ABSTRACT
Cancer has emerged as a formidable global health challenge, with treatment methods like chemotherapy and radiation often exacerbating the situation due to their associated side effects. Opting for natural sources like plants as a safer and environmentally friendly alternative seems promising. Historically, plants have served as valuable sources for treating diverse health conditions, attributable to their rich composition of therapeutic phytochemicals. Within this array of phytochemicals, alkaloids, especially those found in the Solanaceae plant family, are notably prominent. Alkaloids from Solanaceae plant family called Solanum alkaloids demonstrate noteworthy anti-tumour characteristics and exert a potent inhibitory influence on cancer cell proliferation. They trigger programmed cell death in cancerous cells through various molecular pathways, whether administered alone or combined with other medications. Solanum alkaloids act upon cancer cells via multiple mechanisms, including apoptosis induction, suppression of cell growth and migration, as well as inhibition of angiogenesis. This review provides insights into the anti-cancer attributes of Solanum alkaloids found in various Solanum plant species, along with a brief overview of their other medicinal properties.
Subject(s)
Alkaloids , Antineoplastic Agents, Phytogenic , Neoplasms , Solanum , Humans , Neoplasms/drug therapy , Neoplasms/pathology , Solanum/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Agents, Phytogenic/chemistry , Alkaloids/pharmacology , Alkaloids/chemistry , Alkaloids/therapeutic use , Cell Proliferation/drug effects , Apoptosis/drug effects , AnimalsABSTRACT
Histamine performs dual roles as an immune regulator and a neurotransmitter in the mammalian brain. The histaminergic system plays a vital role in the regulation of wakefulness, cognition, neuroinflammation, and neurogenesis that are substantially disrupted in various neurodegenerative and neurodevelopmental disorders. Histamine H3 receptor (H3R) antagonists and inverse agonists potentiate the endogenous release of brain histamine and have been shown to enhance cognitive abilities in animal models of several brain disorders. Microglial activation and subsequent neuroinflammation are implicated in impacting embryonic and adult neurogenesis, contributing to the development of Alzheimer's disease (AD), Parkinson's disease (PD), and autism spectrum disorder (ASD). Acknowledging the importance of microglia in both neuroinflammation and neurodevelopment, as well as their regulation by histamine, offers an intriguing therapeutic target for these disorders. The inhibition of brain H3Rs has been found to facilitate a shift from a proinflammatory M1 state to an anti-inflammatory M2 state, leading to a reduction in the activity of microglial cells. Also, pharmacological studies have demonstrated that H3R antagonists showed positive effects by reducing the proinflammatory biomarkers, suggesting their potential role in simultaneously modulating crucial brain neurotransmissions and signaling cascades such as the PI3K/AKT/GSK-3ß pathway. In this review, we highlight the potential therapeutic role of the H3R antagonists in addressing the pathology and cognitive decline in brain disorders, e.g., AD, PD, and ASD, with an inflammatory component.
ABSTRACT
Introduction: Adherence studies among rheumatoid arthritis (RA) patients, in Egypt and throughout the Middle East region, are lacking. This study aimed to evaluate methotrexate (MTX) adherence in Rheumatoid arthritis (RA) patients and to identify specific non-adherence predictors. Methods: A cross-sectional observational study included 300 RA patients who were administered MTX for at least one year. The survey was completed through direct interviews. The demographic patient data were collected (age, education, sex, work status, disease duration, duration of MTX administration and current dose). Patients' adherence to MTX predictors for non-adherence, MTX side effects and functional disability were assessed in the study. Results: Majority of respondents showed good MTX adherence, and more than 50% of patient's experienced MTX side effects. A large percentage of participants showed low knowledge about MTX nature and side effects. Most participants reported no or some difficulty in quality of life-related activities and functional disability. Conclusion: MTX adherence and awareness were positively correlated to many variables, including, age, educational level and disease duration, which in turn has its positive impact on the patient's quality of life. Still, more research is needed to determine the impact of non-adherence on the patient's health outcomes.
