Antiamnesic effects of tofisopam against scopolamine-induced cognitive impairments in rats

Cardioprotective effect of tofisopam against isoprenaline-induced myocardial infarction in rats via modulation of NLRP3\IL-1β\caspase-1 pathway

PURPOSE

Cardiovascular diseases (CVDs) are a leading cause of morbidity and mortality worldwide. Ischemic heart diseases, particularly acute myocardial infarction (MI), represent the most common cause of death. MI is influenced by multiple factors, including the release of inflammatory mediators. A significant percentage of individuals with CVD experience psychological effects, such as anxiety and depression, which are linked to an increased risk of coronary heart disease. Certain anti-anxiety medications have demonstrated immunomodulatory and anti-inflammatory effects. Tofisopam, a 2,3-benzodiazepine with anxiolytic properties, has been shown to exert in vitro anti-inflammatory and immunomodulatory effects. The present study investigates the potential of tofisopam as a protective adjuvant against isoprenaline-induced MI in rats and explores the possible underlying mechanisms.

METHODS

The study included four groups: a control group, a group pretreated with tofisopam, an isoprenaline toxic group, and an isoprenaline toxic group pretreated with tofisopam.

RESULTS

The findings demonstrated that isoprenaline significantly increased cardiac enzyme levels, as well as elevated oxidative and inflammatory stress parameters, along with evident apoptosis in cardiac cells. In contrast, the tofisopam-pretreated group showed a significant reversal of the cardiac damage induced by isoprenaline.

CONCLUSIONS

Tofisopam protects against isoprenaline-induced MI through its antioxidant, anti-inflammatory, and anti-apoptotic properties.

Ambroxol Improves Amyloidogenic, NF-κB, and Nrf2 Pathways in a Scopolamine-Induced Cognitive Impairment Rat Model of Alzheimer's Disease

Ambroxol (ABX) is used to manage excessive production of mucus in the respiratory system. The present study sought to assess the neuroprotective potential of ambroxol by influencing the amyloidogenic, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and nuclear factor erythroid 2-related factor 2 (Nrf2) pathways in a rat model of Alzheimer's disease (AD) induced by scopolamine. The AD pathology was induced by chronic administration of scopolamine. The rats were given scopolamine at a dose of 2 mg/kg via intraperitoneal injection daily for 14 days, followed by treatment (ABX 121.5, 135, and 180 mg/kg orally and 5 mg/kg orally of donepezil) for the next 28 days while continuing to receive daily scopolamine injection. The behavior of the rats was evaluated using Modified Y-Maze and Novel object recognition tasks. Analyses were carried out on AD pathological markers [Amyloid beta peptide 1-40, Amyloid beta peptide 1-42, acetylcholinesterase, beta-secretase 1 (BACE1), total tau, and p-tau], inflammatory markers [NF-κB, tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interferon γ], antioxidant markers (Nrf2 and heme Oxygenase 1 (HO-1)], along with synaptophysin and glial fibrillary acidic protein (GFAP) immunohistochemistry and histopathological assessment of the hippocampus. Our findings indicated that ABX reduced impairment in behavior. Levels of Acetylcholinesterase, BACE1, amyloid beta 1-40, amyloid beta 1-42, total tau, p-tau, NF-κB, IFN-γ, IL-6, and TNF-α decreased significantly. There was a significant increase in the levels of HO-1 and Nrf2. It stopped the neuronal degeneration, raised synaptophysin immunoreactivity, and lowered GFAP immunoreactivity. The current research indicates that ambroxol may possess senomorphic properties by impacting the transcription factors NF-κB and senescence-associated secretory phenotype (SASP). Consequently, it could provide neuroprotection through alterations in the Nrf2 and NF-κB signaling pathways in AD.

