| 摘要: | 本研究的目的是先利用 HPLC 分析出紅甘藷葉中主要的植物化學物質的種類及含量；並探討給予紅甘藷葉飲食，對健康男性運動後體內壓力指標及發炎反應之影響。實驗共分三個部份，第一部份：將紅甘藷葉進行萃取，利用一般呈色法及 HPLC 配合 PDA 檢測系統，分析其類胡蘿蔔素 (carotenoids)、酚酸 (phenolic acids)、類黃酮 (flavonoids) 及花青素 (anthocyanins) 的種類及含量。第二部份：人體試驗採隨機交叉設計，招募健康成年男性為受試者。實驗為期共五週，第一週為適應期，之後進行兩階段分別為期 7 天的飲食介入期 (紅甘藷葉 vs. 控制/低多酚飲食)，且間隔 14 天的排空期。分別於兩階段飲食介入期結束後，受試者進行 70% VO2max 的運動達 1 小時，並於運動前及結束後第 0、1 及 3 小時 (Post-E0, Post-E1h 及 Post-E3h) 抽取受試者血液樣本以進行氧化壓力指標、IL-6 及熱休克蛋白表現分析。第三部份：人體試驗設計同第一部份，並將飲食介入期延長為 14 天；運動後採集血液的時間點拉長至 48 小時。於兩階段飲食介入期間，會收集實驗飲食樣本以進行植物化學物質含量分析；受試者血液及尿液樣本以進行四大壓力指標、促/抗發炎細胞激素濃度及 NF-κB 蛋白表現分析。綜合三部份研究結果顯示，紅甘藷葉中含有 59.3 ± 3.05 mg gallic acid equivalent (GAE)/g dry weight (DW) 的總多酚類濃度、10.6 ± 0.69 mg quercetin equivalent (QCE)/g DW 的總類黃酮濃度及 1.34 ± 0.04 mg/g DW 的總花青素濃度；經 HPLC 分析後發現含有較高含量屬於類胡蘿蔔素的 lutein 及 β-carotene；屬酚酸的 caffeic acid；屬類黃酮的 quercetin 及屬花青素的 cyanidin。而與控制飲食相比，紅甘藷葉飲食也含有較高含量的總多酚類、總類黃酮及總花青素濃度 (2.85 vs. 0.63 mg GAE/g DW; 0.36 vs. 0.01 mg QCE/g DW; 0.03 vs 0 mg/g DW, p＜0.0001)。因此受試者攝食紅甘藷葉飲食後，血漿及尿液中總多酚類濃度會顯著增加；血中總抗氧化能力 (如 FRAP) 也顯著上升；而受試者進行 1 小時的中強度運動後，血漿中四大壓力指標及PBMC中 NF-κB 蛋白表現量皆呈現顯著的飲食介入效應：氧化壓力指標 (TBARS & PC)、機械性壓力指標 (CK)、代謝性壓力指標 (cortisol) 及熱壓力指標 (HSP72)；然而對於促/抗發炎細胞激素則無顯著影響。結論：長期攝取富含植物化學物質的紅甘藷葉飲食，可增加體內的抗氧化力以抵禦因運動所誘導生成的各種壓力傷害，然而對於發炎反應則無延緩的效果。
PURPOSES: This study was to identify and quantify the phytochemical contents of purple sweet potato leaves (PSPLs) by high-performance liquid chromatography (HPLC) and evaluate the effects of PSPLs diet consumption on the time course of exercise-induced stress markers and inflammation. METHODS: The study was distributed into three parts. Part 1 Study: The carotenoid, flavonoid, and anthocyanin contents of PSPLs extract were measured by spectrophotometry and HPLC coupled to photodiode array (PDA) detection. Part 2 Study: A crossover design was applied, subjects participated in a two-step dietary intervention period. Each subject was given a high- (PSPLs) or low-polyphenol (control) diet for 7 days with a 2 weeks washout period. After each dietary intervention period, all subjects performed 1 hour of treadmill running at a speed corresponding to 70% of each subject’s individual maximal oxygen uptake (VO2max). Blood samples were taken before exercise and at 0, 1, and 3 hours (Post-E0, Post-E1h 及 Post-E3h) after exercise. Part 3 Study: This study followed the design used by Study 1. We extended the dietary intervention for 14 days and the blood collection required up to 48 hours after exercise. RESULTS: The total polyphenol, flavonoid and anthocyanin contents of PSPLs were 59.3 ± 3.05 mg GAE/g DW, 10.6 ± 0.69 mg QCE/g DW, and 1.34 ± 0.04 mg/g DW, respectively. Very high concentrations of lutein, β-carotene, caffeic acid, quercetin, and cyanidin were found in PSPLs. There is a significant difference between two diets in total polyphenol, flavonoid and anthocyanin contents (2.85 vs. 0.63 mg GAE/g DW; 0.36 vs. 0.01 mg QCE/g DW; 0.03 vs 0 mg/g DW, p＜0.0001). PSPLs consumption significantly increased plasma and urine total polyphenols concentration and total antioxidant power (ferric reducing ability of plasma; FRAP). The pattern of change between two dietary interventions was significant for stress markers (oxidative stress: TBARS and PC, intervention main effect, p=0.013 and 0.031; mechanic stress: CK, p=0.049; metabolic stress: cortisol, p=0.014 and thermal stress: HSP72, p=0.002) and NF-κB protein expression. However, there was no significant difference between two diets in pro-/anti- inflammatory cytokines. CONCLUSION: Consumption of PSPLs diet, a meal rich in phytochemical contents, could offer protection against the stress damage caused by exercise, but fail to attenuate inflammation. |
