Efficacy and safety of PDE5 inhibitors in the treatment of diabetes mellitus erectile dysfunction: Protocol for a systematic review

The potential therapeutic effect of phosphodiesterase 5 inhibitors in the acute ischemic stroke (AIS)

Acute ischemic stroke (AIS) is a focal neurological disorder that accounts for 85% of all stroke types, due to occlusion of cerebral arteries by thrombosis and emboli. AIS is also developed due to cerebral hemodynamic abnormality. AIS is associated with the development of neuroinflammation which increases the severity of AIS. Phosphodiesterase enzyme (PDEs) inhibitors have neuro-restorative and neuroprotective effects against the development of AIS through modulation of the cerebral cyclic adenosine monophosphate (cAMP)/cyclic guanosine monophosphate (cGMP)/nitric oxide (NO) pathway. PDE5 inhibitors through mitigation of neuroinflammation may decrease the risk of long-term AIS-induced complications. PDE5 inhibitors may affect the hemodynamic properties and coagulation pathway which are associated with thrombotic complications in AIS. PDE5 inhibitors reduce activation of the pro-coagulant pathway and improve the microcirculatory level in patients with hemodynamic disturbances in AIS. PDE5 inhibitors mainly tadalafil and sildenafil improve clinical outcomes in AIS patients through the regulation of cerebral perfusion and cerebral blood flow (CBF). PDE5 inhibitors reduced thrombomodulin, P-selectin, and tissue plasminogen activator. Herein, PDE5 inhibitors may reduce activation of the pro-coagulant pathway and improve the microcirculatory level in patients with hemodynamic disturbances in AIS. In conclusion, PDE5 inhibitors may have potential roles in the management of AIS through modulation of CBF, cAMP/cGMP/NO pathway, neuroinflammation, and inflammatory signaling pathways. Preclinical and clinical studies are recommended in this regard.

A Review of Antidiabetic Medicinal Plants as a Novel Source of Phosphodiesterase Inhibitors: Future Perspective of New Challenges Against Diabetes Mellitus

Intracellular glucose concentration plays a crucial role in initiating the molecular secretory process of pancreatic β-cells through multiple messengers and signaling pathways. Cyclic nucleotides are key physiological regulators that modulate pathway interactions in β -cells. An increase of cyclic nucleotides is controled by hydrolysed phosphodiesterases (PDEs), which degrades cyclic nucleotides into inactive metabolites. Despite the undeniable therapeutic potential of PDE inhibitors, they are associated with several side effects. The treatment strategy for diabetes based on PDE inhibitors has been proposed for a long time. Hence, the world of natural antidiabetic medicinal plants represents an ideal source of phosphodiesterase inhibitors as a new strategy for developing novel agents to treat diabetes mellitus. This review highlights medicinal plants traditionally used in the treatment of diabetes mellitus that have been proven to have inhibitory effects on PDE activity. The contents of this review were sourced from electronic databases, including Science Direct, PubMed, Springer Link, Web of Science, Scopus, Wiley Online, Scifinder and Google Scholar. These databases were consulted to collect information without any limitation date. After comprehensive literature screening, this paper identified 27 medicinal plants that have been reported to exhibit anti-phosphodiesterase activities. The selection of these plants was based on their traditional uses in the treatment of diabetes mellitus. The review emphasizes the antiphosphodiesterase properties of 31 bioactive components derived from these plant extracts. Many phenolic compounds have been identified as PDE inhibitors: Brazilin, mesozygin, artonin I, chalcomaracin, norartocarpetin, moracin L, moracin M, moracin C, curcumin, gallic acid, caffeic acid, rutin, quercitrin, quercetin, catechin, kaempferol, chlorogenic acid, and ellagic acid. Moreover, smome lignans have reported as PDE inhibitors: (+)-Medioresinol di-O-β-d-glucopyranoside, (+)- Pinoresinol di-O-β-d-glucopyranoside, (+)-Pinoresinol-4-O-β-d-glucopyranosyl (1→6)-β-dglucopyranoside, Liriodendrin, (+)-Pinoresinol 4'-O-β-d-glucopyranoside, and forsythin. This review provides a promising starting point of medicinal plants, which could be further studied for the development of natural phosphodiesterase inhibitors to treat diabetes mellitus. Therefore, it is important to consider clinical studies for the identification of new targets for the treatment of diabetes.

