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Keywords = histamine-2 receptor blocker

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16 pages, 1377 KiB  
Article
Disproportionality Analysis of Renal Adverse Events Associated with a Combination of Immune Checkpoint Inhibitors and Acid-Suppressing Agents—A Pharmacovigilance Study Based on the FAERS Database
by Jinmei Liu, Xu Chen, Cong Zhang, Huiping Hu, Shijun Li, Zhiwen Fu and Ruxu You
J. Clin. Med. 2025, 14(10), 3581; https://doi.org/10.3390/jcm14103581 - 20 May 2025
Viewed by 695
Abstract
Background/Objectives: The nephrotoxicity of immune checkpoint inhibitors (ICIs) combined with proton pump inhibitors (PPIs) has been recognized but lacks a comprehensive analysis. We conducted an in-depth investigation of renal adverse events (rAEs) associated with ICIs and different acid-suppressing agents (ASAs)—including PPIs, histamine-2 [...] Read more.
Background/Objectives: The nephrotoxicity of immune checkpoint inhibitors (ICIs) combined with proton pump inhibitors (PPIs) has been recognized but lacks a comprehensive analysis. We conducted an in-depth investigation of renal adverse events (rAEs) associated with ICIs and different acid-suppressing agents (ASAs)—including PPIs, histamine-2 receptor antagonists (H2RAs), and potassium-competitive acid blockers (P-CABs)—using real-world data from the FDA’s Adverse Event Reporting System (FAERS). Methods: We analyzed rAE reports from the FAERS database covering Q1 2004 to Q1 2023. Disproportionality analysis was conducted to identify rAEs associated with ICI or ASA monotherapy or combination therapy. Univariate logistic regression was employed to explore influencing factors. Results: No eligible rAE reports were retrieved for H2RAs and P-CABs. However, 6,775 reports in the ICI group, 54,055 reports in the PPI group, and 210 reports in the ICI–PPI combination therapy group were included in the final analysis. In PPI–ICI combination settings, tubulointerstitial nephritis had the highest reporting frequency and signal intensity; the overall risk of rAEs was significantly elevated compared to ICI or PPI monotherapy, with reporting odds ratios of 14. 65 (95% confidence interval [CI] 12.93–16.58) and 3.24 (95% CI 2.87–3.66), respectively; the median onset time was shortest at 21 days (interquartile range 5.5–135); and PD-1 monotherapy, omeprazole, and rabeprazole were associated with higher rAE risks. Conclusions: Our findings confirm that the combination of PPIs (but not other ASAs) with ICIs further increases the risk of various acute and chronic rAEs. Healthcare providers should exercise caution when managing patients on these therapies. Full article
(This article belongs to the Section Pharmacology)
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11 pages, 251 KiB  
Review
Proton Pump Inhibitors and Cancer Risk: A Comprehensive Review of Epidemiological and Mechanistic Evidence
by Ibrahim O. Sawaid and Abraham O. Samson
J. Clin. Med. 2024, 13(7), 1970; https://doi.org/10.3390/jcm13071970 - 28 Mar 2024
Cited by 17 | Viewed by 19116
Abstract
Background: Proton pump inhibitors (PPIs) are commonly prescribed long-acting drugs used to treat acid reflux, gastroesophageal reflux disease (GERD), and peptic ulcers. Recently, concerns have been raised about their safety, particularly due to the association between long-term PPI use and cancer development. Multiple [...] Read more.
