Role of nuclear factor-κB activation in bilirubin-induced rat hippocampal neuronal apoptosis and the effect of TAT-NBD intervention / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of nuclear factor-κB (NF-κB) activation in bilirubin-induced apoptosis of rat hippocampal neurons and the effect of TAT-NBD intervention on bilirubin neurotoxicity.</p><p><b>METHODS</b>Primary-cultured rat hippocampal neurons were treated with TAT-NBD in the initial 6 or 24 h or in the latter 6 h during a 24-h bilirubin exposure of the cells (early, continuous and late intervention groups, respectively). Immunocytochemistry was performed to detect NF-κB p65 protein expression, and the cell survival and apoptosis were assessed with a modified MTT assay, Annexin V-FITC/PI and TUNEL assay. IL-1β concentration in the supernatant was determined with ELISA.</p><p><b>RESULTS</b>Compared with the control cells, bilirubin-treated cells showed a significantly increased NF-κB p65 protein expression (P<0.01), which reached the peak level at 6 and 24 h (P<0.01). The cell survival rate in early TAT-NBD intervention group was (80.784∓9.767)%, significantly lower than that of the control group (P<0.01) but higher than that of bilirubin group (P<0.01); the apoptotic rate in early TAT-NBD intervention group was significantly higher than that of control group (P<0.01) but lower than that of bilirubin group (P<0.01). IL-1β concentration was significantly lower in early TAT-NBD intervention group (15.348∓0.812 pg/ml) than in bilirubin group (P<0.05). The continuous and late TAT-NBD intervention groups showed comparable cell survival rate, apoptotic rate and IL-1β concentration with bilirubin group (P>0.05).</p><p><b>CONCLUSION</b>NF-κB bidirectionally regulates bilirubin-induced apoptosis of rat hippocampal neurons. Selective inhibition of the early peak of NF-κB by TAT-NBD offers neuroprotective effect. TAT-NBD can be potentially used for prophylaxis of bilirubin-induced brain injury.</p>

Advanced achievements about neuroprotective mechanisms of paeoniflorin / 中国中药杂志

Paeoniflorin is one of the bioactive components of Paeonia lactiflora, a traditional Chinese herbal medicine. Some recent studies prove its distinguished neuroprotective effect. These neuroprotective mechanisms have become hot points and show closely correlated to activating adenosine A1 receptor, ameliorating the function of cholinergic nerve, regulating ion channel homeostasis, retarding oxidative stress and apoptosis of the neurocytes, promoting nerve growth, having an influence on astrocytes and being ableto penetrate though blood brain barrier. In this review, we present the neuroprotective mechanisms of paeoniflorin in the following eight aspects.