Fermented rice peptides attenuate scopolamine-induced memory impairment in mice by regulating neurotrophic signaling pathways in the hippocampus

Regulation of redox enzymes by nutraceuticals: a review of the roles of antioxidant polyphenols and peptides

Redox enzymes are essential components of the cellular defence system against oxidative stress, which is a common factor in various diseases. Therefore, understanding the role of bioactive nutraceuticals in modulating the activity of these enzymes holds immense therapeutic potential. This paper provides a comprehensive review of the regulation of redox enzymes in cell and animal models by food-derived bioactive nutraceuticals, focusing on polyphenols and peptides. Specifically, this paper discusses the regulation of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), NAPDH oxidase, xanthine oxidase (XO), myeloperoxidase (MPO), and haem oxygenase (HO) in cell and animal models. Polyphenols, which are abundant in fruits, vegetables, and beverages, have diverse antioxidant properties, including direct scavenging of reactive oxygen species and regulation of transcription factors such as nuclear factor erythroid 2-related factor 2, which leads to the increased expression of the redoxenzymes SOD, HO, and GPx. Similarly, bioactive peptides from various food proteins can enhance antioxidative enzyme activity by regulating gene expression and directly activating the enzyme CAT. In other cases, an antioxidative response requires the downregulation or inhibition of the redox enzymes XO, MPO, and NAPDH oxidase. This paper highlights the potential of bioactive nutraceuticals in mitigating oxidative stress-related diseases and their mechanisms in modulating the redox enzyme expression or activity. Furthermore, the review highlights the need for further research to uncover new therapeutic strategies using nutraceuticals for enhancing cellular antioxidant defence mechanisms and improving health outcomes.

Melatonin attenuates scopolamine-induced cognitive dysfunction through SIRT1/IRE1α/XBP1 pathway

BACKGROUND

The prevalence of dementia around the world is increasing, and these patients are more likely to have cognitive impairments, mood and anxiety disorders (depression, anxiety, and panic disorder), and attention deficit disorders over their lifetime. Previous studies have proven that melatonin could improve memory loss, but its specific mechanism is still confused.

METHODS

In this study, we used in vivo and in vitro models to examine the neuroprotective effect of melatonin on scopolamine (SCOP)-induced cognitive dysfunction. The behavioral tests were performed. 18F-FDG PET imaging was used to assess the metabolism of the brain. Protein expressions were determined through kit detection, Western blot, and immunofluorescence. Nissl staining was conducted to reflect neurodegeneration. MTT assay and RNAi transfection were applied to perform the in vitro experiments.

RESULTS

We found that melatonin could ameliorate SCOP-induced cognitive dysfunction and relieve anxious-like behaviors or HT22 cell damage. 18F-FDG PET-CT results showed that melatonin could improve cerebral glucose uptake in SCOP-treated mice. Melatonin restored the cholinergic function, increased the expressions of neurotrophic factors, and ameliorated oxidative stress in the brain of SCOP-treated mice. In addition, melatonin upregulated the expression of silent information regulator 1 (SIRT1), which further relieved endoplasmic reticulum (ER) stress by decreasing the expression of phosphorylate inositol-requiring enzyme (p-IRE1α) and its downstream, X-box binding protein 1 (XBP1).

CONCLUSIONS

These results indicated that melatonin could ameliorate SCOP-induced cognitive dysfunction through the SIRT1/IRE1α/XBP1 pathway. SIRT1 might be the critical target of melatonin in the treatment of dementia.

Fermented foods: Harnessing their potential to modulate the microbiota-gut-brain axis for mental health

Over the past two decades, whole food supplementation strategies have been leveraged to target mental health. In addition, there has been increasing attention on the ability of gut microbes, so called psychobiotics, to positively impact behaviour though the microbiota-gut-brain axis. Fermented foods offer themselves as a combined whole food microbiota modulating intervention. Indeed, they contain potentially beneficial microbes, microbial metabolites and other bioactives, which are being harnessed to target the microbiota-gut-brain axis for positive benefits. This review highlights the diverse nature of fermented foods in terms of the raw materials used and type of fermentation employed, and summarises their potential to shape composition of the gut microbiota, the gut to brain communication pathways including the immune system and, ultimately, modulate the microbiota-gut-brain axis. Throughout, we identify knowledge gaps and challenges faced in designing human studies for investigating the mental health-promoting potential of individual fermented foods or components thereof. Importantly, we also suggest solutions that can advance understanding of the therapeutic merit of fermented foods to modulate the microbiota-gut-brain axis.

