Search Results (33)

Objectives: The incidence of postoperative pain in patients that undergo spinal interventions is significantly increased, affecting their functional outcomes and quality of life. Dexmedetomidine (DEX) belongs to the category of centrally acting nonopioid agents with highly selective α2 adrenoreceptor agonist activity that are frequently applied in spinal surgery based on its antinociceptive and anxiolytic properties. Although many studies displayed the effectiveness of DEX in postoperative pain management, the impact of DEX on functional improvement after spinal surgeries is still debatable. Purpose: This systematic review focuses on the intraoperative and postoperative role of dexmedetomidine (DEX) as an analgesic agent in elective and emergency adult spine surgery. Methods: An electronic literature review search was conducted via Web of Science and PubMed to assess the impact of DEX on postoperative pain management, postoperative delirium (POD), and postoperative cognitive dysfunction (POCD). Discussion: Twenty-one studies were retrieved, three of which were review articles. The effects of DEX were studied for up to 48 h postoperatively. In most cases, its administration was associated with reduced intraoperative and postoperative opioid consumption. However, findings on pain control were less conclusive due to heterogeneity in dosing protocols, concomitant medications, the timing of administration, and pain scoring systems. DEX appears to reduce the incidence of POD and POCD, particularly when used in combination with other drugs. Conclusions: Although the present study supports that the intraoperative administration of dexmedetomidine decreases the pain intensity and/or opioid consumption as well as the development of POD and POCD in patients undergoing spinal surgeries during the first 24 h postoperatively, the current literature should be expanded to allow for the safe generalisation of findings over longer follow-up periods. Further research into the neuroprotective, analgesic, and anti-inflammatory roles of DEX is warranted. Full article

Severe kinds of uterine inflammation in animals cause reproductive and economic problems. Although there are changes in prostaglandin (PG) production and noradrenergic uterine innervation during endometritis, the role of noradrenaline (NA) and adrenoreceptors (ARs) in PGF2α formation is not yet fully understood. To recognize noradrenergic control of the PGF2α generation on the cellular level during endometritis, the action of NA as well as α1-, α2- and β-ARs on protein abundances of PGF synthase (PGFS) and PG 9-ketoreductase/carbonyl reductase (CBR1) in the Escherichia coli lipopolysaccharide (LPS)-influenced pig endometrial epithelial cells and PGF2α release from these cells were studied. The epithelial cells were exposed to LPS and NA alone; LPS with NA; LPS with agonists of α1-, α2- and β-Ars; LPS with antagonists of β1-, β2- and β3-ARs with NA; and LPS with antagonists of β1-, β2- and β3-ARs in combinations with agonists of β1-, β2-, and β3-ARs for 24 h. PGFS and CBR1 protein abundances in cells were determined by Western blotting and PGF2α medium content by ELISA. LPS alone increased CBR1 protein abundance and PGF2α release by epithelial cells in reference to the control value. NA alone exerted a stimulatory effect on PGFS and CBR1 protein abundances and PGF2α secretion. After the exposure of cells to LPS with NA together, CBR1 protein abundance, as well as PGF2α release, was higher than in response to LPS and NA alone. PGFS protein abundance was increased by LPS with NA together compared to LPS action alone. In LPS-exposed endometrial epithelial cells, NA acting by β2- and β3-ARs leads to a rise in CBR1 protein abundance and PGF2α secretion. β2-ARs also participate in the NA excitatory effect on PGFS protein abundance. The NA effect on all the parameters tested is not mediated by α1- and α2-ARs. β2- and β3-ARs mediate the stimulatory effect of NA on PGF2α generation and secretion by the LPS-exposed pig endometrial epithelial cells. The results suggest that these cells may be a significant source of PGF2α under noradrenergic stimulation in the inflamed endometrium, and NA affects processes controlled by PGF2α during endometritis in an indirect manner. Full article