Catechin from Anonna senegalensis is a Potential Inhibitor of Erectile Dysfunction: Implication for Its Use in Male Sexual Enhancement

Erectile dysfunction (ED) is a major challenge for men. The drugs for its treatment are associated with side effects. Hence, in phytomedicinal research, where Anonna senegalensis (A. senegalensis) is a candidate with abundant phytochemicals possessing various pharmacological properties, but the sex-enhancing phytochemical is elusive in the literature. This study aimed to understand the molecular interaction of its potent molecule mediating male sexual enhancement. A library of 69 compounds from A. senegalensis was docked against the ED-targeted proteins. Sildenafil citrate was used as the reference standard. Thereafter, the lead compound was screened for drug-likeness by applying the Lipinski rule of 5 (RO5), pharmacokinetic properties, and bioactivity using SwissADME and Molinspiration web servers, respectively. The results show catechin as the lead phytochemical compound with a stronger binding affinity for most of the proteins of ED. Also, catechin demonstrates good compliance with the RO5, great pharmacokinetic profiles, and could be said to be a polypharmacological molecule with good bioactivity scores. The research findings unravel the potential of catechin (a phytochemical belonging to the flavonoids class) from A. senegalensis leaf as a potential male sexual enhancement molecule via its high binding affinity for most erectile dysfunction-targeted proteins. They may require further toxicity and therapeutic evaluations in vivo.

Ganoderma lucidum polysaccharide ameliorated diabetes mellitus-induced erectile dysfunction in rats by regulating fibrosis and the NOS/ERK/JNK pathway

Background

Diabetes mellitus-induced erectile dysfunction (DMED) is a frequent complication of diabetes mellitus (DM), with limited therapy at present. This study aimed to explore the role and mechanism of Ganoderma lucidum polysaccharide (GLP) on DMED.

Methods

DMED was induced in the experimental rats [male 12-week-old Sprague-Dawley (SD) rats] by treatment with streptozotocin (60 mg/kg) and apomorphine (APO). Next, rats in the GLP low dose (GLP-L)/GLP high dose (GLP-H) groups were treated with GLP (100 or 400 mg/kg/d, respectively) for 8 weeks. Subsequently, erectile function was assessed by APO and electrostimulation of the cavernous nerve (CN). Serum or penile testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and cyclic guanosine monophosphate (cGMP) contents were evaluated by enzyme-linked immunosorbent assay (ELISA). The levels of oxidative stress indicators in the corpus cavernosum (CC) were measured by corresponding kits, and histological changes in the CC were observed by hematoxylin-eosin (HE) and Masson staining. Additionally, the apoptosis index, caspase-3, caspase-9, and eNOS expression, and mitochondrial membrane potential (MMP) were also detected. Furthermore, quantitative polymerase chain reaction (qPCR) and western blot assays were conducted to determine the NOS, TGF-β1 mRNA expression, ERK1/2, eNOS, JNK phosphorylation, and arginase II protein expression.

Results

The erectile function test revealed that erectile dysfunction (ED) was alleviated in the DMED rats following treatment with GLP. Moreover, GLP upregulated the T and cGMP content, improved the oxidative stress and histological injuries of CC, and also inhibited the apoptosis and MMP loss of penile tissues in DMED rats. Furthermore, GLP treatment enhanced the mRNA expression of NOS and TGF-β1 and suppressed the phosphorylation of ERK1/2, eNOS, and JNK, as well as the protein expression of arginase II in DMED rats.

Conclusions

GLP ameliorated DMED by repairing the CC pathological damage and upregulating NOS expression and ERK/JNK phosphorylation, indicating that GLP may be a candidate drug for DMED therapy.

Erectile dysfunction and diabetes: A melting pot of circumstances and treatments

Diabetes mellitus (DM), a chronic metabolic disease characterised by elevated levels of blood glucose, is among the most common chronic diseases. The incidence and prevalence of DM have been increasing over the years. The complications of DM represent a serious health problem. The long-term complications include macroangiopathy, microangiopathy and neuropathy as well as sexual dysfunction (SD) in both men and women. Erectile dysfunction (ED) has been considered the most important SD in men with DM. The prevalence of ED is approximately 3.5-fold higher in men with DM than in those without DM. Common risk factors for the development of DM and its complications include sedentary lifestyle, overweight/obesity and increased caloric consumption. Although lifestyle changes may help improve sexual function, specific treatments are often needed. This study aims to review the definition and prevalence of ED in DM, the impact of DM complications and DM treatment on ED and, finally, the current and emerging therapies for ED in patients with DM.

Effect of leech-centipede medicine on improving erectile function in diabetes-induced erectile dysfunction rats via PDE5 signalling pathway-related molecules

CONTEXT

The leech and centipede granules have good curative effects on many diabetic vascular diseases, including diabetes-induced erectile dysfunction (DIED).

