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Brain Sciences May 2023Erectile dysfunction (ED) is the inability to get and maintain an adequate penile erection for satisfactory sexual intercourse. Due to its negative impacts on men's life... (Review)
Review
Erectile dysfunction (ED) is the inability to get and maintain an adequate penile erection for satisfactory sexual intercourse. Due to its negative impacts on men's life quality and increase during aging (40% of men between 40 and 70 years), ED has always attracted researchers of different disciplines, from urology, andrology and neuropharmacology to regenerative medicine, and vascular and prosthesis implant surgery. Locally and/or centrally acting drugs are used to treat ED, e.g., phosphodiesterase 5 inhibitors (first in the list) given orally, and phentolamine, prostaglandin E1 and papaverine injected intracavernously. Preclinical data also show that dopamine D receptor agonists, oxytocin and α-MSH analogues may have a role in ED treatment. However, since pro-erectile drugs are given on demand and are not always efficacious, new strategies are being tested for long lasting cures of ED. These include regenerative therapies, e.g., stem cells, plasma-enriched platelets and extracorporeal shock wave treatments to cure damaged erectile tissues. Although fascinating, these therapies are laborious, expensive and not easily reproducible. This leaves old vacuum erection devices and penile prostheses as the only way to get an artificial erection and sexual intercourse with intractable ED, with penile prosthesis used only by accurately selected patients.
PubMed: 37239274
DOI: 10.3390/brainsci13050802 -
Indian Journal of Urology : IJU :... 2021Drug-induced priapism is well known and papaverine is the most common drug known to cause priapism. Drotaverine, an analog of papaverine, is used extensively to treat...
Drug-induced priapism is well known and papaverine is the most common drug known to cause priapism. Drotaverine, an analog of papaverine, is used extensively to treat Colicky pain. We report the first case of drotaverine.induced priapism.
PubMed: 33850364
DOI: 10.4103/iju.IJU_240_20 -
Phosphodiesterase type 10A inhibitor attenuates lung fibrosis by targeting myofibroblast activation.IScience May 2023Pulmonary fibrosis (PF) is a fatal and irreversible respiratory disease accompanied by excessive fibroblast activation. Previous studies have suggested that cAMP...
Pulmonary fibrosis (PF) is a fatal and irreversible respiratory disease accompanied by excessive fibroblast activation. Previous studies have suggested that cAMP signaling pathway and cGMP-PKG signaling pathway are continuously down-regulated in lung fibrosis, whereas PDE10A has a specifically expression in fibroblasts/myofibroblasts in lung fibrosis. In this study, we demonstrated that overexpression of PDE10A induces myofibroblast differentiation, and papaverine, as a PDE10A inhibitor used for vasodilation, inhibits myofibroblast differentiation in human fibroblasts, Meanwhile, papaverine alleviated bleomycin-induced pulmonary fibrosis and amiodarone-induced oxidative stress, papaverine downregulated VASP/β-catenin pathway to reduce the myofibroblast differentiation. Our results first demonstrated that papaverine inhibits TGFβ1-induced myofibroblast differentiation and lung fibrosis by VASP/β-catenin pathway.
PubMed: 37138780
DOI: 10.1016/j.isci.2023.106586 -
Molecules (Basel, Switzerland) Mar 2023The pharmacological actions of benzylisoquinoline alkaloids are quite substantial, and have recently attracted much attention. One of the principle benzylisoquinoline... (Review)
Review
The pharmacological actions of benzylisoquinoline alkaloids are quite substantial, and have recently attracted much attention. One of the principle benzylisoquinoline alkaloids has been found in the unripe seed capsules of L. Although it lacks analgesic effects and is unrelated to the compounds in the morphine class, it is a peripheral vasodilator and has a direct effect on vessels. It is reported to inhibit the cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) phosphodiesterase in smooth muscles, and it has been observed to increase intracellular levels of cAMP and cGMP. It induces coronary, cerebral, and pulmonary artery dilatation and helps to lower cerebral vascular resistance and enhance cerebral blood flow. Current pharmacological research has revealed that papaverine demonstrates a variety of biological activities, including activity against erectile dysfunction, postoperative vasospasms, and pulmonary vasoconstriction, as well as antiviral, cardioprotective, anti-inflammatory, anticancer, neuroprotective, and gestational actions. It was recently demonstrated that papaverine has the potential to control SARS-CoV-2 by preventing its cytopathic effect. These experiments were carried out both in vitro and in vivo and require an extensive understanding of the mechanisms of action. With its multiple mechanisms, papaverine can be considered as a natural compound that is used to develop therapeutic drugs. To validate its applications, additional research is required into its precise therapeutic mechanisms as well as its acute and chronic toxicities. Therefore, the goal of this review is to discuss the major studies and reported clinical studies looking into the pharmacological effects of papaverine and the mechanisms of action underneath these effects. Additionally, it is recommended to conduct further research via significant pharmacodynamic and pharmacokinetic studies.
