Single-Nuclei Characterization of Lacrimal Gland in Scopolamine-Induced Dry Eye Disease.

Purpose: The lacrimal gland (LG) is the main organ responsible for tear secretion and an important pathogenic site for dry eye disease (DED). This study aimed to comprehensively characterize LG cellular heterogeneity under normal and DED conditions using single-nucleus RNA sequencing (snRNA-seq). Methods: Single LG nuclei isolated from mice with or without DED induced by scopolamine (SCOP)/desiccating stress (DS) were subjected to snRNA-seq using the 10x Genomics platform. These cells were clustered and annotated using the t-distributed stochastic neighbor embedding (t-SNE) method and unbiased computational informatic analysis. Cluster identification and functional analysis were performed based on marker gene expression and bioinformatic data mining. Results: The snRNA-seq analysis of 30,351 nuclei identified eight major cell types, with acinar cells (∼72.6%) being the most abundant cell type in the LG. Subclustering analysis revealed that the LG mainly contained two acinar cell subtypes, two ductal cell subclusters, three myoepithelial cell (MECs) subtypes, and four immunocyte subclusters. In the SCOP-induced DED model, three major LG parenchymal cell types were significantly altered, characterized by a reduced proportion of acinar cells with a lowered secretion potential and an augmented proportion of ductal cells and MECs. LG immunocytes in DED scenarios showed an intensified inflammatory response and dysregulated intercellular communication with three major LG parenchymal cells. Conclusions: Overall, this study offers a systemic single-nucleus transcriptomic profile of LGs in both normal and DED conditions and an atlas of the complicated interactions of immunocytes with major LG parenchymal cells. The findings also facilitate understanding the pathogenesis of DED.

(m) RVD-hemopressin (α) Ameliorated Oxidative Stress, Apoptosis and Damage to the BDNF/TrkB/Akt Pathway Induced by Scopolamine in HT22 Cells.

Dysfunction in the cholinergic system and oxidative stress are closely related and play roles in Alzheimer's disease (AD). Scopolamine (Scop), which is commonly used to induce cholinergic system damage in cells and animals, also evokes oxidative stress. Our previous study indicated that the peptide (m) RVD-hemopressin (RVD) reversed the memory-impairing effect of Scop in mice by activating cannabinoid receptor 1 (CBR1), but the mechanism was unclear. In this study, we found that RVD inhibited the oxidative stress, apoptosis, decreased cell viability and downregulation of synapse-associated proteins induced by Scop in HT22 cells. The effect was associated with the BDNF/TrkB/Akt pathway, and the effects of RVD outlined above could be blocked by an antagonist of CBR1. These results suggest that RVD may be a potential drug candidate for disorders associated with damage to the cholinergic system and oxidative stress, such as AD.

Capparis spinosa Promoted BDNF and Antioxidant Enzyme Levels to Protect Against Learning and Memory Deficits Induced by Scopolamine.

BACKGROUND: Alzheimer's disease (AD) is a major neurodegenerative disorder with multiple manifestations, including oxidative stress, brain-derived neurotrophic factor (BDNF) depletion, and cholinergic dysfunction. Capparis spinosa (C. spinosa) is identified as a potential source of nutrition for alleviating various ailments. The current study assessed the ameliorating properties of C. spinosa hydroethanolic extract on memory dysfunction and the possible roles of oxidative stress and BDNF in the scopolamine (Scop)-treated rats. METHODS: Forty male Wistar rats were divided into the following four groups: Control, Scop (2 mg/kg, intraperitoneal injection (i.p.)), Scop + C. spinosa 150, and Scop + C. spinosa 300 groups. The rats were given C. spinosa extract (150 or 300 mg/kg, oral) for 3 weeks. During the third week, Passive Avoidance (PA) and Morris Water Maze (MWM) tests were done to assess memory and learning performance. Finally, oxidative stress markers and BDNF in the brain tissue were evaluated. RESULTS: Scop injection was associated with a significant increase in the time latency and travelled distance to reach the platform during the learning phase of MWM In the probe test, the Scoptreated rats showed a lower time and distance in the target area. Furthermore, Scop injection significantly decreased the latency to enter the dark while increasing the dark time and the frequency of entries to the dark zone of the PA task. C. spinosa extract effectively reversed the behavioural changes induced by Scop. Treatment with the extract also significantly increased the levels of superoxide dismutase, catalase, thiols, and BDNF, while decreasing malondialdehyde production in the brains of the Scop-injured rats. CONCLUSION: C. spinosa hydroethanolic extract successfully ameliorated Scop-induced memory impairment by modifying BDNF and oxidative stress markers in the brain of amnesic rats.

