大腸直腸癌為全球最常罹患及造成死亡的癌症之一，有約 50％的患者會癌細胞轉移擴散，需接受化學藥物治療。最常使用的化療藥物為5-fluorouracil (5-FU)，但使用5-FU易會造成腫瘤的抗藥性及對正常細胞的毒性。因此，尋找有效輔助化學藥物治療的保健食品以降低化療藥物用量，降低藥物所致之副作用，已成為治?大腸直腸癌的新興研究議題。研究指出虎杖 (Polygonum cuspidatum)及其活性成分具有抗氧化、增加免疫及抗腫瘤等作用，值得進一步評估其防癌功效。本研究使用細胞存活率試驗、活性氧物質 (ROS) 測定及西方墨點法 (Western blot assay) 觀察細胞增殖和細胞凋亡作用相關蛋白質之表現以探討虎杖根乙酸乙酯分離物 (PcE(H)EA) 及其活性成分之白藜蘆醇 (resveratrol)、大黃素 (emodin) 聯合5-FU對 HT-29 細胞抑制細胞增殖作用之影響。本研究結果顯示各試驗樣品在濃度50-200 μg/mL皆能顯著降低細胞存活率約60~80%，而聯合5-FU (1:1, w/w) 在濃度25/25-100/100 μg/mL可顯著降低細胞存活率約80~95%，PcE(H)EA及resveratrol分別聯合5-FU與 HT-29細胞於24小時抑制細胞存活率皆具正協同效應 (CI<1)。此外，除了PcE(H)EA及resveratrol外，emodin或其聯合5-FU在濃度50-100 μg/mL可顯著促進細胞內活性氧分子的產生。各單獨試驗樣品或聯合5-FU在濃度50 μg/mL皆會增加HT-29細胞內GSK3β蛋白質表現、p-β-Catenin / β-Catenin 及Bax/Bcl-2比值，但不影響caspase-3活性及cleaved-PARP蛋白質。這些研究結果顯示試驗樣品或樣品聯合5-FU可能以增加p-β-Catenin / β-Catenin 及Bax/Bcl-2之比值的途徑，達到抑制癌細胞增殖作用及促進細胞凋亡之效果。 Colorectal cancer is one of the most common cancers and leading to death in the world. There are 50% of patients develop metastatic disease and have to be treated with chemotherapy. The chemistry treatment of the most commonly used chemotherapy drug 5-fluorouracil (5-FU), but the use of 5-FU has two major problems: tumor resistance and the toxicity for normal cells. So finding anti-cancer compounds which can be used in combination with existing drugs may provide an important way forward in the treatment of colorectal carcinoma. This study would observe the cell viability, intracellular reactive oxygen species (ROS) products, cell proliferation-associated protein involved with Wnt/β-catenin pathway and cell apoptosis- associated protein to investigate the effects of ethyl acetate extracts from Polygonum cuspidatum root (PcE(H)EA), and it’s active compounds, emodin and resveratrol, combined with 5-FU on anti-proliferation in human colon cancer cell line (HT-29). In the study showed that each test samples at 50-200 μg/mL led to 60-80% reduction in the viability of HT-29 cells and samples combined with 5-FU (1:1, w/w) at 25/25-100/100 μg/mL could significantly decrease viability about 80-95%. PcE(H)EA or resveratrol combined with 5-FU showed a synergistic effect (CI <1) after 24 hours of exposure. In addition, emodin, but not PcE(H)EA and resveratrol, could significantly promoted the production of intracellular ROS at 50-100 μg/mL concentration. Each test samples or combined with 5-FU could increase GSK3β protein expressions, the ratio of p-β-catenin/β-catenin and Bax/Bcl-2 at 50 μg/mL in HT-29 cells, but did not affect caspase-3 activity and cleaved-PARP protein expression. The results of these studies showed that the test samples or combined with 5-FU might increase the p-β-catenin/β-catenin ratio and Bax/ Bcl-2 ratio to inhibit cancer cell proliferation and promote cell apoptosis.
