Cognitive-enhancing effects of fibrauretine on Aβ1-42-induced Alzheimer's disease by compatibilization with ginsenosides

Mechanistic insights and emerging therapeutic stratagems for Alzheimer's disease

Alzheimer's disease (AD), a multi-factorial neurodegenerative disorder has affected over 30 million individuals globally and these numbers are expected to increase in the coming decades. Current therapeutic interventions are largely ineffective as they focus on a single target. Development of an effective drug therapy requires a deep understanding of the various factors influencing the onset and progression of the disease. Aging and genetic factors exert a major influence on the development of AD. Other factors like post-viral infections, iron overload, gut dysbiosis, and vascular dysfunction also exacerbate the onset and progression of AD. Further, post-translational modifications in tau, DRP1, CREB, and p65 proteins increase the disease severity through triggering mitochondrial dysfunction, synaptic loss, and differential interaction of amyloid beta with different receptors leading to impaired intracellular signalling. With advancements in neuroscience tools, new inter-relations that aggravate AD are being discovered including pre-existing diseases and exposure to other pathogens. Simultaneously, new therapeutic strategies involving modulation of gene expression through targeted delivery or modulation with light, harnessing the immune response to promote clearance of amyloid deposits, introduction of stem cells and extracellular vesicles to replace the destroyed neurons, exploring new therapeutic molecules from plant, marine and biological sources delivered in the free state or through nanoparticles and use of non-pharmacological interventions like music, transcranial stimulation and yoga. Polypharmacology approaches involving combination of therapeutic agents are also under active investigation for superior therapeutic outcomes. This review elaborates on various disease-causing factors, their underlying mechanisms, the inter-play between different disease-causing players, and emerging therapeutic options including those under clinical trials, for treatment of AD. The challenges involved in AD therapy and the way forward have also been discussed.

Palmatine Protects PC12 Cells and Mice from Aβ25-35-Induced Oxidative Stress and Neuroinflammation via the Nrf2/HO-1 Pathway

Alzheimer's disease is a common degenerative disease which has a great impact on people's daily lives, but there is still a certain market gap in the drug research about it. Palmatine, one of the main components of Huangteng, the rattan stem of Fibraurea recisa Pierre (Menispermaceae), has potential in the treatment of Alzheimer's disease. The aim of this study was to evaluate the neuroprotective effect of palmatine on amyloid beta protein 25-35-induced rat pheochromocytoma cells and AD mice and to investigate its mechanism of action. CCK8 assays, ELISA, the Morris water maze assay, fluorescent probes, calcein/PI staining, immunofluorescent staining and Western blot analysis were used. The experimental results show that palmatine can increase the survival rate of Aβ25-35-induced PC12 cells and mouse hippocampal neurons, reduce apoptosis, reduce the content of TNF-α, IL-1β, IL-6, GSH, SOD, MDA and ROS, improve the learning and memory ability of AD mice, inhibit the expression of Keap-1 and Bax, and promote the expression of Nrf2, HO-1 and Bcl-2. We conclude that palmatine can ameliorate oxidative stress and neuroinflammation produced by Aβ25-35-induced PC12 cells and mice by modulating the Nrf2/HO-1 pathway. In conclusion, our results suggest that palmatine may have a potential therapeutic effect on AD and could be further investigated as a promising therapeutic agent for AD. It provides a theoretical basis for the development of related drugs.

Baicalin Exhibits a Protective Effect against Cisplatin-Induced Cytotoxic Damage in Canine Renal Tubular Epithelial Cells