OBJECTIVE

To explore the effect of leech and centipede on erectile function in rats with diabetes-induced erectile dysfunction and its possible mechanism.

MATERIALS AND METHODS

Thirty male Sprague-Dawley DIED rats were randomly divided into the model group (Group M), low-dose group (Group DD), high-dose group (Group DG) and tadalafil group (Group T) (n = 6); diabetic rats were induced by streptozotocin. Apomorphine was used to induce diabetic erectile dysfunction. The 'leech-centipede' granules (0.15 and 0.6 g/kg) were intragastrically administered in the DD and DG groups for 8 weeks. Blood glucose, serum insulin, testosterone, cGMP levels and protein expression changes were measured in each group.

RESULTS

After 8 weeks, the erectile function of rats in the DG group significantly improved (1.26 ± 0.73). Penis tissue cGMP levels were higher in the DG group (1.48 ± 0.11) than in the M group (0.58 ± 0.15). Protein and mRNA expression levels of NOS were significantly higher (0.77 ± 0.05; 0.61 ± 0.02) but those of PDE5 (0.43 ± 0.05; 0.61 ± 0.03) were lower in the DG group than in the M group (0.37 ± 0.06; 0.51 ± 0.01; 0.78 ± 0.06; 0.81 ± 0.04).

CONCLUSION

The leech-centipede can improve erectile dysfunction in DIED rats by regulating the expression of cGMP, NOS, and PDE5-related molecules in the PDE5 pathway. This study provides a potential mechanism for the treatment of DIED with leech-centipede.

Efficacy and safety of low-intensity shockwave therapy plus tadalafil 5 mg once daily in men with type 2 diabetes mellitus and erectile dysfunction: a matched-pair comparison study

Low-intensity extracorporeal shockwave therapy (LiESWT) represents a promising treatment for patients with erectile dysfunction (ED). We investigated the efficacy of LiESWT combined with tadalafil 5 mg once daily in men with type 2 diabetes mellitus (T2DM) and ED and compared LiESWT protocols administering different number of shockwaves. We performed a retrospective matched-pair comparison using data from a prospectively maintained database. Seventy-eight patients who received tadalafil 5 mg once daily for 12 weeks + LiESWT performed with an electrohydraulic source for 3 weeks (Group A) were matched 1:1 to patients who received tadalafil 5 mg once daily alone for 12 weeks (Group B). A subgroup analysis was performed according to the number of shockwaves delivered during each session (1500, 1800, and 2400 in subgroup A1, A2, and A3, respectively). The mean International Index of Erectile Function-5 (IIEF-5) score variations with respect to baseline recorded at 4, 12, and 24 weeks after the end of the treatment were investigated as treatment outcomes. The mean IIEF-5 scores significantly improved in all groups and subgroups at 4-week follow-up without intergroup differences. At 12- and 24-week follow-up, the mean IIEF-5 improvement was significantly higher among patients in the A3 subgroup (+5.0 ± 2.1 [P < 0.001] and +4.7 ± 2.3 [P < 0.001], respectively). The combined approach with tadalafil 5 mg once daily and LiESWT with a protocol involving 2400 shockwaves provides significant advantages in terms of IIEF-5 improvement and durability compared to tadalafil 5 mg once daily alone in patients with T2DM and ED.

Effect of physical exercise combined with shockwave therapy on erectile dysfunction in diabetic patients

Introduction

The aim of the study was to evaluate whether physical exercise (PE) in addition to extracorporeal shockwave therapy (ESWT) is more effective in improving erectile function as compared to ESWT and PE alone in diabetic patients with erectile dysfunction (ED).

Material and methods

Forty-five patients with type 2 diabetes mellitus (DM) and ED were divided into three equal groups: group 1 (ESWT group) received treatment with ESWT twice weekly for 6 weeks, comprising 3000 shockwaves at an energy density of 0.25 mJ/mm2 and an emission frequency of 6 Hz; group 2 (PE group) received treatment with physical exercise three times per week for 12 weeks; and group 3 (combined group) was treated using physical exercise in the form of the program followed by the PE group, plus ESWT in the form of the same parameter and protocol as that of the ESWT group. Treatment outcomes were measured by International Index of Erectile Function-5 (IIEF-5) score variations recorded at 4 and 12 weeks after the end of treatment with respect to the baseline.

Results

The mean IIEF-5 scores significantly improved in all groups at the 4-week follow-up without intergroup differences. At the 12-week follow-up, the mean IIEF-5 improvement and durability were significantly higher among patients in combined groups.

Conclusions

The combined approach of ESWT and PE provides significant advantages in erectile dysfunction improvement and durability as compared to ESWT or PE alone in diabetic patients with ED.