Bridging neurotrophic factors and bioactive peptides to Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder. As the demographic shifting towards an aging population, AD has emerged as a prominent public health concern. The pathogenesis of AD is complex, and there are no effective treatment methods for AD until now. In recent years, neurotrophic factors and bioactive peptides including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), irisin, melatonin, have been discovered to exert neuroprotective functions for AD. Bioactive peptides can be divided into two categories based on their sources: endogenous and exogenous. This review briefly elaborates on the pathogenesis of AD and analyzes the regulatory effects of endogenous and exogenous peptides on the pathogenesis of AD, thereby providing new therapeutic targets for AD and a theoretical basis for the application of bioactive peptides as adjunctive therapies for AD.

Food-derived Peptides as Promising Neuroprotective Agents: Mechanism and Therapeutic Potential

Many food-derived peptides have the potential to improve brain health and slow down neurodegeneration. Peptides are produced by the enzymatic hydrolysis of proteins from different food sources. These peptides have been shown to be involved in antioxidant and anti-inflammatory activity, neuro-transmission modulation, and gene expression regulation. Although few peptides directly affect chromatin remodeling and histone alterations, others indirectly affect the neuroprotection process by interfering with epigenetic changes. Fish-derived peptides have shown neuroprotective properties that reduce oxidative stress and improve motor dysfunction in Parkinson's disease models. Peptides from milk and eggs have been found to have anti-inflammatory properties that reduce inflammation and improve cognitive function in Alzheimer's disease models. These peptides are potential therapeutics for neurodegenerative diseases, but more study is required to assess their efficacy and the underlying neuroprotective benefits. Consequently, this review concentrated on each mechanism of action used by food-derived peptides that have neuroprotective advantages and applications in treating neurodegenerative diseases. This article highlights various pathways, such as inflammatory pathways, major oxidant pathways, apoptotic pathways, neurotransmitter modulation, and gene regulation through which food-derived peptides interact at the cellular level.

Does a pickle a day keep Alzheimer's away? Fermented food in Alzheimer's disease: A review

Fermented food is commonly viewed as healthy, mostly due to its probiotic and digestion-enhancing properties and recently it has been examined with regard to the development of new therapeutic and preventive measures for Alzheimer's disease. Fermented food has been shown to have anti-inflammatory and antioxidant properties and to alter the gut microbiota. However, the exact pathogenesis of Alzheimer's disease is still unknown and its connections to systemic inflammation and gut dysbiosis, as potential targets of fermented food, require further investigation. Therefore, to sum up the current knowledge, this article reviews recent research on the pathogenesis of Alzheimer's disease with emphasis on the role of the gut-brain axis and studies examining the use of fermented foods. The analysis of the fermented food research includes clinical and preclinical in vivo and in vitro studies. The fermented food studies have shown promising effects on amyloid-β metabolism, inflammation, and cognitive impairment in animals and humans. Fermented food has great potential in developing new approaches to Alzheimer's disease treatment.

Betanin mitigates scopolamine-induced cognitive impairment by restoring cholinergic function, boosting brain antioxidative status, and increasing BDNF level in the zebrafish model

Betalains obtained from Beta vulgaris (family Caryophyllales) are regularly consumed as part of the regular diet with medicinal benefits due to antioxidant and anti-inflammatory properties. The objective of this article was to evaluate betanin's neuroprotective properties in a scopolamine-induced zebrafish paradigm. Betanin (BET) (50, 100, and 200 mg/L), and donepezil (10 mg/L) were delivered to zebrafish in a treatment tank once a day for 8 days, while memory impairment was produced by scopolamine (100 µM), which was given 60 min before behavioral assessments. The treatment dosages were determined based on acute toxicity studies. The existence of betacyanin and betaxanthins of BET was tested using liquid chromatography-mass spectrometry (LC-MS). The Y-maze task was used to examine the novelty and spatial memory, while the novel tank diving test was used to assess anxiety-like behavior (NTT). The activities of acetylcholinesterase (AChE) and the oxidative stress sensitivity in zebrafish brains were examined. Also, brain-derived neurotrophic factor (BDNF) level is quantified by an ELISA kit. Scopolamine-induced rises in AChE activity, memory loss, anxiety, and brain oxidant capacity were all reduced by BET. These results suggest that BET (50 and 100 mg/L) has a therapeutic ability to treat brain oxidative stress and cognitive deficits in amnesic zebrafish.

