Vitis labruscana leaf extract ameliorates scopolamine-induced impairments with activation of Akt, ERK and CREB in mice

Rhoifolin, baicalein 5,6-dimethyl ether and agathisflavone prevent amnesia induced in scopolamine zebrafish (Danio rerio) model by increasing the mRNA expression of bdnf, npy, egr-1, nfr2α, and creb1 genes

The increasing attention towards age-related diseases has generated significant interest in the concept of cognitive dysfunction associated with Alzheimer's disease (AD). Certain limitations are associated with the current therapies, and flavonoids have been reported to exhibit multiple biological activities and anti-AD effects in several AD models owing to their antioxidative, anti-inflammatory, and anti-amyloidogenic properties. In this study, we performed an initial in silico predictions of the pharmacokinetic properties of three flavonoids (rhoifolin, baicalein 5,6-dimethyl ether and agathisflavone). Subsequently, we evaluated the antiamnesic and antioxidant potential of flavonoids in concentrations of 1, 3, and 5 μg/L in scopolamine (100 μM)-induced amnesic zebrafish (Danio rerio) model. Zebrafish behavior was analyzed by novel tank diving test (NTT), Y-maze, and novel object recognition test (NOR). Acetylcholinesterase (AChE) activity, brain antioxidant status and the expression of bdnf, npy, egr1, nrf2α, creb1 genes, and CREB-1 protein level was measured to elucidate the underlying mechanism of action. Our flavonoids improved memory and decreased anxiety-like behavior of scopolamine-induced amnesia in zebrafish. Also, the studied flavonoids reduced AChE activity and brain oxidative stress and upregulated the gene expression, collectively contributing to neuroprotective properties. The results of our study add new perspectives on the properties of flavonoids to regulate the evolution of neurodegenerative diseases, especially AD, by modulating the expression of genes involved in the regulation of synaptic plasticity, axonal growth, and guidance, sympathetic and vagal transmission, the antioxidant response and cell proliferation and growth.

Multi-omics reveals aspirin eugenol ester alleviates neurological disease

BACKGROUND

Exosomes play an essential role in maintaining normal brain function due to their ability to cross the blood-brain barrier. Aspirin eugenol ester (AEE) is a new medicinal compound synthesized by the esterification of aspirin with eugenol using the prodrug principle. Aspirin has been reported to have neuroprotective effects and may be effective against neurodegenerative diseases.

PURPOSE

This study wanted to investigate how AEE affected neurological diseases in vivo and in vitro.

EXPERIMENTAL APPROACH

A multi-omics approach was used to explore the effects of AEE on the nervous system. Gene and protein expression changes of BDNF and NEFM in SY5Y cells after AEE treatment were detected using RT-qPCR and Western Blot.

KEY RESULTS

The multi-omics results showed that AEE could regulate neuronal synapses, neuronal axons, neuronal migration, and neuropeptide signaling by affecting transport, inflammatory response, and regulating apoptosis. Exosomes secreted by AEE-treated Caco-2 cells could promote the growth of neurofilaments in SY5Y cells and increased the expression of BDNF and NEFM proteins in SY5Y cells. miRNAs in the exosomes of AEE-treated Caco-2 cells may play an important role in the activation of SY5Y neuronal cells.

CONCLUSIONS

In conclusion, AEE could play positive effects on neurological-related diseases.

Evidence of disturbed insulin signaling in animal models of Alzheimer's disease

Since glucose reuptake by neurons is mostly independent of insulin, it has been an intriguing question whether insulin has or not any roles in the brain. Consequently, the identification of insulin receptors in the central nervous system has fueled investigations of insulin functions in the brain. It is also already known that insulin can influence glucose reuptake by neurons, mostly during activities that have the highest energy demand. The identification of high density of insulin receptors in the hippocampus also suggests that insulin may present important roles related to memory. In this context, studies have reported worse performance in cognitive tests among diabetic patients. In addition, alterations in the regulation of central insulin pathways have been observed in the brains of Alzheimer's disease (AD) patients. In fact, some authors have proposed AD as a third type of diabetes and recently, our group proposed insulin resistance as a common link between different AD hypotheses. Therefore, in the present narrative review, we intend to revise and gather the evidence of disturbed insulin signaling in experimental animal models of AD.