Renal failure is a common chronic disease in dogs that substantially affects both their quality of life and longevity. The objective of this study was to assess the protective mechanisms of baicalin in cisplatin-induced Madin-Darby canine kidney (MDCK) epithelial cells' apoptosis model and explore the impacts of baicalin at varying doses on various indexes, such as cisplatin-induced MDCK cell apoptosis, oxidation and antioxidation, and inflammatory factors. (Methods) MDCK cells in the logarithmic growth phase were randomly divided into a control group, a model group (20 μmol/L cisplatin), and a baicalin-protection group (20 μmol/L cisplatin + 50, 25 μmol/L baicalin) and received the corresponding treatments for 24 h. The effects of cisplatin on MDCK cell apoptosis, oxidation and antioxidation, inflammatory factors, and other indicators were studied, and the relieving effect of baicalin on cisplatin-induced MDCK cell damage was explored. Calcein/PI staining and Annexin V-FITC/PI staining showed that cisplatin induced the apoptosis of MDCK cells, while baicalin effectively reduced the damage caused by cisplatin. The ELISA results demonstrated a significant elevation in the nitric oxide (NO) and malondialdehyde (MDA) levels within the MDCK cells following treatment with cisplatin (p < 0.01). In addition, superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT) activities remarkably declined (p < 0.01), while tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) expression within the MDCK cells were apparently elevated (p < 0.01). However, baicalin treatment resulted in opposite changes in these factors. The findings suggested that baicalin exhibits potential in mitigating cisplatin-induced oxidative stress and inflammation in MDCK cells. As revealed with the Western blot results, cisplatin promoted P62, P53, and BAX protein levels, increased mTOR phosphorylation, inhibited AMPK phosphorylation, and reduced Beclin1 and BCL-2 protein levels. However, a contrasting trend was observed following baicalin treatment. Cisplatin can inhibit the activity of MDCK cells, lead to abnormalities in oxidation and antioxidation functions and cell inflammatory factors, and accelerate cell apoptosis. Moreover, baicalin can significantly alleviate the damage of cisplatin to MDCK cells.

FGF-18 alleviates memory impairments and neuropathological changes in a rat model of Alzheimer's disease

Alzheimer's disease (AD) is a multifactorial pathology marked by amyloid beta (Aβ) accumulation, tau hyperphosphorylation, and progressive cognitive decline. Previous studies show that fibroblast growth factor 18 (FGF18) exerts a neuroprotective effect in experimental models of neurodegeneration; however, how it affects AD pathology remains unknown. This study aimed to ascertain the impact of FGF18 on the behavioral and neuropathological changes in the rat model of sporadic AD induced by intracerebroventricular (ICV) injection of streptozotocin (STZ). The rats were treated with FGF18 (0.94 and 1.88 pmol, ICV) on the 15th day after STZ injection. Their cognitive function was assessed in the Morris water maze and passive avoidance tests for 5 days from the 16th to the 21st days. Aβ levels and histological signs of neurotoxicity were detected using the enzyme-linked immunosorbent assay (ELISA) assay and histopathological analysis of the brain, respectively. FGF18 mildly ameliorated the STZ-induced cognitive impairment; the Aβ accumulation was reduced; and the neuronal damage including pyknosis and apoptosis was alleviated in the rat brain. This study highlights the promising therapeutic potential for FGF18 in managing AD.

Identification of Ecdysteroid Sinapate Esters with COX-2 Inhibitory Effects from Fibraurea recisa Using Molecular Networking and MS2LDA

The roots of Fibraurea recisa are recognized as a rich source of protoberberine and aporphine alkaloids, but the non-alkaloidal metabolites in this plant are underexplored. The present study investigated the chemical composition of the plant roots using untargeted metabolomics-based molecular networking and MS2LDA motif annotation, revealing the presence of a characteristic fragment motif related to several sinapoyl-functionalized metabolites. Guided by the targeted motif, two new sinapic acid-ecdysteroid hybrids, named 3-O-sinapoyl makisterone A (1) and 2-O-sinapoyl makisterone A (2), were isolated. The structures of these compounds, including their absolute configuration, were elucidated by HR-ESIQTOFMS, MS2 fragmentation, NMR spectroscopy, and chemical degradation coupled with optical rotation measurements. Although neither compound inhibited nitric oxide (NO) production or inducible nitric oxide synthase (iNOS) protein expression on lipopolysaccharide-induced RAW 264 cells, 2 significantly suppressed cyclooxygenase 2 (COX-2) protein expression at 1-30 μM. Additionally, decreased expression of COX-2 protein was barely observed after treatment with methyl sinapate or makisterone A, the steroid skeleton of 1 and 2. These results indicated that the presence of the sinapoyl moiety at C-2 on the C28-ecdysteroid skeleton played a key role in the selectivity for the suppression of the COX-2 protein expression.

Potential bioactive compounds and mechanisms of Fibraurea recisa Pierre for the treatment of Alzheimer's disease analyzed by network pharmacology and molecular docking prediction

Introduction

Heat-clearing and detoxifying Chinese medicines have been documented to have anti-Alzheimer's disease (AD) activities according to the accumulated clinical experience and pharmacological research results in recent decades. In this study, Fibraurea recisa Pierre (FRP), the classic type of Heat-clearing and detoxifying Chinese medicine, was selected as the object of research.