PAYCS Alleviates Scopolamine-Induced Memory Deficits in Mice by Reducing Oxidative and Inflammatory Stress and Modulation of Gut Microbiota-Fecal Metabolites-Brain Neurotransmitter Axis

The bioactive peptide PAYCS (Pro-Ala-Tyr-Cys-Ser) identified from anchovy hydrolysates has been reported to be positive in memory alleviation. The gut microbiota-brain axis plays a vital role in brain functions, which could be affected by nutritional supplementation. Herein, we found that PAYCS at different concentrations (PAYCS-L and PAYCS-H) showed various improving effects in behavioral tests and alleviation effects on oxidative as well as inflammatory stress in the scopolamine-induced AD mouse model. The 16S rRNA results illustrated that PAYCS-L altered the ratio of Bacteroidetes/Firmicutes and PAYCS treatment elevated the relative abundance of Cacteroidaceae and Prevotellaceae. Notably, administration of PAYCS significantly upregulated memory-related metabolites and neurotransmitters. Overall, PAYCS-L reversed memory deficits of amnesiac mice partially via the modulation of gut microbiota-metabolites-brain neurotransmitter axis. For PAYCS-H, functions might be involved in the reversal of oxidative and inflammatory impairments in the liver and serum, which was also associated with the changed intestinal microbiota and fecal metabolites.

Sea Cucumber Peptides Attenuated the Scopolamine-Induced Memory Impairment in Mice and Rats and the Underlying Mechanism

Social stress and unhealthy diets lead to memory impairment, triggering health problems. This study aimed to determine the mitigating effect and regulation mechanism of sea cucumber peptides (SCP) against memory impairment. Here, scopolamine-induced memory impairment in mouse and rat models was used based on behavioral tests, a histological staining technique, Fourier transform infrared microscopy, and gas-chromatographic analysis as well as a Western blotting method. SCP improved the behavioral performance and regulated the disorder of the cholinergic system in mouse models in a dose-dependent manner. Therefore, the underlying mechanism was explored in high-dose SCP using mouse and rat models. SCP repaired damaged neuronal cells, enhanced the Nissl body number, increased the unsaturated lipid level, and activated the long-term potentiation (LTP) pathway (p-CaMKII, p-CREB, and BDNF), both in the mouse and rat hippocampus. The results indicated that SCP upregulated the LTP pathway and unsaturated lipid level to combat scopolamine-induced memory impairment, suggesting that SCP was a potential candidate for neurological recovery.

Preventive and Therapeutic aspects of Fermented Foods

In recent times, the status of some fermented foods which are considered as functional foods that confer health benefits in certain disease conditions has grown rapidly. The health benefits of fermented foods are due to the presence of probiotic microbes and the bioactive compound formed during fermentation. Microbes involved and metabolites produced by them are highly species-specific and contribute to the authenticity of the fermented foods. Several studies pertaining to the effect of fermented foods on various disease conditions have been conducted in recent years using both animal models and clinical trials on humans. This review focuses on the impact of fermented foods on conditions like diabetes, cardiovascular disease (CVD), obesity, gastrointestinal disorder, cancer and neurodegenerative disorders.

Tilapia Head Protein Hydrolysate Attenuates Scopolamine-Induced Cognitive Impairment through the Gut-Brain Axis in Mice

The destruction of the homeostasis in the gut-brain axis can lead to cognitive impairment and memory decline. Dietary intervention with bioactive peptides from aquatic products is an innovative strategy to prevent cognitive deficits. The present study aimed to determine the neuroprotective effect of tilapia head protein hydrolysate (THPH) on scopolamine-induced cognitive impairment in mice, and to further explore its mechanism through the microbiota–gut-brain axis. The results showed that THPH administration significantly improved the cognitive behavior of mice, and normalized the cholinergic system and oxidative stress system of the mice brain. The histopathological observation showed that THPH administration significantly reduced the pathological damage of hippocampal neurons, increased the number of mature neurons marked by NeuN and delayed the activation of astrocytes in the hippocampus of mice. In addition, THPH administration maintained the stability of cholinergic system, alleviated oxidative stress and further improved the cognitive impairment by reshaping the gut microbiota structure of scopolamine-induced mice and alleviating the disorder of lipid metabolism and amino acid metabolism in serum. In conclusion, our research shows that THPH supplementation is a nutritional strategy to alleviate cognitive impairment through the gut-brain axis.

