Gongjin-Dan Enhances Neurite Outgrowth of Cortical Neuron by Ameliorating H(2)O(2)-Induced Oxidative Damage via Sirtuin1 Signaling Pathway

Gongjin-dan (GJD) is a multiherbal formula produced from 10 medicinal herbs and has been traditonally used as an oriental medicine to treat cardiovascular diseases, alcoholic hepatitis, mild dementia, and anemia. Additionally, increasing evidence suggests that GJD exerts neuroprotective effects by suppressing inflammation and oxidative stress-induced events to prevent neurological diseases. However, the mechanism by which GJD prevents oxidative stress-induced neuronal injury in a mature neuron remains unknown. Here, we examined the preventive effect and mechanism of GJD on primary cortical neurons exposed to hydrogen peroxide (H(2)O(2)). In the neuroprotection signaling pathway, Sirtuin1 is involved in neuroprotective action as a therapeutic target for neurological diseases. After pre-treatment with GJD at three concentrations (10, 25, and 50 µg/mL) and stimulation by H(2)O(2) (30 µM) for 24 h, the influence of GJD on Sirtuin1 activation was assessed using immunocytochemistry, real-time PCR, western blotting, and flow cytometry. GJD effectively ameliorated H(2)O(2)-induced neuronal death against oxidative damage through Sirtuin1 activation. In addition, GJD-induced Sirtuin1 activation accelerated elongation of new axons and formation of synapses via increased expression of nerve growth factor and brain-derived neurotrophic factor, as well as regeneration-related genes. Thus, GJD shows potential for preventing neurological diseases via Sirtuin1 activation.