Methods

12 components with anti-AD activities were identified in FRP by a variety of methods, including silica gel column chromatography, multiple databases, and literature searches. Then, network pharmacology and molecular docking were adopted to systematically study the potential anti-AD mechanism of these compounds. Consequently, it was found that these 12 compounds could act on 235 anti-AD targets, of which AKT and other targets were the core targets. Meanwhile, among these 235 targets, 71 targets were identified to be significantly correlated with the pathology of amyloid beta (Aβ) and Tau.

Results and discussion

In view of the analysis results of the network of active ingredients and targets, it was observed that palmatine, berberine, and other alkaloids in FRP were the key active ingredients for the treatment of AD. Further, Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis revealed that the neuroactive ligand-receptor interaction pathway and PI3K-Akt signaling pathway were the most significant signaling pathways for FRP to play an anti-AD role. Findings in our study suggest that multiple primary active ingredients in FRP can play a multitarget anti-AD effect by regulating key physiological processes such as neurotransmitter transmission and anti-inflammation. Besides, key ingredients such as palmatine and berberine in FRP are expected to be excellent leading compounds of multitarget anti-AD drugs.

Antidepressant effects of total alkaloids of Fibraurea recisa on improving corticosterone-induced apoptosis of HT-22 cells and chronic unpredictable mild stress-induced depressive-like behaviour in mice

CONTEXT

Fibraurea recisa Pierre. (Menispermaceae) (FR) is a traditional Chinese medicine known as "Huangteng." The total alkaloids of FR (AFR) are the main active ingredients. However, the pharmacological effects of AFR in the treatment of depression have not been reported.

OBJECTIVES

This study investigates the antidepressant effects of AFR by network pharmacology and verification experiments.

MATERIALS AND METHODS

Compound-Target-Pathway (C-P-T) network of FR and depression was constructed through network pharmacology. In vitro, HT-22 cells were treated with corticosterone (CORT) solution (0.35 mg/mL), then AFR (0.05 mg/mL) solution and inhibitor AZD6244 (14 μM/mL) or BAY11-7082 (10 μM/mL) were added, respectively. The cell viability was detected by CCK-8. In vivo, C57BL/6 mice were divided into 5 groups, namely the normal group, the CUMS group, the AFR (400 mg/kg) group, and the 2 groups that were simultaneously administered the inhibitory group AZD6244 (8 mg/kg) and BAY11-7082 (5 mg/kg). Western blotting was used to assess the expression level of the proteins.

RESULTS

AFR could protect HT-22 cells from CORT-induced damage and increase the cell viability from 49.12 ± 3.4% to 87.26 ± 1.5%. Moreover, AFR significantly increased the levels of BDNF (1.3, 1.4-fold), p-ERK (1.4, 1.2-fold) and p-CERB (1.6, 1.3-fold), and decreased the levels of NLRP3 (11.3%, 31.6%), ASC (19.2%, 34.2%) and caspase-1 (18.0%, 27.6%) in HT-22 cells and the hippocampus, respectively.

DISCUSSION AND CONCLUSIONS

AFR can improve depressive-like behaviours and can develop drugs for depression treatment. Further studies are needed to validate its potential in clinical medicine.

Protective effect of total saponins of ginseng stems and leaves (GSLS) on chlorpyrifos-induced brain toxicity in mice through the PTEN/PI3K/AKT axis

