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Neurochemical Research Dec 2023Xanthones are natural secondary metabolites that possess great potential as neuroprotective agents due to their prominent biological effects on Alzheimer's disease (AD).... (Review)
Review
Xanthones are natural secondary metabolites that possess great potential as neuroprotective agents due to their prominent biological effects on Alzheimer's disease (AD). However, their underlying mechanisms in AD remain unclear. This study aimed to systematically review the effects and mechanisms of xanthones in cell culture and animal studies, gaining a better understanding of their roles in AD. A comprehensive literature search was conducted in the Medline and Scopus databases using specific keywords to identify relevant articles published up to June 2023. After removing duplicates, all articles were imported into the Rayyan software. The article titles were screened based on predefined inclusion and exclusion criteria. Relevant full-text articles were assessed for biases using the OHAT tool. The results were presented in tables. Xanthones have shown various pharmacological effects towards AD from the 21 preclinical studies included. Cell culture studies demonstrated the anti-cholinesterase activity of xanthones, which protects against the loss of acetylcholine. Xanthones exhibited neuroprotective effects by promoting cell viability, reducing the accumulation of β-amyloid and tau aggregation. The administration of xanthones in animal models resulted in a reduction in neuronal inflammation by decreasing microglial and astrocyte burden. In terms of molecular mechanisms, xanthones prevented neuroinflammation through the modulation of signaling pathways, including TLR4/TAK1/NF-κB and MAPK pathways. Mechanisms such as activation of caspase-3 and -9 and suppression of endoplasmic reticulum stress were also reported. Despite the various neuroprotective effects associated with xanthones, there are limited studies reported on their underlying mechanisms in AD. Further studies are warranted to fully understand their potential roles in AD.
Topics: Animals; Alzheimer Disease; Amyloid beta-Peptides; Antioxidants; Neuroprotective Agents; Xanthones
PubMed: 37578655
DOI: 10.1007/s11064-023-04005-8 -
Frontiers in Pharmacology 2023Motilin (MLN) is a gastrointestinal (GI) hormone produced in the upper small intestine. Its most well understood function is to participate in Phase III of the...
Motilin (MLN) is a gastrointestinal (GI) hormone produced in the upper small intestine. Its most well understood function is to participate in Phase III of the migrating myoelectric complex component of GI motility. Changes in MLN availability are associated with GI diseases such as gastroesophageal reflux disease and functional dyspepsia. Furthermore, herbal medicines have been used for several years to treat various GI disorders. We systematically reviewed clinical and animal studies on how herbal medicine affects the modulation of MLN and subsequently brings the therapeutic effects mainly focused on GI function. We searched the PubMed, Embase, Cochrane, and Web of Science databases to collect all articles published until 30 July 2023, that reported the measurement of plasma MLN levels in human randomized controlled trials and herbal medicine studies. The collected characteristics of the articles included the name and ingredients of the herbal medicine, physiological and symptomatic changes after administering the herbal medicine, changes in plasma MLN levels, key findings, and mechanisms of action. The frequency patterns (FPs) of botanical drug use and their correlations were investigated using an FP growth algorithm. Nine clinical studies with 1,308 participants and 20 animal studies were included in the final analyses. Herbal medicines in clinical studies have shown therapeutic effects in association with increased levels of MLN, including GI motility regulation and symptom improvement. Herbal medicines have also shown anti-stress, anti-tumor, and anti-inflammatory effects . Various biochemical markers may correlate with MLN levels. Markers may have a positive correlation with plasma MLN levels included ghrelin, acetylcholine, and secretin, whereas a negative correlation included triglycerides and prostaglandin E. Markers, such as gastrin and somatostatin, did not show any correlation with plasma MLN levels. Based on the FP growth algorithm, and were the most frequently used species. Herbal medicine may have therapeutic effects mainly on GI symptoms with involvement of MLN regulation and may be considered as an alternative option for the treatment of GI diseases. Further studies with more solid evidence are needed to confirm the efficacy and mechanisms of action of herbal medicines. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=443244, identifier CRD42023443244.