Scopolamine causes delirium-like brain network dysfunction and reversible cognitive impairment without neuronal loss.

Delirium is a severe acute neuropsychiatric syndrome that commonly occurs in the elderly and is considered an independent risk factor for later dementia. However, given its inherent complexity, few animal models of delirium have been established and the mechanism underlying the onset of delirium remains elusive. Here, we conducted a comparison of three mouse models of delirium induced by clinically relevant risk factors, including anesthesia with surgery (AS), systemic inflammation, and neurotransmission modulation. We found that both bacterial lipopolysaccharide (LPS) and cholinergic receptor antagonist scopolamine (Scop) induction reduced neuronal activities in the delirium-related brain network, with the latter presenting a similar pattern of reduction as found in delirium patients. Consistently, Scop injection resulted in reversible cognitive impairment with hyperactive behavior. No loss of cholinergic neurons was found with treatment, but hippocampal synaptic functions were affected. These findings provide further clues regarding the mechanism underlying delirium onset and demonstrate the successful application of the Scop injection model in mimicking delirium-like phenotypes in mice.

Lantana camara leaf extract ameliorates memory deficit and the neuroinflammation associated with scopolamine-induced Alzheimer's-like cognitive impairment in zebrafish and mice.

CONTEXT: Lantana camara Linn. (Verbenaceae) is used for improving memory in certain African societies. OBJECTIVE: This study investigated the effect of prophylactic treatment with hydroethanolic leaf extract of Lantana camara (LCE) on short-term memory deficit and neuroinflammation induced with scopolamine in zebrafish and mice. MATERIALS AND METHODS: Zebrafish (AB strain) and mice (ICR) were given donepezil (0.65 mg/kg, oral) and LCE (10, 30, 100 mg/kg, oral) for 7, and 10 days, respectively, before induction of cognitive impairment with scopolamine immersion (200 µM) and intraperitoneal injection (2 mg/kg), respectively. Spatial short-term memory was assessed in zebrafish using both Y- and T-mazes, whereas Y-maze was used in mice. Mice hippocampal and cortical tissues were analyzed for mRNA expression of proinflammatory genes (IL-1ß, IL-6, TNF-α, COX-2) using qRT-PCR. RESULTS: In the zebrafish Y-maze, LCE (10 and 100 mg/kg) increased time spent in the novel arm by 55.89 ± 5.70%, and 68.21 ± 2.75%, respectively, but not at 30 mg/kg. In the zebrafish T-maze, there was an increase in time spent in the food-containing arm at 30 (44.23 ± 2.13) and 100 mg/kg (52.30 ± 1.94). In the mouse Y-maze, spontaneous alternation increased by 52.89 ± 4.98% at only 10 mg/kg. LCE (10, 30, 100 mg/kg) inhibited proinflammatory gene (IL-1ß, IL-6, TNF-α, COX-2) mRNA expression, with the highest inhibitory effect on IL-6 in both the hippocampus (83.27 ± 2.49%; 100 mg/kg) and the cortex (98.74 ± 0.11%; 10 mg/kg). DISCUSSION AND CONCLUSION: LCE ameliorated scopolamine-induced AD in both zebrafish and mice.

Thymus daenensis extract prevents scopolamine­induced memory impairment through declining oxidative stress in rats.

