紫檀芪誘導肝癌細胞凋亡及自噬導致細胞增生抑制之研究

紫檀芪(Pterostilbene)是白藜蘆醇(Resveratrol)的天然雙甲基類似物，廣泛的存在於藍莓、葡萄等植物當中，具有抗發炎、抗氧化以及抗腫瘤等生理活性。目前許多研究顯示Pterostilbene可在透過細胞凋亡或是細胞自噬造成數種癌細胞死亡，但是Pterostilbene造成肝癌細胞死亡的機制仍不清楚。因此，本研究主要目的是想藉由Huh 7和SK-Hep 1細胞探討Pterostilbene造成肝癌細胞死亡的相關機轉。由MTT分析結果得知，Pterostilbene抑制肝癌細胞增生的能力會隨著處理濃度和時間增加而上升。透過DAPI染色發現，Pterostilbene可使細胞產生細具有細胞凋亡特徵的變化；但透過西方墨點法分析Caspase 3、8和9之表現量並未發現明顯改變，顯示Pterostilbene引起的可能是caspase-independent apoptosis。透過流式細胞儀分析細胞週期，則是發現細胞週期分布被改變了。而透過AO染色發現，Pterostilbene會增加細胞內酸性胞器的形成；同時，LC3-II蛋白的表現量也會增加。顯示Pterostilbene會啟動這兩株肝癌細胞之自噬反應。綜合以上所述，Pterostilbene可透過引起細胞週期停滯以及細胞自噬來抑制Huh 7和SK-Hep 1細胞之增生，具有作為抗癌藥物之潛力。

Petrostilbene is a natural dimethyl analog of resveratrol and found in many grapes and berries, with multiple pharmacologic activities, including anti-inflammation, anti-oxidation and cancer prevention. Many studies showed that pterostilbene can induce apoptosis and autophagy in various cancer cell lines and further inhibit their viability. However, the exact mechanism of pterostilbene-aused growth inhibition in hepato- cellular carcinoma (HCC) cell lines remains unclear. The main goal of this study is to elucidate how pterostilbene inhibit cell proliferation of HCC cells. Results from MTT assay and DAPI staining showed that pterostilbene caused both dose- and time-dependent inhibition of viability of both cells while the morphology of both cells was changed into a more apoptotic fashion. Cell cycle analysis showed that the phase distribution was changed by pterostilbene treatment. However, the expression of caspase 3, 8 and 9 were not affected, indicating that caspase-independent apoptosis may be activated. Meanwhile, results form AO staining showed that pterostilbene treatment can increase the percentage of AVOs positive cells in both dose- and time-dependent manner. Furthermore, the expression level of LC3-II was also increased in both dose- and time-dependent manner by pterostilbene. In summary, pterostilbene inhibit the cellular viabilities of Huh 7 and SK-Hep 1 via cell cycle arrest and the activation of autophagy.