Phytochemical profiling, antioxidant potential and protective effect of leaves extract of tunisian Vitis vinifera autochthonous accessions against acute CCl4-injured hepatotoxicity in mice

Vitis vinifera leaves (VVL) are agro-industrial waste. In the current study, the phytochemical profile of V. vinifera leaves extracts (VVLE) of two Tunisian autochthonous accessions was determined via LC-UV-ESI/MS, and their antioxidant and hepatoprotective properties were also assessed. Mice were pretreated orally with VVLE (7.5, 15 and 30 mg/kg) for 7 days, and then received acutely and by i.p. a solution CCl₄ at 12% in sunflower oil (v/v). Serum levels of hepatic markers, oxidative stress indicators in liver tissue and histological changes were assessed. LC-UV-ESI/MS analysis revealed four phenolic compounds identified in both extracts with quercetin-3-O-glucuronide being the dominant constituent (23.32 ± 1.06 vs. 10.24 ± 0.12 mg/g DM, p < 0.05 for wild and cultivated accessions, respectively). The Antioxidant activity revealed a significant difference between the genotypes. Moreover, the VVLE of the wild "Nefza-I" ecotype was the most active based on antioxidant assays. Furthermore, the results showed that pre-treatment, especially with VVLE, of the wild ecotype "Nefza-I", attenuated CCl₄-induced acute liver injury in a dose-dependent manner, as demonstrated by the decrease in the activities of hepatic serum function markers. This was also evidenced by a decrease in the levels of lipoperoxidation and histological damage in the liver, as well as a restoration of antioxidant enzyme activities (SOD and catalase) and an increase in the hepatic glutathione content. Our results demonstrate that VVLE possesses protective effects on CCl₄-induced liver injury. Overall, the wild ecotype "Nefza-I" extract could serve as an effective protector against CCl₄-induced hepatocellular oxidative stress.

Translationally controlled tumor protein restores impaired memory and altered synaptic protein expression in animal models of dementia

This study describes the effects of translationally controlled tumor protein (TCTP) on mice with memory impairment caused by scopolamine (SCO) administration. Specifically, memory functions and expression levels of hippocampal synaptic proteins in 7- to 12-month-old SCO-treated wild-type (WT-SCO) mice were compared to those of TCTP-overexpressing (TG) and TCTP knocked-down (KD) mice similarly treated with SCO. Passive-avoidance tasks were performed with WT, TG, and KD mice for four weeks after intraperitoneal injection of SCO or saline followed by an acquisition test. After completing behavioral studies, hippocampi of all mice groups were collected and their synaptic protein contents were subjected to Western blotting or immunohistochemical analyses, and compared with those of 5x familial Alzheimer's disease (5xFAD) mice and postmortem AD patients. Results of passive avoidance tests revealed that SCO-induced memory impairment was repaired in TCTP-TG mice, but not in TCTP-KD mice. Hippocampal expression levels of synaptophysin, synapsin-1, and PSD-95 were increased in TCTP-TG mice treated with SCO (TG-SCO) but decreased in TCTP-KD mice treated with SCO (KD-SCO). Decreased levels of TCTP, synaptophysin, and PSD-95 were also found in hippocampi of 5xFAD mice and AD patients. Expression levels of p-CREB/CREB and brain-derived neurotrophic factor (BDNF) in TCTP-TG and TG-SCO mice were similar to or increased compared to those in WT mice, but decreased in TCTP-KD and KD-SCO mice. BDNF immunoreactivity was restored in CA1 regions of hippocampi of TG-SCO mice, but not in KD-SCO mice. These results suggest that TCTP can restore damaged memory in mice possibly through restored synaptic protein expression.

Smart Farming Enhances Bioactive Compounds Content of Panax ginseng on Moderating Scopolamine-Induced Memory Deficits and Neuroinflammation

Korean ginseng (Panax ginseng) is a traditional herbal supplement known to have a variety of pharmacological activities. A smart farm system could provide potential standardization of ginseng seedlings after investigating plant metabolic responses to various parameters in order to design optimal conditions. This research was performed to investigate the effect of smart-farmed ginseng on memory improvement in a scopolamine-induced memory deficit mouse model and an LPS-induced microglial cell model. A smart farming system was applied to culture ginseng. The administration of its extract (S2 extract) under specific culture conditions significantly attenuated cognitive and spatial memory deficits by regulating AKT/ERK/CREB signaling, as well as the cortical inflammation associated with suppression of COX-2 and NLRP3 induced by scopolamine. In addition, S2 extract improved the activation of iNOS and COX-2, and the secretion of NO in LPS-induced BV-2 microglia. Based on the HPLC fingerprint and in vitro data, ginsenosides Rb2 and Rd were found to be the main contributors to the anti-inflammatory effects of the S2 extract. Our findings suggest that integrating a smart farm system may enhance the metabolic productivity of ginseng and provides evidence of its potential impact on natural bioactive compounds of medicinal plants with beneficial qualities, such as ginsenosides Rb2 and Rd.