Background: Proton pump inhibitors (PPIs) are commonly prescribed long-acting drugs used to treat acid reflux, gastroesophageal reflux disease (GERD), and peptic ulcers. Recently, concerns have been raised about their safety, particularly due to the association between long-term PPI use and cancer development. Multiple comprehensive studies have consistently suggested a noteworthy link between prolonged PPI usage and an increased risk of developing gastric, esophageal, colorectal, and pancreatic cancers, yet the precise underlying mechanism remains elusive. Methods: First, we review the extensive body of research that investigates the intricate relationship between cancer and PPIs. Then, we predict PPI toxicity using the prodrug structures with the ProTox-II webserver. Finally, we predict the relative risk of cancer for each PPI, using PubMed citation counts of each drug and keywords related to cancer. Results: Our review indicates that prolonged PPI use (exceeding three months) is significantly associated with an elevated risk of cancer, while shorter-term usage (less than three months) appears to pose a comparatively lower risk. Our review encompasses various proposed mechanisms, such as pH and microbiome alterations, vitamin and mineral malabsorption, hypergastrinemia, and enterochromaffin-like cell proliferation, while ProTox-II also suggests aryl hydrocarbon receptor binding. Potentially, the PubMed citations count suggests that the PPIs omeprazole and lansoprazole are more associated with cancer than pantoprazole and esomeprazole. In comparison, the H2R blocker, famotidine, is potentially less associated with cancer than PPIs, and may serve as a safer alternative treatment for periods beyond 3 months. Conclusions: Despite the well-established cancer risk associated with PPIs, it is notable that these medications continue to be widely prescribed for periods longer than 3 months. Thus, it is of paramount importance for clinicians and patients to thoughtfully evaluate the potential risks and benefits of long-term PPI usage and explore alternative treatments before making informed decisions regarding their medical management. Full article
(This article belongs to the Section Oncology)
16 pages, 658 KiB  
Review
Clinical Dilemma Involving Treatments for Very Low-Birth-Weight Infants and the Potential Risk of Necrotizing Enterocolitis: A Narrative Literature Review
by Shigeo Iijima
J. Clin. Med. 2024, 13(1), 62; https://doi.org/10.3390/jcm13010062 - 22 Dec 2023
Cited by 7 | Viewed by 3102
Abstract
Necrotizing enterocolitis (NEC) is a critical gastrointestinal emergency with substantial morbidity and mortality risks, especially for very low-birth-weight (VLBW) infants, and unclear multifactorial pathophysiology. Whether common treatments for VLBW infants increase the NEC risk remains controversial. Indomethacin (utilized for patent ductus arteriosus) offers [...] Read more.
Necrotizing enterocolitis (NEC) is a critical gastrointestinal emergency with substantial morbidity and mortality risks, especially for very low-birth-weight (VLBW) infants, and unclear multifactorial pathophysiology. Whether common treatments for VLBW infants increase the NEC risk remains controversial. Indomethacin (utilized for patent ductus arteriosus) offers benefits but is concerning because of its vasoconstrictive impact on NEC susceptibility. Similarly, corticosteroids used to treat bronchopulmonary dysplasia may increase vulnerability to NEC by compromising immunity and altering the mesenteric blood flow. Histamine-2 receptor blockers (used to treat gastric bleeding) may inadvertently promote NEC by affecting bacterial colonization and translocation. Doxapram (used to treat apnea) poses a risk of gastrointestinal disturbance via gastric acid hypersecretion and circulatory changes. Glycerin enemas aid meconium evacuation but disrupt microbial equilibrium and trigger stress-related effects associated with the NEC risk. Prolonged antibiotic use may unintentionally increase the NEC risk. Blood transfusions for anemia can promote NEC via interactions between the immune response and ischemia–reperfusion injury. Probiotics for NEC prevention are associated with concerns regarding sepsis and bacteremia. Amid conflicting evidence, this review unveils NEC risk factors related to treatments for VLBW infants, offers a comprehensive overview of the current research, and guides personalized management strategies, thereby elucidating this clinical dilemma. Full article
(This article belongs to the Section Clinical Pediatrics)
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19 pages, 1849 KiB  
Article
Antioxidant and Anti-Glycation Potential of H2 Receptor Antagonists—In Vitro Studies and a Systematic Literature Review
by Grzegorz Biedrzycki, Blanka Wolszczak-Biedrzycka, Justyna Dorf, Daniel Michalak, Małgorzata Żendzian-Piotrowska, Anna Zalewska and Mateusz Maciejczyk
Pharmaceuticals 2023, 16(9), 1273; https://doi.org/10.3390/ph16091273 - 8 Sep 2023
Cited by 7 | Viewed by 2291
Abstract
Background: Histamine H2 receptor antagonists are a group of drugs that inhibit gastric juice secretion in gastrointestinal diseases. However, there is evidence to suggest that H2 blockers have a broader spectrum of activity. The antioxidant properties of H2 blockers have not been fully [...] Read more.