Anti-Amnesic Effect of Agastache rugosa on Scopolamine-Induced Memory Impairment in Mice

Agastache rugosa, a traditional Asian herbal medicine, is primarily used for digestive problems; yet, its cognitive benefits remain unexplored. This study evaluated the anti-amnesic effects of A. rugosa extract (ARE) on scopolamine (SCO)-induced memory impairment in mice. Mice received 100 or 200 mg/kg ARE orally for 5 days, followed by SCO injection. The ARE demonstrated significant antioxidant (DPPH IC50: 75.3 µg/mL) and anti-inflammatory effects (NO reduction). Furthermore, the ARE significantly improved memory performance in the passive avoidance test (escape latency: 157.2 s vs. 536.9 s), the novel object recognition test (novel object preference: 47.6% vs. 66.3%) and the Morris water maze (time spent in the target quadrant: 30.0% vs. 45.1%). The ARE reduced hippocampal acetylcholinesterase activity (1.8-fold vs. 1.1-fold) while increasing choline acetyltransferase (0.4-fold vs. 1.0-fold) and muscarinic acetylcholine receptor subtype I (0.3-fold vs. 1.6-fold) expression. The ARE improved hippocampal neurogenesis via doublecortin- (0.4-fold vs. 1.1-fold) and KI-67-positive (6.3 vs. 12.0) cells. Therefore, the ARE exerts protective effects against cognitive decline through cholinergic system modulation and antioxidant activity, supporting its potential use as a cognitive enhancer.

Post-exposure self-recovery reverses oxidative stress, ameliorates pathology and neurotransmitters imbalance and rescues spatial memory after time-dependent aluminum exposure in rat brain

Aluminum is a potent neurotoxin, responsible for memory impairment and cognitive dysfunction. The neurotoxic effect of aluminum on cognitive impairment is well documented, however, exposure to aluminum in a time-dependent manner and post-exposure self-recovery still needs to be elaborated. This research aimed to (1) study the time-dependent effect of aluminum exposure by administering a total dose of 5850 mg/kg of Al over two different time periods: 30 and 45 days (130 and 195 mg/kg of AlCl3 respectively), and (2) study 20 days post-exposure self-recovery effect in both aluminum-exposed groups by giving distilled water. Cognitive abilities were investigated through Morris water maze test and hole board test and compared in both exposure and recovery groups. Oxidative stress markers and neurotransmitter levels were measured for both exposure and recovery groups. To understand the mechanism of aluminum exposure and recovery, immunohistochemical analysis of synaptophysin (Syp) and glial fibrillary acidic protein (GFAP) was performed. Results showed cognitive dysfunction, oxidative stress-induced damage, reduced neurotransmitter levels, decreased immunoreactivity of Syp, and increased GFAP. However, these parameters showed a larger improvement in the recovery group where rats were given aluminum for 30 days period in comparison to recovery group followed by 45 days of aluminum exposure. These results suggest that restoration of cognitive ability is affected by the duration of aluminum exposure. The study findings provide us with insight into the adverse effects of aluminum exposure and can be utilized to guide future preventive and therapeutic strategies against aluminum neurotoxicity.

A Comparison of the Anxiolytic Properties of Tofisopam and Diazepam: A Double-Blind, Randomized, Crossover, Placebo-Controlled Pilot Study

New clinical reports have recently been published on tofisopam-an anxiolytic drug currently registered as a benzodiazepine-after a long break in this research area. Neurobiological studies concerning its properties, which differ from those of benzodiazepines, are underway. The analyses presented in this study aimed to compare the effects of tofisopam, diazepam, and a placebo in the treatment of anxiety symptoms. A total of 66 outpatients (43 women and 23 men) with generalized anxiety disorder aged 19 to 74 years (M = 41.4; SD = 13.2) were randomized in three groups receiving (1) tofisopam (50 mg three times a day), (2) diazepam (5 mg three times a day), or (3) a placebo for 2 weeks. Then, throughout a 2-week washout period, the patients were monitored for withdrawal symptoms. During the last 2 weeks, the effects of tofisopam (50 mg three times a day) and diazepam (5 mg three times a day) were compared (crossover design). The mean improvement on the Hamilton Anxiety Rating Scale was significantly higher in both the tofisopam and diazepam groups compared to the placebo group. There were no significant differences between the effects of diazepam and tofisopam, whereas adverse effects and withdrawal symptoms occurred less frequently in the tofisopam group. Tofisopam did not impair cognitive abilities, and related withdrawal symptoms resembled those of the placebo. If larger future studies corroborate these findings, tofisopam should be classified as a homophtalazine.

Montelukast Ameliorates Scopolamine-induced Alzheimer's Disease: Role on Cholinergic Neurotransmission, Antioxidant Defence System, Neuroinflammation and Expression of BDNF

BACKGROUND

Alzheimer's disease (AD) is an overwhelming neurodegenerative disease with progressive loss of memory. AD is characterized by the deposition of the senile plaques mainly composed of β-amyloid (Aβ) fragment, BDNF decline, Cholinergic system overactivity and neuroinflammation. Montelukast (MTK), a leukotriene receptor antagonist, showed astounding neuroprotective effects in a variety of neurodegenerative disorders.

