Sildenafil improves hemodynamic changes caused by acute pulmonary embolism by inhibiting Rho kinase activity.

OBJECTIVE: This study examined the effects of sildenafil on acute pulmonary embolism (APE) using a rat model. METHODS: Sprague-Dawley rats were randomly divided into the sham, pulmonary thromboembolism (PTE), and sildenafil groups. The sham and PTE groups received normal saline once daily via gavage for 14 consecutive days, whereas the sildenafil group received sildenafil (0.5 mg/kg/day) once daily via gavage for 14 consecutive days. Autologous emboli were prepared from blood samples collected from the left femoral artery of rats in each group on day 13, and autologous emboli were injected into the jugular vein cannula of rats in the PTE and sildenafil groups on day 14. Sham-treated rats received the same volume of saline. Right systolic ventricular pressure (RVSP) and mean pulmonary arterial pressure (MPAP) were used to assess pulmonary embolism, and western blotting and enzyme-linked immunosorbent assay were used to detect relevant markers. RESULTS: The Rho kinase signaling pathway was significantly activated in rats with APE, and sildenafil significantly inhibited this activation. CONCLUSIONS: Sildenafil protected against APE through inhibiting Rho kinase activity, thereby reducing pulmonary vasoconstriction and decreasing elevated pulmonary arterial pressure. These findings might provide new ideas for the clinical treatment of acute pulmonary thromboembolism.

A novel strategy to induce penile erection during penile doppler ultrasound: oral sildenafil administration plus alprostadil injection.

OBJECTIVES: To evaluate the efficacy of a novel approach to achieve the optimal penile erection during the penile doppler ultrasound (PDU) examination, which was oral sildenafil combined alprostadil injection. MATERIALS AND METHODS: A total of 60 ED patients were enrolled in our prospective study, and they were randomly assigned to two group with different PDU order. The approaches assisted the PDU included two models, mode A meaning injection of 15 µg alprostadil and model B meaning oral sildenafil 100 mg plus injection of 15 µg alprostadil. The PDU parameters were measured continuously before induced erection, and 5, 10, 15, 20, 25 min. RESULTS: Each group included 30 ED patients with similar clinical characteristics. After pooling the results together, the PSV, EDV, and RI were all improved significantly, when adding the oral sildenafil administration to assist PDU. Also, the clinical response of oral sildenafil administration plus alprostadil injection was better than that in alprostadil injection alone (p = 0.016). The arterial ED were decreased from 31.67% to 15.00% with the P value 0.031, and the mixed ED was also decreased statistically (23.33% vs 8.33%, p = 0.024). CONCLUSION: Oral sildenafil administration plus alprostadil injection could improve the diagnostic accuracy of PDU.

Association of sildenafil use with age-related macular degeneration: a retrospective cohort study.

OBJECTIVE: Despite significant advances in clinical care and understanding of the underlying pathophysiology, age-related macular degeneration (AMD)-a major cause of global blindness-lacks effective treatment to prevent the irreversible degeneration of photoreceptors leading to central vision loss. Limited studies suggest phosphodiesterase type 5 (PDE5) inhibitors, such as sildenafil, may prevent AMD by increasing retinal blood flow. This study explores the potential association between sildenafil use and AMD risk in men with erectile dysfunction using UK data. METHODS AND ANALYSIS: Using the UK's IQVIA Medical Research Data, the study analysed 31 575 men prescribed sildenafil for erectile dysfunction and no AMD history from 2007 to 2015, matched with a comparator group of 62 155 non-sildenafil users in a 1:2 ratio, over a median follow-up of approximately three years. RESULTS: The primary outcome was the incidence of AMD in the two groups. The study found no significant difference in AMD incidence between the sildenafil users and the non-users, with an adjusted hazard ratio (HR) of 0.99 (95% CI 0.84 to 1.16), after accounting for confounders such as age, ethnicity, Townsend deprivation quintile, body mass index category, and diagnosis of hypertension and type 2 diabetes. CONCLUSION: The study results indicated no significant association between sildenafil use and AMD prevention in UK men with erectile dysfunction, suggesting sildenafil's protective effect on AMD is likely insignificant.

Treatment preferences of patients with erectile dysfunction: a systematic review of randomized controlled trials.

