title: Cyanidin-3-glucoside inhibits glutamate-induced Zn2+ signaling and neuronal cell death in cultured rat hippocampal neurons by inhibiting Ca2+-induced mitochondrial depolarization and formation of reactive oxygen species.
abstract: Cyanidin-3-glucoside (C3G), a member of the anthocyanin family, is a potent natural antioxidant. However, effects of C3G on glutamate-induced [Zn(2+)]i increase and neuronal cell death remain unknown. We studied the effects of C3G on glutamate-induced [Zn(2+)]i increase and cell death in cultured rat hippocampal neurons from embryonic day 17 maternal Sprague-Dawley rats using digital imaging methods for Zn(2+), Ca(2+), reactive oxygen species (ROS), mitochondrial membrane potential and a MTT assay for cell survival. Treatment with glutamate (100 µM) for 7 min induces reproducible [Zn(2+)]i increase at 35 min interval in cultured rat hippocampal neurons. The intracellular Zn(2+)-chelator TPEN markedly blocked glutamate-induced [Zn(2+)]i increase, but the extracellular Zn(2+) chelator CaEDTA did not affect glutamate-induced [Zn(2+)]i increase. C3G inhibited the glutamate-induced [Zn(2+)]i response in a concentration-dependent manner (IC50 of 14.1 ± 1.1 µg/ml). C3G also significantly inhibited glutamate-induced [Ca(2+)]i increase. Two antioxidants such as Trolox and DTT significantly inhibited the glutamate-induced [Zn(2+)]i response, but they did not affect the [Ca(2+)]i responses. C3G blocked glutamate-induced formation of ROS. Trolox and DTT also inhibited the formation of ROS. C3G significantly inhibited glutamate-induced mitochondrial depolarization. However, TPEN, Trolox and DTT did not affect the mitochondrial depolarization. C3G, Trolox and DTT attenuated glutamate-induced neuronal cell death in cultured rat hippocampal neurons, respectively. Taken together, all these results suggest that cyanidin-3-glucoside inhibits glutamate-induced [Zn(2+)]i increase through a release of Zn(2+) from intracellular sources in cultured rat hippocampal neurons by inhibiting Ca(2+)-induced mitochondrial depolarization and formation of ROS, which is involved in neuroprotection against glutamate-induced cell death.
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Ji Seon
authors.initials: JS
authors.lastname: Yang
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Shazia
authors.initials: S
authors.lastname: Perveen
authors.affiliation: Department of Functional Crop, National Institute of Crop Science, Rural Development Administration, 1085 Neidong, Miryang 627-803, Republic of Korea.
authors.forename: Tae Joung
authors.initials: TJ
authors.lastname: Ha
authors.affiliation: Department of Pharmacology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea.
authors.forename: Seong Yun
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Physiology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea; Catholic Agro-Medical Center, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Republic of Korea. Electronic address: s-hyoon@catholic.ac.kr.
authors.forename: Shin Hee
authors.initials: SH
authors.lastname: Yoon
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000008:administration & dosage / Q000494:pharmacology*; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D005960:Glucosides / Q000008:administration & dosage / Q000494:pharmacology*; D005971:Glutamates / Q000008:administration & dosage / Q000494:pharmacology*; D006624:Hippocampus / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D015032:Zinc / Q000378:metabolism*
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D005960:Glucosides; D005971:Glutamates; D017382:Reactive Oxygen Species; C462279:cyanidin-3-O-beta-glucopyranoside; D015032:Zinc; D002118:Calcium
keywords: Cell death; Flavonoid; Glutamate; Mitochondrial membrane potential; Reactive oxygen species; Zn(2+)