Memory and cognitive impairment induced by oxidative stress are among the main hallmarks of Alzheimer's disease's (AD) pathology. The present study aimed to investigate the potential neuroprotective effects of Thymus daenensis (T. daenensis) extract against scopolamine­induced memory impairment and oxidative stress in rats. T. daenensis, widely distributed in Iran and Europe, is known to be a rich source of natural antioxidants and has been traditionally used for various medical purposes. The present study investigated the post­treatment effects of T. daenensis on learning and memory functions, antioxidant cellular defense, and oxidative stress using the scopolamine rat model of AD. The experiments were performed by intraperitoneal injection of scopolamine for 10 consecutive days in Wistar male rats (180-220 g). Additionally, the animals received T. daenensis extract (50­200 mg/kg) by gavage for 14 consecutive days after induction of memory impairment. The animals were divided into 8 groups, namely: control, 200 mg/kg of T. daenensis extract (D200), donepezil (DON), scopolamine (ALZ), ALZ animals treated with different doses of the extract (ALZ+D50 or 100 or 200 mg/kg) and ALZ animals treated with (ALZ+DON). The animals were then subjected to the Morris water maze (MWM) paradigm as a standard criterion for memory function assessment, and after extracting the brain tissues, the related biochemical oxidative stress parameters were determined in the brain. Our results indicated that T. daenensis extract significantly improved animals' performance in the MWM while significantly reducing oxidative stress and antioxidant imbalance. Furthermore, the extract did not show hepatotoxic effects on treated animals. In addition, the extract treatment significantly decreased both cellular malondialdehyde (MDA) and protein carbonyl (PCO) content while conversely increasing the total reduced glutathione (GSH) content and also the levels of total and endogenous antioxidants in the ferric reducing antioxidant power (FRAP) assay. It seems that the administration of T. daenensis significantly improved both cellular biochemical aspects and memory performance in animal models. Conclusively, it could be beneficial for scopolamine­induced neurotoxicity.

Sea Cucumber-Derived Peptide Attenuates Scopolamine-Induced Cognitive Impairment by Preventing Hippocampal Cholinergic Dysfunction and Neuronal Cell Death.

The incidence of neurodegenerative diseases related to cognitive decline and memory loss is on the rise as the global elderly population increases. In this study, we evaluated the effect of the sea cucumber-derived peptide Phe-Tyr-Asp-Trp-Pro-Lys (FYDWPK) on scopolamine-induced neurotoxicity in an animal model. The Morris water maze, passive avoidance apparatus, and shuttle box test were used to assess learning and memory abilities. In behavioral tests, FYDWPK effectively alleviated learning and memory impairment. FYDWPK also alleviated cholinergic dysfunction in mice with dementia. Furthermore, FYDWPK significantly improved oxidative imbalance by increasing superoxide dismutase activity and decreasing malondialdehyde levels (P < 0.05). The pathological results showed that FYDWPK alleviated neuronal loss, blurred caryotheca, and pyknotic nuclei in the hippocampus, and a high dose of FYDWPK had the best effect. In conclusion, FYDWPK alleviated cognitive and memory impairments by regulating oxidative imbalance, reducing cholinergic dysfunction, and relieving pathological alterations.

Shaddock (Citrus maxima) peels extract restores cognitive function, cholinergic and purinergic enzyme systems in scopolamine-induced amnesic rats.

This study investigated the effect of shaddock peels extract on cognitive function in scopolamine-induced amnesic rats. Wistar rats were pretreated with shaddock peels extract (50 and 100 mg/kg) and donepezil (5 mg/kg) for fourteen days via oral administration. Memory impairment was induced at the end of the treatment period via a single intraperitoneal administration of scopolamine (3 mg/kg). Thereafter, the animals were subjected to behavioral studies (Morris water maze and Y-maze tests). Finally, the rats were sacrificed and the hippocampus of the rat's brain was isolated for biochemical analyses. The results showed a significant decrease in memory and cognitive function as revealed by Morris water maze and Y-maze tests in scopolamine-induced rats which were reversed by shaddock peels extract. Also, there was a significant decrease in the activity of adenosine monophosphohydrolase (AMPase) with a simultaneous increase in activities of adenosine deaminase (ADA), adenosine triphosphate diphosphohydrolase (ATPdase), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in scopolamine-induced rats when compared with the control. Besides, a significant increase in malondialdehyde (MDA) and reactive oxygen species (ROS) levels were observed in scopolamine-induced rats. However, donepezil or shaddock peels extract (50 and 100 mg/kg) caused a significant inhibitory effect on AChE, and ADA activities when compared to scopolamine-induced rats. Rats treated with shaddock peels extract also showed a significant reduction in MDA and ROS levels compared to scopolamine-induced rats. Therefore, our findings showed that the cognitive-enhancing effects of shaddock peels extract could be due to antioxidant activities and modulation of some enzymes linked with cognitive dysfunction.