INTRODUCTION: Patients' treatment preferences (PTP) depend on the complex interaction of numerous patient- and treatment-related factors; their assessment can guide therapy and promote compliance of patients with erectile dysfunction (ED). We aimed to systematically describe the literature evaluating the treatment preferences of patients with ED, published in the last 25 years. EVIDENCE ACQUISITION: A comprehensive bibliographic search of multiple databases was conducted in June, 2023. The literature search was limited to the articles published since 1998. Articles were deemed eligible if they described male patients with ED (P) undergoing treatment for this condition (I) compared with other treatments, placebo or sham therapy (C), and reported PTP (O). Only randomized controlled trials (RCTs) and post-hoc analyses of RCTs were selected (S). The data were presented in a narrative fashion. The risk of bias (RoB) was evaluated using the RoB 2 tool and the Mulhall-Montorsi model. EVIDENCE SYNTHESIS: A total 14 RCTs evaluating 6,841 patients and 4 post-hoc analyses of RCTs were included. All RCTs were considered to be at high RoB. No validated tool was used to investigate PTP. Sildenafil was the most frequently evaluated ED treatment (9 RCTs). Sildenafil was chosen over placebo by 78-100% of subjects and over ICI in 70% of patients due to its easier route of administration. No significant difference in patient preference was recorded between Sildenafil tablets and orodispersible (53% vs. 47%, P>0.05). Tadalafil was preferred over Sildenafil by 66-73% of patients (P<0.05), mainly because it allowed an erection long after taking the drug (55-67%). Tadalafil as-needed was chosen over Tadalafil 3 times/week by 57-59% of the patients (P<0.05). CONCLUSIONS: The available RCTs support the preference of ED patients for Sildenafil over ICI, Tadalafil over Sildenafil, and Tadalafil as-needed over Tadalafil 3 times/week. However, these findings should be considered at high RoB.

Sildenafil as a Candidate Drug for Alzheimer's Disease: Real-World Patient Data Observation and Mechanistic Observations from Patient-Induced Pluripotent Stem Cell-Derived Neurons.

Background: Alzheimer's disease (AD) is a chronic neurodegenerative disease needing effective therapeutics urgently. Sildenafil, one of the approved phosphodiesterase-5 inhibitors, has been implicated as having potential effect in AD. Objective: To investigate the potential therapeutic benefit of sildenafil on AD. Methods: We performed real-world patient data analysis using the MarketScan® Medicare Supplemental and the Clinformatics® databases. We conducted propensity score-stratified analyses after adjusting confounding factors (i.e., sex, age, race, and comorbidities). We used both familial and sporadic AD patient induced pluripotent stem cells (iPSC) derived neurons to evaluate the sildenafil's mechanism-of-action. Results: We showed that sildenafil usage is associated with reduced likelihood of AD across four new drug compactor cohorts, including bumetanide, furosemide, spironolactone, and nifedipine. For instance, sildenafil usage is associated with a 54% reduced incidence of AD in MarketScan® (hazard ratio [HR] = 0.46, 95% CI 0.32- 0.66) and a 30% reduced prevalence of AD in Clinformatics® (HR = 0.70, 95% CI 0.49- 1.00) compared to spironolactone. We found that sildenafil treatment reduced tau hyperphosphorylation (pTau181 and pTau205) in a dose-dependent manner in both familial and sporadic AD patient iPSC-derived neurons. RNA-sequencing data analysis of sildenafil-treated AD patient iPSC-derived neurons reveals that sildenafil specifically target AD related genes and pathobiological pathways, mechanistically supporting the beneficial effect of sildenafil in AD. Conclusions: These real-world patient data validation and mechanistic observations from patient iPSC-derived neurons further suggested that sildenafil is a potential repurposable drug for AD. Yet, randomized clinical trials are warranted to validate the causal treatment effects of sildenafil in AD.

Formulation and evaluation of inhaled Sildenafil-loaded PLGA microparticles for treatment of pulmonary arterial hypertension (PAH): A novel high drug loaded formulation and scalable process via hot melt extrusion technology (Part â ).