Chlorpyrifos (CPF) is a class of toxic compounds which has been widely used in agriculture that can cause multi-organ damage to the liver, kidneys, testes, and nervous system. Currently, most studies on ginseng have concentrated on the roots and rhizomes, and less research has been conducted on the above-ground parts. Our laboratory found that ginseng stem and leaf total saponin (GSLS) features strong antioxidant activity. In this experiment, we selected different concentrations of CPF to induce hippocampal neuronal cell injury model in mice, conducted a cell survival screening test, and also selected appropriate concentrations of CPF to induce brain injury model in mice. CCK-8, flow cytometry, Elisa, Hoechst 33258 staining, Annexin V-FITC/PI staining, HE staining, Morris water maze, and qRT-PCR were adopted for detecting the effects of GSLS treatment on CPF-induced cell viability, mitochondrial membrane potential, reactive oxygen species (ROS) levels, Ca2+ concentration and GSLS treatment on CPF-induced brain injury and related signaling in mice, respectively. The effects of GSLS treatment on CPF-induced brain injury and the related signaling pathways in mice were examined. The results showed that GSLS at 60 μg/ml and 125 μg/ml concentrations elevated the viability of CPF-induced HT22 cells, increased mitochondrial membrane potential, depleted ROS, decreased Ca2+ concentration, and decreased apoptosis rate. Meanwhile, GSLS treatment significantly reduced CPF-induced escape latency in mice, elevated the number of entries into the plateau and effective area, increased the effective area and target quadrant residence time, as well as improved the pathological damage of mouse hippocampal neurons. The results of mouse brain sections demonstrated that GSLS treatment significantly increased SOD and CAT activities and lowered MDA accumulation in CPF-induced mice. qRT-PCR revealed that PTEN mRNA expression was significantly decreased with PI3K and AKT expression being significantly increased in GSLS-treated CPF-induced mice. Thus, the obtained results indicate that GSLS can effectively antagonize CPF-induced brain toxicity in mice through regulating PTEN/PI3K/AKT pathway.

Network pharmacology and molecular docking integrated strategy to investigate the pharmacological mechanism of palmatine in Alzheimer's disease

OBJECTIVE

The key molecular mechanism of palmatine in the treatment of Alzheimer's disease (AD) was investigated in this article.

METHODS

Network pharmacology techniques constructed drug-target-disease relationship networks and predictive pathways of action. At the cellular level, lipopolysaccharide (LPS) was used to induce Raw 264.7 cells to establish an inflammation model, and interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α indicators were examined. Apoptosis was detected using Hoechst 33258. At the animal level, LPS was used to induce AD animal model, and behavioral performance were examined by water maze, and serum biochemical indexes were measured by ELISA. And the expression of PI3K and P-AKT was observed by immunohistochemistry. Finally, molecular level validation was performed using the molecular docking technique.

RESULTS

The result of Network pharmacological was predicted that palmatine may treat AD mainly through the PI3K pathway. Palmatine has no significant effect on Raw264.7 cells viability within 0.05 mg/ml, Palmatine can significantly induce Raw264.7 cells to secret IL-6 and IL1-β in a concentration-dependent manner, but it has not obvious impact on NO and TNF-α. Palmatine has a significant restorative effect on the cell viability of Raw264.7 in a concentration of 0.1 mg/ml. Palmatine can be concentration-dependent to downregulate the secretion of LPS-induced IL-6. At the same time, Palmatine also has a significant effect on the level of TNF-α induced by LPS, it also can slightly downregulate the secretion of IL-1β. The results of Hoechst33258 showed that cells in the 0.025 mg/ml and 0.5 mg/ml delivery groups increased with different degrees of bright blue fluorescence, and apoptosis rate decreased. Animal experiments showed that palmatine effectively improved the learning and memory ability of AD mice. The immunohistochemical results exhibited that the expression of PI3K and P-AKT in the model group decreased, but they were obvious reversed by palmatine The molecular docking results showed that palmatine and key targets had good docking, among which the binding to ERBB2, CDC42, MDM2, and mTOR was the most likely.

CONCLUSION

Palmatine has neuroprotective effects. Palmatine could effectively ameliorate memory impairment in AD mice by promoting the PI3K-AKT pathway. Molecular docking results showed that palmatine has a better binding ability with mTOR.

Mining Therapeutic Efficacy from Treasure Chest of Biodiversity and Chemodiversity: Pharmacophylogeny of Ranunculales Medicinal Plants

