Cyanidin-3-glucoside inhibits amyloid β25-35-induced neuronal cell death in cultured rat hippocampal neurons

Grape juice reduces the effects of amyloid β aggregation phenotype and extends the longevity in Caenorhabditis elegans

OBJECTIVES

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the presence of aggregated amyloid-β (Aβ) peptides. Several natural compounds have been proposed against this disease and grape products are among these. However, little is known about grape juice potential. Transgenic Caenorhabditis elegans (C. elegans) strains that express human Aβ have been used as an in vivo model for AD.

METHODS

In this study, we have exposed CL2006 worms to nine different juices obtained from different cultivars.

RESULTS

Cora, Bordo, Isabel, Isabel Precoce, BRS-Magna, BRS-Rubea and BRS-Violeta juices improved the behavioral phenotype (paralysis) that is caused by Aβ aggregation in the transgenic animals at the concentrations tested and no toxic effects were found. Some juices were also able to increase the worm's lifespan. We could not attribute lifespan increase and paralysis reduction with any specific compound found in the phytochemical analysis.

DISCUSSION

Our data indicate that the rich constitution of the juices is responsible for attenuating the phenotype caused by Aβ aggregation in C. elegans.

Comparative Transcriptome Analysis of the Expression of Antioxidant and Immunity Genes in the Spleen of a Cyanidin 3-O-Glucoside-Treated Alzheimer's Mouse Model

Cyanidin 3-O-glucoside (C3G) is a well-known antioxidant found as a dietary anthocyanin in different fruits and vegetables. It has protective and therapeutic effects on various diseases. It can reduce neuronal death from amyloid-beta (Aβ)-induced toxicity and promote the inhibition of Aβ fibrillization. Antioxidant and immune modulation might play a critical role in the properties of C3G against Alzheimer's disease (AD) and other diseases. However, limited studies have been performed on the mechanism involved in the effect of C3G through transcriptome analysis. Thus, the objective of this study was to perform comparative transcriptome analysis of the spleen to determine gene expression profiles of wild-type mice (C57BL/6J Jms), an Alzheimer's mouse model (APPswe/PS1dE9 mice), and a C3G-treated Alzheimer's mouse model. Differentially expressed antioxidant, immune-related, and AD pathways genes were identified in the treated group. The validation of gene expression data via RT-PCR studies further supported the current findings. Six important antioxidant genes (S100a8, S100a9, Prdx2, Hp, Mpst, and Prxl2a) and a high number of immune-related genes were found to be upregulated in the treatment groups, suggesting the possible antioxidant and immunomodulatory mechanisms of C3G, respectively. Further studies are strongly recommended to elucidate the precise role of these essential genes and optimize the therapeutic function of C3G in AD and other disease conditions.

Cyanidin-3-O-glucoside and its phenolic metabolites ameliorate intestinal diseases via modulating intestinal mucosal immune system: potential mechanisms and therapeutic strategies

The incidence of the intestinal disease is globally increasing, and the intestinal mucosa immune system is an important defense line. A potential environmental cause to regulate gut health is diet. Cyanidin-3-O-glucoside is a natural plant bioactive substance that has shown rising evidence of improving intestinal disease and keeping gut homeostasis. This review summarized the intestinal protective effect of Cyanidin-3-O-glucoside in vivo and in vitro and discussed the potential mechanisms by regulating the intestinal mucosal immune system. Cyanidin-3-O-glucoside and phenolic metabolites inhibited the presence and progression of intestinal diseases and explained from the aspects of repairing the intestinal wall, inhibiting inflammatory reaction, and regulating the gut microbiota. Although the animal and clinical studies are inadequate, based on the accumulated evidence, we propose that the interaction of Cyanidin-3-O-glucoside with the intestinal mucosal immune system is at the core of most mechanisms by which affect host gut diseases. This review puts forward the potential mechanism of action and targeted treatment strategies.

TPEN attenuates amyloid-β25-35-induced neuronal damage with changes in the electrophysiological properties of voltage-gated sodium and potassium channels

To understand the role of intracellular zinc ion (Zn²⁺) dysregulation in mediating age-related neurodegenerative changes, particularly neurotoxicity resulting from the generation of excessive neurotoxic amyloid-β (Aβ) peptides, this study aimed to investigate whether N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), a Zn²⁺-specific chelator, could attenuate Aβ_25-35-induced neurotoxicity and the underlying electrophysiological mechanism. We used the 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay to measure the viability of hippocampal neurons and performed single-cell confocal imaging to detect the concentration of Zn²⁺ in these neurons. Furthermore, we used the whole-cell patch-clamp technique to detect the evoked repetitive action potential (APs), the voltage-gated sodium and potassium (K⁺) channels of primary hippocampal neurons. The analysis showed that TPEN attenuated Aβ_25-35-induced neuronal death, reversed the Aβ_25-35-induced increase in intracellular Zn²⁺ concentration and the frequency of APs, inhibited the increase in the maximum current density of voltage-activated sodium channel currents induced by Aβ_25-35, relieved the Aβ_25-35-induced decrease in the peak amplitude of transient outward K⁺ currents (I_A) and outward-delayed rectifier K⁺ currents (I_DR) at different membrane potentials, and suppressed the steady-state activation and inactivation curves of I_A shifted toward the hyperpolarization direction caused by Aβ_25-35. These results suggest that Aβ_25-35-induced neuronal damage correlated with Zn²⁺ dysregulation mediated the electrophysiological changes in the voltage-gated sodium and K⁺ channels. Moreover, Zn²⁺-specific chelator-TPEN attenuated Aβ_25-35-induced neuronal damage by recovering the intracellular Zn²⁺ concentration.