In recent years, several techniques were employed to develop a local sustained pulmonary delivery of sildenafil citrate (SC) as an alternative for the intravenous and oral treatment of pulmonary arterial hypertension (PAH). Most of these methods, however, need to be improved due to limitations of scalability, low yield production, low drug loading, and stability issues. In this study, we report the use of hot-melt extrusion (HME) as a scalable process for making Poly (lactic-co-glycolic acid) (PLGA) microparticles with high SC load. The prepared particles were tested in vitro for local drug delivery to the lungs by inhalation. Sodium bicarbonate was included as a porogen in the formulation to make the particles more brittle and to impart favorable aerodynamic properties. Six formulations were prepared with different formulation compositions. Laser diffraction analysis was used to estimate the geometric particle size distribution of the microparticles. In-vitro aerodynamic performance was evaluated by the next-generation cascade impactor (NGI). It was reported in terms of an emitted dose (ED), an emitted fraction (EF%), a respirable fraction (RF%), a fine particle fraction (FPF%), a mass median aerodynamic diameter (MMAD), and geometric standard deviation (GSD). The formulations have also been characterized for surface morphology, entrapment efficiency, drug load, and in-vitro drug release. The results demonstrated that PLGA microparticles have a mean geometric particle size between 6 and 14 µm, entrapment efficiency of 77 to 89 %, and SC load between 17 and 33 % w/w. Fifteen percent of entrapped sildenafil was released over 24 h from the PLGA microparticles, and seventy percent over 7 days. The aerodynamic properties included fine particle fraction ranging between 19 and 33 % and an average mass median aerodynamic diameter of 6-13 µm.

Bioavailability enhancement of sildenafil citrate via hydrogel-forming microneedle strategy in combination with cyclodextrin complexation.

Sildenafil citrate (SIL) as a first-line treatment for erectile dysfunction is currently reported to have poor solubility and bioavailability. Moreover, SIL undergoes first-pass metabolism when taken orally and its injection can lead to discomfort. In this study, we introduce a novel transdermal delivery system that integrates hydrogel-forming microneedles with the inclusion complex tablet reservoir. The hydrogel-forming microneedle was prepared from a mixture of polymers and crosslinkers through a crosslinking process. Importantly, the formulations showed high swelling capacity (>400 %) and exhibited adequate mechanical and penetration properties (needle height reduction < 10 %), penetrating up to five layers of Parafilm® M (assessed to reach the dermis layer). Furthermore, to improve the solubility of SIL in the reservoir, the SIL was pre-complexed with ß-cyclodextrin. Molecular docking analysis showed that SIL was successfully encapsulated into the ß-cyclodextrin cavity and was the most suitable conformation compared to other CD derivatives. Moreover, to maximize SIL delivery, sodium starch glycolate was also added to the reservoir formulation. As a proof of concept, in vivo studies demonstrated the effectiveness of this concept, resulting in a significant increase in AUC (area under the curve) compared to that obtained after administration of pure SIL oral suspension, inclusion complex, and Viagra® with relative bioavailability > 100 %. Therefore, the approach developed in this study could potentially increase the efficacy of SIL in treating erectile dysfunction by being non-invasive, safe, avoiding first-pass metabolism, and increasing drug bioavailability.

A phase 1 study of regorafenib and sildenafil in adults with advanced solid tumors.

The purpose of this study is to establish the recommended phase 2 dose for regorafenib in combination with sildenafil for patients with advanced solid tumors. Secondary outcomes included identification of antitumor effects of regorafenib and sildenafil, toxicity of the combination, determination of PDE5 expression in tumor samples, and the impact of sildenafil on the pharmacokinetics of regorafenib. This study was a phase 1, open-label single-arm dose-escalation trial using a 3 + 3 design. Additional patients were enrolled at the maximum tolerated dose (MTD) until a total of 12 patients were treated at the MTD. A total of 29 patients were treated in this study. The median duration of treatment was 8 weeks. The recommended phase 2 doses determined in this study are regorafenib 160 mg daily with sildenafil 100 mg daily. The most common toxicities included palmar-plantar erythrodysesthesia syndrome (20 patients, 69%) and hypophosphatemia (18 patients, 62%). Two patients (7%) experienced grade 4 lipase increase. Objective responses were not observed; however, 14 patients (48%) had a period of stable disease during the study. Stable disease for up to 12 months was observed in patients with ovarian cancer as well as up to 20 months for a patient with cervical cancer. The combination of regorafenib and sildenafil at the recommended phase 2 dose is safe and generally well tolerated. Disease control in patients with gynecologic malignancies was especially encouraging. Further evaluation of the combination of regorafenib and sildenafil in gynecologic malignancies is warranted. Clinical Trial Registration Number: NCT02466802.