Background: Histamine H2 receptor antagonists are a group of drugs that inhibit gastric juice secretion in gastrointestinal diseases. However, there is evidence to suggest that H2 blockers have a broader spectrum of activity. The antioxidant properties of H2 blockers have not been fully elucidated, and their anti-glycation potential has not been studied to date. Therefore, this is the first study to compare the antioxidant and antiglycation potentials of the most popular H2 antagonists (ranitidine, cimetidine, and famotidine) on protein glycoxidation in vitro. Methods: Bovine serum albumin (BSA) was glycated using sugars (glucose, fructose, galactose, and ribose) as well as aldehydes (glyoxal and methylglyoxal). Results: In the analyzed group of drugs, ranitidine was the only H2 blocker that significantly inhibited BSA glycation in all tested models. The contents of protein carbonyls, protein glycoxidation products (↓dityrosine, ↓N-formylkynurenine), and early (↓Amadori products) and late-stage (↓AGEs) protein glycation products decreased in samples of glycated BSA with the addition of ranitidine relative to BSA with the addition of the glycating agents. The anti-glycation potential of ranitidine was comparable to those of aminoguanidine and Trolox. In the molecular docking analysis, ranitidine was characterized by the lowest binding energy for BSA sites and could compete with protein amino groups for the addition of carbonyl groups. H2 blockers also scavenge free radicals. The strongest antioxidant properties are found in ranitidine, which additionally has the ability to bind transition metal ions. The systematic literature review also revealed that the anti-glycation effects of ranitidine could be attributed to its antioxidant properties. Conclusions: Ranitidine showed anti-glycation and antioxidant properties. Further research is needed, particularly in patients with diseases that promote protein glycation. Full article
(This article belongs to the Special Issue Histamine Receptor Ligands in Medicinal Chemistry)
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8 pages, 3550 KiB  
Communication
Insight into the Mode of Action of 8-Hydroxyquinoline-Based Blockers on the Histamine Receptor 2
by Amisha Patel, Paola L. Marquez-Gomez, Lily R. Torp, Lily Gao and Pamela Peralta-Yahya
Biosensors 2023, 13(6), 571; https://doi.org/10.3390/bios13060571 - 23 May 2023
Cited by 1 | Viewed by 2502
Abstract
Histamine receptor 2 (HRH2) blockers are used to treat peptic ulcers and gastric reflux. Chlorquinaldol and chloroxine, which contain an 8-hydroxyquinoline (8HQ) core, have recently been identified as blocking HRH2. To gain insight into the mode of action of [...] Read more.
Histamine receptor 2 (HRH2) blockers are used to treat peptic ulcers and gastric reflux. Chlorquinaldol and chloroxine, which contain an 8-hydroxyquinoline (8HQ) core, have recently been identified as blocking HRH2. To gain insight into the mode of action of 8HQ-based blockers, here, we leverage an HRH2-based sensor in yeast to evaluate the role of key residues in the HRH2 active site on histamine and 8HQ-based blocker binding. We find that the HRH2 mutations D98A, F254A, Y182A, and Y250A render the receptor inactive in the presence of histamine, while HRH2:D186A and HRH2:T190A retain residual activity. Based on molecular docking studies, this outcome correlates with the ability of the pharmacologically relevant histamine tautomers to interact with D98 via the charged amine. Docking studies also suggest that, unlike established HRH2 blockers that interact with both ends of the HRH2 binding site, 8HQ-based blockers interact with only one end, either the end framed by D98/Y250 or T190/D186. Experimentally, we find that chlorquinaldol and chloroxine still inactivate HRH2:D186A by shifting their engagement from D98 to Y250 in the case of chlorquinaldol and D186 to Y182 in the case of chloroxine. Importantly, the tyrosine interactions are supported by the intramolecular hydrogen bonding of the 8HQ-based blockers. The insight gained in this work will aid in the development of improved HRH2 therapeutics. More generally, this work demonstrates that Gprotein-coupled receptor (GPCR)-based sensors in yeast can help elucidate the mode of action of novel ligands for GPCRs, a family of receptors that bind 30% of FDA therapeutics. Full article
(This article belongs to the Special Issue Genetically Encoded, Small-Molecule Biosensors and Their Applications)
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20 pages, 3593 KiB  
Article
Antiulcerogenic Potential of the Ethanolic Extract of Ceiba speciosa (A. St.-Hil.) Ravenna Evaluated by In Vitro and In Vivo Studies
by Juliana Andréa Dörr, Fernanda Majolo, Luísa Bortoluzzi, Evelin Zen de Vargas, Joana Silva, Manoela Pasini, Stefani Natali Stoll, Rafael Lopes da Rosa, Mariana Moreira Figueira, Márcio Fronza, Walter O. Beys-da-Silva, Alice Martins, Helena Gaspar, Rui P. Pedrosa, Stefan Laufer and Márcia Inês Goettert
Int. J. Mol. Sci. 2022, 23(24), 15634; https://doi.org/10.3390/ijms232415634 - 9 Dec 2022
Cited by 7 | Viewed by 2758
Abstract
Gastrointestinal diseases, such as peptic ulcers, are caused by a damage in the gastric mucosa provoked by several factors. This stomach injury is regulated by many inflammatory mediators and is commonly treated with proton-pump inhibitors, histamine H2 receptor blockers and antacids. However, various [...] Read more.