Comprehensive Analysis of Mouse Hippocampal Lysine Acetylome Mediated by Sea Cucumber Peptides Preventing Memory Impairment

Memory impairment is becoming a potential health issue with the delicacy of diet and social stress. Sea cucumber peptides (SCP) prevent memory impairment, as previously reported. In this study, further research was performed using hippocampal lysine-acetylome to explore molecular regulation mechanisms. C57BL/6 mice were treated with scopolamine via intraperitoneal injection to simulate memory impairment. To determine the influence of SCP on the total acetylated-protein level of the hippocampus, acetylated-proteomics was performed. SCP increased the acetylation level of histone (H3 and H4). Meanwhile, for non-histones, the differentially acetylated proteins were involved in multiple memory-related pathways, as shown by KEGG enrichment analysis. Additionally, long-term potentiation was confirmed by western blotting. Finally, a combined analysis of proteome and lysine acetylome revealed that SCP contributed to synaptic vesicle cycle regulation and dopamine metabolism. Consequently, our findings revealed that SCP was potentially neuroprotective by regulating post-transcriptional hippocampal protein acetylation.

Round Scad-Derived Octapeptide WCPFSRSF Confers Neuroprotection by Regulating Akt/Nrf2/NFκB Signaling

We previously identified peptides derived from round scad as potential Nrf2 activators. However, the neuroprotection of these peptides is still unclear. In this study, we aimed to investigate the neuroprotective effect of WCPFSRSF against glutamate-induced neurotoxicity, and the memory-improving effects of WCPFSRSF in mice were also explored. Results showed that WCPFSRSF ameliorated oxidative stress by improving the activities of antioxidant enzymes and promoting the Nrf2-mediated endogenous defense system. Moreover, there is an interaction between the up-regulation of Nrf2 and the down-regulation of NFκB induced by the peptide, which was related to the generation of reactive oxygen species (ROS) and could be abolished by the Akt inhibitor LY294002. Further analysis demonstrated that WCPFSRSF may act as a radical scavenger and Nrf2 activator. The antioxidant and anti-inflammatory effects might be related to the Cys and Trp in WCPFSRSF. Moreover, WCPFSRSF could improve spatial memory impairment in sleep-deprived mice. Thus, this work provided evidence for WCPFSRSF as a potential candidate against neurotoxicity and memory deficits.

Potential of plant-derived peptides for the improvement of memory and cognitive function

Recently, there has been an increased demand for functional foods, to reduce the risk of age-related cognitive impairment, dementia, and Alzheimer's disease. Among them, plant-derived bioactive compounds, such as phytochemicals and peptides, have notable potential in improving memory and cognitive functions. Many studies have provided potential data concerning the characteristics and structure-activity relationships of memory-enhancing peptides. When considering the proof of efficacy of these plant-based peptides in humans as neurological treatment options, it is necessary to accumulate evidence concerning their bioavailability and permeability through blood-brain barrier (BBB). This review focuses on the memory-enhancing effects of peptides derived from plant proteins and presents a current perspective on their structure-activity relationships and BBB permeability.

Combination of Polygoni Multiflori Radix Praeparata and Acori Tatarinowii Rhizoma Alleviates Learning and Memory Impairment in Scopolamine-Treated Mice by Regulating Synaptic-Related Proteins

Polygoni Multiflori Radix Praeparata (ZhiHeShouWu, PMRP) and Acori Tatarinowii Rhizoma (ShiChangPu, ATR) and their traditional combination (PA) are frequently used in traditional Chinese medicine to prevent and treat Alzheimer disease (AD) based on the theory that PMRP tonifies the kidney and ATR dissipates phlegm. However, the components of PA and their mechanisms of action are not known. The present study analyzed the active components of PA, and investigated the protective effect of PA against cognitive impairment induced by scopolamine in mice along with the underlying mechanism.The aqueous extract of PA was analyzed by high-performance liquid chromatography–mass spectrometry (HPLC-MS) and gas chromatography (GC)-MS in order to identify the major components. To evaluate the protective effect of PA against cognitive dysfunction, mice were orally administered PA, PMRP, or ATR for 30 days before treatment with scopolamine. Learning and memory were assessed in mice with the Morris water maze test; neurotransmitter levels in the hippocampus were analyzed by HPLC-MS; and the expression of synapse-related proteins in the hippocampus was detected by western blotting and immunohistochemistry. Eight active compounds in PA and rat plasma were identified by HPLC-MS and GC-MS. Plasma concentrations of 2,3,5,4′-tetrahydroxystilbene-2-O-β-d-glucoside, emodin, α-asarone, and asarylaldehyde were increased following PA administration; meanwhile, gallic acid, emodin-8-O-β-d-glucopyranoside, β-asarone, and cis-methyl isoeugenol concentrations were similar in rats treated with PA, PMRP, and ATR. In scopolamine-treated mice, PA increased the concentrations of neurotransmitters in the hippocampus, activated the brain-derived neurotrophic factor (BDNF)/extracellular signal-regulated kinase (ERK)/cAMP response element binding protein (CREB) signaling pathway, and increased the expression of p90 ribosomal S6 kinase (p90RSK) and postsynaptic density (PSD)95 proteins. Thus, PA alleviates cognitive deficits by enhancing synaptic-related proteins, suggesting that it has therapeutic potential for the treatment of aging-related diseases such as AD.

