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
Bioavailibility and Effect on Lipid Metabolism of Crude β- Carotene Extract from Sweet Potato Leaves and Synthetic β- Carotene in Rats Fed Different High Fat Diets
中文摘要
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。
英文摘要
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
concentration are significant lower than the synthetic
beta-carotene group, but the groups under the lard injection are not statistically different. The effects on fatty acid
were as follows: Among the soybean oil groups, the serum and liver linoleic acid (18:2,n-6) ratios were
significantly higher in the synthetic beta-carotene groups than in the beta-carotene extract groups (P<0.05); and Among the lard groups the serum and liver oleic acid (18:1,n-9)
ratios were significantly higher in the synthetic beta-carotene groups than in the beta-carotene extract groups (P<0.05).
These results suggest that ingestion of beta-carotene crude extract from sweet potato leaves, as compared to injestion of the synthetic beta-carotene, has the benefit of decreasing serum lipids. Except this, the lard diet could cause more beta-carotene deposit in the liver and increase beta-carotene bioavailability.