Backgrounds: Approximately 18 million individuals were diagnosed with cancer in 2018. The rate is predicted to exceed 22 million by 2030. Radiotherapy is an essential part of cancer therapy, with well documented local and systemic side effects, including oxidative stress and apoptosis. Kidney tissues are also exposed to the deleterious effects of radiotherapy, resulting in acute or chronic kidney function impairment. This study compared the effects of the potent selective α2-adrenoreceptor agonist dexmedetomidine and amifostine on oxidative stress and apoptosis in kidney damage induced by x-irradiation in rats. Methods: Forty Sprague Dawley rats were assigned into five groups: control, x-irradiation, x-irradiation + amifostine, x-irradiation + dexmedetomidine 100 µg/kg, and X-ray irradiation + dexmedetomidine 200 µg/kg. Results: Necrotic tubules and degenerative Bowman’s capsules were present in the x-irradiation group. An increase was determined in malondialdehyde (MDA), Cleaved Caspase-3, and 8-OHdG levels compared to the control group (p ≤ 0.05). In contrast, there was a decrease in necrotic tubules, degenerative Bowman’s capsules, and the levels of MDA, Cleaved Caspase-3, and 8-OHdG in the amifostine and dexmedetomidine 100 µg/kg and 200 µg/kg treatment groups (p ≤ 0.05). Conclusions: Alpha 2 adrenergic receptor agonists exhibit protective effects against kidney injury induced in association with x-irradiation by reducing oxidative stress and apoptosis. Full article

Background/Objectives: Complex regional pain syndrome (CRPS) is characterized by severe pain and reduced functionality, which can significantly affect an individual’s quality of life. The current treatment of CRPS is challenging. However, recent advances in diagnostic and treatment methods show promise for improving patient outcomes. This review aims to place the question of CRPS in a broader context and highlight the objectives of the research for future directions in the management of CRPS. Methods: This study involved a comprehensive literature review. Results: Research has identified three primary pathophysiological pathways that may explain the clinical variability observed in CRPS: inflammatory mechanisms, vasomotor dysfunction, and maladaptive neuroplasticity. Investigations into these pathways have spurred the development of novel diagnostic and treatment strategies focused on N-Methyl-D-aspartate Receptor Antagonists (NMDA), Toll-like receptor 4 (TLR-4), α1 and α2 adrenoreceptors, as well as the identification of microRNA (miRNA) biomarkers. Treatment methods being explored include immune and glial-modulating agents, intravenous immunoglobulin (IVIG) therapy, plasma exchange therapy, and neuromodulation techniques. Additionally, there is ongoing debate regarding the efficacy of other treatments, such as free radical scavengers, alpha-lipoic acid (ALA), dimethyl fumarate (DMF), adenosine monophosphate-activated protein kinase (AMPK) activators such as metformin, and phosphodiesterase-5 inhibitors such as tadalafil. Conclusions: The controversies surrounding the mechanisms, diagnosis, and treatment of CRPS have prompted researchers to investigate new approaches aimed at enhancing understanding and management of the condition, with the goal of alleviating symptoms and reducing associated disabilities. Full article

Endometritis is a common disease in animals, leading to disruption of reproductive processes and economic losses. Noradrenergic control of prostaglandin (PG)I2 formation by inflamed endometrium is unknown. We determined the involvement of α1-, α2- and β-adrenoreceptors (ARs) in noradrenaline-influenced PGI synthase (PGIS) protein abundance and PGI2 release from porcine (1) endometrial explants with Escherichia coli (E. coli)-induced inflammation in vivo, and (2) E. coli lipopolysaccharide (LPS)-treated endometrial epithelial cells. Experiment 1. E. coli suspension (E. coli group) or saline (CON group) was injected into the uterine horns. In both groups, noradrenaline increased endometrial PGIS abundance and PGI2 release versus the control values, and it was higher in the E. coli group than in the CON group. In the CON group, a noradrenaline stimulating effect on both parameters takes place through α1D-, α2C- and β2-ARs. In the E. coli group, noradrenaline increased PGIS abundance and PGI2 release via α1A-, α2(B,C)- and β(1,2)-ARs, and PGI2 release also by α2A-ARs. Experiment 2. LPS and noradrenaline augmented the examined parameters in endometrial epithelial cells versus the control value. In LPS-treated cells, β(1,2)-ARs mediate in noradrenaline excitatory action on PGIS protein abundance and PGI2 release. β3-ARs also contribute to PGI2 release. Under inflammatory conditions, noradrenaline via ARs increases PGI2 synthesis and release from the porcine endometrium, including epithelial cells. Our findings suggest that noradrenaline may indirectly affect processes regulated by PGI2 in the inflamed uterus. Full article