Topics: Humans; Papaverine; Opium; COVID-19; SARS-CoV-2; Alkaloids; Benzylisoquinolines
PubMed: 37049912
DOI: 10.3390/molecules28073149 -
Proceedings of the National Academy of... Aug 2022Tetrahydropapaverine (THP) and papaverine are plant natural products with clinically significant roles. THP is a precursor in the production of the drugs atracurium and...
Tetrahydropapaverine (THP) and papaverine are plant natural products with clinically significant roles. THP is a precursor in the production of the drugs atracurium and cisatracurium, and papaverine is used as an antispasmodic during vascular surgery. In recent years, metabolic engineering advances have enabled the production of natural products through heterologous expression of pathway enzymes in yeast. Heterologous biosynthesis of THP and papaverine could play a role in ensuring a stable supply of these clinically significant products. Biosynthesis of THP and papaverine has not been achieved to date, in part because multiple pathway enzymes have not been elucidated. Here, we describe the development of an engineered yeast strain for de novo biosynthesis of THP. The production of THP is achieved through heterologous expression of two enzyme variants with activity on nonnative substrates. Through protein engineering, we developed a variant of -methylcoclaurine hydroxylase with activity on coclaurine, enabling de novo norreticuline biosynthesis. Similarly, we developed a variant of scoulerine 9--methyltransferase capable of -methylating 1-benzylisoquinoline alkaloids at the 3' position, enabling de novo THP biosynthesis. Flux through the heterologous pathway was improved by knocking out yeast multidrug resistance transporters and optimization of media conditions. Overall, strain engineering increased the concentration of biosynthesized THP 600-fold to 121 µg/L. Finally, we demonstrate a strategy for papaverine semisynthesis using hydrogen peroxide as an oxidizing agent. Through optimizing pH, temperature, reaction time, and oxidizing agent concentration, we demonstrated the ability to produce semisynthesized papaverine through oxidation of biosynthesized THP.
Topics: Biological Products; Cytochrome P-450 Enzyme System; Hydrogen Peroxide; Oxidants; Papaverine; Plant Proteins; Protein Engineering; Saccharomyces cerevisiae
PubMed: 35939674
DOI: 10.1073/pnas.2205848119 -
EClinicalMedicine Sep 2021Although tinnitus has a prevalence between 20 and 42.8%, the currently recommended management for tinnitus, such as tinnitus support and psychologic therapies, are...
BACKGROUND
Although tinnitus has a prevalence between 20 and 42.8%, the currently recommended management for tinnitus, such as tinnitus support and psychologic therapies, are relatively time-consuming and expensive. Several new pharmacologic treatments designed for tinnitus patients without specific origin had been developed but their efficacy remains unclear.
METHODS
The current Network Meta-Analysis (NMA) of randomised controlled trials (RCTs) was conducted to evaluate the efficacy of different pharmacologic treatments for tinnitus management in tinnitus patients without specific or treatable origin (i.e. primary tinnitus). Databases were searched from inception to April 5, 2021. All network meta-analytic procedures were conducted under the frequentist model. We calculated the effect size of outcomes with different rating scales with standardized mean difference. PROSPERO registration: CRD42020177742.
FINDINGS
Overall, 36 RCTs were included with 2,761 participants. The main results revealed that pharmacologic interventions with brain-acting effect (for example, amitriptyline, acamprosate, and gabapentin) and those with anti-inflammation/anti-oxidant effect (for example, intra-tympanic dexamethasone injection plus oral melatonin) were associated with superior improvement in tinnitus severity and response rate compared to placebo/control. Oral amitriptyline were associated with the highest improvement in tinnitus severity and the fourth highest response rate. None of the investigated interventions was associated with different changes in quality of life compared to placebo/control. All the investigated treatments were associated with similar drop-out rate to placebo/control.