OBJECTIVE

This study aims to investigate the ameliorative effects of Montelukast in the scopolamineinduced Alzheimer's disease (AD) model in rats and evaluate its activity against neuroinflammation.

METHODS

Thirty rats were split into five groups: Control group (1 mL/kg normal saline, i.p.), Montelukast perse (10 mg/kg, i.p.), Disease group treated with Scopolamine (3 mg/kg, i.p.), Donepezil group (3 mg/kg, i.p.), Montelukast treatment group (10 mg/kg, i.p.) and behavioural and biochemical tests were carried out to assess the neuro protective effect.

RESULTS

Scopolamine treatment led to a significant reduction in learning and memory and an elevation in cholinesterase levels when compared with the control group (p < 0.01). Additionally, elevated oxidative stress and Amyloid-β levels were associated with enhanced neuroinflammation (p < 0.05, p < 0.01). Furthermore, the decline in neurotrophic factor BDNF is also observed when compared with the normal control group (p < 0.01). Montelukast pre-treatment significantly attenuated learning and memory impairment and cholinesterase levels. Besides, Montelukast and standard drug donepezil administration significantly suppressed the oxidative stress markers (p < 0.01), Amyloid-β levels, neuroinflammatory mediators (p < 0.05) and caused a significant increase in BDNF levels (p < 0.05).

CONCLUSION

Montelukast bestowed ameliorative effects in scopolamine-induced AD animal models as per the previous studies via attenuation of memory impairment, cholinesterase neurotransmission, oxidative stress, Amyloid-β levels, neuroinflammatory mediators and enhanced BDNF levels.

The effect of the calcium channel blocker nimodipine on hippocampal BDNF/Ach levels in rats with experimental cognitive impairment

OBJECTIVE

Alzheimer's disease (AD) occurs in approximately 10% to 30% of individuals aged 65 or older worldwide. Novel therapeutic agents therefore need to be discovered in addition to traditional medications. Nimodipine appears to possess the potential to reverse cognitive impairment-induced dysfunction in learning and memory through its regulatory effect on the brain-derived neurotrophic factor (BDNF), acetylcholine (Ach), and acetylcholinesterase (AChE) pathway in the hippocampus and prefrontal cortex.

METHODS

Twenty-four male Sprague Dawley rats weighing 380 ± 10 g were used for behavioral and biochemical analyses. These were randomly and equally assigned into one of three groups. Group 1 received saline solution alone via the intraperitoneal (i.p) route, and Group 2 received 1 mg/kg/day i.p. scopolamine once a day for three weeks for induction of learning and memory impairments. In Group 3, 10 mg/kg/day nimodipine was prepared in tap water and administered orally every day for three weeks, followed after 30 min by 1 mg/kg/day scopolamine i.p. Behavior was evaluated using the Morris Water Maze test. BDNF, ACh, and AChE levels were determined using the ELISA test in line with the manufacturer's instructions.

RESULTS

Nimodipine treatment significantly increased the time spent in the target quadrant and the number of entries into the target quadrant compared to the scopolamine group alone. Additionally, BDNF and ACh levels in the hippocampus and prefrontal cortex decreased following 20-day scopolamine administration, while AChE activation increased.

CONCLUSION

Nimodipine exhibited potentially beneficial effects by ameliorating cognitive decline following scopolamine administration in the hippocampus and prefrontal cortex.

Antidepressant-like effect of tofisopam in mice: A behavioural, molecular docking and MD simulation study

BACKGROUND

Depression is a disease that affects millions of people worldwide, and the discovery and development of effective and safe antidepressant drugs is one of the important topics of psychopharmacology.

OBJECTIVES

In this study, it was aimed to investigate the antidepressant-like activity potential of tofisopam, an anxiolytic drug with 2,3-benzodiazepine structure, and to elucidate the pharmacological mechanisms mediating this effect.

METHODS

The antidepressant-like activity of tofisopam was investigated using tail suspension and modified forced swimming tests. Possible interactions of tofisopam with µ- and δ-opioid receptor subtypes were clarified by pharmacological antagonism, molecular docking and molecular dynamics simulation studies.

