8.0 for Windows.

Results

Serum total cholesterol and triglyceride levels were significantly higher in the HFD and BCH groups than the NC and MS groups. High density lipoprotein levels were significantly lower in the HFD and BCH groups than the NC and MS groups. The ICP values and mount and intromission numbers were significantly lower in the BIIAL, HFD, and BCH groups than in the NC and MS groups. ICP was significantly lower in the BCH group than in the BIIAL and HFD groups. Cavernous smooth muscle and endothelial damage increased in the HFD and BCH groups. Cavernous smooth muscle to collagen ratio, nNOS and eNOS staining decreased significantly in the BIIAL, HFD, and BCH groups compared to the NC and MS groups.

Conclusions

The novel BCH model mimics the chronic pathophysiology of ED in humans and avoids the drawbacks of traditional ED models.

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.