Potential effect of herbal antidepressants on cognitive deficit: Pharmacological activity and possible molecular mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Cognitive symptom is a "core" symptom of major depressive disorder (MDD) patients with clear deficit in memory, social and occupational function, and may persist during the remitting phase. Therefore, the remission of cognitive symptom has been considered as one of the main objectives in the treatment of MDD. Herbal antidepressants have been used to treat MDD, and there has been great advances in the understanding of the ability of these herbs to improve cognitive deficit linked to brain injury and various diseases including depression, Alzheimer disease, diabetes and age-related disorders. This systematic review summarizes the evidence from preclinical studies and clinical trials of herbal antidepressants with positive effects on cognitive deficit. The potential mechanisms by which herbal antidepressants prevent cognitive deficit are also reviewed. This review will facilitate further research and applications.

MATERIALS AND METHODS

We conducted an open-ended, English restricted search of MEDLINE (PubMed), Web of Science and Scopus for all available articles published or online before 31 December 2019, using terms pertaining to medical herb/phytomedicine/phytochemical/Chinese medicine and depression/major depressive disorder/antidepressant and/or cognitive impairment/cognitive deficit/cognitive dysfunction.

RESULTS

7 prescriptions, more than 30 individual herbs and 50 phytochemicals from China, Japan, Korea and India with positive effects on the depressive state and cognitive deficit are reviewed herein. The evidence from preclinical studies and clinical trials proves that these herbal antidepressants exhibit positive effects on one or more aspects of cognitive defect including spatial, episodic, aversive, and short- and long-term memory. The action mode of the improvement of cognitive deficit by these herbal antidepressants is mediated mainly through two pathways. One pathway is to promote hippocampal neurogenesis through activating brain derived neurotrophic factor-tropomyosin-related kinase B signaling. The other pathway is to prevent neuronal apoptosis through the inhibition of neuro-inflammation and neuro-oxidation.

CONCLUSION

These herbal antidepressants, having potential therapy for cognitive deficit, may prevent pathological processes of neurodegenerative diseases. Furthermore, these herbal medicines should provide a treasure trove, which will accelerate the development of new antidepressants that can effectively improve cognitive symptom in MDD. Studies on their molecular mechanisms may provide more potential targets and therapeutic approaches for new drug discovery.

Protective Effects of Compounds from Cimicifuga dahurica against Amyloid Beta Production in Vitro and Scopolamine-Induced Memory Impairment in Vivo

Cimicifuga dahurica has traditionally been used as an antipyretic, analgesic, and anti-inflammatory agent and as a treatment for uterine and anal prolapse. This study has investigated the potential beneficial effects of this medicinal plant and its components on Alzheimer's disease (AD) with a focus on amyloid beta (Aβ) production and scopolamine-induced memory impairment in mice. An ethanol extract from C. dahurica roots decreased Aβ production in APP-CHO cells [Chinese hamster ovarian (CHO) cells stably expressing amyloid precursor protein (APP)], as determined by an enzyme-linked immunosorbent assay and Western blot analysis. Then, the compounds isolated from C. dahurica were tested for their antiamyloidogenic activities. Four compounds (1-4) efficiently interrupted Aβ generation by suppressing the level of β-secretase in APP-CHO cells. Moreover, the in vivo experimental results demonstrated that compound 4 improved the cognitive performances of mice with scopolamine-induced disruption on behavioral tests and the expression of memory-related proteins. Taken together, these results suggest that C. dahurica and its constituents are potential agents for preventing or alleviating the symptoms of AD.

Ameliorative effect of deoxyvasicine on scopolamine-induced cognitive dysfunction by restoration of cholinergic function in mice

BACKGROUND

Aerial parts of Peganum harmala Linn is used as a traditional medical herb for treatment of amnesia in Uighur medicine in China. Deoxyvasicine (DVAS) is one of the chief active ingredients in P. harmala, it possesses strong acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in vitro, but the therapeutic effect and mechanisms on amnesia in vivo are unclear.

PURPOSE

The objective of this study was to investigate the improvement effect of DVAS from P. harmala in learning and memory deficits of scopolamine-induced mice and elucidate the underlying mechanisms involved.