During their lifetime, sheep undergo many painful husbandry and disease processes. Procedures undertaken on the farm, such as tail docking, castration, and mulesing, all cause considerable pain. In addition, sheep may experience painful diseases and injuries that require treatment by veterinary practitioners, and in biomedical research, sheep may undergo painful experimental procedures or conditions. It is important due to ethics, animal welfare, social licence, and, at times, legal requirements for farmers, veterinary practitioners, and researchers to provide pain relief for animals in their care. While there is a heightened awareness of and a greater interest in animal welfare, there remain few licensed and known analgesia options for sheep within Australia. A literature review was undertaken to identify currently known and potential future options for analgesic agents in sheep in farm and biomedical settings. Non-steroidal anti-inflammatories, opioids, local anaesthetics, α₂ adrenoreceptor agonists, and NMDA receptor antagonists are some of the more common classes of analgesic drugs referred to in the literature, but few drugs are registered for use in sheep, with even fewer proven to be effective. Only six analgesic product formulations, namely, lignocaine (e.g., Numocaine^®), Tri-Solfen^®, ketamine, xylazine, and meloxicam (oral transmucosal and injectable formulations), are currently registered in Australia and known to be efficacious in some types of painful conditions in sheep. The gap in knowledge and availability of analgesia in sheep can pose risks to animal welfare, social licence, and research outcomes. This article presents a summary of analgesic agents that have been used in sheep on farms and in clinical veterinary and biomedical research settings along with details on whether their efficacy was assessed, doses, routes of administration, indication for use, and pain assessment techniques (if any) used. The outcome of this research highlights the challenges, gaps, and opportunities for better analgesia options in sheep. Full article

Centhaquine is a novel vasopressor acting on α2A- and α2B-adrenoreceptors, increasing venous return and improving tissue perfusion. We investigated the effects of centhaquine on blood coagulation in normal state and uncontrolled hemorrhage using ex vivo and in vivo experiments in different species. Thromboelastography (TEG) parameters included clotting time (R), clot kinetics [K and angle (α)], clot strength (MA), and percent lysis 30 min post-MA (LY30). In normal rat blood, centhaquine did not alter R, K, α, MA, or LY30 values of the normal vehicle group or the antithrombotic effects of aspirin and heparin. Subsequently, New Zealand white rabbits with uncontrolled hemorrhage were assigned to three resuscitation groups: Sal-MAP 45 group (normal saline to maintain a mean arterial pressure, MAP, of 45 mmHg), Centh-MAP 45 group (0.05 mg kg⁻¹ centhaquine plus normal saline to maintain a MAP of 45 mmHg), and Sal-MAP 60 group (normal saline to maintain a MAP of 60 mmHg). The Sal-MAP 45 group was characterized by no change in R, reduced K and MA, and increased α. In the Centh-MAP 45 group, TEG showed no change in R, K, and α compared to saline; however, MA increased significantly (p = 0.018). In the Sal-MAP 60 group, TEG showed no change in R, an increase in α (p < 0.001), a decrease in K (p < 0.01), and a decrease in MA (p = 0.029) compared to the Centh-MAP 45 group. In conclusion, centhaquine does not impair coagulation and facilitates hemostatic resuscitation. Full article

