Carloni Silvia, Facchinetti Fabrizio, Pelizzi Nicola, Buonocore Giuseppe, Balduini Walter
Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy.
Corporate R&D, Chiesi Farmaceutici S.p.A., Parma, Italy.
Neonatology. 2018;114(4):364-371. doi: 10.1159/000491859. Epub 2018 Aug 28.
Hypoxic-ischemic encephalopathy is a major cause of neonatal morbidity. Therapeutic hypothermia, while beneficial, still leaves many treated infants with lifelong disabilities. Thus, adjunctive therapies, such as melatonin, are needed to provide additional neuroprotection.
The aim of this study was to determine a range of melatonin concentrations that could result in neuroprotective synergy with hypothermia.
Hypoxia-ischemia was simulated by transient oxygen-glucose deprivation (OGD) in organotypic hippocampal slice cultures derived from neonatal rats. Cell damage was quantified by propidium iodide (PI) labeling.
Melatonin reduced OGD- induced cell death in a concentration-dependent manner (1-100 μM) with an EC50 of about 25 μM. Hypothermia attenuated cell death in a time-dependent manner, with a nearly full protection upon 24-h exposure (78%) and partial protection (40%) upon 6-h exposure. When submaximal effective concentrations of melatonin (25 or 50 μM, resulting in 54 and 64% protection) were combined with 6 h of hypothermia, nearly full protection (73 and 78%, respectively; p < 0.05 and p < 0.01) was observed.
Melatonin acts in synergy with hypothermia in attenuating OGD-induced damage in organotypic hippocampal cultures. This reductionist approach allows the determination of a range of concentrations of melatonin capable of enhancing hypothermic neuroprotection. This information, coupled with pharmacokinetic data, will help to define the therapeutic dosage of melatonin in vivo and, ultimately, in patients.
缺氧缺血性脑病是新生儿发病的主要原因。治疗性低温虽然有益，但仍使许多接受治疗的婴儿终身残疾。因此，需要辅助疗法，如褪黑素，以提供额外的神经保护作用。
本研究的目的是确定一系列能与低温产生神经保护协同作用的褪黑素浓度。
在源自新生大鼠的器官型海马切片培养物中，通过短暂氧糖剥夺（OGD）模拟缺氧缺血。通过碘化丙啶（PI）标记对细胞损伤进行定量。
褪黑素以浓度依赖性方式（1-100μM）减少OGD诱导的细胞死亡，半数有效浓度（EC50）约为25μM。低温以时间依赖性方式减轻细胞死亡，暴露24小时时几乎完全保护（78%），暴露6小时时部分保护（40%）。当将亚最大有效浓度的褪黑素（25或50μM，分别产生54%和64%的保护）与6小时低温联合使用时，观察到几乎完全保护（分别为73%和78%；p<0.05和p<0.01）。
褪黑素与低温协同作用，减轻器官型海马培养物中OGD诱导的损伤。这种简化方法能够确定一系列能够增强低温神经保护作用的褪黑素浓度。这些信息，结合药代动力学数据，将有助于确定褪黑素在体内以及最终在患者中的治疗剂量。
