本研究以本土海洋褐藻:重緣葉馬尾藻（Sargassum duplicatum）為實驗樣品，比較傳統熱水萃取法（Water extraction, WE）、乙醇萃取法(Ethanol extraction, EE)、以及超臨界二氧化碳流體萃取法（Supercritical carbon-dioxide fluid extraction, SFE）之馬尾藻萃取物的抗氧化特性，並以體外細胞模式評估重緣葉馬尾藻萃取物對於人類大腸癌細胞株HT29 細胞增生之影響。研究結果顯示，以三種不同萃取法獲得之重緣葉馬尾藻萃取物之抗氧化特性表現，包括總多酚含量（total phenolic contents）、類黃酮含量（flavonoid contents）、DPPH（α,α-diphenyl-β-picrylhydrazyl）自由基清除能力、以及還原力（Reducing power），均明顯以熱水萃取物和超臨界二氧化碳流體萃取物較乙醇萃取物佳（P<0.05）；此外，三種不同萃取法獲得之重緣葉馬尾藻萃取物，均對人類大腸癌細胞株HT29細胞之增生產生抑制作用，且以超臨界二氧化碳流體萃取物對H29細胞之抑制作用較佳、其次為乙醇萃取物、而以熱水萃取物之抑制作用較差（P<0.05）。綜合本研究之結果，本土重緣葉馬尾藻之萃取物具有良好的抗氧化活性，且其對於大腸癌腫瘤細胞之增生具有抑制作用。

The antioxidant properties and antiproliferative activity of the brown alga, "Sargassum duplicatum" C. Agardh, were tested in this study. S. "duplicatum" were extracted with hot water (WE), ethanol (EE), and supercritical carbon-dioxide fluid (SFE), respectively. The total phenolic contents, flavonoid contents, and antioxidant activities, including DPPH (α, α-diphenyl-2-pricrylhydrazyl) radical scavenging and reducing power were assayzed. And, the anti-proliferative activity of S. "duplicatum", extracted from hot water, ethanol, and supercritical carbon-dioxide fluid, were tests in human colorectal adencarcinoma cell line HT29 using the MTT assay. The result showed that the WE and SFE of S. "duplicatum" have higher phenolic compounds and strong antioxidant activities than EE (p<0.05); The proliferation of HT29 cells was significantly inhibited at 48hr after exposure to the SFE, EE and WE, and the antiproliferative effect was highest in cells treated with SFE, follow by EE, and the lowest in cells treated WE, the differences among all groups were significant (p<0.05). This study suggested that brown alga, S. "duplicatum" is a useful healthy seafood having antioxidant properties and antiproliferative activity.