Trace amine-associated receptor 1 (TAAR1) is an attractive target for the design of innovative drugs to be applied in diverse pharmacological settings. Due to a non-negligible structural similarity with endogenous ligands, most of the agonists developed so far resulted in being affected by a low selectivity for TAAR1 with respect to other monoaminergic G protein-coupled receptors, like the adrenoreceptors. This study utilized comparative molecular docking studies and quantitative–structure activity relationship (QSAR) analyses to unveil key structural differences between TAAR1 and alpha2-adrenoreceptor (α₂-ADR), with the aim to design novel TAAR1 agonists characterized by a higher selectivity profile and reduced off-target effects. While the presence of hydrophobic motives is encouraged towards both the two receptors, the introduction of polar/positively charged groups and the ligand conformation deeply affect the TAAR1 or α₂-ADR putative selectivity. These computational methods allowed the identification of the α₂A-ADR agonist guanfacine as an attractive TAAR1-targeting lead compound, demonstrating nanomolar activity in vitro. In vivo exploration of the efficacy of guanfacine showed that it is able to decrease the locomotor activity of dopamine transporter knockout (DAT-KO) rats. Therefore, guanfacine can be considered as an interesting template molecule worthy of structural optimization. The dual activity of guanfacine on both α₂-ADR and TAAR1 signaling and the related crosstalk between the two pathways will deserve more in-depth investigation. Full article

A recent in vivo study in pigs demonstrated the hypotensive properties of essential oil extracted from the blossoming plant Elsholtzia ciliata. This study was designed to examine the effect of E. ciliata essential oil (EO) on smooth muscle contraction. Tension measurements were performed on prostate strips and intact aortic rings isolated from rats. Results showed that EO caused a concentration-dependent reduction in phenylephrine-induced contraction of both the prostate and aorta, with a more pronounced inhibitory effect in the prostate. The IC₅₀ of EO for the prostate was 0.24 ± 0.03 µL/mL (n = 10) and for the aorta was 0.72 ± 0.11 µL/mL (n = 4, p < 0.05 vs. prostate). The chromatographic analysis identified elsholtzia ketone (10.64%) and dehydroelsholtzia ketone (86.23%) as the predominant compounds in the tested EO. Since both compounds feature a furan ring within their molecular structure, other furan ring-containing compounds, 2-acetylfuran (2AF) and 5-methylfurfural (5MFF), were examined. For the first time, our study demonstrated the relaxant effects of 2AF and 5MFF on smooth muscles. Further, results showed that EO, 2AF, and 5MFF altered the responsiveness of prostate smooth muscle cells to phenylephrine. Under control conditions, the EC50 of phenylephrine was 0.18 ± 0.03 µM (n = 5), while in the presence of EO, 2AF, or 5MFF, the EC50 values were 0.81 ± 0.3 µM (n = 5), 0.89 ± 0.11 µM (n = 5), and 0.69 ± 0.23 µM (n = 4), respectively, p < 0.05 vs. control. Analysis of the affinity of EO for α₁-adrenergic receptors in the prostate suggested that EO at a certain range of concentrations has a competitive antagonistic effect on α₁-adrenergic receptors. In conclusion, EO elicits a relaxant effect on smooth muscles which may be related to the inhibition of α₁-adrenoreceptors. Full article

Argemone ochroleuca Sweet (Papaveraceae) is used in folk medicine as a sedative and hypnotic agent. This study aimed to evaluate the anxiolytic-like, sedative, antidepressant-like, and anticonvulsant activities of a dichloromethane extract of A. ochroleuca stems (AOE), chemically standardized using gas chromatography–mass spectrometry (GC–MS), and its active compound dihydrosanguinarine (DHS). The anxiolytic-like, sedative, antidepressant-like, and anticonvulsant activities of the AOE (0.1–50 mg/kg p.o.) and DHS (0.1–10 mg/kg p.o.) were evaluated using murine models. A possible mechanism for the neurological actions induced by the AOE or DHS was assessed using inhibitors of neurotransmission pathways and molecular docking. Effective dose 50 (ED₅₀) values were calculated by a linear regression analysis. The AOE showed anxiolytic-like activity in the cylinder exploratory test (ED₅₀ = 33 mg/kg), and antidepressant-like effects in the forced swimming test (ED₅₀ = 3 mg/kg) and the tail suspension test (ED₅₀ = 23 mg/kg), whereas DHS showed anxiolytic-like activity (ED₅₀ = 2 mg/kg) in the hole board test. The AOE (1–50 mg/kg) showed no locomotive affectations or sedation in mice. A docking study revealed the affinity of DHS for α2-adrenoreceptors and GABA_A receptors. The anxiolytic-like and anticonvulsant effects of the AOE are due to GABAergic participation, whereas the antidepressant-like effects of the AOE are due to the noradrenergic system. The noradrenergic and GABAergic systems are involved in the anxiolytic-like actions of DHS. Full article

