邊緣性葉酸缺乏對F344大白鼠葉酸營養狀態、肝臟抗氧化能力及脂質過氣化傷害之影響

Effects of Marginal Folate Deficiency on Folate Status, Antioxidant Capacity and Lipid Peroxidation in F344 Rat Livers

許玉卿(Yu-Chin Hsu) ； 許瑞芬(Rwei-Fen S. Huang)

《中華民國營養學會雜誌》 24卷3期 (1999/08) Pp. 228-240

https://doi.org/10.6691/JCNS.199908_24(3).0002

摘要

本研究以雄性離乳F344大白鼠為實驗動物，採用無葉酸之amino acid-de-fined飼料配方為基礎（含1% succinylsulfathiazole），分別添加葉酸使為對照組(8mg/kg diet)、中葉酸組(2mg/kg diet)及低葉酸組(0.5mg/kg diet), 探討因葉酸攝取不足導致低血葉酸濃度之邊緣性葉酸缺乏對動物體肝臟抗氧化防禦系統及誘發脂質過氧化傷害之影響。研究結果顯示，大白鼠攝取中、低葉酸飲食8周，血清及血漿葉酸量依序顯著降低。降低葉酸攝取量對F344鼠肝臟中麩胱苷肽還原醇及過氧化氫醇活性沒有影響，有降低麩胱苷肽過氧化醇活性之趨勢，尤以中葉酸組之麩胱苷肽過氧化醇活性顯著降低。中、低量葉酸攝取也沒有顯著改變肝內之麩胱苷肽的含量。若以TBARS (thiobarbituric acid reactive substances)的評估脂質過氧化傷害，肝臟均質液之TBARS值並沒有受到葉酸攝取降低而有顯著差異。萃取肝臟微粒體加鐵誘發脂質過氧化傷害，降低葉酸攝取使TBARS值有增加趨勢，但無顯著差異。因此，邊緣性葉酸缺乏會使動物體肝臟內麩胱苷肽過氧化酶活性降低，而對脂質過氧化之增加並無顯著影響。

關鍵字

邊緣性葉酸缺乏 ； 抗氧化酵素 ； 脂質過氧化

並列摘要

The purpose of this study was to investigate the effect of marginal folate deficiency on blood folate status, hepatic antioxidant capacity and lipid peroxidation in male weanling F344 rats. Rats were fed an amino acid-defined folate-deficient diet supplemented with 0.5 (low folate), 2 (moderate folate) or 8 (control) mg folic acid/kg for 8 weeks. As dietary folate intake decreased, plasma folate concentrations and serum were graded-lower in rats fed moderate or low folate diet than in rats fed a control diet. Folate levels in erythrocytes were significantly lower in rats fed the low folate diet than in rats fed a control or moderate folate diet. This profile in decreasing blood folate status of rats fed folate-lowering diets mimicked the situation of marginal folate deficiency in humans. Decreasing folate intake did not affect glutathione reductase and catalase activity in rat livers. The glutathione peroxidase activity was significantly decreased in the liver of rats fed a moderate folate diet. Hepatic GSH and GSSG levels remained unchanged. Thiobarbituric acid reactive substance (TBARS) values in liver homogenate of rats fed control, moderate or low folate diets were not significantly different. Extracted microsomal fractions from liver homogenate and incubated with Fe(superscript 2+), TBARS values of rats fed moderate or low folate diet were higher, though not significantly, than those of rats in the control groups. The results indicated that marginal folate deficiency affected hepatic antioxidant enzyme activity and may result in lipid peroxidation under Fe(superscript 2+) stimulation, which suggested the increased liver susceptibility to oxidative damage in rats fed folate-lowering diets.

並列關鍵字

marginal folate deficient ； antioxidant enzyme ； lipid peroxidation