[Total flavonoids of Drynariae Rhizoma regulates ER-p38 MAPK signaling pathway to improve scopolamine-induced learning and memory impairments in model mice].

This study intended to explore the effect and mechanism of total flavonoids of Drynariae Rhizoma in improving scopola-mine-induced learning and memory impairments in model mice. Ninety four-month-old Kunming(KM) mice were randomly divided into six groups. The ones in the model group and blank group were treated with intragastric administration of normal saline, while those in the medication groups separately received the total flavonoids of Drynariae Rhizoma, Kangnaoshuai Capsules, donepezil, as well as total flavonoids of Rhizoma Drynariae plus estrogen receptor(ER) blocker by gavage. The mouse model of learning and memory impairments was established via intraperitoneal injection of scopolamine. Following the measurement of mouse learning and memory abilities in Morris water maze test, the hippocampal ERß expression was detected by immunohistochemistry, and the expression levels of ERß and phosphorylated p38(p-p38) in the hippocampus and B-cell lymphoma 2(Bcl-2), Bcl-2-associated death promoter(Bad), and cysteinyl aspartate-specific protease-3(caspase-3) in the apoptotic system were assayed by Western blot. The contents of malondia-ldehyde(MDA), superoxide dismutase(SOD), and nitric oxide(NO) in the hippocampus were then determined using corresponding kits. Compared with the control group, the model group exhibited significantly prolonged incubation period, reduced frequency of cros-sing the platform, shortened residence time in the target quadrant, lowered ERß, Bcl-2 and SOD activity in the hippocampus, and increased p-p38/p38, Bad, caspase-3, MDA, and NO. Compared with the model group, the total flavonoids of Rhizoma Drynariae increased the expression of ERß and SOD in the hippocampus, down-regulated the expression of neuronal pro-apoptotic proteins, up-re-gulated the expression of anti-apoptotic proteins, and reduced p-p38/p38, MDA, and NO. The effects of total flavonoids of Drynariae Rhizoma on the above indexes were reversed by ER blocker. It has been proved that the total flavonoids of Drynariae Rhizoma obviously alleviate scopolamine-induced learning and memory impairments in mice, which may be achieved by regulating the neuronal apoptotic system and oxidative stress via the ER-p38 mitogen-activated protein kinase(ER-p38 MAPK) signaling pathway.

Trichoderma reesei fungal degradation boosted the potentiality of date pit extract in fighting scopolamine-induced neurotoxicity in male rats.

Date pits are nutritious by-products, containing high levels of indigestible carbohydrates and polyphenols. To maximize the biological effects of the active ingredients, the hard shell of the polysaccharide must be degraded. Therefore, the current study aimed to assess the protective potentials of date pits extract (DP) and fungal degraded date pits extract (FDDP) against scopolamine (SCO)-induced neurodegeneration in male rats. Date pits were subjected to fungal degradation and extraction, followed by the measurement of phytochemicals and free radical scavenging activities. Forty-two adult Sprague-Dawley male rats were divided into seven groups: three control groups administered with either saline, DP or FDDP; four groups with neurodegeneration receiving SCO (ip 2 mg/kg/day, SCO group) with no treatment, SCO with DP (oral 100 mg/kg/day, DP + SCO group), SCO with FDDP (oral, 100 mg/kg/day, FDDP + SCO group), and SCO with donepezil (DON, oral, 2.25 mg/kg/day, DON + SCO group). The treatment duration was 28 days, and in the last 14 days, SCO was administered daily. Morris water maze test, acetylcholine esterase activity, oxidative stress, markers of inflammation and amyloidogenesis, and brain histopathology were assessed.

α-MSH ameliorates corneal surface dysfunction in scopolamine-induced dry eye rats and human corneal epithelial cells via enhancing EGFR expression.