ABSTRACT
Microglial activation contributes to the neuropathology of Parkinson's disease (PD). Inhibiting M1 while simultaneously boosting M2 microglia activation may therefore be a potential treatment for PD. Apilarnil (API) is a bee product produced from drone larvae. Recent research has demonstrated the protective effects of API on multiple body systems. Nevertheless, its impact on PD or the microglial M1/M2 pathway has not yet been investigated. Thus, we intended to evaluate the dose-dependent effects of API in rotenone (ROT)-induced PD rat model and explore the role of M1/M2 in mediating its effect. Seventy-two Wistar rats were equally grouped as; control, API, ROT, and groups in which API (200, 400, and 800 mg/kg, p.o.) was given simultaneously with ROT (2 mg/kg, s.c.) for 28 days. The high dose of API (800 mg/kg) showed enhanced motor function, higher expression of tyrosine hydroxylase and dopamine levels, less dopamine turnover and α-synuclein expression, and a better histopathological picture when compared to the ROT group and the lower two doses. API's high dose exerted its neuroprotective effects through abridging the M1 microglial activity, illustrated in the reduced expression of miR-155, Iba-1, CD36, CXCL10, and other pro-inflammatory markers' levels. Inversely, API high dose enhanced M2 microglial activity, witnessed in the elevated expression of miR-124, CD206, Ym1, Fizz1, arginase-1, and other anti-inflammatory indices, in comparison to the diseased group. To conclude, our study revealed a novel neuroprotective impact for API against experimentally induced PD, where the high dose showed the highest protection via rebalancing M1/M2 polarization.
Subject(s)
MicroRNAs , Microglia , Neuroprotective Agents , Rats, Wistar , Rotenone , Animals , MicroRNAs/genetics , MicroRNAs/metabolism , Microglia/drug effects , Microglia/metabolism , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Male , Rats , Disease Models, Animal , Dopamine/metabolism , Parkinson Disease/drug therapy , Parkinson Disease/metabolism , Parkinson Disease, Secondary/chemically induced , Parkinson Disease, Secondary/drug therapy , Parkinson Disease, Secondary/metabolism , Parkinson Disease, Secondary/pathology , alpha-Synuclein/metabolism , alpha-Synuclein/genetics , Tyrosine 3-Monooxygenase/metabolism , Tyrosine 3-Monooxygenase/geneticsABSTRACT
MicroRNAs (miRNAs) are short RNA molecules that are not involved in coding for proteins. They have a significant function in regulating gene expression after the process of transcription. Their participation in several biological processes has rendered them appealing subjects for investigating age-related disorders. Increasing data indicates that miRNAs can be influenced by dietary variables, such as macronutrients, micronutrients, trace minerals, and nutraceuticals. This review examines the influence of dietary factors and nutraceuticals on the regulation of miRNA in relation to the process of aging. We examine the present comprehension of miRNA disruption in age-related illnesses and emphasize the possibility of dietary manipulation as a means of prevention or treatment. Consolidating animal and human research is essential to validate the significance of dietary miRNA control in living organisms, despite the abundance of information already provided by several studies. This review elucidates the complex interaction among miRNAs, nutrition, and aging, offering valuable insights into promising areas for further research and potential therapies for age-related disorders.
ABSTRACT
There has been a lot of interest in using naturally occurring substances to treat a wide variety of chronic disorders in recent years. From the gum resin of Boswellia serrata and Boswellia carteri, the pentacyclic triterpene molecules known as boswellic acid (BA) are extracted. We aimed to provide a detailed overview of the origins, chemistry, synthetic derivatives, pharmacokinetic, and biological activity of numerous Boswellia species and their derivatives. The literature searched for reports of B. serrata and isolated BAs having anti-cancer, anti-microbial, anti-inflammatory, anti-arthritic, hypolipidemic, immunomodulatory, anti-diabetic, hepatoprotective, anti-asthmatic, and clastogenic activities. Our results revealed that the cytotoxic and anticancer effects of B. serrata refer to its triterpenoid component, including BAs. Three-O-acetyl-11-keto-BA was the most promising cytotoxic molecule among tested substances. Activation of caspases, upregulation of Bax expression, downregulation of nuclear factor-kappa B (NF-kB), and stimulation of poly (ADP)-ribose polymerase (PARP) cleavage are the primary mechanisms responsible for cytotoxic and antitumor effects. Evidence suggests that BAs have shown promise in combating a wide range of debilitating disease conditions, including cancer, hepatic, inflammatory, and neurological disorders.
