甘藷葉粗萃取與人工合成之 β- 胡蘿蔔素在高大豆油 或高豬油攝取下對大 白鼠體內 β- 胡蘿蔔素之利用
率及脂質代謝的影響
近年來研究發現補充合成之 β- 胡蘿蔔素會造成心血管疾病之死亡率相對 的增加，而引發 對合成 β- 胡蘿蔔素作為飲食補充劑合適與否之
爭議；為探討合成與天然 β- 胡蘿蔔素粗 萃取物之利用率及對
脂質代謝是否有不同的影響效應，遂從事本實驗研究。以 40 隻 Wistar 品系雄性大白鼠隨機分成五組，以不同來源之 (- 胡蘿蔔素（合成及萃取自 甘藷葉之 β- 胡 蘿蔔素粗萃取物， 0.01﹪ 飼料）及油脂（大豆油
及豬油， 15﹪ 飼料）作為本實驗設計並 以不添加 β- 胡蘿蔔素 之大豆油組為控制組，各組飼料中添加 1﹪ 膽固醇，水及飼料採自由 飲食，實驗期 40 天。實驗結果顯示：合成組血清及肝臟 β- 胡蘿蔔素濃度 顯著高於粗萃取 物組（ P<0.05 ）。 給予高濃度且相同劑量之合
成或甘藷葉粗萃取之 β- 胡蘿蔔素皆會使血 清及器官中維生素 A 濃 度升高，而兩組間無顯著差異。在脂質代謝方面，給予 β- 胡蘿蔔素
具有降低血清 LDL-C 濃度與升高 HDL-C 濃度的效應，而又以粗萃取物組最顯 著，此外，合成 組及粗萃取組皆會造成肝臟總膽固醇濃度及含量
的下降，以來自天然甘藷葉的 β- 胡蘿蔔素 粗萃取物更顯著。合成 組血清及肝臟三酸甘油酯濃度顯著高於粗萃取物組。合成組的大白 鼠血清、肝臟及腎上腺 β- 胡蘿蔔素濃度皆為豬油組顯著高於大豆油組。
不同油脂的攝取 對血清及器官中維生素 A 濃度並無影響。此外，
在大豆油攝取下，粗萃取物組血清及肝臟 三酸甘油酯濃度顯著
低於合成之 β- 胡蘿蔔素組，但在豬油攝取下，兩組間均無統計上差異
。在脂肪酸方面，在大豆油組中，合成組血清及肝臟中亞麻油酸（
linoleic acid,18:2 n-6 ） 相對比例顯著高於粗萃取物組（ P<0.05 ）
；在豬油組中，合成組血清及肝臟中油酸（ oleic acid, 18:1 n-9 ）相對 比例顯著高於粗萃取物組（ P<0.05 ）。研究顯示攝取甘藷葉粗萃取之 β- 胡 蘿蔔素比攝取合成之 β- 胡蘿蔔素有利於降低血脂質的趨勢，此 外，豬油飲食可使較多 β- 胡 蘿蔔素在大白鼠體內蓄積，而增加 β- 胡蘿蔔素之生物利用率。
Recently clinical trials indicate that an increasing relative risk of death from cardiovascular disease following synthesized beta-carotene supplement. We are
interested in the problem whether synthetic beta-carotene is suitable for use as a dietary supplement. The purpose of this study was to investigate the effects of different sources of beta-carotene and lipids on lipid metabolism and beta-carotene availability in rats. Forty adult male Wistar rats were randomly divided into five groups with the variables including the sources the sources of beta-carotene (synthetic and natural beta-carotene crude extract from sweet potato leaves ) and lipids (soybean oil and lard ). Diets and water were given ad libitum, and was 10g/kg cholesterol added in diets for forty days. The results showed that for (-carotene concentration in the serum and liver, the synthetic (-carotene groups were significantly higher than the beta-carotene extract groups (P<0.05). Comparison of the effect of different lipids under the same beta-carotene source indicated that, the lard groups were
significantly higher in beta-carotene concentration than the soybean oil groups. Different sources of beta-carotene and lipid fed did not affect the serum and liver retinol concentration in both the soybean oil-fed groups and the lard- fed groups (P>0.05). The effects on lipid metabolism were as follows: The synthetic beta-carotene groups had significantly higher ratio between high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) than the beta-carotene extract groups (P<0.05), the beta-carotene extract groups is the most significant. Besides, the synthetic beta-carotene groups and the beta-carotene extract groups could both cause liver total cholesterol content decreasing, and the beta-carotene extract groups is the most significant. The synthetic beta- carotene groups serum and liver acyltriglyceride concentration are significant higher than the beta-carotene extract groups. The rat serum, liver and adrenal gland beta- carotene concentration in the synthetic beta-carotene groups are all the lard group significant higher than the soybean oil group. Under the injection of soybean oil, the beta- carotene extract group serum and liver acyltriglyceride
Bioavailibility and Effect on Lipid Metabolism of Cr ude β- Carotene Extract from Sweet Potato Leave s and Synthetic β- Carotene in Rats Fed Different High Fat Diets