METHODS

Mice were pretreated with DVAS (5, 15 and 45 mg/kg) and huperzine-A (0.2 mg/kg) by gavage for 7 days, and subsequently were daily intraperitoneally injected with scopolamine (1 mg/kg) to induce learning and memory deficits and behavioral performance was assessed by Morris water maze. To further evaluate the potential mechanisms of DVAS in improving learning and memory capabilities, pathological change, levels of various biochemical markers and protein expressions related to cholinergic system, oxidative stress, and neuroinflammation were examined.

RESULTS

The results showed that DVAS could alleviate learning and memory deficits in scopolamine-treated mice. DVAS could regulate cholinergic function by inhibiting AChE and activating choline acetyltransferase (ChAT) activities and protein expressions. DVAS could induce brain-derived neurotrophic factor and protect hippocampal pyramidal cells against neuronal damage. DVAS also enhanced antioxidant defense via increasing the antioxidant enzyme level and activity of glutathione peroxidase, and anti-inflammatory function through suppressing tumor necrosis factor-α. Additionally, DVAS could regulate the neurotransmitters by elevating acetylcholine, 5-hydroxytryptamine, γ-aminobutyric acid and reducing 5-hydroxyindole-3-acetic acid and glutamic acid.

CONCLUSION

Results illustrated that DVAS may be a promising candidate compound against amnesia via restoration of cholinergic function, regulating neurotransmitters, attenuating neuroinflammation and oxidative stress.

Total Polysaccharides of Lily Bulb Ameliorate Menopause-Like Behavior in Ovariectomized Mice: Multiple Mechanisms Distinct from Estrogen Therapy

Our previous study has demonstrated the effects of aqueous extract of lily bulb in alleviating menopause-related psychiatric symptoms in ovariectomized (OVX) mice. This study sought to further investigate the psychotropic effects of total polysaccharides of lily bulb (TPLB) against anxiety, depression, and cognitive deterioration and the underlying mechanisms in OVX mice using behavioral, neurochemical, molecular, and proteomic approaches in comparison with estrogen therapy. While TPLB and estradiol showed similar effects in reducing OVX-induced anxiety, depression, and cognitive impairment, the psychotropic effects of TPLB were more closely associated with the predominant activation of estrogen receptors (ERs) and regulation of brain regional neurotransmitters and neurotrophins with minor effects on the uterus. Estradiol had similar potencies in binding affinity at ERα and ERβ, which caused widespread genetic and epigenetic effects. In contrast, TPLB displayed a higher affinity at ERβ than ERα, triggering the specific Ras/Akt/ERK/CREB signaling pathway without affecting any epigenetic activity. TPLB additionally modulated multiple proteins associated with mitochondrial oxidative stress, but estradiol did not. These results indicate that TPLB has comparable efficacy in reducing menopause-associated neuropsychological symptoms with a better safety profile compared to estrogen therapy. We suggest that TPLB could serve as a novel agent for menopause syndrome.

Histone Deacetylase 4 Downregulation Elicits Post-Traumatic Psychiatric Disorders through Impairment of Neurogenesis

An enduring deficit in neurogenesis largely contributes to the development of severe post-traumatic psychiatric disorders such as anxiety, depression, and memory impairment following traumatic brain injury (TBI); however, the mechanism remains obscure. Here we have shown that an imbalance in the generation of γ-aminobutyric acid (GABA)ergic and glutamatergic neurons due to aberrant induction of vesicular glutamate transporter 1 (vGlut1)-positive glutamatergic cells is responsible for impaired neuronal differentiation in the hippocampus following TBI. To elucidate the molecular mechanism, we found that TBI activates a transcription factor, Pax3, by increasing its acetylation status, and subsequently induces Ngn2 transcription. This event, in turn, augments the vGlut1-expressing glutamatergic neurons and accumulation of excess glutamate in the hippocampus that can affect neuronal differentiation. In our study the acetylation of Pax3 was increased due to loss of its interaction with a deacetylase, histone deacetylase 4 (HDAC4), which was downregulated after TBI. TBI-induced activation of GSK3β was responsible for the degradation of HDAC4. We also showed that overexpression of HDAC4 before TBI reduces Pax3 acetylation by restoring an interaction between HDAC4 and Pax3 in the hippocampus. This event prevents the aberrant induction of vGlut1-positive glutamatergic neurons by decreasing the Ngn2 level and subsequently reinforces the balance between GABAergic and glutamatergic neurons following TBI. Further, we found that overexpression of HDAC4 in the hippocampus improves anxiety, depressive-like behavior, and memory functions following TBI.