Nadjafi Shabnam, Ebrahimi Soltan-Ahmad, Rahbar-Roshandel Nahid
Department of Pharmacology, Iran University of Medical Sciences, Tehran, Iran.
Int J Prev Med. 2014 Sep;5(9):1153-60.
Oligodendrocytes, the myelinating glial cells of central nervous system, are highly vulnerable to ischemic-induced excitotoxic insult, a phenomenon in which calcium overload triggers cell death. Berberine is an alkaloid extracted from medicinal herbs as Coptidis Rhizoma with several pharmacological effects like inhibition of neuronal apoptosis in cerebral ischemia.
We examined the effects of berberine (0.5-4 μM) and glutamate receptors antagonists (MK-801 [10 μM] and NBQX [30 μM]) on OLN-93 cell line (a permanent immature rat oligodendrocyte) during (30, 60, 240 min) oxygen-glucose deprivation (OGD)/24 h reperfusion. The cells were cultured in 12-well plates. The cells were exposed to glucose-free medium and hypoxia in a small anaerobic chamber. Cell viability was evaluated by MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) assay. The intracellular calcium levels also were evaluated by Ca(2+)-sensitive indicator Fura-2/AM in presence or absence of berberine (2 μM) during 30 min chemical OGD by NaN3 (20 mM). Student's t-test and ANOVA were used for statistical analysis.
Berberine, MK-801and NBQX significantly increased oligodendrocyte viability in all 3 time-scheduled oxygen-glucose deprivation/reperfusion. Berberine at 2 μM produced peak of protection, and increased cell viability to 83%, 77%, and 79% during 30, 60, 240 min ischemic experiments, respectively (P < 0.001). Berberine significantly attenuated intracellular Ca(2+) rise induced by chemical ischemia, and this effect of berberine was significantly stronger than MK-801 and NBQX (P < 0.001).
We concluded that berberine protected OLN-93 oligodendrocyte against ischemic induced excitotoxic injury. Attenuation of intracellular Ca(2+) overload by berberine may be the key mechanism that saved OLN-93 from excitotoxicity damage.
少突胶质细胞是中枢神经系统的髓鞘形成神经胶质细胞，极易受到缺血诱导的兴奋性毒性损伤，即钙超载触发细胞死亡的现象。黄连素是从黄连等草药中提取的一种生物碱，具有多种药理作用，如抑制脑缺血中的神经元凋亡。
我们检测了黄连素（0.5 - 4 μM）和谷氨酸受体拮抗剂（MK - 801 [10 μM] 和 NBQX [30 μM]）在氧糖剥夺（OGD）/再灌注（30、60、240分钟）/24小时期间对OLN - 93细胞系（一种永久性未成熟大鼠少突胶质细胞）的影响。细胞培养于12孔板中。细胞置于小型厌氧培养箱中，暴露于无糖培养基和低氧环境。通过MTT（3 - [4,5 - 二甲基噻唑 - 2 - 基] - 2,5 - 二苯基溴化四氮唑）法评估细胞活力。在NaN3（20 mM）诱导的30分钟化学性OGD期间，无论有无黄连素（2 μM），均通过Ca(2 +)敏感指示剂Fura - 2/AM评估细胞内钙水平。采用学生t检验和方差分析进行统计分析。
黄连素、MK - 801和NBQX在所有3个时间点的氧糖剥夺/再灌注实验中均显著提高了少突胶质细胞的活力。2 μM的黄连素产生了最大保护作用，在30、60、240分钟缺血实验期间，分别将细胞活力提高到83%、77%和79%（P < 0.001）。黄连素显著减轻了化学性缺血诱导的细胞内Ca(2 +)升高，且黄连素的这种作用明显强于MK - 801和NBQX（P < 0.001）。
我们得出结论，黄连素可保护OLN - 93少突胶质细胞免受缺血诱导的兴奋性毒性损伤。黄连素减轻细胞内Ca(2 +)超载可能是使OLN - 93免受兴奋性毒性损伤的关键机制。