Subject(s)
Plant Extracts , Triterpenes , Plant Extracts/pharmacology , Anti-Inflammatory Agents/pharmacology , Triterpenes/pharmacology , Caspases , Immunologic FactorsABSTRACT
Lipid and/or polymer-based drug conjugates can potentially minimize side effects by increasing drug accumulation at target sites and thus augment patient compliance. Formulation factors can present a potent influence on the characteristics of the obtained systems. The selection of an appropriate solvent with satisfactory rheological properties, miscibility, and biocompatibility is essential to optimize drug release. This work presents a computational study of the effect of the basic formulation factors on the characteristics of the obtained in situ-forming particulates (IFPs) encapsulating a model drug using a 21.31 full factorial experimental design. The emulsion method was employed for the preparation of lipid and/or polymer-based IFPs. The IFP release profiles and parameters were computed. Additionally, a desirability study was carried out to choose the optimum formulation for further morphological examination, rheological study, and PBPK physiological modeling. Results revealed that the type of particulate forming agent (lipid/polymer) and the incorporation of structure additives like Brij 52 and Eudragit RL can effectively augment the release profile as well as the burst of the drug. The optimized formulation exhibited a pseudoplastic rheological behavior and yielded uniformly spherical-shaped dense particulates with a PS of 573.92 ± 23.5 nm upon injection. Physiological modeling simulation revealed the pioneer pharmacokinetic properties of the optimized formulation compared to the observed data. These results assure the importance of controlling the formulation factors during drug development, the potentiality of the optimized IFPs for the intramuscular delivery of piroxicam, and the reliability of PBPK physiological modeling in predicting the biological performance of new formulations with effective cost management.
ABSTRACT
The role of histamine H3 receptors (H3Rs) in memory and the prospective of H3R antagonists in pharmacological control of neurodegenerative disorders, e.g., Alzheimer's disease (AD), is well-accepted. Therefore, the procognitive effects of acute systemic administration of H3R antagonist E169 (2.5-10 mg/kg, i.p.) on MK801-induced amnesia in C57BL/6J mice using the novel object recognition test (NORT) were evaluated. E169 (5 mg) provided a significant memory-improving effect on MK801-induced short- and long-term memory impairments in NORT. The E169 (5 mg)-provided effects were comparable to those observed with the reference phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 and were abrogated with the H3R agonist (R)-α-methylhistamine (RAMH). Additionally, our results demonstrate that E169 ameliorated MK801-induced memory deficits by antagonism of H3Rs and by modulation of the level of disturbance in the expression of PI3K, Akt, and GSK-3ß proteins, signifying that E169 mitigated the Akt-mTOR signaling pathway in the hippocampus of tested mice. Moreover, the results observed revealed that E169 (2.5-10 mg/kg, i.p.) did not alter anxiety levels and locomotor activity of animals in open field tests, demonstrating that performances improved following acute systemic administration with E169 in NORT are unrelated to changes in emotional response or in spontaneous locomotor activity. In summary, these obtained results suggest the potential of H3R antagonists such as E169, with good in silico physicochemical properties and stable retained key interactions in docking studies at H3R, in simultaneously modulating disturbed brain neurotransmitters and the imbalanced Akt-mTOR signaling pathway related to neurodegenerative disorders, e.g., AD.
Subject(s)
Alzheimer Disease , Histamine H3 Antagonists , Animals , Mice , Mice, Inbred C57BL , Glycogen Synthase Kinase 3 beta , Phosphatidylinositol 3-Kinases , Dizocilpine Maleate , Histamine H3 Antagonists/pharmacology , Histamine H3 Antagonists/therapeutic use , Proto-Oncogene Proteins c-akt , Phosphatidylinositol 3-Kinase , TOR Serine-Threonine Kinases , Amnesia/chemically induced , Amnesia/drug therapy , Alzheimer Disease/drug therapy , Signal Transduction , CognitionABSTRACT
Altered regulation of neurotransmitters may lead to many pathophysiological changes in brain disorders including autism spectrum disorder (ASD). Given the fact that there are no FDA-approved effective treatments for the social deficits in ASD, the present study determined the effects of chronic systemic treatment of the novel multiple-active H3R/D2R/D3R receptor antagonist ST-2223 on ASD-related social deficits in a male Black and Tan Brachyury (BTBR) mice. ST-2223 (2.5, 5, and 10 mg/kg, i.p.) significantly and dose-dependently mitigated social deficits and disturbed anxiety levels of BTBR mice (p < 0.05) in comparison to the effects of aripiprazole (1 mg/kg, i.p.). Moreover, levels of monoaminergic neurotransmitters quantified by LC-MS/MS in four brain regions including the prefrontal cortex, cerebellum, striatum, and hippocampus unveiled significant elevation of histamine (HA) in the cerebellum and striatum; dopamine (DA) in the prefrontal cortex and striatum; as well as acetylcholine (ACh) in the prefrontal cortex, striatum, and hippocampus following ST-2223 (5 mg/kg) administration (all p < 0.05). These in vivo findings demonstrate the mitigating effects of a multiple-active H3R/D2R/D3R antagonist on social deficits of assessed BTBR mice, signifying its pharmacological potential to rescue core ASD-related behaviors and altered monoaminergic neurotransmitters. Further studies on neurochemical alterations in ASD are crucial to elucidate the early neurodevelopmental variations behind the core symptoms and heterogeneity of ASD, leading to new approaches for the future therapeutic management of ASD.