Gastrointestinal diseases, such as peptic ulcers, are caused by a damage in the gastric mucosa provoked by several factors. This stomach injury is regulated by many inflammatory mediators and is commonly treated with proton-pump inhibitors, histamine H2 receptor blockers and antacids. However, various medicinal plants have demonstrated positive effects on gastric ulcer treatment, including plants of the Ceiba genus. The aim of this study was to evaluate the antiulcer and anti-inflammatory activities of the stem bark ethanolic extract of Ceiba speciosa (A. St.-Hil.) Ravenna. We performed a preliminary quantification of phenolic compounds by high-performance liquid chromatography-diode array detection (HPLC-DAD), followed by the prospection of other chemical groups through nuclear magnetic resonance (NMR) spectroscopy. A set of in vitro assays was used to evaluate the extract potential regarding its antioxidant activity (DPPH: 19.83 ± 0.34 µg/mL; TPC: 307.20 ± 6.20 mg GAE/g of extract), effects on cell viability and on the release of TNF-α in whole human blood. Additionally, in vivo assays were performed to evaluate the leukocyte accumulation and total protein quantification in carrageenan-induced air pouch, as well as the antiulcerogenic effect of the extract on an ethanol-induced ulcer in rats. The extract contains flavonoids and phenolic compounds, as well as sugars and quinic acid derivatives exhibiting potent antioxidant activity and low toxicity. The extract reduced the release of TNF-α in human blood and inhibited the activity of p38α (1.66 µg/mL), JAK3 (5.25 µg/mL), and JNK3 (8.34 µg/mL). Moreover, it reduced the leukocyte recruitment on the pouch exudate and the formation of edema, reverting the effects caused by carrageenan. The extract presented a significant prevention of ulcer formation and a higher reduction than the reference drug, Omeprazole. Therefore, C. speciosa extract has demonstrated relevant therapeutic potential for the treatment of gastric diseases, deserving the continuation of further studies to unveil the mechanisms of action of plant bioactive ingredients. Full article
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12 pages, 399 KiB  
Article
Potentially Inappropriate Medication Use in Patients with Dementia
by Kyungwon Yoon, Jung-Tae Kim, Won-Gun Kwack, Donghyun Kim, Kyung-Tae Lee, Seungwon Yang, Sangmin Lee, Yeo-Jin Choi and Eun-Kyoung Chung
Int. J. Environ. Res. Public Health 2022, 19(18), 11426; https://doi.org/10.3390/ijerph191811426 - 10 Sep 2022
Cited by 10 | Viewed by 3999
Abstract
The objective of this study was to characterize the epidemiology of using potentially inappropriate medications associated with dementia exacerbation (DPIMs) in elderly outpatients with dementia. Electronic medical records were retrospectively reviewed for geriatric patients with dementia who were prescribed at least one medication [...] Read more.
The objective of this study was to characterize the epidemiology of using potentially inappropriate medications associated with dementia exacerbation (DPIMs) in elderly outpatients with dementia. Electronic medical records were retrospectively reviewed for geriatric patients with dementia who were prescribed at least one medication in 2016 at a tertiary, university-affiliated hospital. The 2015 Beers criteria were used to define DPIMs. Logistic regression was performed to identify factors associated with prescribing DPIMs in patients with dementia. Among 2100 patients included in our study, 987 (47.0%) patients were prescribed at least one DPIM. Benzodiazepines were the most frequently prescribed DPIM followed by anticholinergics, histamine H2-receptor blockers, and zolpidem. The risk of prescribing DPIMs was significantly increased in female patients (odds ratio (OR) 1.355) with polypharmacy (OR 5.146) and multiple comorbidities (OR 1.129) (p < 0.05 for all). Coexistence of Parkinson’s disease (OR 1.799), mood disorder (OR 1.373), or schizophrenia (OR 4.116) in patients with dementia further increased the likelihood of receiving DPIMs. In conclusion, DPIMs were commonly used in elderly patients with dementia in Korea with benzodiazepines most frequently prescribed followed by anticholinergics. Female patients using polypharmacy with multiple comorbidities should be closely monitored to minimize unnecessary DPIM use and, ultimately, DPIM-related harms. Full article
16 pages, 1745 KiB  
Review
Connections between Immune-Derived Mediators and Sensory Nerves for Itch Sensation
by Sumika Toyama, Mitsutoshi Tominaga and Kenji Takamori
Int. J. Mol. Sci. 2021, 22(22), 12365; https://doi.org/10.3390/ijms222212365 - 16 Nov 2021
Cited by 15 | Viewed by 4504
Abstract
Although histamine is a well-known itch mediator, histamine H1-receptor blockers often lack efficacy in chronic itch. Recent molecular and cellular based studies have shown that non-histaminergic mediators, such as proteases, neuropeptides and cytokines, along with their cognate receptors, are involved in [...] Read more.