PubMed: 38161695
DOI: 10.3389/fphar.2023.1286333 -
Cureus Jan 2024Parkinson's disease (PD) is a terminal, debilitating neurodegenerative disorder typically affecting individuals over 60. It is associated with various conditions that... (Review)
Review
Parkinson's disease (PD) is a terminal, debilitating neurodegenerative disorder typically affecting individuals over 60. It is associated with various conditions that drastically affect the patient's quality of life (QoL). Although there is no cure for PD, its symptoms can be significantly improved and even resolved through different treatments. Mainstay treatments for PD include levodopa combined with carbidopa, dopamine agonists, and even deep brain stimulation (DBS) of the subthalamic nucleus. New treatment methods have emerged, such as botulinum toxin (BoNT), which further improve symptoms and, thus, the QoL of patients with PD. Botulinum toxin is a potent neurotoxin produced by that typically causes descending paralysis by suppressing acetylcholine secretion. Serotypes used to treat various disorders include serotype A (BoNT-A) and serotype B (BoNT-B). This paper aims to evaluate the outcomes of BoNT injection on different symptoms associated with PD. An extensive review using PubMed, ScienceDirect, and ProQuest articles concerning 'botulinum toxin and Parkinson's disease' was done per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, resulting in 23,803 articles. After applying strict inclusion and exclusion criteria, the total number of articles was finally 41. The results showed that movement disorders were a common occurrence in PD, consisting of tremors, dystonia, and freezing of gait (FOG), with tremors being the most common symptom. Tremors and dystonia were significantly improved following BoNT-A, correlating with significant improvements in various scales subjectively and objectively evaluating the symptoms and QoL. In contrast, FOG was not significantly improved by either BoNT-A or BoNT-B. Pain is associated with movement disorders such as PD and was the primary indication for the administration of BoNT; studies found pain and QoL were significantly improved following BoNT injection. Quality of life can also be affected by sialorrhea and overactive bladder, which often occur as the disease progresses. Injections of BoNT-A and BoNT-B were shown to significantly improve saliva production, flow rate, drooling frequency, voiding frequency, and urinary urge incontinence. Across all studies analyzed, it is evident that BoNT may have a significant effect on improving the QoL of patients suffering from PD. While research continues to find a cure or stop the progression of PD, it remains critical to continue focusing on improving patients' QoL. Future research should evaluate whether BoNT can be used to successfully treat other symptoms of PD, such as epiphora or constipation.
PubMed: 38435899
DOI: 10.7759/cureus.53309 -
Advances in Clinical and Experimental... Mar 2024Alzheimer's disease (AD) affects millions of people worldwide. The most commonly used drugs are acetylcholinesterase inhibitors, i.e., donepezil, galantamine and...
Alzheimer's disease (AD) affects millions of people worldwide. The most commonly used drugs are acetylcholinesterase inhibitors, i.e., donepezil, galantamine and rivastigmine, which increase levels of acetylcholine. However, the exact efficacy and safety of acetylcholinesterase inhibitors in the treatment of AD is still unclear. The main objective of the current study was to determine the exact safety and efficacy profile of acetylcholinesterase inhibitors in the treatment of AD by conducting a systematic review and meta-analysis of clinical trials according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted a web-based literature search of PubMed and clinical trial websites using relevant keywords. Data were extracted from eligible records and pooled as mean difference (MD) or risk ratio (RR) values with their 95% confidence interval (95% CI) using Review Manager software (v. 5.3 for Windows). Heterogeneity was calculated using χ2 and I2 tests. The standard mean difference (SMD) was -0.33 [-0.52, -0.13] for donepezil, -0.48 [-0.58, -0.38] for galantamine and -0.65 [-1.06, -0.23] for rivastigmine, indicating a significant effect of these drugs on cognitive outcomes. Here we show the significant effects of all available acetylcholinesterase inhibitors on cognitive function in patients with AD. However, further studies are needed to draw valid conclusions about the effects of acetylcholinesterase inhibitors on functional outcomes and adverse events.
PubMed: 38439609
DOI: 10.17219/acem/176051 -
Toxins Apr 2024Botulinum toxin type A (BONT-A) has shown promise in improving the mood-related symptoms of psychiatric disorders by targeting muscles linked to the expression of... (Review)
Review
Botulinum toxin type A (BONT-A) has shown promise in improving the mood-related symptoms of psychiatric disorders by targeting muscles linked to the expression of negative emotions. We conducted a systematic review of past and ongoing efficacy trials of BONT-A therapy for psychiatric disorders to identify relevant trends in the field and discuss the refinement of therapeutic techniques. A comprehensive search for published clinical trials using BONT-A injections for psychiatric disorders was performed on 4 May 2023 through OVID databases (MEDLINE, Embase, APA PsycINFO). Unpublished clinical trials were searched through the ClinicalTrials.gov and International Clinical Trial Registry Platform public registries. The risk of bias was assessed using the JBI Critical Appraisal tools for use in systematic reviews. We identified 21 studies (17 published, 4 unpublished clinical trials) involving 471 patients. The studies focused on evaluating the efficacy of BONT-A for major depressive, borderline personality, social anxiety, and bipolar disorders. BONT-A was most commonly injected into the glabellar area, with an average dose ranging between 37.75 U and 44.5 U in published studies and between 32.7 U and 41.3 U in unpublished trials. The results indicated significant symptom reductions across all the studied psychiatric conditions, with mild adverse effects. Thus, BONT-A appears to be safe and well-tolerated for psychiatric disorders of negative affectivity. However, despite the clinical focus, there was a noted shortage of biomarker-related assessments. Future studies should focus on pursuing mechanistic explorations of BONT-A effects at the neurobiological level.
