褪黑激素對於急性酒精作用Pc12細胞株抗氧化狀態之影響   全文下載

Effect of Melatonin on Antioxidation in the PC12 Cell Line after Exposure to Ethanol

因過量酒精的消耗，可能增加活性氧的產生，進而造成組織的氧化性傷害。本實驗探討當PC12細胞株經急性酒精作用之後，褪黑激素（melatonin）對於抗氧化狀態的影響評估。在本研究中，我們先施予不同濃度的褪黑激素24 hr後，再以150 mM酒精作用4 hr；之後我們分析下列各項：細胞存活率（cell viability）、乳酸去氫?釋出百分比（% lactate dehydrogenase released）、麩胱甘?濃度（glutathione，簡稱GsH）、超氧陰離子歧化?（superoxide dismutase，簡稱sOd）和麩胱甘?還原?（glutathione reductase，簡稱GRx）的活性及羰基化蛋白質濃度（protein carbonyl）等，以觀察其氧化性傷害與評估抗氧化狀態。結果顯示：當PC12細胞株經10、100與1000 μM褪黑激素處理後，在急性酒精作用組別中的細胞存活率及GsH濃度皆呈現增加現象，而酒精引起的細胞毒性及羰基化蛋白質濃度則呈現減少趨勢，但對於sOd活性則無影響。另外，10及100μM褪黑激素對於GRx活性並無顯著差異，但在1000 μM的褪黑激素作用組別，GRx活性則呈現下降的現象。由上述結果顯示：褪黑激素可提升GsH濃度以降低急性酒精作用PC12細胞株引起的氧化性傷害，因此若給予適當的褪黑激素，可能可達到保護細胞的效果。

Excessive ethanol consumption may increase the production of reactive oxygen species (ROS), which results in the oxidative damage of tissues. The purpose of this study was to evaluate the effects of melatonin on the antioxidative status in the PC12 cell line after exposure to ethanol. In this study, the PC12 cells were treated with the different concentrations of melatonin for 24 hr. Subsequently, the cells were incubated with a fresh medium containing 150 mM of ethanol for 4 hr. To observe the oxidative damage and evaluate the antioxidative status after acute exposure to ethanol, cell viability, percentage of lactate dehydrogenase released (% LDH released), glutathione (GSH) level, activities of superoxide dismutase (SOD) and glutathione reductase (GRx), and concentrations of the protein carbonyls were assayed. The results showed that cell viability and GSH were increased, whereas the ethanolinduced cytotoxicity and protein carbonyl concentration decreased when the PC12 cells were treated with 10, 100 and 1000 μM melatonin. In contrary, there was no significant difference in the activity of SOD in the ethanol-treated group. In addition, there were no significant differences in the activity of GRx in the groups with the treatment of 10 and 100 μM melatonin; however, GRx activity decreased in the cells treated with 1000 μM melatonin. In conclusion, melatonin of moderate concentration may be a protective agent to alleviate acute ethanol-induced oxidative damage by the generation of GSH in the PC12 cell line.