Anthocyanin Extracts from Black Soybean (Glycine max L.) Protect Human Glial Cells Against Oxygen-Glucose Deprivation by Promoting Autophagy

Abstract

Anthocyanins have received growing attention as dietary antioxidants for the prevention of oxidative damage. Astrocytes, which are specialized glial cells, exert numerous essential, complex functions in both healthy and diseased central nervous system (CNS) through a process known as reactive astrogilosis. Therefore, the maintenance of glial cell viability may be important because of its role as a key modulator of neuropathological events. The aim of this study was to investigate the effect of anthocyanin on the survival of glial cells exposed to oxidative stress. Our results demonstrated that anthocyanin extracts from black soybean increased survival of U87 glioma cells in a dose dependent manner upon oxygen-glucose deprivation (OGD), accompanied by decrease levels of reactive oxygen species (ROS). While treatment cells with anthocyanin extracts or OGD stress individually activated autophagy induction, the effect was significantly augmented by pretreatment cells with anthocyanin extracts prior to OGD. The contribution of autophagy induction to the protective effects of anthocyanin was verified by the observation that silencing the Atg5 expression, an essential regulator of autophagy induction, reversed the cytoprotective effect of anthocyanin extracts against OGD stress. Treatment of U87 cells with rapamycin, an autophagy inducer, increased cell survival upon OGD stress comparable to anthocyanin, indicating that autophagy functions as a survival mechanism against oxidative stress-induced cytotoxicity in glial cells. Our results, therefore, provide a rationale for the use of anthocyanin as a preventive agent for brain dysfunction caused by oxidative damage, such as a stroke.

Protective effects of blueberry- and strawberry diets on neuronal stress following exposure to 56Fe particles

“…Blueberries are a rich source of anthocyanins and have been shown to act on autophagy regulating proteins such as mTOR (Kim et al, 2012). Similarly, strawberries, which contain high amounts of phenolic acids and ellagitannins, also have been shown to improve neuronal signaling via their antioxidant and anti-inflammatory mechanisms (Miller and Shukitt-Hale, 2012).…”

Anthocyanins in the black soybean (Glycine max L.) protect U2OS cells from apoptosis by inducing autophagy via the activation of adenosyl monophosphate-dependent protein kinase

“…To address this issue, we used ATCs extracted from black soybeans (cv Cheongja 3). These ATC extracts were shown to promote apoptosis in a model of prostate hyperplasia in vivo and to induce autophagy in glial cells, which proved to contain biologically active components of autophagy induction as well as apoptosis (14,24). In the present study, we observed the induction of autophagy and AMPK activation by ATCs and analyzed the role of AMPK in this autophagy.…”

“…Based on these apoptosis-inducing and anti-inflammatory as well as anti-invasive and anti-angiogenic effects (9,10), attempts have been made to develop ATCs as a chemopreventive agent, and promising results of pilot studies in rodent models of esophageal and colorectal cancers and human colorectal cancer patients have provided support for this hypothesis (11,12). In addition to inducing apoptosis, it has been suggested that ATCs induce autophagy in cancer and glial cells (13,14), although the mechanism for this remains to be clarified. Autophagy is considered to be a cellular defense system that can protect cancer cells from anticancer therapeutics.…”

Total flavones of Dracocephalum moldavica L. protect astrocytes against H2O2-induced apoptosis through a mitochondria-dependent pathway

“…After stroke, astrocytes tend to rupture, leading to an imbalance in glutamate absorption and release and an increase in pro-apoptotic factors, which may ultimately accelerate the death of peripheral neurons [30,31]. Oxidative stress is the basis of the pathogenesis of stroke.…”