PKC Inhibition Improves Human Penile Vascular Function and the NO/cGMP Pathway in Diabetic Erectile Dysfunction: The Role of NADPH Oxidase.

Erectile dysfunction (ED) is a frequent and difficult-to-treat condition in diabetic men. Protein kinase C (PKC) is involved in diabetes-related vascular and cavernosal alterations. We aimed to evaluate the role of PKC in endothelial dysfunction and NO/cGMP impairment associated with diabetic ED in the human corpus cavernosum (CC) and penile resistance arteries (PRAs) and the potential mechanisms involved. Functional responses were determined in the CC and PRAs in patients with non-diabetic ED and diabetic ED undergoing penile prosthesis insertion. PKC activator 12,13-phorbol-dibutyrate (PDBu) impaired endothelial relaxations and cGMP generation in response to acetylcholine in the CC from non-diabetic ED. PDBu also impaired responses to a PDE5 inhibitor, sildenafil, in non-diabetic ED patients. Conversely, a PKC inhibitor, GF109203X, improved endothelial, neurogenic, and PDE5-inhibitor-induced relaxations and cGMP generation only in the CC in diabetic ED patients. Endothelial and PDE5-inhibitor-induced vasodilations of PRAs were potentiated only in diabetes. Improvements in endothelial function in diabetes were also achieved with a specific inhibitor of the PKCß2 isoform or an NADPH-oxidase inhibitor, apocynin, which prevented PDBu-induced impairment in non-diabetic patients. PKC inhibition counteracted NO/cGMP impairment and endothelial dysfunction in diabetes-related ED, potentially improving response to PDE5 inhibition.

Sildenafil delays bone remodeling of fractured femora in aged mice by reducing the number and activity of osteoclasts within the callus tissue.

The elderly exhibit a reduced healing capacity after fracture, which is often associated with delayed or failed bone healing. This is due to a plethora of factors, such as an impaired bone vascular system and delayed angiogenesis. The phosphodiesterase-5 (PDE-5) inhibitor sildenafil exerts pro-angiogenic and pro-osteogenic effects. Hence, we herein investigated in aged mice whether sildenafil can improve fracture healing. For this purpose, 40 aged CD-1 mice (16-18 months) were daily treated with 5 mg/kg body weight sildenafil (n = 20) or vehicle (control, n = 20) by oral gavage. The callus tissue of their femora was analyzed at 2 and 5 weeks after fracture by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry as well as Western blotting. These analyses revealed a significantly increased bone volume and higher ratio of callus to femoral bone diameter in sildenafil-treated mice at 5 weeks after fracture when compared to controls. This was associated with a reduced number and activity of osteoclasts at 2 weeks after fracture, most likely caused by an increased expression of osteoprotegerin (OPG). Taken together, these findings indicate that sildenafil does not improve fracture healing in the elderly but delays the process of bone remodeling most likely by reducing the number and activity of osteoclasts within the callus tissue.

Correlates of Plasma NT-proBNP/Cyclic GMP Ratio in Heart Failure With Preserved Ejection Fraction: An Analysis of the RELAX Trial.

BACKGROUND: Phosphodiesterases degrade cyclic GMP (cGMP), the second messenger that mediates the cardioprotective effects of natriuretic peptides. High natriuretic peptide/cGMP ratio may reflect, in part, phosphodiesterase activity. Correlates of natriuretic peptide/cGMP in patients with heart failure with preserved ejection fraction are not well understood. Among patients with heart failure with preserved ejection fraction in the RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure With Preserved Ejection Fraction) trial, we examined (1) cross-sectional correlates of circulating NT-proBNP (N-terminal pro-B-type natriuretic peptide)/cGMP ratio, (2) whether selective phosphodiesterase-5 inhibition by sildenafil changed the ratio, and (3) whether the effect of sildenafil on 24-week outcomes varied by baseline ratio. METHODS AND RESULTS: In 212 subjects, NT-proBNP/cGMP ratio was calculated at randomization and 24 weeks. Correlates of the ratio and its change were examined in multivariable proportional odds models. Whether baseline ratio modified the sildenafil effect on outcomes was examined by interaction terms. Higher NT-proBNP/cGMP ratio was associated with greater left ventricular mass and troponin, the presence of atrial fibrillation, and lower estimated glomerular filtration rate and peak oxygen consumption. Compared with placebo, sildenafil did not alter the ratio from baseline to 24 weeks (P=0.17). The effect of sildenafil on 24-week change in peak oxygen consumption, left ventricular mass, or clinical composite outcome was not modified by baseline NT-proBNP/cGMP ratio (P-interaction >0.30 for all). CONCLUSIONS: Among patients with heart failure with preserved ejection fraction, higher NT-proBNP/cGMP ratio associated with an adverse cardiorenal phenotype, which was not improved by selective phosphodiesterase-5 inhibition. Other phosphodiesterases may be greater contributors than phosphodiesterase-5 to the adverse phenotype associated with a high natriuretic peptide/cGMP ratio in HFpEF. REGISTRATION INFORMATION: clinicaltrials.gov. Identifier: NCT00763867.

