摘要: | 藥用植物可做為抗癌藥物的首要來源,尤其是荖葉經酒精萃取後得到幾種生物類化合物如羥夏酚、丁香酚、沙維貝醇、異丁香酚對癌細胞有毒殺效用,丹參二?類也可抑制直腸癌細的生長。儘管有這些關注,異丁香酚和二?類的作用確切機制仍未清楚。故本論文研究目的是探討檳榔荖葉萃取物、異丁香酚和丹參二?類對HCT-116結腸癌生長、遷移和侵入能力的抑制作用,以及了解其作用機制。結果顯示:經由MTT和群落形成能力的分析,荖葉萃取物和異丁香酚會抑制人類 HCT-116結直腸癌細胞的生長,且呈現劑量依賴、時間依賴性。使用傷口癒合爬行能力實驗,結果顯示:荖葉提取物和異丁香酚都劑量依賴性的抑制HCT-116細胞的爬行。使用Boyden chamber分析癌細胞的侵入能力,結果呈顯荖葉提取物和異丁香酚都劑量依賴性的抑制HCT-116細胞的侵入。進一步西方點墨法分析,發現荖葉提取物和異丁香酚會下降ERK和JNK、增加p38 MAPK蛋白的磷酸化,也改變AKT和AMPK蛋白的磷酸化,也升高E-cadherin蛋白質表現水平、降低Snail蛋白質表達、及抑制第二型和第九型金屬蛋白?的活性。這些數據都指出荖葉提取物和異丁香酚可藉由ERK-、JNK-、p38 MAPK、AKT-、 AMPK等路徑而抑制結直腸癌細胞的生長,也藉由EMT訊息蛋白和金屬蛋白?等路徑而抑制直腸癌細胞的轉移。研究成果也發現丹參二?類例如Cryptotanshinone、Dihydrotanshinone、Tanshinone、Tanshinone IIA 會抑制直腸癌細胞的生長、爬行及侵入能力,其48小時處理後的IC50值分別是5.9、1.2、4.8及3.3 ?M。這些結果表示荖葉提取物、異丁香酚和丹參二?類具有潛力成為抗癌劑用於人類結直腸癌的治療。;ABSTRACT
Medicinal plants play an important role for being the paramount sources of drug discovery against cancer. The alcoholic extract of Piper betle leaf containing several biophenolic compounds such as hydroxychavicol, eugenol, chavibetol and isoeugenol has been demonstrated to be cytotoxic against cancer cells. Danshen diterpenes were also found to inhibit the proliferation of colon cancer cells. Despite these attentions, the exact mechanisms of these actions are still not clear. The present study aims to investigate the inhibitory effect of P. betle extract (PBE), isoeugenol and danshen diterpenes on the growth, cell migration and invasion of HCT-116 colorectal cancer cells, and understood their possible action mechanisms. The results indicated that PBE and isoeugenol inhibited HCT-116 cell growth in time-dependent and dose-dependent manner by using MTT assay and colony formation assay. Wound healing assay showed that PBE and isoeugenol dose-dependently inhibited the migration of colorectal cancer cells. Moreover, Boyden chamber assay indicated that the number of invaded cells significantly decreased after PBE and isoeugenol treatment. Further western blotting assay showed that PBE and isoeugenol decreased pERK and pJNK and increased pp38 MAPK levels. Also, PBE and isoeugenol altered the phosphorylation of AKT and AMPK. PBE and isoeugenol tended to increase E-cadherin and decrease Snail-1 protein levels, as well as decreasing the activities of MMP-9, not MMP-2. These findings suggest the possible ERK-, JNK-, p38-, AKT- and AMPK-dependent effects of PBE and isoeugenol on the growth of colorectal cancer cells, as well as the EMT-signaling proteins and MMP-dependent effect on cell metastasis. Similar inhibitory effect of danshen diterpenes such as cryptotanshiones, dihydrotanshinones, tanshinones I and tanshinones IIA on the growth, migration and invasion of colon cancer cells were observed. The IC50 values of cryptotanshinone, dihydrotanshinone, tanshinone I and tanshinone IIA on the cell viability of HCT-116 cells at 48 h were 5.9, 1.2, 4.8, 3.3 ?M. These results reveal significant potentials of PBE, isoeugenol and danshen diterpenes as anticancer agents for human colorectal cancer treatment. |