Although histamine is a well-known itch mediator, histamine H1-receptor blockers often lack efficacy in chronic itch. Recent molecular and cellular based studies have shown that non-histaminergic mediators, such as proteases, neuropeptides and cytokines, along with their cognate receptors, are involved in evocation and modulation of itch sensation. Many of these molecules are produced and secreted by immune cells, which act on sensory nerve fibers distributed in the skin to cause itching and sensitization. This understanding of the connections between immune cell-derived mediators and sensory nerve fibers has led to the development of new treatments for itch. This review summarizes current knowledge of immune cell-derived itch mediators and neuronal response mechanisms, and discusses therapeutic agents that target these systems. Full article
(This article belongs to the Special Issue Immune Mediators and Disruptors of Neural Functions)
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17 pages, 3240 KiB  
Article
Sea Anemone Kunitz-Type Peptides Demonstrate Neuroprotective Activity in the 6-Hydroxydopamine Induced Neurotoxicity Model
by Oksana Sintsova, Irina Gladkikh, Margarita Monastyrnaya, Valentin Tabakmakher, Ekaterina Yurchenko, Ekaterina Menchinskaya, Evgeny Pislyagin, Yaroslav Andreev, Sergey Kozlov, Steve Peigneur, Jan Tytgat, Dmitry Aminin, Emma Kozlovskaya and Elena Leychenko
Biomedicines 2021, 9(3), 283; https://doi.org/10.3390/biomedicines9030283 - 10 Mar 2021
Cited by 22 | Viewed by 3535
Abstract
Kunitz-type peptides from venomous animals have been known to inhibit different proteinases and also to modulate ion channels and receptors, demonstrating analgesic, anti-inflammatory, anti-histamine and many other biological activities. At present, there is evidence of their neuroprotective effects. We have studied eight Kunitz-type [...] Read more.
Kunitz-type peptides from venomous animals have been known to inhibit different proteinases and also to modulate ion channels and receptors, demonstrating analgesic, anti-inflammatory, anti-histamine and many other biological activities. At present, there is evidence of their neuroprotective effects. We have studied eight Kunitz-type peptides of the sea anemone Heteractis crispa to find molecules with cytoprotective activity in the 6-OHDA-induced neurotoxicity model on neuroblastoma Neuro-2a cells. It has been shown that only five peptides significantly increase the viability of neuronal cells treated with 6-OHDA. The TRPV1 channel blocker, HCRG21, has revealed the neuroprotective effect that could be indirect evidence of TRPV1 involvement in the disorders associated with neurodegeneration. The pre-incubation of Neuro-2a cells with HCRG21 followed by 6-OHDA treatment has resulted in a prominent reduction in ROS production compared the untreated cells. It is possible that the observed effect is due to the ability of the peptide act as an efficient free-radical scavenger. One more leader peptide, InhVJ, has shown a neuroprotective activity and has been studied at concentrations of 0.01–10.0 µM. The target of InhVJ is still unknown, but it was the best of all eight homologous peptides in an absolute cell viability increment on 38% of the control in the 6-OHDA-induced neurotoxicity model. The targets of the other three active peptides remain unknown. Full article
(This article belongs to the Special Issue Peptide-Based Drug Development)
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23 pages, 7701 KiB  
Review
Molecular Background, Clinical Features and Management of Pediatric Mastocytosis: Status 2021
by Magdalena Lange, Karin Hartmann, Melody C. Carter, Frank Siebenhaar, Ivan Alvarez-Twose, Inés Torrado, Knut Brockow, Joanna Renke, Ninela Irga-Jaworska, Katarzyna Plata-Nazar, Hanna Ługowska-Umer, Justyna Czarny, Anna Belloni Fortina, Francesca Caroppo, Roman J. Nowicki, Bogusław Nedoszytko, Marek Niedoszytko and Peter Valent
Int. J. Mol. Sci. 2021, 22(5), 2586; https://doi.org/10.3390/ijms22052586 - 4 Mar 2021
Cited by 51 | Viewed by 6975
Abstract
Pediatric mastocytosis is a heterogeneous disease characterized by accumulation of mast cells in the skin and less frequently in other organs. Somatic or germline mutations in the KIT proto-oncogene are detected in most patients. Cutaneous mastocytosis is the most common form of the [...] Read more.
