Nasrollahzadeh Javad, Siassi Fereydoun, Doosti Mahmood, Eshraghian Mohammad Reza, Shokri Fazel, Modarressi Mohammad Hossein, Mohammadi-Asl Javad, Abdi Khosro, Nikmanesh Arash, Karimian Seyed Morteza
Department of Nutrition and Biochemistry, Tehran University of Medical Sciences, Tehran, Iran.
Lipids Health Dis. 2008 Nov 16;7:45. doi: 10.1186/1476-511X-7-45.
Experimental studies indicate that gamma linolenic acid (GLA) and docosahexaenoic acid (DHA) may inhibit glioma cells growth but effects of oral consumption of these fatty acids on brain tumor fatty acid composition have not been determined in vivo.
GLA oil (GLAO; 72% GLA), DHA oil (DHAO; 73% DHA) were fed to adult wistar rats (1 mL/rat/day) starting one week prior to C6 glioma cells implantation and continued for two weeks after implantation. Control group were fed same amount of high linoleic acid safflower oil (74-77% linoleic acid). Fatty acid composition of tumor samples was determined in a set of 8-12 animals in each group and serum fatty acid in 6 animals per each group. Gene expression of tumor fatty acid binding protein 7 (FABP7), epidermal growth factor receptor (EGFR), peroxisome proliferator activated receptor gamma (PPAR-gamma) and retinoid x receptor-alpha (RXR-alpha) were determined in a set of 18 animals per group.
DHAO feeding increased EPA of brain tumors and decreased ratio of n-6/n-3 fatty acids. Serum levels of EPA were also increased in DHAO group. A similar trend in serum and tumor levels of DHA were observed in DHAO group but it did not achieve statistical significance. GLAO increased serum concentration of GLA but had no significant effect on tumor GLA or dihomo-gamma linolenic acid (DGLA) concentrations. Gene expression of FABP7 was up-regulated in tumors of DHAO group but no other significant effects were observed on EGFR, PPAR-gamma or RXR-alpha expression, and expression of these genes in tumors of GLAO were not different from SFO group.
Dietary supplementation of DHA containing oil could be an effective way to increase levels of long chain n-3 fatty acids in brain tumors and this increase may be mediated partly by up-regulation of FABP7 expression.
实验研究表明，γ-亚麻酸（GLA）和二十二碳六烯酸（DHA）可能抑制胶质瘤细胞生长，但这些脂肪酸口服对脑肿瘤脂肪酸组成的影响尚未在体内得到确定。
在将C6胶质瘤细胞植入前一周开始，给成年Wistar大鼠喂食GLA油（GLAO；72% GLA）、DHA油（DHAO；73% DHA）（1毫升/大鼠/天），并在植入后持续两周。对照组喂食等量的高亚油酸红花油（74 - 77%亚油酸）。测定每组8 - 12只动物的肿瘤样本脂肪酸组成以及每组6只动物的血清脂肪酸。测定每组18只动物肿瘤脂肪酸结合蛋白7（FABP7）、表皮生长因子受体（EGFR）、过氧化物酶体增殖物激活受体γ（PPAR-γ）和视黄醇X受体α（RXR-α）的基因表达。
喂食DHAO增加了脑肿瘤中的二十碳五烯酸（EPA）含量，并降低了n-6/n-3脂肪酸比例。DHAO组血清中EPA水平也有所升高。在DHAO组中观察到血清和肿瘤中DHA水平有类似趋势，但未达到统计学显著性。GLAO增加了血清中GLA浓度，但对肿瘤GLA或二高-γ-亚麻酸（DGLA）浓度无显著影响。DHAO组肿瘤中FABP7基因表达上调，但对EGFR、PPAR-γ或RXR-α表达未观察到其他显著影响，且GLAO组肿瘤中这些基因的表达与红花油组无差异。
饮食补充含DHA的油可能是增加脑肿瘤中长链n-3脂肪酸水平的有效方法，这种增加可能部分由FABP7表达上调介导。