INTERPRETATION
The current NMA suggests a potential role for treatments with brain-acting effect (for example, amitriptyline, acamprosate, and gabapentin) or anti-inflammation/anti-oxidant effect (for example, intra-tympanic dexamethasone injection plus oral melatonin) as the preferable effective treatments for tinnitus without specific or treatable origin.
FUNDING
none.
PubMed: 34611615
DOI: 10.1016/j.eclinm.2021.101080 -
CNS Neuroscience & Therapeutics Oct 2019Aneurysmal subarachnoid hemorrhage (aSAH) continues to be associated with significant morbidity and mortality despite advances in care and aneurysm treatment strategies.... (Review)
Review
Aneurysmal subarachnoid hemorrhage (aSAH) continues to be associated with significant morbidity and mortality despite advances in care and aneurysm treatment strategies. Cerebral vasospasm continues to be a major source of clinical worsening in patients. We intended to review the clinical and experimental aspects of aSAH and identify strategies that are being evaluated for the treatment of vasospasm. A literature review on aSAH and cerebral vasospasm was performed. Available treatments for aSAH continue to expand as research continues to identify new therapeutic targets. Oral nimodipine is the primary medication used in practice given its neuroprotective properties. Transluminal balloon angioplasty is widely utilized in patients with symptomatic vasospasm and ischemia. Prophylactic "triple-H" therapy, clazosentan, and intraarterial papaverine have fallen out of practice. Trials have not shown strong evidence supporting magnesium or statins. Other calcium channel blockers, milrinone, tirilazad, fasudil, cilostazol, albumin, eicosapentaenoic acid, erythropoietin, corticosteroids, minocycline, deferoxamine, intrathecal thrombolytics, need to be further investigated. Many of the current experimental drugs may have significant roles in the treatment algorithm, and further clinical trials are needed. There is growing evidence supporting that early brain injury in aSAH may lead to significant morbidity and mortality, and this needs to be explored further.
Topics: Calcium Channel Blockers; Endovascular Procedures; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Subarachnoid Hemorrhage; Vasodilator Agents; Vasospasm, Intracranial
PubMed: 31583833
DOI: 10.1111/cns.13222 -
Cells Oct 2022Papaverine (PPV), a benzylisoquinoline alkaloid, extracted from the plant, is currently in clinical use as a vasodilator. Research has shown that PPV inhibits... (Review)
Review
Papaverine (PPV), a benzylisoquinoline alkaloid, extracted from the plant, is currently in clinical use as a vasodilator. Research has shown that PPV inhibits phosphodiesterase 10A (PDE10A,) resulting in the accumulation of cyclic adenosine 3', 5'-monophosphate (cAMP) that affects multiple downstream pathways, including phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt), a mammalian target of rapamycin (mTOR) and vascular endothelial growth factor (VEGF). The accumulation of cAMP can further affect mitochondrial metabolism through the activation of protein kinase A (PKA), which activates the mitochondrial complex I. Literature has shown that PPV exerts anti-proliferative affects in several tumorigenic cell lines including adenocarcinoma alveolar cancer (A549) and human hepatoma (HepG-2) cell lines. Cell cycle investigations have shown varying results with the effects dependent on concentration and cell type with data suggesting an increase in cells occupying the sub-G phase, which is indicative of cell death. These results suggest that PPV may be a beneficial compound to explore for the use in anticancer studies. More insight into the effects of the compound on cellular and molecular mechanisms is needed. Understanding the effects PPV may exert on tumorigenic cells may better researchers' understanding of phytomedicines and the effects of PPV and PPV-derived compounds in cancer.
Topics: Humans; Papaverine; Phosphatidylinositol 3-Kinases; Vascular Endothelial Growth Factor A; Cyclic AMP-Dependent Protein Kinases; Cell Cycle; Neoplasms; Phosphoric Diester Hydrolases
PubMed: 36359780
DOI: 10.3390/cells11213385