Assessment of the treatment effectiveness of men with mild and medium degree of erectile dysfunction.

OBJECTIVE: . Aim: To assess the effectiveness of monotherapy and complex treatment of patients with erectile dysfunction depending on its severity. PATIENTS AND METHODS: Materials and Methods: Men with moderate and mild erectile dysfunction took part in the study, who, in turn, were divided into groups, depending on the treatment, with the evaluation of the results of the International Index of Erectile Function (MIEF-15), the state of cavernous hemodynamics and the function of the vascular endothelium before and after treatment. RESULTS: Results: In patients with an average degree of severity, who received complex treatment including a course of low-energy shock wave therapy, against the background of taking sildenafil and L-arginine, the best results were obtained in the quality of erection and increased cavernous blood flow, which positively affected satisfaction with sexual intercourse and overall satisfaction. It has also been proven that the function of the endothelium was improved in patients receiving L-arginine, due to which there was a probable decrease in endothelin-1. A probable improvement of erectile function was obtained in the group of patients with a mild degree who received L-arginine, and there was no statistical difference from the indicators in the group who received sildenafil, which was confirmed by the data of dopplerography. CONCLUSION: Conclusions: Patients with an average degree of erectile dysfunction require comprehensive treatment. The use of L-arginine can be an alternative to phosphodiesterase type 5 inhibitors in the treatment of mild erectile dysfunction.

Sildenafil, alone and in combination with imipramine or escitalopram, display antidepressant-like effects in an adrenocorticotropic hormone-induced (ACTH) rodent model of treatment-resistant depression.

BACKGROUND: Major depressive disorder (MDD) represents a challenge with high prevalence and limited effectiveness of existing treatments, particularly in cases of treatment-resistant depression (TRD). Innovative strategies and alternative drug targets are therefore necessary. Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is known to exert neuroplastic, anti-inflammatory, and antioxidant properties, and is a promising antidepressant drug candidate. AIM: To investigate whether sildenafil monotherapy or in combination with a known antidepressant, can elicit antidepressant-like effects in an adrenocorticotropic hormone (ACTH)-induced rodent model of TRD. METHODS: ACTH-naïve and ACTH-treated male Sprague-Dawley (SD) rats received various sub-acute drug treatments, followed by behavioural tests and biochemical analyses conversant with antidepressant actions. RESULTS: Sub-chronic ACTH treatment induced significant depressive-like behaviour in rats, evidenced by increased immobility during the forced swim test (FST). Sub-acute sildenafil (10 mg/kg) (SIL-10) (but not SIL-3), and combinations of imipramine (15 mg/kg) (IMI-15) and sildenafil (3 mg/kg) (SIL-3) or escitalopram (15 mg/kg) (ESC-15) and SIL-3, exhibited significant antidepressant-like effects. ACTH treatment significantly elevated hippocampal levels of brain-derived neurotrophic factor (BDNF), serotonin, norepinephrine, kynurenic acid (KYNUA), quinolinic acid (QUINA), and glutathione. The various mono- and combined treatments significantly reversed some of these changes, whereas IMI-15 + SIL-10 significantly increased glutathione disulfide levels. ESC-15 + SIL-3 significantly reduced plasma corticosterone levels. CONCLUSION: This study suggests that sildenafil shows promise as a treatment for TRD, either as a stand-alone therapy or in combination with a traditional antidepressant. The neurobiological mechanism underlying the antidepressant-like effects of the different sildenafil mono- and combination therapies reflects a multimodal action and cannot be explained in full by changes in the individually measured biomarker levels.

Design, synthesis, and biological evaluation of some new 2-phenyl-3,6-pyridazinedione derivatives as PDE-5 inhibitors.