Neuroprotective effects of NDEELNK from sea cucumber ovum against scopolamine-induced PC12 cell damage through enhancing energy metabolism and upregulation of the PKA/BDNF/NGF signaling pathway

The aim of the study was to evaluate the neuroprotective function of sea cucumber ovum peptide-derived NDEELNK and explore the underlying molecular mechanisms. NDEELNK exerted the neuroprotective effect by improving the acetylcholine (ACh) level and reducing the acetylcholinesterase (AChE) activity in PC12 cells. By molecular docking, we confirmed that the NDEELNK backbone and AChE interacted through hydrophobic and hydrogen bonds in contact with the amino acid residues of the cavity wall. NDEELNK increased superoxide dismutase (SOD) activity and decreased reactive oxygen species (ROS) production, thereby reducing mitochondrial dysfunction and enhancing energy metabolism. Our results demonstrated that NDEELNK supplementation alleviated scopolamine-induced PC12 cell damage by improving the cholinergic system, increasing energy metabolism and upregulating the expression of phosphorylated protein kinase A (p-PKA), brain-derived neurotrophic factor (BNDF) and nerve growth factor (NGF) signaling proteins in in vitro experiments. These results demonstrated that the sea cucumber ovum peptide-derived NDEELNK might play a protective role in PC12 cells.

Bay Leaf (Laurus Nobilis L.) Incense Improved Scopolamine-Induced Amnesic Rats by Restoring Cholinergic Dysfunction and Brain Antioxidant Status

Bay leaf (Laurus nobilis L.) has been shown to possesses various biological activities such as wound healing activity, antioxidant activity, antibacterial activity, antiviral activity, immunostimulant activity, anticholinergic activity, antifungal activity, insect repellant activity, anticonvulsant activity, antimutagenic activity, and analgesic and anti-inflammatory activity. The present study aimed to investigate whether the bay leaf incense (BL) elicits the memory formation via the action on the cholinergic system using a scopolamine (Sco)-induced rat model. Rats were exposed to BL over 5 min in a smoking chamber apparatus once daily for 22 days, whereas memory impairment was induced by Sco (0.7 mg/kg), a muscarinic receptor antagonist, delivered 30 min before each behavioral test. The phytochemical composition of BL was achieved by gas chromatograph–mass spectrometry (GCMS). Behavioral effects in rats were assessed by Y-maze, radial arm maze (RAM), and novel object recognition (NOR) paradigms. Additionally, the acetylcholinesterase (AChE) activity and the oxidative stress markers in the rat hippocampus were also evaluated. Exposure to BL significantly ameliorated Sco-induced cognitive impairment and oxidative stress in the rat hippocampus. The obtained results suggested that BL-induced ameliorative cognitive effects are mediated by enhancement of the cholinergic system and antioxidant activities.

AGLPM and QMDDQ peptides exert a synergistic action on memory improvement against scopolamine-induced amnesiac mice

This study aimed to explore the synergistic action of pentapeptides Gln-Met-Asp-Asp-Gln (QMDDQ) and Ala-Gly-Leu-Pro-Met (AGLPM) on memory improvement against scopolamine-induced impairment in mice compared to those of either peptide alone. In behavioral tests, the codelivery of QMDDQ and AGLPM was superior to the individual supplements of either peptide alone not only in enhancing the memory ability at training trials but also in recovering the memory impairment in scopolamine-induced amnesiac mice in test trials. Furthermore, combination treatment with QMDDQ and AGLPM could significantly reduce the acetylcholinesterase (AChE) level and increase the acetylcholine (ACh) level in the hippocampus, and noticeably improve the pathological morphology of the neuron cells in hippocampal regions CA1 and CA2 and dentate gyrus (DG). The findings indicated that the combination treatment with QMDDQ and AGLPM could improve the memory function by regulating the cholinergic system.

