番茄中酚類化合物對抗氧化、調降血脂及癌症化學預防之貢獻

Contribution of tomato phenolics to antioxidation, down-regulation of blood lipids, and cancer chemoprevention

沈祐成(You-Cheng Shen)

指導教授 ： 王進崑 ； 陳肅霖

中山醫學大學/健康管理學院/營養學研究所/博士(2009年)

https://doi.org/10.6834/CSMU.2009.00085

摘要

番茄是遍及全球的天然蔬果。許多研究結果顯示，攝食多量番茄及番茄相關的食物能有效地降低許多疾病(如癌症、心血管疾病) 的罹患率，這些功效主要是番茄中之天然物質(如ascorbic acid、tocopherols、carotenoids 及phytochemicals)所貢獻。近年來，番茄中的主要紅色素也是具有抗氧化性之茄紅素 (lycopene) 被認為是番茄促進健康的最主要因子，有關茄紅素之代謝以及加工處理所引起之異構化與氧化反應對人體健康之促進被報導極多，但茄紅素是否是番茄功能特性之主要貢獻成份，是否有其他成分可與茄紅素呈現相加甚至是相乘之作用，則至今仍不清楚。聖女番茄 (Lycopersicon esculentum Mill cv. Santa) 與大番茄(L. esculentum Mill cv. Farmers301) 為我國常作為生吃或烹調用之品種，但對於如何食用才可獲得最佳之保健功效，以及這兩種番茄經烹調後酚類化合物之變化的相關研究卻付之蹶如。本研究之目的在於瞭解番茄中酚類化合物的生物活性與特性，並觀察番茄對於血脂調控的影響。實驗使用聖女番茄和大番茄以及兩者分別經過殺菁、殺菁後置於100℃水浴中分別加熱10分鐘與30分鐘等處理樣品，比較加工前後酚類化合物之組成特性變化。並針對這兩種番茄在不同加工處理後酚類化合物粗萃物與類胡蘿蔔素粗萃物在番茄功能特性中所扮演之角色，以及兩種番茄經人體消化吸收後之情形進行探討，在人體臨床試驗上給予24位受試者等量茄紅素（40mg/day）之新鮮番茄、番茄汁、或茄紅素汁後，觀察其血漿抗氧化力、血脂、以及酚類化合物之變化。另外，也探討新鮮和加熱番茄之酚類化合物在口腔癌細胞(KB cell)化學預防特性上所扮演之角色。
結果發現，番茄中酚類化合物含量會隨加熱條件的嚴苛而增加，其中以殺菁並加熱100°C/30分鐘處理有極顯著的增加，大、小番茄中的酚類化合物分別增加了23%，34%。番茄中酚類化合物具有良好的抗氧化活性(57~71%)，並與番茄中類胡蘿蔔素的抗氧化作用具有相乘效果 (81~100%)。人體臨床試驗則發現，攝取新鮮番茄和番茄汁後，受試者血漿的總抗氧化能力與酚類化合物含量都有上升，但單獨攝取茄紅素汁組則無顯著的變化。另外，在攝取新鮮番茄和番茄汁後，血漿中三酸甘油酯和低密度脂蛋白之膽固醇含量皆有顯著下降，而高密度脂蛋白之膽固醇則有顯著的上升。在細胞試驗中則可知，番茄中的酚類化合物經加熱處理後，較新鮮番茄中之酚類化合物更能抑制TPA所誘發之第二型環氧合酶的表現，新鮮番茄酚類化合物之效果主要來自不含縮合單寧之區分物，而加熱處理過的番茄，縮合單寧區分物和不含縮合單寧區分物均具有效果。本研究顯示，番茄中酚類化合物在促進人體健康與癌症化學預防上的確扮演著重要角色，而加熱處理是較有利健康之番茄食用方式。

關鍵字

番茄 ； 酚類化合物 ； 茄紅素 ； 抗氧化 ； 第二型環氧合酶血脂

並列摘要

Tomato consumption is worldwide. Many studies showed that increased consumption of tomatoes and tomato-based foods could effectively reduce the risk of some diseases (e.g., cancer and cardiovascular disease). These beneficial effects were generally contributed from natural substances (e.g., ascorbic acid, tocopherols and carotenoids and phytochemicals). Recently, lycopene is considered the main contributor of tomato to health promotion in human. All metabolism, isomerization, and oxidation of lycopene are well obtained. However, it is worthy investigating whether lycopene is the main contributory substance of tomato for health promotion, or any other substances show additive or synergistic effect with lycopene. Small tomatoes (Lycopersicon esculentum Mill cv. Santa) and big tomatoes (L. esculentum Mill cv. Farmers301) are often used as fresh or cooked in Taiwan. However, the best eating way to achieve the health benefits is still unknown. Furthermore, the associated study about the characteristics and the role of phenolics in tomatoes are still deficient. The objective of this study is to understand the profile and characteristics of phenolics of fresh and cooked tomatoes. In addition, the biological activities of the tomato phenolic extracts (vs. tomato carotenoid extracts) and its role in health, down-regulation of blood lipid, and cancer chemoprevention are also determined. Moreover, a human clinical trial was conducted to examine antioxidation status of plasma, blood lipid profile, and phenolic responses after ingestion of fresh tomato, tomato juice, and lycopene drink.
The contents of tomato phenolics were increased by 34% for small tomato and 23% for big tomato after treatment of blanching and heating at 100°C for 30 min. Tomato phenolics showed fair antioxidant activity (57~71%) and also synergistically promoted the antioxidation (81~100%) of tomato carotenoids. Cell study showed that phenolic extract of heated tomato had better suppression on COX-2 expression than that of fresh tomato. In human clinical study, total antioxidant capacity and phenolic contents in plasma were increased after administration of fresh tomato and tomato juice, but no significant difference was found for lycopene drink consumption. TG levels and LDL-C were decreased after administration of fresh tomato and tomato juice, and HDL-C was increased. Cell studies showed that phenolic extracts of heated tomatoes resulted in increased suppression of COX-2 expression than that of fresh tomato. Non-condensed tannin containing fraction of fresh tomato greatly suppressed COX-2 expression (p<0.05), but both non-condensed tannin containing and condensed tannin containing fractions of heated tomatoes showed suppression on COX-2 expression. These results suggest that tomato phenolics greatly played an important role in the health promotion and cancer chemoprevention. Cooked tomato could be helpful to health.

並列關鍵字

Tomato ； Phenolics ； Lycopene ； Antioxidation ； Cyclooxygenase-2 ； Blood lipids

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