Topics: Humans; Mental Disorders; Botulinum Toxins, Type A; Clinical Trials as Topic; Treatment Outcome
PubMed: 38668616
DOI: 10.3390/toxins16040191 -
Critical Reviews in Toxicology Sep 2023Malathion and diazinon are pesticides commonly used in agriculture to avoid insects that damage crops; however, they may cause impairment to the male genital system of... (Review)
Review
Malathion and diazinon are pesticides commonly used in agriculture to avoid insects that damage crops; however, they may cause impairment to the male genital system of exposed humans. The present work carried out a systematic review of the literature concerning the primary studies that assessed the reproductive effects resulting from male rats and mice exposed to malathion or diazinon. The search for articles was performed on the databases PubMed, LILACS, Scopus, and SciELO, using different combinations of the search terms "malathion," "diazinon," "mice," "rats," "male reproduction," "fertility," and "sperm," followed by the Boolean operators AND or OR. The results obtained indicate that both pesticides act as reproductive toxicants by reducing sperm quality, diminishing hormonal concentrations, inducing increased oxidative stress, and provoking histopathological damage in reproductive organs. Then, the exposure to malathion and diazinon may provoke diminished levels of testosterone by increasing acetylcholine stimulation in the testis through muscarinic receptors, thus, providing a reduction in steroidogenic activity in Leydig cells, whose effect is related to lower levels of testosterone in rodents, and consequently, it is associated with decreased fertility. Considering the toxic effects on the male genital system of rodents and the possible male reproductive toxicity in humans, it is recommended the decreased use of these pesticides and their replacement for others that show no or few toxic effects for non-target animals.
Topics: Humans; Male; Rats; Animals; Mice; Malathion; Diazinon; Insecticides; Rodentia; Semen; Pesticides; Reproduction; Testosterone
PubMed: 37922518
DOI: 10.1080/10408444.2023.2270494 -
Cells Jan 2024Acetylcholine signaling is attenuated in early Alzheimer's disease (AD) and other dementias. A significant reduction in the expression of nicotinic acetylcholine... (Review)
Review
Acetylcholine signaling is attenuated in early Alzheimer's disease (AD) and other dementias. A significant reduction in the expression of nicotinic acetylcholine receptors (nAChRs) in the brain of AD patients has also been reported in several molecular biological and in situ labeling studies. The modulation of the functional deficit of the cholinergic system as a pharmacological target could therefore have a clinical benefit, which is not to be neglected. This systematic review was conducted to identify clinical trials, which evaluated the safety and efficacy of nicotinic acetylcholine receptor agonists using Clinicaltrial (CT) and EudraCT databases. Structured searches identified 39 trials, which used 15 different drugs designed to increase the function of the nAChRs. Most of the identified clinical trials were phase II trials, with some of them classified as ongoing for several years. The systematic screening of the literature led to the selection of 14 studies out of the 8261 bibliographic records retrieved. Six trials reported detailed data on adverse events associated with the intervention, while twelve trials reported data on efficacy measures, such as attention, behavior and cognition. Overall, smost of the physical side effects of cholinergic agonists were reported to be well tolerated. Some trials also reported improvements in attention. However, the efficacy of these drugs in other cognitive and behavioral outcomes remains highly controversial.
Topics: Humans; Alzheimer Disease; Receptors, Nicotinic; Brain; Nicotinic Agonists; Cognition
PubMed: 38334629
DOI: 10.3390/cells13030237 -
Frontiers in Pharmacology 2023Recently, multiple preclinical studies have reported the beneficial effect of berberine in the treatment of Alzheimer's disease (AD). Nevertheless, the neuroprotective...