ABSTRACT
A relationship appears to exist between dysfunction of brain histamine (HA) and various neuropsychiatric brain disorders. The possible involvement of brain HA in neuropathology has gained attention recently, and its role in many (patho)physiological brain functions including memory, cognition, and sleep-wake cycle paved the way for further research on the etiology of several brain disorders. Histamine H3 receptor (H3R) evidenced in the brains of rodents and humans remains of special interest, given its unique position as a pre- and postsynaptic receptor, controlling the synthesis and release of HA as well as different other neurotransmitters in different brain regions, respectively. Despite several disappointing outcomes for several H3R antagonists/inverse agonists in clinical studies addressing their effectiveness in Alzheimer's disease (AD), Parkinson's disease (PD), and schizophrenia (SCH), numerous H3R antagonists/inverse agonists showed great potentials in modulating memory and cognition, mood, and sleep-wake cycle, thus suggesting its potential role in neurocognitive and neurodegenerative diseases such as AD, PD, SCH, narcolepsy, and major depression in preclinical rodent models. In this review, we present preclinical applications of selected H3R antagonists/inverse agonists and their pharmacological effects on cognitive impairment, anxiety, depression, and sleep-wake cycle disorders. Collectively, the current review highlights the behavioral impact of developments of H3R antagonists/inverse agonists, aiming to further encourage researchers in the preclinical drug development field to profile the potential therapeutic role of novel antagonists/inverse agonists targeting histamine H3Rs.
ABSTRACT
Dysregulation in brain neurotransmitters underlies several neuropsychiatric disorders, e.g., autism spectrum disorder (ASD). Also, abnormalities in the extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway pave the way for neuroinflammation, neurodegeneration, and altered learning phenotype in ASD. Therefore, the effects of chronic systemic administration of the multiple-targeting antagonist ST-713 at the histamine H3 receptor (H3R) and dopamine D2/D3 receptors (D2/D3R) on repetitive self-grooming, aggressive behaviors, and abnormalities in the MAPK pathway in BTBR T + Itpr3tf/J (BTBR) mice were assessed. The results showed that ST-713 (2.5, 5, and 10 mg/kg, i.p.) mitigated repetitive self-grooming and aggression in BTBR mice (all p < 0.05), and the ameliorative effects of the most promising dose of ST-713 (5 mg/kg, i.p.) on behaviors were completely abrogated by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. Moreover, the elevated levels of several MAPK pathway proteins and induced proinflammatory markers such as tumor necrosis factor (TNF-α), interleukin-1ß (IL-1ß), and IL-6 were significantly suppressed following chronic administration of ST-713 (5 mg/kg, i.p.) (all p < 0.01). Furthermore, ST-713 significantly increased the levels of histamine and dopamine in hippocampal tissue of treated BTBR mice (all p < 0.01). The current observations signify the potential role of such multiple-targeting compounds, e.g., ST-713, in multifactorial neurodevelopmental disorders such as ASD.
Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Receptors, Histamine H3 , Mice , Animals , Autistic Disorder/genetics , Autism Spectrum Disorder/drug therapy , Receptors, Histamine H3/metabolism , Grooming , Dopamine/pharmacology , Mice, Inbred C57BL , Mice, Inbred Strains , Extracellular Signal-Regulated MAP Kinases , Aggression , Disease Models, AnimalABSTRACT
Several brain neurotransmitters, including histamine (HA), acetylcholine (ACh), and dopamine (DA) are suggested to be involved in several brain disorders including cognitive deficits, depression, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with Autism spectrum disorder (ASD). Therefore, the ameliorative effects of the novel multiple-active compound ST-713 with high binding affinities at histamine H3 receptor (H3R), dopamine D2sR and D3R on ASD-like behaviors in male BTBR T+tf/J mice model were assessed. ST-713 (3-(2-chloro-10H-phenothiazin-10-yl)-N-methyl-N-(4-(3-(piperidin-1-yl)propoxy)benzyl)propan-1-amine; 2.5, 5, and 10 mg/kg, i.p.) ameliorated dose-dependently social deficits, and significantly alleviated the repetitive/compulsive behaviors of BTBR mice (all P < 0.05). Moreover, ST-713 modulated disturbed anxiety levels, but failed to obliterate increased hyperactivity of tested mice. Furthermore, ST-713 (5 mg/kg) attenuated the increased levels of hippocampal and cerebellar protein expressions of NF-κB p65, COX-2, and iNOS in BTBR mice (all P < 0.05). The ameliorative effects of ST-713 on social parameters were entirely reversed by co-administration of the H3R agonist (R)-α-methylhistamine or the anticholinergic drug scopolamine. The obtained results demonstrate the potential of multiple-active compounds for the therapeutic management of neuropsychiatric disorders, e.g. ASD.
