Bast A, van der Plas R M, van den Berg H, Haenen G R
Department of Pharmacochemistry, Leiden/Amsterdam Center for Drug Research, Vrije Universiteit, Netherlands.
Eur J Clin Nutr. 1996 Jul;50 Suppl 3:S54-6.
Beta-carotene has been shown to exhibit a good radical-trapping antioxidant activity in vitro. We were interested to see if dietary beta-carotene in combination with various intake levels for vitamin A would also inhibit lipid peroxidation.
Sixty male Wistar rats received vitamin A (as retinyl palmitate) for 14 weeks in the diet (40,000, 4000 and 400 IU/kg food). In the last 5 weeks one half of each group received beta-carotene (50 mg/kg food). Lipid peroxidation (induced by 10 microM Fe2+ and 0.2 mM ascorbate) was measured ex vivo in liver microsomes.
The beta-carotene-treated group had similar beta-carotene levels in liver microsomes (3.4 nmol per mg protein) as the other group, irrespective of vitamin A intake. No difference in lipid peroxidation was seen between the groups with different beta-carotene and vitamin A diets.
Beta-carotene is not effective in vitro as antioxidant in liver microsomes of rats fed beta-carotene with various intakes of vitamin A.
β-胡萝卜素已被证明在体外具有良好的自由基捕获抗氧化活性。我们想了解膳食中的β-胡萝卜素与不同摄入量的维生素A联合使用是否也能抑制脂质过氧化。
60只雄性Wistar大鼠在饮食中摄入维生素A（以棕榈酸视黄酯形式）14周（食物中含量分别为40,000、4000和400国际单位/千克）。在最后5周，每组的一半大鼠接受β-胡萝卜素（50毫克/千克食物）。在离体肝脏微粒体中测量脂质过氧化（由10微摩尔/升Fe2+和0.2毫摩尔/升抗坏血酸诱导）。
无论维生素A摄入量如何，β-胡萝卜素处理组肝脏微粒体中的β-胡萝卜素水平（每毫克蛋白质3.4纳摩尔）与另一组相似。不同β-胡萝卜素和维生素A饮食组之间在脂质过氧化方面未见差异。
在给大鼠喂食不同摄入量维生素A的同时补充β-胡萝卜素，β-胡萝卜素在体外对大鼠肝脏微粒体无抗氧化作用。