Recently, multiple preclinical studies have reported the beneficial effect of berberine in the treatment of Alzheimer's disease (AD). Nevertheless, the neuroprotective effects and possible mechanisms of berberine against AD are not universally recognized. This study aimed to conduct a systematic review and meta-analysis by integrating relevant animal studies to assess the neuroprotective effects and potential mechanisms of berberine on AD. We systematically searched PubMed, Embase, Scopus and Web of Science databases that reported the effects of berberine on AD models up to 1 February 2023. The escape latency, times of crossing platform, time spent in the target quadrant and pro-oligomerized amyloid beta 42 (Aβ) were included as primary outcomes. The secondary outcomes were the Tau-ps 204, Tau-ps 404, β-site of APP cleaving enzyme (BACE1), amyloid precursor protein (APP), acetylcholine esterase (AChE), tumor necrosis factor ⍺ (TNF-α), interleukin 1β (IL-1β), IL-6, nitric oxide (NO), glial fibrillary acidic protein (GFAP), malonaldehyde (MDA), glutathione S-transferase (GST), glutathione (GSH), glutathione peroxidase (GPx), Beclin-1 and neuronal apoptosis cells. This meta-analysis was conducted using RevMan 5.4 and STATA 15.1. The SYRCLE's risk of bias tool was used to assess the methodological quality. Twenty-two studies and 453 animals were included in the analysis. The overall results showed that berberine significantly shortened the escape latency ( < 0.00001), increased times of crossing platform ( < 0.00001) and time spent in the target quadrant ( < 0.00001), decreased Aβ deposition ( < 0.00001), Tau-ps 202 ( < 0.00001) and Tau-ps 404 ( = 0.002), and improved BACE1, APP, AChE, Beclin-1, neuronal apoptosis cells, oxidative stress and inflammation levels. Berberine may be a promising drug for the treatment of AD based on preclinical evidence (especially when the dose was 5-260 mg/kg). The potential mechanisms for these protective effects may be closely related to anti-neuroinflammation, anti-oxidative stress, modulation of autophagy, inhibition of neuronal apoptosis and protection of cholinergic system. However, these results may be limited by the quality of existing research. Larger and methodologically more rigorous preclinical research are needed to provide more convincing evidence.
PubMed: 38259291
DOI: 10.3389/fphar.2023.1287750 -
Pain Mar 2024Botulinum toxin (BoNT), a presynaptic inhibitor of acetylcholine (Ach) release at the neuromuscular junction (NMJ), is a successful and safe drug for the treatment of...
Botulinum toxin (BoNT), a presynaptic inhibitor of acetylcholine (Ach) release at the neuromuscular junction (NMJ), is a successful and safe drug for the treatment of several neurological disorders. However, a wide and recent literature review has demonstrated that BoNT exerts its effects not only at the "periphery" but also within the central nervous system (CNS). Studies from animal models, in fact, have shown a retrograde transport to the CNS, thus modulating synaptic function. The increasing number of articles reporting efficacy of BoNT on chronic neuropathic pain (CNP), a complex disease of the CNS, demonstrates that the central mechanisms of BoNT are far from being completely elucidated. In this new light, BoNT might interfere with the activity of spinal, brain stem, and cortical circuitry, modulating excitability and the functional organization of CNS in healthy conditions. Botulinum toxins efficacy on CNP is the result of a wide and complex action on many and diverse mechanisms at the basis of the maladaptive plasticity, the core of the pathogenesis of CNP. This systematic review aims to discuss in detail the BoNT's mechanisms and effects on peripheral and central neuroplasticity, at the basis for the clinical efficacy in CNP syndromes.
PubMed: 38452215
DOI: 10.1097/j.pain.0000000000003204 -
Journal of Orthopaedic Translation May 2024The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves... (Review)
Review
The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves nerve terminal and postsynaptic decline, denervation, and loss of motor units, significantly contributes to muscle weakness and dysfunction. Although physical training has been shown to make substantial modifications in NMJ of both young and aged animals, the results are often influenced by methodological variables in existing studies. Moreover, there is still lack of strong consensus on the specific effects of exercise on improving the morphology and function of the ageing NMJ. Consequently, the purpose of this study was to conduct a systematic review to elucidate the effects of exercise training on NMJ compartments in the elderly. We conducted a systematic review using PubMed, Embase, and Web of Science databases, employing relevant keywords. Two independent reviewers selected studies that detailed NMJ changes during exercise in ageing, written in English, and available in full text. In total, 20 papers were included. We examined the altered adaptation of the NMJ to exercise, focusing on presynaptic and postsynaptic structures and myofibers in older animals or humans. Our findings indicated that aged NMJs exhibited different adaptive responses to physical exercise compared to younger counterparts. Endurance training, compared with resistance and voluntary exercise regimens, was found to have a more pronounced effect on NMJ structural remodeling, particularly in fast twitch muscle fibers. Physical exercise was observed to promote the formation and maintenance of acetylcholine receptor (AChR) clusters by increasing the recombinant docking protein 7 (Dok7) expression and stabilizing Agrin and lipoprotein receptor-related protein 4 (LRP4). These insights suggest that research on exercise-related therapies could potentially attenuate the progression of neuromuscular degeneration. Translational potential of this article: This systematic review provides a detailed overview of the effects of different types of physical exercise on improving NMJ in the elderly, providing scientific support for the timely intervention of muscle degeneration in the elderly by physical exercise, and providing help for the development of new therapeutic interventions in the future.
PubMed: 38817243
DOI: 10.1016/j.jot.2024.03.007