Subject(s)
Autistic Disorder/drug therapy , Dopamine Antagonists/therapeutic use , Dopamine D2 Receptor Antagonists/therapeutic use , Histamine Antagonists/therapeutic use , Receptors, Dopamine D3/antagonists & inhibitors , Receptors, Histamine H3 , Animals , Autistic Disorder/genetics , Autistic Disorder/metabolism , Cerebellum/drug effects , Cerebellum/metabolism , Dopamine Antagonists/pharmacology , Dopamine D2 Receptor Antagonists/pharmacology , Dose-Response Relationship, Drug , Hippocampus/drug effects , Hippocampus/metabolism , Histamine Antagonists/pharmacology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Receptors, Dopamine D2/metabolism , Receptors, Dopamine D3/metabolism , Receptors, Histamine H3/metabolismABSTRACT
Autism spectrum disorder (ASD) is a complex heterogeneous neurodevelopmental disorder characterized by social and communicative impairments, as well as repetitive and restricted behaviors (RRBs). With the limited effectiveness of current pharmacotherapies in treating repetitive behaviors, the present study determined the effects of acute systemic treatment of the novel multi-targeting ligand ST-2223, with incorporated histamine H3 receptor (H3R) and dopamine D2/D3 receptor affinity properties, on ASD-related RRBs in a male Black and Tan BRachyury (BTBR) mouse model of ASD. ST-2223 (2.5, 5, and 10 mg/kg, i.p.) significantly mitigated the increase in marble burying and self-grooming, and improved reduced spontaneous alternation in BTBR mice (all p < 0.05). Similarly, reference drugs memantine (MEM, 5 mg/kg, i.p.) and aripiprazole (ARP, 1 mg/kg, i.p.), reversed abnormally high levels of several RRBs in BTBR (p < 0.05). Moreover, ST-2223 palliated the disturbed anxiety levels observed in an open field test (all p < 0.05), but did not restore the hyperactivity parameters, whereas MEM failed to restore mouse anxiety and hyperactivity. In addition, ST-2223 (5 mg/kg, i.p.) mitigated oxidative stress status by decreasing the elevated levels of malondialdehyde (MDA), and increasing the levels of decreased glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) in different brain parts of treated BTBR mice (all p < 0.05). These preliminary in vivo findings demonstrate the ameliorative effects of ST-2223 on RRBs in a mouse model of ASD, suggesting its pharmacological prospective to rescue core ASD-related behaviors. Further confirmatory investigations on its effects on various brain neurotransmitters, e.g., dopamine and histamine, in different brain regions are still warranted to corroborate and expand these initial data.
Subject(s)
Autism Spectrum Disorder/drug therapy , Brain/metabolism , Dopamine D2 Receptor Antagonists/administration & dosage , Grooming/drug effects , Histamine H3 Antagonists/administration & dosage , Oxidative Stress/drug effects , Receptors, Dopamine D3/antagonists & inhibitors , Animals , Anxiety/drug therapy , Brain/drug effects , Disease Models, Animal , Dopamine D2 Receptor Antagonists/metabolism , HEK293 Cells , Histamine H3 Antagonists/metabolism , Humans , Ligands , Locomotion/drug effects , Male , Mice , Mice, Inbred C57BL , Receptors, Dopamine D2/metabolism , Receptors, Dopamine D3/metabolism , Receptors, Histamine H3/metabolismABSTRACT
Autism spectrum disorder (ASD) is a heterogenous neurodevelopmental disorder defined by persistent deficits in social interaction and the presence of patterns of repetitive and restricted behaviors. The central neurotransmitters histamine (HA) and acetylcholine (ACh) play pleiotropic roles in physiological brain functions that include the maintenance of wakefulness, depression, schizophrenia, epilepsy, anxiety and narcolepsy, all of which are found to be comorbid with ASD. Therefore, the palliative effects of subchronic systemic treatment using the multiple-active test compound E100 with high H3R antagonist affinity and AChE inhibitory effect on ASD-like behaviors in male BTBR T+tf/J (BTBR) mice as an idiopathic ASD model were assessed. E100 (5, 10 and 15 mg/kg, i.p.) dose-dependently palliated social deficits of BTBR mice and significantly alleviated the repetitive/compulsive behaviors of tested animals. Moreover, E100 modulated disturbed anxiety levels, but failed to modulate hyperactivity parameters, whereas the reference AChE inhibitor donepezil (DOZ, one milligram per kilogram) significantly obliterated the increased hyperactivity measures of tested mice. Furthermore, E100 mitigated the increased levels of AChE activity in BTBR mice with observed effects comparable to that of DOZ and significantly reduced the number of activated microglial cells compared to the saline-treated BTBR mice. In addition, the E100-provided effects on ASD-like parameters, AChE activity, and activated microglial cells were entirely reversed by co-administration of the H3R agonist (R)-α-methylhistamine (RAM). These initial overall results observed in an idiopathic ASD mice model show that E100 (5 mg/kg) alleviated the assessed behavioral deficits and demonstrate that simultaneous targeting of brain histaminergic and cholinergic neurotransmissions is crucial for palliation of ASD-like features, albeit further in vivo assessments on its effects on brain levels of ACh as well as HA are still needed.