Thymus vulgaris Essential Oil Protects Zebrafish against Cognitive Dysfunction by Regulating Cholinergic and Antioxidants Systems

Thymus vulgaris L. is an aromatic herb used for medicinal purposes such as antimicrobial, spasmolytic, antioxidant, anti-inflammatory, antinociceptive, antitumor, and may have beneficial effects in the treatment of Alzheimer’s disease. The present study aimed to investigate whether Thymus vulgaris L. essential oil enhances cognitive function via the action on cholinergic neurons using scopolamine (Sco)-induced zebrafish (Danio rerio) model of memory impairments. Thymus vulgaris L. essential oil (TEO, 25, 150, and 300 µL/L) was administered by immersion to zebrafish once daily for 13 days, whereas memory impairment was induced by Sco (100 μM), a muscarinic receptor antagonist, delivered 30 min before behavioral tests. Spatial memory was assessed using the Y-maze test and novel object recognition test (NOR). Anxiety and depression were measured in the novel tank diving test (NTT). Gas Chromatograph-Mass Spectrometry (GC-MS) analysis was used to study the phytochemical composition of TEO. Acetylcholinesterase (AChE) activity and oxidative stress response in the brain of zebrafish were determined. TEO ameliorated Sco-induced increasing of AChE activity, amnesia, anxiety, and reduced the brain antioxidant capacity. These results suggest that TEO may have preventive and/or therapeutic potentials in the management of memory deficits and brain oxidative stress in zebrafish with amnesia.

Bioactive peptides from food fermentation: A comprehensive review of their sources, bioactivities, applications, and future development

Bioactive peptides (BPs) are specific protein fragments that exert various beneficial effects on human bodies and ultimately influence health, depending on their structural properties and amino acid composition and sequences. By offering promising solutions to solve diverse health issues, the production, characterization, and applications of food-derived BPs have drawn great interest in the current literature and are of particular interest to the food and pharmaceutical industries. The microbial fermentation of protein from various sources is indubitably a novel way to produce BPs with numerous beneficial health effects. Apart from its lower cost as compared to enzymes, the BPs produced from microbial fermentation can be purified without further hydrolysis. Despite these features, current literature shows dearth of information on the BPs produced from food via microbial fermentation. Hence, there is a strong necessity to explore the BPs obtained from food fermentation for the development of commercial nutraceuticals and functional foods. As such, this review focuses on the production of BPs from different food sources, including the extensively studied milk and milk products, with emphasis on microbial fermentation. The structure-activity (antihypertensive, antioxidant, antimicrobial, opiate-like, anti-inflammatory, anticancer/antiproliferative, antithrombotic, hypolipidemic, hypocholesterolemic, and mineral binding) relationship, potential applications, future development, and challenges of BPs obtained from food fermentation are also discussed.

Protective effect of ginsenoside Rh2 on scopolamine-induced memory deficits through regulation of cholinergic transmission, oxidative stress and the ERK-CREB-BDNF signaling pathway

Rh2 is a rare ginsenoside and there are few reports of its effect on cognition compared with other similar molecules. This study aimed to establish the impact of Rh2 treatment on improving scopolamine (Scop)-induced memory deficits in mice and illuminate the underlying mechanisms. First, memory-related behavior was evaluated using two approaches: object location recognition (OLR), based on spontaneous activity, and a Morris water maze (MWM) task, based on an aversive stimulus. Our results suggested that Rh2 treatment effectively increased the discrimination index of the mice in the OLR test. In addition, Rh2 elevated the crossing numbers and decreased the escape latency during the MWM task. Moreover, Rh2 markedly upregulated the phosphorylation of the extracellular signal-regulated kinase (ERK)-cAMP response element binding (CREB)-brain derived neurotrophic factor (BDNF) pathway in the hippocampus. Meanwhile, the administration of Rh2 significantly promoted the cholinergic system and dramatically suppressed oxidative stress in the hippocampus. Taken together, Rh2 exhibited neuroprotective effects against Scop-induced memory dysfunction in mice. Rh2 activity might be ascribed to several underlying mechanisms, including its effects on modulating the cholinergic transmission, inhibiting oxidative stress and activating the ERK-CREB-BDNF signaling pathway. Consequently, the ginsenoside Rh2 might serve as a promising candidate compound for Alzheimer's disease.