Dry eye (DE) is a chronic, multifactorial ocular surface disease associated with visual disturbance, tear film instability, hyperosmolarity, ocular surface inflammation and damage. Effective intervention is necessary to control this disease. In this study we topically applied α-melanocyte stimulating hormone (α-MSH) on the ocular surface of scopolamine-induced DE rats and found that it promoted tear secretion, reduced tear breakup time and fluorescein sodium staining and increased the number of conjunctival goblet cells. To investigate the mechanism, protein array was conducted, which showed that α-MSH exerted its effects via epithelial growth factor receptor (EGFR) in the JAK-STAT signaling pathway. Furthermore, in vitro experiments showed that α-MSH protected human corneal epithelial cells (hCECs) by maintaining their migration ability and viability and decreasing apoptosis. However, blockade of EGFR abolished these protective effects. Moreover, α-MSH decreased the level of autophagy in benzalkonium chloride (BAC)-stressed hCECs via EGFR. These results demonstrated that α-MSH ameliorated lesions and restored ocular surface functions by upregulating EGFR expression.

Sulforaphane enhances long-term potentiation and ameliorate scopolamine-induced memory impairment.

Increases in human life expectancy have led to increases in the prevalence of senile dementia and neurodegenerative diseases. This is a major problem because there are no curative treatments for these diseases, and patients with unmanaged cognitive and neurodegenerative symptoms experience many social problems. Sulforaphane is a type of organosulfur compound known as an isothiocyanate. It is derived from glucoraphanin, a compound found in cruciferous vegetables such as broccoli, brussels sprouts, and cabbages, via an enzymatic reaction that is triggered by plant damage (e.g., chewing). Sulforaphane exhibits activity against cancer, inflammation, depression, and severe cardiac diseases. It can also alleviate oxidative stress and neural dysfunction in the brain. However, there is insufficient knowledge about the electrophysiological and behavioral basis of the effects of sulforaphane on learning and memory. Therefore, we evaluated whether acute sulforaphane administration affected long-term potentiation (LTP) in organotypic cultured rat hippocampal tissues. We also measured the effect of sulforaphane on the performance of three behavioral tests, the Y-maze test, the passive avoidance test, and the Morris water maze, which assess short-term memory, avoidance memory, and short and long-term spatial memory, respectively. We found that sulforaphane increased the total field excitatory postsynaptic potential (fEPSP) in a dose-dependent manner after high frequency stimulation and attenuated scopolamine-induced interference of the fEPSP in the hippocampal CA1 area. Sulforaphane also restored cognitive function and inhibited memory impairment as indicated by the alleviation of the negative neurological effects of scopolamine, i.e, a lowered ratio of spontaneous alternation in the Y-maze, a reduced step-through latency in the passive avoidance test, and an increased navigation time in the Morris water maze. These results indicate that sulforaphane can effectively prevent the attenuation of LTP and cognitive abilities induced by cholinergic and muscarinic receptor blockade. Further research is warranted to explore the potential therapeutic and prophylactic utility of sulforaphane for improving learning and memory, especially in those suffering from neurodegenerative disorders.

Differential effects of alkaloids on memory in rodents.

Nicotinic acetylcholine receptors (nAChRs) play a critical role in the neuropharmacology of learning and memory. As such, naturally occurring alkaloids that regulate nAChR activity have gained interest for understanding and potentially improving memory function. In this study, we tested the acute effects of three known nicotinic alkaloids, nicotine, cotinine, and anatabine, in suppressing scopolamine-induced memory deficit in rodents by using two classic memory paradigms, Y-maze and novel object recognition (NOR) in mice and rats, respectively. We found that all compounds were able to suppress scopolamine-induced spatial memory deficit in the Y-maze spontaneous alternation paradigm. However, only nicotine was able to suppress the short-term object memory deficit in NOR, despite the higher doses of cotinine and anatabine used to account for their potential differences in nAChR activity. These results indicate that cotinine and anatabine can uniquely regulate short-term spatial memory, while nicotine seems to have more robust and general role in memory regulation in rodents. Thus, nAChR-activating alkaloids may possess distinct procognitive properties in rodents, depending on the memory types examined.

