- 學位論文
西蘭花 (Brassica oleracea L. var. italica) 之多酚含量及不同之生物活性：比較可食用及非食用部位之研究
Polyphenolic Profile and Varied Bioactivities of Broccoli (Brassica oleracea L. var. italica): A Comparative Study of Edible and Non-Edible Parts
摘要
西蘭花 (Brassica oleracea L. var. italica) 含有大量之生物活性化合物，如芥子油苷、酚類及必需營養素，其與促進健康作用有正相關。本研究將探討西蘭花可食用部位 (小花 (FE) 及新芽 (SPE)) 及非食用部位 (葉子 (LE) 及種子 (SE)) 其萃取物之體外抗氧化能力、細胞毒性、細胞凋亡及抗菌活性。以HPLC和LC–MS兩者於各項測定中均顯示其所有萃取物具有很高之抗氧化活性，其中以SPE之含量最高與其多酚含量相關；於MTT assay 之結果顯示，SPE對A549、Caco-2及HepG2癌細胞產生顯著之細胞毒性，IC50分別為0.117、0.168及0.189 mg/mL；並藉由流式細胞儀判定，萃取物於Caco-2細胞具有增加subG1群體及降低粒線體膜電位之作用，因此可誘導細胞發生凋亡；在抗菌試驗中以瓊脂擴散法測定並計算其最小抑菌濃度 (MIC)，其中LE及SPE對Bacillus subtilis及Salmonella typhimurium有較顯著之抗菌活性 (MIC分別為0.39–0.78 mg/mL)，反之，對Staphylococcus aureus及Escherichia coli之抗菌活性較弱 (MIC分別為1.56–3.13 mg/mL)。綜合上述結果顯示，西蘭花及其副產物可作為功能性食品或藥物應用之潛在來源。
並列摘要
Broccoli (Brassica oleracea L. var. italica) contains a substantial amount of bioactive compounds such as glucosinolates, phenolics, and essential nutrients, which are positively linked to health-promoting effects. This work aimed to evaluate whether both edible and non-edible parts of broccoli could be effective by examining in vitro antioxidant, cytotoxic, apoptotic, and antibacterial activities of its floret, sprout, leaf, and seed extracts (FE, SPE, LE, and SE, correspondingly). High-performance liquid chromatography (HPLC) and liquid chromatography–mass spectrometry (LC-MS) were used to perform polyphenolic profile of samples. Various assays exhibited strong antioxidant properties of all samples. SPE obtained the highest capacity, correlated to its polyphenolic contents. SPE also exerted the significant cytotoxicity against A549, Caco-2, and HepG2 cancer cell lines at low inhibitory concentration (IC50) values (0.117, 0.168 and 0.189 mg/mL, respectively), as tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry confirmed the apoptosis induction of all extracts in Caco-2 cells by revealing an increased subG1 population, a cell cycle arrest, and a decreased mitochondrial membrane potential. The considerable antibacterial efficacy was observed in either LE and SPE against Bacillus subtilis and Salmonella typhimurium (0.39–0.78 mg/mL) using the well-agar diffusion and minimum inhibitory concentration (MIC) methods, along with the weak ability against Staphylococcus aureus and Escherichia coli (1.56–3.13 mg/mL). These findings suggest that broccoli and its byproducts might serve as a potential source for applications of functional food or pharmaceutical products.