Subject(s)
Acetylcholinesterase/metabolism , Autistic Disorder/drug therapy , Cholinesterase Inhibitors/therapeutic use , Histamine Antagonists/therapeutic use , Receptors, Histamine H3/metabolism , Animals , Anxiety/drug therapy , Autistic Disorder/enzymology , Behavior, Animal/drug effects , Brain/enzymology , Brain/metabolism , Disease Models, Animal , Locomotion/drug effects , Male , Mice , Mice, Inbred C57BL , Microglia/drug effects , Social BehaviorABSTRACT
Many behavioral and psychological symptoms of dementia (BPSD) share similarities in executive functioning and communication deficits with those described in several neuropsychiatric disorders, including Alzheimer's disease (AD), epilepsy, schizophrenia (SCH), and autism spectrum disorder (ASD). Numerous studies over the last four decades have documented altered neuroinflammation among individuals diagnosed with ASD. The purpose of this review is to examine the hypothesis that central histamine (HA) plays a significant role in the regulation of neuroinflammatory processes of microglia functions in numerous neuropsychiatric diseases, i.e., ASD, AD, SCH, and BPSD. In addition, this review summarizes the latest preclinical and clinical results that support the relevance of histamine H1-, H2-, and H3-receptor antagonists for the potential clinical use in ASD, SCH, AD, epilepsy, and BPSD, based on the substantial symptomatic overlap between these disorders with regards to cognitive dysfunction. The review focuses on the histaminergic neurotransmission as relevant in these brain disorders, as well as the effects of a variety of H3R antagonists in animal models and in clinical studies.
ABSTRACT
The histamine H3 receptor (H3R) functions as auto- and hetero-receptors, regulating the release of brain histamine (HA) and acetylcholine (ACh), respectively. The enzyme acetylcholine esterase (AChE) is involved in the metabolism of brain ACh. Both brain HA and ACh are implicated in several cognitive disorders like Alzheimer's disease, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with autistic spectrum disorder (ASD). Therefore, the novel dual-active ligand E100 with high H3R antagonist affinity (hH3R: Ki = 203 nM) and balanced AChE inhibitory effect (EeAChE: IC50 = 2 µM and EqBuChE: IC50 = 2 µM) was investigated on autistic-like sociability, repetitive/compulsive behaviour, anxiety, and oxidative stress in male C57BL/6 mice model of ASD induced by prenatal exposure to valproic acid (VPA, 500 mg/kg, intraperitoneal (i.p.)). Subchronic systemic administration with E100 (5, 10, and 15 mg/kg, i.p.) significantly and dose-dependently attenuated sociability deficits of autistic (VPA) mice in three-chamber behaviour (TCB) test (all p < 0.05). Moreover, E100 significantly improved repetitive and compulsive behaviors by reducing the increased percentage of marbles buried in marble-burying behaviour (MBB) (all p < 0.05). Furthermore, pre-treatment with E100 (10 and 15 mg/kg, i.p.) corrected decreased anxiety levels (p < 0.05), however, failed to restore hyperactivity observed in elevated plus maze (EPM) test. In addition, E100 (10 mg/kg, i.p.) mitigated oxidative stress status by increasing the levels of decreased glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT), and decreasing the elevated levels of malondialdehyde (MDA) in the cerebellar tissues (all p < 0.05). Additionally, E100 (10 mg/kg, i.p.) significantly reduced the elevated levels of AChE activity in VPA mice (p < 0.05). These results demonstrate the promising effects of E100 on in-vivo VPA-induced ASD-like features in mice, and provide evidence that a potent dual-active H3R antagonist and AChE inhibitor (AChEI) is a potential drug candidate for future therapeutic management of autistic-like behaviours.