Dietary n-3 PUFA Deficiency Increases Vulnerability to Scopolamine-Induced Cognitive Impairment in Male C57BL/6 Mice.

BACKGROUND: DHA (22:6n-3), a long-chain n-3 PUFA, is essential for normal brain development and function. Our previous study demonstrated that DHA significantly improves scopolamine-induced dementia. However, there are no reports on the relation between n-3 PUFA deficiency and scopolamine-induced cognitive impairment. OBJECTIVES: The aim of this study was to evaluate whether n-3 PUFA deficiency increases vulnerability to scopolamine-induced cognitive impairment. METHODS: Male and female C57BL/6 mice were mated and fed an n-3 PUFA-adequate [containing 2.88% α-linolenic acid (ALA; 18:3n-3)] or -deficient (containing 0.09% ALA) diet for 2 consecutive generations. The corresponding second-generation male offspring were kept on the same diet as their mothers after weaning, and were randomly assigned to 2 subgroups at 7 wk of age, in which they were intraperitoneally injected with saline [fed n-3 PUFA-adequate (Con) or -deficient (Def) diet] or scopolamine [5 mg/kg body weight; fed n-3 PUFA-adequate (Sco) or -deficient (Def + Sco) diet] once per day for 7 d before killing. Behavioral performance was analyzed using the Morris Water Maze test. Fatty acid composition, protein expression, and indicators of cholinergic and oxidative stress in the brain were measured. RESULTS: The Def group showed lower brain DHA (-63.7%, P ≤ 0.01) and higher n-6 PUFA (+65.5%, P ≤ 0.05) concentrations than the Con group. The Def + Sco group and the Sco group showed poorer spatial learning and memory (escape latency on the sixth day: +60.3% and +36.8%; platform crossings: -43.9% and -28.2%, respectively) and more obvious cholinergic dysfunction (acetylcholine: -47.6% and -27.7%, respectively), oxidative stress (glutathione peroxidase: -64.2% and -32.5%, respectively), apoptosis [B-cell lymphoma 2 (BCL2)-associated X protein/BCL2: +230.8% and +153.8%; phosphorylated P38/P38: +232% and +130%, phosphorylated c-Jun N-terminal kinase (JNK)/JNK: +104.5% and +58.8%, respectively], neuroinflammation (IL-1ß: +317.6% and +95%, respectively), and neurodevelopmental delay (brain-derived neurotrophic factor: -54.4% and -7.25%, respectively) than their corresponding saline-treated controls. CONCLUSIONS: Dietary n-3 PUFA deficiency significantly decreases brain DHA concentrations and increases vulnerability to scopolamine-induced cognitive impairment in C57BL/6 male mice.

Scopolamine promotes neuroinflammation and delirium-like neuropsychiatric disorder in mice.

Postoperative delirium is a common neuropsychiatric syndrome resulting a high postsurgical mortality rate and decline in postdischarge function. Extensive research has been performed on both human and animal delirium-like models due to their clinical significance, focusing on systematic inflammation and consequent neuroinflammation playing a key role in the pathogenesis of postoperative cognitive dysfunctions. Since animal models are widely utilized for pathophysiological study of neuropsychiatric disorders, this study aimed at examining the validity of the scopolamine-induced delirium-like mice model with respect to the neuroinflammatory hypothesis of delirium. Male C57BL/6 mice were treated with intraperitoneal scopolamine (2 mg/kg). Neurobehavioral tests were performed to evaluate the changes in cognitive functions, including learning and memory, and the level of anxiety after surgery or scopolamine treatment. The levels of pro-inflammatory cytokines (IL-1ß, IL-18, and TNF-α) and inflammasome components (NLRP3, ASC, and caspase-1) in different brain regions were measured. Gene expression profiles were also examined using whole-genome RNA sequencing analyses to compare gene expression patterns of different mice models. Scopolamine treatment showed significant increase in the level of anxiety and impairments in memory and cognitive function associated with increased level of pro-inflammatory cytokines and NLRP3 inflammasome components. Genetic analysis confirmed the different expression patterns of genes involved in immune response and inflammation and those related with the development of the nervous system in both surgery and scopolamine-induced mice models. The scopolamine-induced delirium-like mice model successfully showed that analogous neuropsychiatric changes coincides with the neuroinflammatory hypothesis for pathogenesis of delirium.