Various 2-phenyl-3,6-pyridazinedione derivatives 4a-j, 5a-c, 6a,b, 7a-c, 8, 9, 10a-d, and 11a-d, were effectivelysynthesized, and tested for their potential inhibition of phosphodiesterase enzyme at 10 µM. Then fourteen compounds exhibiting the highest inhibition 4b, 4d, 4e, 4g, 4h, 4i, 5a, 6a,b, 7c, 10a,b, 11a, and 11d were selected for screening their PDE-5 inhibition, where compounds 4b,g,h, and 11a revealed promising PDE-5 inhibition having IC50 values = 25, 53, 22, and 42 nM, respectively in comparison with Sildenafil (IC50 = 16 nM). Additionally, these four most active compounds were safe to normal fibroblast cell line WI-38. Moreover, 4f, 4h, 4j, 10d, and 11d had almost the same anti-proliferative effect against the aortic cell line as Sildenafil. Furthermore, molecular docking illustrated that the binding of the target compounds with the key amino acids in the binding site of PDE-5 (PDB 2H42) was like to that of the cocrystallized ligand Sildenafil. Additionally, molecular dynamics simulation for the most active compound 4h revealed high stability of the 4h -PDE5 complex explaining its promising activity as a PDE-5 inhibitor. Therefore, the 2-phenyl-3,6-pyridazinedione scaffold can be considered an important core for designing more promising PDE-5 inhibitors.

Efficient administration of a combination of nifedipine and sildenafil citrate versus only nifedipine on clinical outcomes in women with threatened preterm labor: a systematic review and meta-analysis.

BACKGROUND: Preterm labor (PTL) is a common and serious pregnancy disorder that can cause long-term neurological issues in the infant. There are conflicting studies concerning whether sildenafil citrate (SC) reduces preterm labor complications. Therefore, the meta-analysis aimed to examine the clinical outcomes in women with threatened PTL who received nifedipine plus SC therapy versus only nifedipine. METHODS: For the original articles, six databases were searched using relevant keywords without restriction on time or language until January 13, 2024. The Cochrane risk-of-bias tool for randomized trials (RoB) and the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS) were both used to assess the risk of bias in randomized and non-randomized studies, and GRADE determined the quality of our evidence. Meta-analysis of all data was carried out using Review Manager (RevMan) version 5.1. RESULTS: Seven studies with mixed quality were included in the meta-analysis. The study found that combining nifedipine and SC resulted in more prolongation of pregnancy (MD = 6.99, 95% CI: 5.32, 8.65, p < 0.00001), a lower rate of delivery in the 1st to 3rd days after hospitalization (RR = 0.62, 95% CI: 0.50, 0.76, p < 0.00001), a higher birth weight (252.48 g vs. nifedipine alone, p = 0.02), and the risk ratio of admission to the neonatal intensive care unit (NICU) was significantly lower (RR = 0.62, 95% CI: 0.50, 0.76, p < 0.00001) compared to nifidepine alone. The evidence was high for prolongation of pregnancy, delivery rate 24-72 h after admission, and NICU admission, but low for newborn birth weight. CONCLUSIONS: Given the effectiveness of SC plus nifedipine in increased prolongation of pregnancy and birth weight, lower delivery in the 1st to 3rd days after hospitalization, and NICU admission, Gynecologists and obstetricians are suggested to consider this strategy for PTL management, although additional article rigor is required to improve the quality of the evidence.

Synergistic effect of sildenafil combined with controlled hypothermia to alleviate microglial activation after neonatal hypoxia-ischemia in rats.