Indian Red Scorpion (Mesobuthus tamulus) stings are a neglected public health problem in tropical and sub-tropical countries, including India. The drawbacks of conventional therapies using commercial anti-scorpion antivenom (ASA) and α1-adrenoreceptor antagonists (AAA) have prompted us to search for an adequate formulation to improve treatment against M. tamulus stings. Novel therapeutic drug formulations (TDF) of low doses of commercial ASA, AAA, and ascorbic acid have remarkably improved in neutralising the in vivo toxic effects of M. tamulus venom (MTV) tested in Caenorhabditis elegans and Wistar strain albino rats in vivo models. The neutralisation of MTV-induced production of free radicals, alteration of the mitochondrial transmembrane potential, and upregulated expression of genes involved in apoptosis, detoxification, and stress response in C. elegans by TDF surpassed the same effect shown by individual components of the TDF. Further, TDF efficiently neutralized the MTV-induced increase in blood glucose level within 30 to 60 min post-treatment, organ tissue damage, necrosis, and pulmonary oedema in Wistar rats, indicating its clinical application for effecting treating M. tamulus envenomation. This study demonstrates for the first time that C. elegans can be a model organism for screening the neutralization potency of the drug molecules against a neurotoxic scorpion venom. Full article

Alzheimer’s disease (AD) is one of the most widespread neurodegenerative diseases. Most of the current AD therapeutic developments are directed towards improving neuronal cell function or facilitating Aβ amyloid clearance from the brain. However, some recent evidence suggests that astrocytes may play a significant role in the pathogenesis of AD. In this paper, we evaluated the effects of the optogenetic activation of Gq-coupled exogenous receptors expressed in astrocytes as a possible way of restoring brain function in the AD mouse model. We evaluated the effects of the optogenetic activation of astrocytes on long-term potentiation, spinal morphology and behavioral readouts in 5xFAD mouse model of AD. We determined that in vivo chronic activation of astrocytes resulted in the preservation of spine density, increased mushroom spine survival, and improved performance in cognitive behavioral tests. Furthermore, chronic optogenetic stimulation of astrocytes resulted in the elevation of EAAT-2 glutamate uptake transporter expression, which could be a possible explanation for the observed in vivo neuroprotective effects. The obtained results suggest that the persistent activation of astrocytes may be considered a potential therapeutic approach for the treatment of AD and possibly other neurodegenerative disorders. Full article