Ranunculales, comprising of 7 families that are rich in medicinal species frequently utilized by traditional medicine and ethnomedicine, represents a treasure chest of biodiversity and chemodiversity. The phylogenetically related species often have similar chemical profile, which makes them often possess similar therapeutic spectrum. This has been validated by both ethnomedicinal experiences and pharmacological investigations. This paper summarizes molecular phylogeny, chemical constituents, and therapeutic applications of Ranunculales, i.e., a pharmacophylogeny study of this representative medicinal order. The phytochemistry/metabolome, ethnomedicine and bioactivity/pharmacology data are incorporated within the phylogenetic framework of Ranunculales. The most studied compounds of this order include benzylisoquinoline alkaloid, flavonoid, terpenoid, saponin and lignan, etc. Bisbenzylisoquinoline alkaloids are especially abundant in Berberidaceae and Menispermaceae. The most frequent ethnomedicinal uses are arthritis, heat-clearing and detoxification, carbuncle-abscess and sore-toxin. The most studied bioactivities are anticancer/cytotoxic, antimicrobial, and anti-inflammatory activities, etc. The pharmacophylogeny analysis, integrated with both traditional and modern medicinal uses, agrees with the molecular phylogeny based on chloroplast and nuclear DNA sequences, in which Ranunculales is divided into Ranunculaceae, Berberidaceae, Menispermaceae, Lardizabalaceae, Circaeasteraceae, Papaveraceae, and Eupteleaceae families. Chemical constituents and therapeutic efficacy of each taxonomic group are reviewed and the underlying connection between phylogeny, chemodiversity and clinical uses is revealed, which facilitate the conservation and sustainable utilization of Ranunculales pharmaceutical resources, as well as developing novel plant-based pharmacotherapy.

MiR-27a-3p suppresses cerebral ischemia-reperfusion injury by targeting FOXO1

Cerebral ischemia-reperfusion (CI/R) injury is a serious complication when treating patients experiencing ischemic stroke. Although the microRNA miR-27a-3p reportedly participates in ischemia/reperfusion (I/R) injury, its actions in CI/R remain unclear. To mimic CI/R in vitro, HT22 cells were subjected to oxygen glucose deprivation/reoxygenation (OGD/R). The results indicate that OGD inhibited growth and induced apoptosis among HT22 cells. The apoptosis was accompanied by increases in activated caspases 3 and 9 and decreases in Bcl-2. Oxidative stress was also increased, as indicated by increases in ROS and malondialdehyde and decreases in glutathione and superoxide dismutase. In addition, OGD induced G1 arrest in HT22 cells with corresponding upregulation of FOXO1 and p27 Kip1, suggesting the cell cycle arrest was mediated by FOXO1/p27 Kip1 signaling. Notably, FOXO1 was found to be the direct target of miR-27a-3p in HT22 cells. MiR-27a-3p was downregulated in OGD/R-treated HT22 cells, and miR-27a-3p mimics partially or entirely reversed all of the in vitro effects of OGD. Moreover, miR-27a-3p agomir significantly alleviated the symptoms of CI/R in vivo in a rat model of CI/R. Thus, MiR-27a-3p appears to suppress CI/R injury by targeting FOXO1.

Neuroprotective Effects of OMO within the Hippocampus and Cortex in a D-Galactose and Aβ 25-35-Induced Rat Model of Alzheimer's Disease

Morinda officinalis F.C. How. (Rubiaceae) is a herbal medicine. It has been recorded that its oligosaccharides have neuroprotective properties. In order to understand the oligosaccharides extracted from Morinda officinalis (OMO), a systematic study was conducted to provide evidence that supports its use in neuroprotective therapies for Alzheimer's disease (AD). AD rat models were prepared with D-galactose and Aβ_25–35. The following groups were used in the present experiment: normal control group, sham-operated group, model group, Aricept group, OMO low-dose group, OMO medium-dose group, and OMO high-dose group. The effects on behavioral tests, antioxidant levels, energy metabolism, neurotransmitter levels, and AD-related proteins were detected with corresponding methodologies. AD rats administered with different doses of OMO all exhibited a significant (P < 0.05) decrease in latency and an increase (P < 0.05) in the ratio of swimming distance to total distance in a dose-dependent manner in the Morris water maze. There was a significant (P < 0.05) increase in antioxidant enzyme activities (SOD, GSH-Px, and CAT), neurotransmitter levels (acetylcholine, γ-GABA, and NE and DA), energy metabolism (Na⁺/K⁺-ATPase), and relative synaptophysin (SYP) expression levels in AD rats administered with OMO. Furthermore, there was a significant (P < 0.05) decrease in MDA levels and relative expression levels of APP, tau, and caspase-3 in AD rats with OMO. The present research suggests that OMO protects against D-galactose and Aβ_25–35-induced neurodegeneration, which may provide a novel strategy for improving AD in clinic.