Neuroprotective effect of Minocycline on neuronal apoptosis induced by a synthetic gingerdione compound

• Main Authors: Yang-Jung Yu, 余泱蓉
• Other Authors: Po-Wu Gean
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/27152459430977902353

碩士 === 國立成功大學 === 藥理學研究所 === 96 === Besides being used as a spice, ginger has been applied in oriental medicine to ameliorate symptoms such as inflammatory, rheumatic disorders and gastrointestinal discomforts. Present study indicated that the effect of 1-(3,4-dimethoxyphenyl)-3,5-dodecenedione(I6), a derivative of gingerdione, could induce HL-60 cell G1 arrest and apoptosis. Therefore, we would investigate if I6 affect neuron. In the present study, we further studied the mechanism of I6 on the cortical neurons. After a 5-day maturation period in vitro, cortical neurons were treated with I6 at different concentration for 24 h and cell viability was assessed by using MTT assay. We found that I6 induced neuronal death in a concentration-dependent manner. Furthermore, using Hoechst 33342, propidium iodide (PI) and TUNEL staining confirmed that the reduced cell viability induced by I6 was due to apoptosis. Here we want to study the neuroprotective mechanism of Minocycline by I6 inducing neuronal apoptosis. We treated Minocycline prior to I6 to cortical neurons, and after 18 hours we were assessed by MTT assay, Western blot, Immuocytochemistry and ELISA. Here, we show that pre-treatment of cell with Minocycline prevented cell death in a concentration-dependent manner. Constitutive expression of the 32-kD a pro-caspase-3 protein was detected in controls. After treatment with I6, the expression of cleaved caspase-3、reactive oxygen species (ROS)、cleaved caspase-9 and cleaved PARP gradually increased. Pre-treatment of cell with Minocycline prevented the increase of cleaved fragment of those caspases. Furthermore, we revealed that DNA fragmentation was made by I6 treatment and this effect was blocked by Minocycline treatment. Therefore, these results suggest that Minocycline may have the protective effects on I6-induced neuronal apoptosis via inhibition of caspase activation. Additionally, We investigate I6 cause Bcl-2 level decrease and Minocycline could reverse it。