七層塔水萃物誘導胃癌細胞壞死以及凋亡的機轉

中草藥的研究在近年來成為十分重要的研究之一，因為其副作用低，來源天然無害且效果良好。七層塔 ( Ocimum gratissimum , OE) 屬於羅勒的一種，是台灣特有的民間草藥，其功效為抗氧化、抗癌等，具有高效用之藥用價值。在最近的文獻中，已經發現OE對乳癌和肺癌細胞有抗癌作用；然而，OE對人類胃腹癌細胞( AGS )的作用仍不清楚。因此，本研究目的是調查 OE 之萃取物 OGE 是否影響 AGS 的生長與分子機制。首先以MTT 測試七層塔對 AGS 細胞毒殺效果，結果顯示在48小時中隨著濃度增加下，有明顯抑制胃腺癌細胞生長現象。使用 propidium iodide ( PI ) 和 Annexin V 利用流式細胞儀觀察，發現處理 OGE 48小時細胞同時呈現凋亡與壞死現象，利用Jc-1 測其粒腺體膜電位，可清楚看到處理OGE 48小時，膜電位均有下降趨勢；蛋白表現方面，在48小時中隨著 OGE 濃度增加，claeved-caspase-3 表現上升，Poly (ADP-ribose) polymerase (PARP) 蛋白被切割； Phospho-Extracellular signal-regulated kinases 1/2(p-Erk) 減少，p-38 上升，使用N-acetyl cysteine (NAC) 前處理48小時中，發現細胞存活均有恢復的情況。綜合以上的結果顯示OGE 可能成為一種治療胃腺癌的抗癌藥物。

Recently, mounting evidences reveal that use of medicinal plants may be regarded as a supplement with well efficacy and few side effects for the current cancer treatment. Among the medicinal plants, Ocimum gratissimum (OE) has been extensively used in Taiwan. Recently, anti-tumor effect of OG on breast cancer cell and lung cancer cell are also reported. However, the effects of OE on gastric cancer remain unclear. Therefore, we aimed to investigate whether aqueous OE extract (OGE) affects viability of gastric cancer and the molecular mechanism by OGE in gastric cancer. Treated gastric cancer cells with OGE for 48 h significantly reduced cell viability in concentration-dependent manner, as measured by MTT assay. We also used propidium iodide (PI) alone and PI/ Annexin V assay by flow cytometry, results showed that the ratio of the apoptotic DNA fragmentation increased in 48hr in a dose dependent manner. OGE treatment also reduced mitochondrial membrane potential (MMP) as measured by Jc-1 assay. Furthermore, OGE enhanced activation of caspase-3and p-38, decreased activation of extracellular signal-regulated kinase 1/2 (Erk1/2), and trigger cleavage of Poly (ADP-ribose) polymerase (PARP). Pretreatment with the anti-oxidant agent N-acetyl cysteine (NAC) not only reversed the OGE induced phenomenon. In conclusion, our results indicate that OGE suppressed the cell viability of gastric cancer cell, which may result from the activation of apoptotic signaling. Our findings suggested that OGE might be beneficial to treat gastric cancer.