Subject(s)
Autistic Disorder/drug therapy , Cholinesterase Inhibitors/pharmacology , Histamine H3 Antagonists/pharmacology , Oxidative Stress/drug effects , Receptors, Histamine H3/metabolism , Animals , Antioxidants/metabolism , Autistic Disorder/chemically induced , Behavior, Animal , Cerebellum/metabolism , Female , Glutathione/metabolism , Kinetics , Lipid Peroxidation , Male , Maternal Exposure , Maze Learning , Mice , Mice, Inbred C57BL , Movement , Pregnancy , Pregnancy, Animal , Valproic AcidABSTRACT
Postnatal exposure to valproic acid (VPA) in rodents induces autism-like neurobehavioral defects which are comparable to the motor and cognitive deficits observed in humans with autism spectrum disorder (ASD). Histamine H3 receptor (H3R) and acetylcholine esterase (AChE) are involved in several cognitive disorders such as Alzheimer's disease, schizophrenia, anxiety, and narcolepsy, all of which are comorbid with ASD. Therefore, the present study aimed at evaluating effect of the novel dual-active ligand E100 with high H3R antagonist affinity and balanced AChE inhibition on autistic-like repetitive behavior, anxiety parameters, locomotor activity, and neuroinflammation in a mouse model of VPA-induced ASD in C57BL/6 mice. E100 (5, 10, and 15â¯mg/kg) dose-dependently and significantly ameliorated repetitive and compulsive behaviors by reducing the increased percentages of nestlets shredded (all Pâ¯<â¯0.05). Moreover, pretreatment with E100 (10 and 15â¯mg/kg) attenuated disturbed anxiety levels (Pâ¯<â¯0.05) but failed to restore the hyperactivity observed in the open field test. Furthermore, pretreatment with E100 (10â¯mg/kg) the increased microglial activation, proinflammatory cytokines and expression of NF-κB, iNOS, and COX-2 in the cerebellum as well as the hippocampus (all Pâ¯<â¯0.05). These results demonstrate the ameliorative effects of E100 on repetitive compulsive behaviors in a mouse model of ASD. To our knowledge, this is the first in vivo demonstration of the effectiveness of a potent dual-active H3R antagonist and AChE inhibitor against autistic-like repetitive compulsive behaviors and neuroinflammation, and provides evidence for the role of such compounds in treating ASD.
Subject(s)
Autism Spectrum Disorder/pathology , Behavior, Animal/drug effects , Cholinesterase Inhibitors/pharmacology , Histamine H3 Antagonists/pharmacology , Animals , Autism Spectrum Disorder/chemically induced , Autism Spectrum Disorder/drug therapy , Cholinesterase Inhibitors/therapeutic use , Cytokines/metabolism , Disease Models, Animal , Dose-Response Relationship, Drug , Hippocampus/metabolism , Histamine H3 Antagonists/therapeutic use , Mice , Mice, Inbred C57BL , Microglia/metabolism , Nitric Oxide Synthase Type II/metabolism , Transcription Factor RelA/metabolism , Valproic Acid/toxicityABSTRACT
The need for new antibacterial agents is increasingly becoming of great importance as bacterial resistance to current drugs is quickly spreading. Enoyl-acyl carrier protein reductases (FabI) are important enzymes for fatty acid biosynthesis in bacteria and other micro-organisms. In this project, we conducted structure-based virtual screening against the FabI enzyme, and accordingly, 37 compounds were selected for experimental testing. Interestingly, five compounds were able to demonstrate antimicrobial effect with variable inhibition activity against various strains of bacteria and fungi. Minimum inhibitory concentrations of the active compounds were determined and showed to be in low to medium micromolar range. Subsequently, enzyme inhibition assay was carried out for our five antimicrobial hits to confirm their biological target and determine their IC50 values. Three of these tested compounds exhibited inhibition activity for the FabI enzyme where our best hit MN02 had an IC50 value of 7.8 µM. Furthermore, MN02 is a small bisphenolic compound that is predicted to have all required features to firmly bind with the target enzyme. To sum up, hits discovered in this work can act as a good starting point for the future development of new and potent antimicrobial agents.