RESULTS

Tofisopam (50 and 100 mg/kg) significantly shortened the immobility time of mice in both the tail suspension and the modified forced swimming tests. The drug, at the same doses, prolonged the duration of swimming and climbing behaviours measured in modified forced swimming tests. A dosage of 25 mg/kg was ineffective. Mechanistic studies showed that the pretreatment with p-chlorophenylalanine methyl ester (serotonin synthesis inhibitor; 4 consecutive days, 100 mg/kg), α-methyl-para-tyrosine methyl ester (catecholamine synthesis inhibitor; 100 mg/kg), naloxonazine (selective µ-opioid receptor blocker, 7 mg/kg) and naltrindole (a selective δ-opioid receptor blocker, 0.99 mg/kg) abolished the anti-immobility effect induced by the 50 mg/kg dose of tofisopam in the tail suspension tests. Our in silico studies supported the behavioural findings that the antidepressant-like effect of tofisopam is mediated by μ- and δ-opioid receptors.

CONCLUSION

This study is the first to show that tofisopam has antidepressant-like activity mediated by the serotonergic, catecholaminergic and opioidergic systems.

Maternal Neu5Ac Supplementation During Pregnancy Improves Offspring Learning and Memory Ability in Rats

Sialic acids are postulated to improve cognitive abilities. This study aimed to evaluate the effects of sialic acid on behavior when administered in a free form as N-acetylneuraminic acid (Neu5Ac) to pregnant mothers or rat pups. The experiment involved 40 male 21-day-old rat pups and 20 15-day-pregnant rats that were randomized into four Neu5Ac treated groups: 0 (control), or 10, 20, and 40 mg/kg. Morris water maze test and shuttle box test were performed on the rat pups and maternal Neu5Ac-supplemented offspring on day 100 to evaluate their cognitive performance. The Neu5Ac levels in the cerebral cortex and hippocampus were tested with high-performance liquid chromatography-fluorescence detection (HPLC-FLD). We found that the maternal Neu5Ac-supplemented offspring showed better cognitive performance, less escape latency in the Morris water maze test, and less electric shock time shuttle box test, compared with the untreated control. In the meantime, the Neu5Ac level in the cerebral cortex and hippocampus of the offspring was higher in the Neu5Ac treatment group than that in the untreated control group. However, no significant differences were observed between rat pups in the treated and the untreated control groups in terms of cognitive performance and Neu5Ac content in the cerebral cortex and hippocampus. Maternal Neu5Ac supplementation during pregnancy could effectively promote the brain Neu5Ac content of the offspring and enhance their cognitive performance, but Neu5Ac had no such effect on rat pups while directly supplemented with Neu5Ac.

Antioxidant Activity and Cytotoxicity against Cancer Cell Lines of the Extracts from Novel Xylaria Species Associated with Termite Nests and LC-MS Analysis

Xylaria species associated with termite nests or soil have been considered rare species in nature and the few which have been reported upon have been found to act as a rich source of bioactive metabolites. This study evaluated 10 ethyl acetate extracts of five new Xylaria species associated with termite nests or soil for their antioxidant activity, and cytotoxicity against different cancer and normal cell lines. DPPH and ABTS radical scavenging activities of the extracts demonstrated strong capacity with low IC₅₀ values. The highest observed activities belonged to X. vinacea SWUF18-2.3 having IC₅₀ values of 0.194 ± 0.031 mg/mL for DPPH assay and 0.020 ± 0.004 mg/mL for ABTS assay. Total phenolic content ranged from 0.826 ± 0.123 to 3.629 ± 0.381 g GAE/g crude extract which correlated with antioxidant activities. The high total phenolic content could contribute to the high antioxidant activities. Cytotoxicity was recorded against A549, HepG2, HeLa and PNT2 and resulted in broad spectrum to specific activity depending on the cell lines. The highest activities were observed with X. subintraflava SWUF16-11.1 which resulted in 11.15 ± 0.32 to 13.17 ± 2.37% cell viability at a concentration of 100 µg/mL. Moreover, LC-MS fingerprints indicated over 61 peaks from all isolates. There were 18 identified and 43 unidentified compounds compared to mass databases. The identified compounds were from various groups of diterpenoids, diterpenes, cytochalasin, flavones, flavonoids, polyphenols, steroids and derivatives, triterpenoids and tropones. These results indicate that Xylaria spp. has abundant secondary metabolites that could be further explored for their therapeutic properties.