Cyanidin-3-glucoside activates Nrf2-antioxidant response element and protects against glutamate-induced oxidative and endoplasmic reticulum stress in HT22 hippocampal neuronal cells

Abstract

Background: Cyanidin-3-glucoside (C3G), a major anthocyanin present in berries, exhibits a strong antioxidant and has been shown to possess a neuroprotection. Prolonged exposure to glutamate will lead to oxidative damage and endoplasmic reticulum stress which could play a key detrimental role in the development of neurodegenerative disorders (NDs). In the present study, we investigated the neuroprotective effect and underlying mechanisms of C3G on the reduction of oxidative/ER stress-induced apoptosis by glutamate in HT22 mouse hippocampal neuronal cells.Method: Cells were pre-treated with C3G in various concentrations, followed by glutamate. Cell viability and toxicity were examined using MTT and LDH assays. The apoptotic and necrotic cell death were carried out by Annexin V-FITC/propidium iodide co-staining assays. Generation of intracellular reactive oxygen species (ROS) in cells was measured by flow cytometry using DCFH-DA probe. Expression of antioxidant genes was evaluated by Real-time polymerase chain reaction analysis. The possible signaling pathways and proteins involved were subsequently demonstrated by Western blot analysis.Result: The pretreatment of the HT22 cells with C3G protected cell death from oxidative toxicity induced by glutamate. We demonstrated that treatment cells with glutamate caused several radical forms of ROS formation, and they were abolished by specific ROS inhibitors. Interestingly, C3G directly scavenged radical activity and inhibited intracellular ROS generation in our cell-based system. In addition, C3G pretreatment suppressed the up-regulation of specific ER proteins namely calpain, caspase-12 and C/EBP homologous proteins (CHOP) induced by glutamate-mediated oxidative and ER stress signal by upregulating the expressions of survival proteins, including extracellular regulated protein kinase (ERK) and nuclear factor E2related factor 2 (Nrf2). Furthermore, dramatically activated gene expression of endogenous antioxidant enzymes (i.e. superoxide dismutases (SODs), catalase (CAT) and glutathione peroxidase (GPx)), and phase II enzymes (glutathione-Stransferases (GSTs)) was found in C3G-treated with cells.Conclusions: Our finding suggest that C3G could be a promising neuroprotectant via inhibition of glutamate-induced oxidative and ER stress signal and activation of ERK/Nrf2 antioxidant mechanism pathways.

Neuroprotective Effects of Extracts from Tiger Milk Mushroom Lignosus rhinocerus Against Glutamate-Induced Toxicity in HT22 Hippocampal Neuronal Cells and Neurodegenerative Diseases in Caenorhabditis elegans

“…Similarly, LRE also induced a decrease in PolyQ40 aggregation that is related to the neurodegenerative diseases including Huntington’s disease and other polyglutamine diseases [ 55 ]. Our findings agree with several previous studies about phenolic compounds that have been found in plants or natural products and reported their effectiveness in preventing many diseases including neurodegenerative diseases [ 19 , 43 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ]. Only LRE exerted the neuroprotective effect both in vitro and in vivo.…”

“…In the present study, we report, for the first time to our knowledge, the neuroprotection of LR extracts against glutamate-induced oxidative stress in HT22 cells and neurotoxicity in C. elegans . In this cell line, we induced oxidative stress by using 5 mM glutamate which has been reported to reduce approximately 50% of the cells [ 19 , 43 ]. Interestingly, we found that only LRE prevented cells from undergoing apoptosis after cotreatment by using Annexin V/PI straining that interacts strongly and specifically with exposed phosphatidylserine (PS), the marker of apoptosis [ 44 ].…”

“…Then, the specific genes CAT, SOD1, SOD2 and GPx were determined by the Exicycler Real Time Quantitative Thermal Block (Bioneer). The specific primers were previously reported by our research group [ 19 ]. The relative expression of each gene was normalized to the internal control gene (β-actin).…”

Anxiolytic effects of NLRP3 inflammasome inhibition in a model of chronic sleep deprivation

“…Treatment with grape-derived polyphenols from a variety of sources, including CGJ, in patients suffering from mild age-related cognitive decline, resulted in benefits in working memory and improved verbal learning 54 , 55 . The anti-inflammatory and anti-oxidant properties of FDP-derived metabolites, demonstrated in vitro, in vivo using models of stress 15 , 16 , 46 , 47 , have been recapitulated in preclinical and clinical trials 53 – 55 . Our current study, along with these preclinical successes demonstrate that FDP may serve as a potential therapeutic for addressing the immunological pathologies associated with mood disorders and cognitive decline.…”

“…While our studies did not directly examine markers of mitochondrial oxidative stress, treatment with GSPE (a component of FDP) preserves memory function in a mouse model of vascular dementia through alleviation of oxidative stress 45 . Individual metabolites that potently inhibited the production of IL-1β in vitro, including MG and CG, upregulate superoxide dismutases and phase II enzymes such as Glutathione S-transferases, while inhibiting the expression of xanthine oxidase 46 , 47 . Metabolites derived from FDP may have pleiotropic effects in the preservation of cognitive function during stress including the inhibition of inflammasome activity as well as amelioration of oxidative stress, thus inhibiting the activation of microglia 48 .…”