In the inflamed uterus, the production and secretion of prostaglandins (PGs) and noradrenergic innervation pattern are changed. Receptor-based control of prostaglandin E2 (PGE2) production and secretion by noradrenaline during uterine inflammation is unknown. The aim of this study was to determine the role of α1-, α2- and β-adrenoreceptors (ARs) in noradrenaline-influenced PG-endoperoxidase synthase-2 (PTGS-2) and microsomal PTGE synthase-1 (mPTGES-1) protein levels in the inflamed pig endometrium, and in the secretion of PGE2 from this tissue. E. coli suspension (E. coli group) or saline (CON group) was injected into the uterine horns. Eight days later, severe acute endometritis developed in the E. coli group. Endometrial explants were incubated with noradrenaline and/or α1-, α2- and β-AR antagonists. In the CON group, noradrenaline did not significantly change PTGS-2 and mPTGES-1 protein expression and increased PGE2 secretion compared to the control values (untreated tissue). In the E. coli group, both enzyme expression and PGE2 release were stimulated by noradrenaline, and these values were higher versus the CON group. The antagonists of α1- and α2-AR isoforms and β-AR subtypes do not significantly alter the noradrenaline effect on PTGS-2 and mPTGES-1 protein levels in the CON group, compared to noradrenaline action alone. In this group, α1A-, α2B- and β2-AR antagonists partly eliminated noradrenaline-stimulated PGE2 release. Compared to the noradrenaline effect alone, α1A-, α1B-, α2A-, α2B-, β1-, β2- and β3-AR antagonists together with noradrenaline reduced PTGS-2 protein expression in the E. coli group. Such effects were also exerted in this group by α1A-, α1D-, α2A-, β2- and β3-AR antagonists with noradrenaline on mPTGES-1 protein levels. In the E. coli group, the antagonists of all isoforms of α1-ARs and subtypes of β-ARs as well as α2A-ARs together with noradrenaline decreased PGE2 secretion versus noradrenaline action alone. Summarizing, in the inflamed pig endometrium, α1(A, B)-, α2(A, B)- and β(1, 2, 3)-ARs mediate the noradrenaline stimulatory effect on PTGE-2 protein expression, while noradrenaline via α1(A, D)-, α2A- and β(2, 3)-ARs increases mPTGES-1 protein expression and α1(A, B, D)-, α2A- and β(1, 2, 3)-ARs are involved in PGE2 release. Data suggest that noradrenaline may indirectly affect the processes regulated by PGE2 by influencing its production. Pharmacological modulation of particular AR isoforms/subtypes can be used to change PGE2 synthesis/secretion to alleviate inflammation and improve uterine function. Full article

Ceiba aesculifolia (Kunth) Britten & Baker f (Malvaceae) is used for the folk treatment of mood disorders. C. aesculifolia bark was extracted in ethanol, and the extract (CAE) was chemically standardized using gas chromatography–mass spectrometry (GC-MS). This study evaluated the effects of CAE (10–100 mg/kg p.o.) on anxiolytic-like activity, sedation, locomotor activity, depression-like activity, and spatial working memory using in vivo rodent models. A possible mechanism for the anxiolytic-like and antidepressant-like actions induced by CAE was assessed using neurotransmission pathway inhibitors. Myristic acid was one of the compounds found in CAE using GC-MS. This study also evaluated the anxiolytic-like activity and the sedative actions of myristic acid and assessed a possible mechanism of action using neurotransmission pathway inhibitors and an in silico analysis. CAE elicited anxiolytic-like activity and antidepressant-like effects (ED₅₀ = 57 mg/kg). CAE (10–100 mg/kg) did not affect locomotor coordination or induce sedation. The anxiolytic-like and antidepressant-like actions of CAE were reverted by prazosin, suggesting a possible participation of the noradrenergic system. The anxiolytic-like activity of myristic acid was reverted by the co-administration of prazosin and partially reverted by ketanserin. The docking study revealed that myristic acid can form favorable interactions within 5-HT2A and α1A-adrenoreceptor binding pockets. Full article

Epidemiological studies and preclinical models suggest that chronic stress might accelerate breast cancer (BC) growth and the development of metastasis via sympathetic neural mechanisms. Nevertheless, the role of each adrenergic pathway (α1, α2, and β) in human samples remains poorly depicted. Herein, we propose to characterize the profile of the sympathetic system (e.g., release of catecholamines, expression of catecholamine metabolic enzymes and adrenoreceptors) in BC patients, and ascertain its relevance in the development of distant metastasis. Our results demonstrated that BC patients exhibited increased plasma levels of catecholamines when compared with healthy donors, and this increase was more evident in BC patients with distant metastasis. Our analysis using the BC-TCGA database revealed that the genes coding the most expressed adrenoreceptors in breast tissues (ADRA2A, ADRA2C, and ADRB2, by order of expression) as well as the catecholamine synthesizing (PNMT) and degrading enzyme (MAO-A and MAO-B) genes were downregulated in BC tissues. Importantly, the expression of ADRA2A, ADRA2C, and ADRB2 was correlated with metastatic BC and BC subtypes, and thus the prognosis of the disease. Overall, we gathered evidence that under stressful conditions, both the α2- and β2-signaling pathways might work on a synergetic matter, thus paving the way for the development of new therapeutic approaches. Full article