Inhibitory Effects of Acorn Extract on Glutamate-Induced Calcium Signaling in Cultured Rat Hippocampal Neurons

Abstract

Various effects of acorn extract have been reported including antioxidant activity, cytotoxicity against cancer cells, and the levels of acetylcholine and its related enzyme activities in the dementia mouse models. However, it is unclear whether acorn extract inhibits glutamate-induced calcium signaling in hippocampal neurons. This study was an investigation into the effect of acorn extract on intracellular free Ca ] i ) can also be elevated by the release of Ca 2+ from IP 3 -sensitive intracellular stores through the metabotrophic glutamate receptor-induced activation of phospholipase C (PLC). Ca 2+ plays a role as an intracellular messenger and a key regulatory factor for a large number of cellular processes such as muscle contraction, metabolism, secretion or even cell differentiation and apoptosis.

Cyanidin-3-glucoside Inhibits ATP-induced Intracellular Free Ca2+Concentration, ROS Formation and Mitochondrial Depolarization in PC12 Cells

“…A simple phenolic compound octyl gallate has been reported to inhibit ATP-induced calcium signaling in PC12 cells by inhibiting a release of Ca 2+ from intracellular stores and an influx of Ca 2+ from the extracellular space through P2X receptor non-selective cation channels and voltage-gated Ca 2+ channels [30]. In addition, apigenin [12] and phenolic compound-containing acorn extract [31] have been reported to inhibit glutamate-induced calcium signaling by inhibiting a release of Ca 2+ from intracellular stores and an influx of Ca 2+ from the extracellular space through ionotropic glutamate receptors and voltage-gated Ca 2+ channels in cultured rat hippocampal neurons. Another flavonoid proanthocyanidin has been reported to inhibit the glutamate-induced calcium signaling by inhibiting a release of Ca 2+ from intracellular stores and an influx of Ca 2+ through ionotropic glutamate receptors without affecting the voltage-gated Ca 2+ channels in cultured rat hippocampal neurons [13].…”