Effect of Andrographis paniculata leaves extract on neurobehavioral and biochemical indices in scopolamine-induced amnesic rats.

Andrographis paniculata is a medicinal herb that is used to treat various disease conditions due to its pharmacological properties. Thus, this study sought to assess the effect of A. paniculata extract on neurobehavioral and some biochemical parameters in scopolamine-induced amnesic rats. Thirty-five male rats were divided into seven groups and treated with aqueous extract of A. paniculata (50 and 500 mg/kg) and donepezil (5 mg/kg) for 14 days before administration of scopolamine. Behavioral studies (Morris water maze and Y-maze) were carried out to evaluate cognitive dysfunction in scopolamine-induced rats. Biochemical assays such as cholinesterases (AChE and BChE), monoamine oxidase (MAO), and purinergic activities were determined. Results revealed the presence of orientin, quercetin, caffeic acid, apigenin, and gallic acid in A. paniculata. Also, findings from this study showed that aqueous extract of A. paniculata had a modulatory effect on scopolamine-induced cognitive impairment and could be used in the management of memory loss. PRACTICAL APPLICATIONS: Aqueous extract of A. paniculata characterized revealed the presence of polyphenols which are antioxidants. The inhibitory activity possessed by A. paniculata on some enzymes linked to neurodegeneration could be due to the antioxidant activity. Given this, we recommend that results gotten from this study could be used to develop treatment therapy for neurodegeneration. However, in-depth studies should be carried out on the toxic effect of A. paniculata to ascertain a safe dose for treatment.

Maillard Reaction Products and Phenolic Compounds from Roasted Peanut Flour Extracts Prevent Scopolamine-Induced Amnesia Via Cholinergic Modulation and Antioxidative Effects in Mice.

Research on the beneficial effects of Maillard reaction products (MRPs) and phenolic compounds derived from roasted peanut flour on the nervous system remains insufficient. This study aimed to evaluate the effect of a 28-day oral administration of defatted peanut extract rich in MPRs and polyphenolic compounds on the cognitive impairments and oxidative injury induced by scopolamine in a mouse model. Light and dark extracts from peanut flour were prepared by heating peanuts at 187°C for two different times (8.6 and 12.7 min) and defatted using soxhlet apparatus. The mice were orally pretreated with either roasted defatted peanuts extracts (100 mg/kg) or donepezil (3 mg/kg) for 21 days. On day 19 and until day 28, mice were injected subcutaneously with water or scopolamine (1 mg/kg body weight) 15 min after roasted defatted peanuts extracts/water feeding. Mice were subsequently subjected to a battery of behavioral tests including open field locomotor activity assay, and Morris water maze test. Brain tissues were collected to measure acetylcholine, acetylcholinesterase, and oxidative parameters (glutathione and malondialdehyde). Roasted defatted peanuts (light and dark) (100 mg/kg) treatment significantly ameliorated cognitive performance and reversed the oxidative damage when compared with the scopolamine group. These data demonstrate the defatted peanuts extracts exert potent anti-amnesic effects via the modulation of cholinergic and antioxidant activities.

NFE2L2 activator RS9 protects against corneal epithelial cell damage in dry eye models.