Pediatric mastocytosis is a heterogeneous disease characterized by accumulation of mast cells in the skin and less frequently in other organs. Somatic or germline mutations in the KIT proto-oncogene are detected in most patients. Cutaneous mastocytosis is the most common form of the disease in children. In the majority of cases, skin lesions regress spontaneously around puberty. However, in few patients, mastocytosis is not a self-limiting disease, but persists into adulthood and can show signs of systemic involvement, especially when skin lesions are small-sized and monomorphic. Children with mastocytosis often suffer from mast cell mediator-related symptoms. Severe hypersensitivity reactions can also occur, mostly in patients with extensive skin lesions and blistering. In a substantial number of these cases, the triggering factor of anaphylaxis remains unidentified. Management of pediatric mastocytosis is mainly based on strict avoidance of triggers, treatment with H1 and H2 histamine receptor blockers, and equipment of patients and their families with epinephrine auto-injectors for use in severe anaphylactic reactions. Advanced systemic mastocytosis occurs occasionally. All children with mastocytosis require follow-up examinations. A bone marrow investigation is performed when advanced systemic mastocytosis is suspected and has an impact on therapy or when cutaneous disease persists into adulthood. Full article
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16 pages, 1821 KiB  
Article
Marjoram Relaxes Rat Thoracic Aorta Via a PI3-K/eNOS/cGMP Pathway
by Adnan Badran, Elias Baydoun, Ali Samaha, Gianfranco Pintus, Joelle Mesmar, Rabah Iratni, Khodr Issa and Ali H. Eid
Biomolecules 2019, 9(6), 227; https://doi.org/10.3390/biom9060227 - 11 Jun 2019
Cited by 20 | Viewed by 4553
Abstract
Despite pharmacotherapeutic advances, cardiovascular disease (CVD) remains the primary cause of global mortality. Alternative approaches, such as herbal medicine, continue to be sought to reduce this burden. Origanum majorana is recognized for many medicinal values, yet its vasculoprotective effects remain poorly investigated. Here, [...] Read more.
Despite pharmacotherapeutic advances, cardiovascular disease (CVD) remains the primary cause of global mortality. Alternative approaches, such as herbal medicine, continue to be sought to reduce this burden. Origanum majorana is recognized for many medicinal values, yet its vasculoprotective effects remain poorly investigated. Here, we subjected rat thoracic aortae to increasing doses of an ethanolic extract of Origanum majorana (OME). OME induced relaxation in a dose-dependent manner in endothelium-intact rings. This relaxation was significantly blunted in denuded rings. N(ω)-nitro-l-arginine methyl ester (L-NAME) or 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ) significantly reduced the OME-induced vasorelaxation. Cyclic guanosine monophosphate (cGMP) levels were also increased by OME. Moreover, wortmannin or LY294002 significantly reduced OME-induced vasorelaxation. Blockers of ATP-sensitive or Ca2+-activated potassium channels such as glibenclamide or tetraethylamonium (TEA), respectively, did not significantly affect OME-induced relaxation. Similarly, verapamil, a Ca2+ channel blocker, indomethacin, a non-selective cyclooxygenase inhibitor, and pyrilamine, a H1 histamine receptor blocker, did not significantly modulate the observed relaxation. Taken together, our results show that OME induces vasorelaxation via an endothelium-dependent mechanism involving the phosphoinositide 3-kinase (PI3-K)/ endothelial nitric oxide (NO) synthase (eNOS)/cGMP pathway. Our findings further support the medicinal value of marjoram and provide a basis for its beneficial intake. Although consuming marjoram may have an antihypertensive effect, further studies are needed to better determine its effects in different vascular beds. Full article
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