title: Hydroxysafflor Yellow A Protects Neurons From Excitotoxic Death through Inhibition of NMDARs.
abstract: Excessive glutamate release causes overactivation of N-methyld-aspartate receptors (NMDARs), leading to excitatory neuronal damage in cerebral ischemia. Hydroxysafflor yellow A (HSYA), a compound extracted from Carthamus tinctorius L., has been reported to exert a neuroprotective effect in many pathological conditions, including brain ischemia. However, the underlying mechanism of HSYA's effect on neurons remains elusive. In the present study, we conducted experiments using patch-clamp recording of mouse hippocampal slices. In addition, we performed Ca(2+) imaging, Western blots, as well as mitochondrial-targeted circularly permuted yellow fluorescent protein transfection into cultured hippocampal neurons in order to decipher the physiological mechanism underlying HSYA's neuroprotective effect.Through the electrophysiology experiments, we found that HSYA inhibited NMDAR-mediated excitatory postsynaptic currents without affecting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor and γ-aminobutyric acid A-type receptor-mediated currents. This inhibitory effect of HSYA on NMDARs was concentration dependent. HSYA did not show any preferential inhibition of either N-methyld-aspartate receptor subtype 2A- or N-methyld-aspartate receptor subtype 2B- subunit-containing NMDARs. Additionally, HSYA exhibits a facilitatory effect on paired NMDAR-mediated excitatory postsynaptic currents. Furthermore, HSYA reduced the magnitude of NMDAR-mediated membrane depolarization currents evoked by oxygen-glucose deprivation, and suppressed oxygen-glucose deprivation-induced and NMDAR-dependent ischemic long-term potentiation, which is believed to cause severe reperfusion damage after ischemia. Through the molecular biology experiments, we found that HSYA inhibited the NMDA-induced and NMDAR-mediated intracellular Ca(2+)concentration increase in hippocampal cultures, reduced apoptotic and necrotic cell deaths, and prevented mitochondrial damage. Together, our data demonstrate for the first time that HSYA protects hippocampal neurons from excitotoxic damage through the inhibition of NMDARs. This novel finding indicates that HSYA may be a promising pharmacological candidate for the treatment of brain ischemia.
authors.affiliation: Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China.
authors.forename: Xingtao
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Public Economics and Administration, Shanghai University of Finance and Economics, Shanghai, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Ma
authors.affiliation: CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Zhongxiao
authors.initials: Z
authors.lastname: Fu
authors.affiliation: Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China.
authors.forename: Su
authors.initials: S
authors.lastname: Gao
authors.affiliation: Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.affiliation: CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Pharmacology, Binzhou Medical University, Yantai, Shandong, China.
authors.forename: Chaoyun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China.
authors.forename: Weiming
authors.initials: W
authors.lastname: Fan
authors.affiliation: CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Internal Neurology, Affiliated Hospital of Binzhou Medical University, Binzhou, Shandong, China.
authors.forename: Qing-Yin
authors.initials: QY
authors.lastname: Zheng
authors.affiliation: CAS Key Laboratory of Brain Function and Diseases, School of Life Science, University of Science and Technology of China, Hefei, Anhui, China.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Bi
authors.affiliation: Department of Physiology, Binzhou Medical University, Yantai, Shandong, China "Brain stroke" Key Lab of Shandong Health Administration Institute, Binzhou Medical University, Yantai, Shandong, China clma1985@126.com.
authors.forename: Chun-Lei
authors.initials: CL
authors.lastname: Ma
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D056547:CA1 Region, Hippocampal / Q000166:cytology; D002118:Calcium / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D002599:Chalcone / Q000031:analogs & derivatives* / Q000494:pharmacology; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D005947:Glucose / Q000172:deficiency; D018684:Glycine Agents / Q000494:pharmacology; D000860:Hypoxia; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010852:Picrotoxin / Q000494:pharmacology; D011809:Quinones / Q000494:pharmacology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013331:Strychnine / Q000494:pharmacology
chemical_list: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D002118:Calcium; D000697:Central Nervous System Stimulants; D002599:Chalcone; D018683:Excitatory Amino Acid Agents; D018691:Excitatory Amino Acid Antagonists; D005947:Glucose; D018684:Glycine Agents; D018696:Neuroprotective Agents; D010852:Picrotoxin; D011809:Quinones; D016194:Receptors, N-Methyl-D-Aspartate; D013331:Strychnine; C085278:hydroxysafflor yellow A
keywords: Ca2+ imaging; NMDA receptor; hydroxysafflor yellow A; oxygen-glucose deprivation; whole-cell patch-clamp recording