Oxidative stress may cause ocular surface damage during the development of dry eye. Mammalian cells have defense systems against oxidative stress. A central regulator of the stress response is nuclear factor-erythroid 2-related factor 2 (NFE2L2). NFE2L2 is activated by the novel triterpenoid RS9 (a biotransformation compound of RTA 402). The purpose of this study was to assess the efficacy of RS9 against dry eye using in vitro and in vivo models. Bioactivity was estimated by the induction of mRNAs for two NFE2L2-targeted genes: NQO1 (prevents radical species) and GCLC (glutathione synthesis), using a corneal epithelial cell line (HCE-T). Protection against oxidation and cell damage was tested in vitro by culturing cells under hyperosmotic stress or by the addition of menadione, a generator of reactive oxygen species (ROS). Dry eye in vivo was induced by the injection of scopolamine into rats. Then, 930 nM of RS9 was applied to both eyes for 2 weeks. Oxidative stress was measured by the accumulation of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Corneal wound healing was measured by scoring for superficial punctate keratitis (SPK). Corneal epithelial cell densities were evaluated histologically. RS9 and RTA 402 induced the expression of NQO1 and GCLC mRNAs in HCE-T cells. And both compounds suppressed hyperosmotic-ROS generation and menadione induced cellular damage. However RS9 had a stronger protective effect than RTA 402. Ocular instillation of RS9 also significantly upregulated the expression of Nqo1 mRNA in the corneal epithelium. Accumulation of 8-OHdG, increase of SPK scores and decrement of basal cell density were observed in corneal epithelium from scopolamine-injected rats. These changes were significantly ameliorated by the topical administration of RS9. RS9 induced Nfe2l2 activation and Nfe2l2-targeted genes, reduced oxidation, and ameliorated symptoms of dry eye using in vitro and in vivo models. Thus, RS9 might be a potent candidate agent against dry eye disease.

Neuroprotective Effects of Apocynin and Galantamine During the Chronic Administration of Scopolamine in an Alzheimer's Disease Model.

Alzheimer's disease (AD) is one of the most complicated neurodegenerative diseases, and several hypotheses have been associated with its development and progression, such as those involving glucose hypometabolism, the cholinergic system, calcium imbalance, inflammation, oxidative imbalance, microtubule instability, and the amyloid cascade, several of which are related to oxidative stress (free radical generation), which contributes to neuronal death. Therefore, several efforts have been made to establish a sporadic AD model that takes into account these hypotheses. One model that replicates the increase in amyloid beta (Aß) and oxidative stress in vivo is the scopolamine model. In the present work, the chronic administration (6 weeks) of scopolamine was used to analyze the neuroprotective effects of apocynin and galantamine. The results showed that scopolamine induced cognitive impairment, which was evaluated 24 h after the final dose was administered. In addition, after scopolamine administration, the Aß and superoxide anion levels were increased, and NADPH oxidase 2 (NOX2), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor kappa B (NFkB) genes were overexpressed. These effects were not observed when either apocynin or galantamine was administered during the last 3 weeks of scopolamine treatment, and although the results from both molecules were related to lower Aß production and, consequently, lower superoxide anion production, they were likely realized through different pathways. That is, both apocynin and galantamine diminished NADPH oxidase expression, but their effects on transcription factor expression differed. Moreover, experiments in silico showed that galantamine did not interact with the active site of beta secretase, whereas diapocynin, an apocynin metabolite, interacted with the beta-site APP-cleaving enzyme (BACE1) at the catalytic site.

Design, synthesis, in vitro and in vivo evaluation of novel pyrrolizine-based compounds with potential activity as cholinesterase inhibitors and anti-Alzheimer's agents.

Novel series of pyrrolizine based compounds (4-6 and 9-11) were designed, synthesized and evaluated as potential anti-Alzheimer agents. Most of the tested compounds showed selectivity to hAChE over hBChE and effectively inhibited self-induced amyloid beta aggregation in vitro. Among these derivatives, compound 10 displayed high selectivity towards hAChE (Ki = 1.47 ±â€¯0.63 µM for hAChE and Ki = 40.15 ±â€¯3.31 µM for hBChE). However, compound 11 displayed dual inhibitory effect against hAChE and hBChE at submicromolar range (Ki = 0.40 ±â€¯0.03 and 0.129 ±â€¯0.009 µM, respectively). Kinetic studies of the new ligands showed competitive type inhibition for both hAChE and hBChE. Moreover, compounds 10 and 11 showed lower or comparable cytotoxicity to donepezil against human neuroblastoma (SH-SY5Y) and normal human hepatic (THLE2) cell lines. In vivo studies confirmed that both compounds were able to improve cognitive dysfunction of scopolamine-induced AD mice. Finally, molecular docking simulation of compounds 10 and 11 in hAChE active site showed good agreement with the obtained pharmaco-biological results.