title: Hypothermia attenuates protective effects of ginkgolides on astrocytes from ischemia/reperfusion injury.
abstract: The neuroprotective roles of both hypothermia and ginkgolides have been well confirmed. We first examined whether hypothermia (32 or 28 degrees C) or ginkgolides have a protective effect on astrocytes against ischemia and reperfusion-induced injury. We demonstrated that ginkgolides, but not hypothermia, have a significantly time- and concentration-dependent protective role in ischemic astrocytes. We then investigated whether co-treatment with hypothermia and ginkgolides has a synergistic role to protect astrocytes against ischemia and reperfusion-induced injury. Cells were incubated with 18.75, 37.5 or 75 microg/ml of ginkgolides at 37, 32 or 28 degrees C for 24, 48 or 72 h before exposure to ischemia (24h) and then reperfusion (24h). Data showed that the co-treatment induced a significant decrease, rather than an increase as we had expected, in their cellular viabilities and anti-apoptotic abilities as compared with the cells treated by ginkgolides only. Western blot analysis demonstrated that hypothermia (32 or 28 degrees C for 24h) has no effect on the expression of Hypoxia-inducible factor-1 alpha (HIF-1 alpha) protein, suggesting that HIF-1 alpha is not associated with the adverse effect of hypothermia on ginkgolides. The findings imply the importance of further investigating the effects of hypothermia on the pharmacological role or therapeutic efficacy of drugs commonly used clinically.
authors.affiliation: Institute for Nautical Medicine and Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, PR China.
authors.forename: Du
authors.initials: D
authors.lastname: Fang
authors.forename: Qian Zhong
authors.initials: QZ
authors.lastname: Ming
authors.forename: Zhu
authors.initials: Z
authors.lastname: Li
authors.forename: Wu Xiao
authors.initials: WX
authors.lastname: Mei
authors.forename: Ke
authors.initials: K
authors.lastname: Ya
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D046934:Ginkgolides / Q000494:pharmacology / Q000627:therapeutic use*; D007036:Hypothermia, Induced / Q000009:adverse effects*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D018696:Neuroprotective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015427:Reperfusion Injury / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D013997:Time Factors
chemical_list: D046934:Ginkgolides; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D018696:Neuroprotective Agents