BACKGROUND AND PURPOSE: The only validated treatment to prevent brain damage associated with hypoxia-ischemia (HI) encephalopathy of the newborn is controlled hypothermia with limited benefits. Additional putative neuroprotective drug candidates include sildenafil citrate, a phosphodiesterase-type 5 inhibitor. The main objective of this preclinical study is to assess its ability to reduce HI-induced neuroinflammation, in particular through its potential effect on microglial activation. METHODS: HI was induced in P10 Sprague-Dawley rats by unilateral carotid permanent artery occlusion and hypoxia (HI) and treated by either hypothermia (HT) alone, Sildenafil (Sild) alone or combined treatment (SildHT). Lesion size and glial activation were analyzed by immunohistochemistry, qRT-PCR, and proteomic analyses performed at P13. RESULTS: None of the treatments was associated with a significant early reduction in lesion size 72h after HI, despite significant changes in tissue loss distribution. Significant reductions in both Iba1 + (within the ipsilateral hemisphere) and GFAP + cells (within the ipsilateral hippocampus) were observed in SildHT group, but not in the other treatment groups. In microglia-sorted cells, pro-inflammatory markers, i.e. Il1b, Il6, Nos2, and CD86 were significantly downregulated in SildHT treatment group only. These changes were restricted to the ipsilateral hemisphere, were not evidenced in sorted astrocytes, and were not sex dependent. Proteomic analyses in sorted microglia refined the pro-inflammatory effect of HI and confirmed a biologically relevant impact of SildHT on specific molecular pathways including genes related to neutrophilic functions. CONCLUSIONS: Our findings suggest that Sildenafil combined with controlled hypothermia produces maximum effect in mitigating microglial activation induced by HI through complex proteomic regulation. The reduction of neuroinflammation induced by Sildenafil may represent an interesting therapeutic strategy for neonatal neuroprotection.

Sildenafil Use and Cigarette Smoking Associated with Intracerebral Hemorrhage: A Rare Case Report.

Background: Intracerebral hemorrhage (ICH) is a serious condition characterized by bleeding within the brain tissue. Although the use of sildenafil, a vasodilator agent for erectile dysfunction, has been associated with rare cases of ICH, the combination of sildenafil usage and smoking as risk factors for ICH has not yet been reported. This case report describes the occurrence of ICH in a patient with a history of both sildenafil usage and heavy smoking. Case Presentation: A 53-year-old male, with a history of smoking and regular sildenafil use, was brought to the emergency department due to loss of consciousness with right-side weakness, he initially experienced with nausea, vomiting and dizziness after taking sildenafil 100mg tablet once. The Glasgow Coma Score (GCS) was 10 with side hemiparesis. Non-contrast CT revealed left thalamic acute hemorrhage with ventricular extension. Furthermore, a head CT angiography ruled out any vascular anomalies after that the patient was admitted to the intensive care unit (ICU) for conservative management. After three days on clinical and neurological improvement, the patient was transferred to the inpatient ward for further management, monitoring and physiotherapy. On day 6, the patient was discharged and planned for flow up. Conclusion: This rare case highlights the need for further research and awareness regarding the potential risks associated with the combination of sildenafil and heavy smoking. Healthcare professionals should carefully evaluate the individual risk factors of patients, educate them about potential complications, and consider alternative treatments if necessary. Additionally, patients should be encouraged to quit smoking and adopt a healthy lifestyle to minimize the risk of cerebrovascular events.

Effect of Benidipine Alone and in Combination With Bosentan and Sildenafil in Amelioration of Pulmonary Arterial Hypertension in Experimental Model in Rats.

ABSTRACT: Pulmonary arterial hypertension (PAH) is a persistent condition affecting the pulmonary arteries' endothelium. Benidipine, a calcium channel blocker, possesses vasodilatory, anti-inflammatory activity, reduces oxidative stress, and inhibits the activity of Transforming growth factor-ß (TGF-ß) and α-smooth muscle actin (α-SMA). The present study was designed to investigate the effect of benidipine alone and in combination with bosentan and sildenafil on monocrotaline (MCT)-induced pulmonary hypertension in a rat model. PAH was induced by a single-dose administration of MCT in rats. Animals were randomized into different groups and treated with benidipine alone and in combination with bosentan or sildenafil. Various parameters such as hemodynamic parameters, Fulton's index and oxidative stress parameters were performed. Additionally, histopathology of lung and right ventricular of heart tissue, immunohistochemistry, expression of α-SMA, endothelial nitric oxide synthase (eNOS), TGF-ß, and RT-PCR, and an in vitro study using human umbilical vein endothelial cells (HUVECs) was also carried out. Treatment of benidipine and its combination exhibited better prevention in the elevated right ventricular systolic pressure, right ventricular hypertrophy, rise in oxidative stress, and increase in expression of α-SMA and TGF-ß receptor 1 compared with MCT control group rats. In HUVECs, the expression of α-SMA was increased, whereas that of eNOS decreased after TGF-ß exposure and was substantially reversed after pretreatment with benidipine. We concluded that benidipine and its combination with bosentan and sildenafil exhibit beneficial effects in MCT-induced PAH through the eNOS/TGF-ß/α-SMA signaling pathway.