Subject(s)
Anti-Bacterial Agents , Bacteria/enzymology , Bacterial Proteins/antagonists & inhibitors , Drug Design , Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)/antagonists & inhibitors , Enzyme Inhibitors , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)/chemistry , Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)/metabolism , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacologyABSTRACT
Autistic spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in social communication and restricted/repetitive behavior patterns or interests. Antagonists targeting histamine H3 receptor (H3R) are considered potential therapeutic agents for the therapeutic management of different brain disorders, e.g., cognitive impairments. Therefore, the effects of subchronic treatment with the potent and selective H3R antagonist DL77 (5, 10, or 15 mg/kg, i.p.) on sociability, social novelty, anxiety, and aggressive/repetitive behavior in male Tuck-Ordinary (TO) mice with ASD-like behaviors induced by prenatal exposure to valproic acid (VPA, 500 mg/kg, i.p.) were evaluated using the three-chamber test (TCT), marble burying test (MBT), nestlet shredding test (NST), and elevated plus maze (EPM) test. The results showed that VPA-exposed mice exhibited significantly lower sociability and social novelty preference compared to VPA-exposed mice that were pretreated with DL77 (10 or 15 mg/kg, i.p.). VPA-exposed mice presented a significantly higher percentage of buried marbles in MBT and shredded nestlet significantly more in NST compared to the control groups. However, VPA-exposed animals pretreated with DL77 (10 or 15 mg/kg, i.p.) buried a reduced percentage of marbles in MBT and presented a significantly lower percentage of shredding behavior in NST. On the other hand, pretreatment with DL77 (5, 10, or 15 mg/kg, i.p.) failed to restore the disturbed anxiety levels and hyperactivity observed in VPA-exposed animals in EPM, whereas the reference drug donepezil (DOZ, 1 mg/kg, i.p.) significantly palliated the anxiety and reduced the hyperactivity measures of VPA-exposed mice. Furthermore, pretreatment with DL77 (10 or 15 mg/kg, i.p.) modulated oxidative stress status by increasing GSH and decreasing MDA, and it attenuated the proinflammatory cytokines IL-1ß, IL-6 and TNF-α exacerbated by lipopolysaccharide (LPS) challenge, in VPA-exposed mouse brain tissue. Taken together, these results provide evidence that modulation of brain histaminergic neurotransmission, such as by subchronic administration of the H3R antagonist DL77, may serve as an effective pharmacological therapeutic target to rescue ASD-like behaviors in VPA-exposed animals, although further investigations are necessary to corroborate and expand these initial data.
Subject(s)
Autistic Disorder/chemically induced , Autistic Disorder/drug therapy , Behavior, Animal , Histamine H3 Antagonists/therapeutic use , Phenyl Ethers/therapeutic use , Piperidines/therapeutic use , Receptors, Histamine H3/metabolism , Valproic Acid/adverse effects , Animals , Anxiety/complications , Anxiety/physiopathology , Autistic Disorder/physiopathology , Behavior, Animal/drug effects , Brain/drug effects , Brain/metabolism , Brain/pathology , Choice Behavior/drug effects , Cytokines/metabolism , Disease Models, Animal , Donepezil/pharmacology , Donepezil/therapeutic use , Exploratory Behavior/drug effects , Female , Histamine H3 Antagonists/pharmacology , Inflammation Mediators/metabolism , Malondialdehyde/metabolism , Maze Learning/drug effects , Mice , Motor Activity/drug effects , Oxidative Stress/drug effects , Phenyl Ethers/pharmacology , Piperidines/pharmacology , Social Behavior , Stereotyped Behavior/drug effectsABSTRACT
Autistic Spectrum Disorder (ASD) is a complex neurodevelopmental brain disorder characterized by two core behavioral symptoms, namely impairments in social communication and restricted/repetitive behavior. The molecular mechanisms underlying ASD are not well understood. Recent genetic as well as non-genetic animal models contributed significantly in understanding the pathophysiology of ASD, as they establish autism-like behavior in mice and rats. Among the genetic causes, several chromosomal mutations including duplications or deletions could be possible causative factors of ASD. In addition, the biochemical basis suggests that several brain neurotransmitters, e.g., dopamine (DA), serotonin (5-HT), gamma-amino butyric acid (GABA), acetylcholine (ACh), glutamate (Glu) and histamine (HA) participate in the onset and progression of ASD. Despite of convincible understanding, risperidone and aripiprazole are the only two drugs available clinically for improving behavioral symptoms of ASD following approval by Food and Drug Administration (FDA). Till date, up to our knowledge there is no other drug approved for clinical usage specifically for ASD symptoms. However, many novel drug candidates and classes of compounds are underway for ASD at different phases of preclinical and clinical drug development. In this review, the diversity of numerous aetiological factors and the alterations in variety of neurotransmitter generation, release and function linked to ASD are discussed with focus on drugs currently used to manage neuropsychiatric symptoms related to ASD. The review also highlights the clinical development of drugs with emphasis on their pharmacological targets aiming at improving core symptoms in ASD.