【作者】 杨静；

【导师】 李铎；

【作者基本信息】 浙江大学 ， 食品科学， 2014， 博士

【摘要】 动物和细胞实验结果表明,共轭亚麻酸(Conjugated linolenic acid, CLN)具有很多生理功能,如抗癌、减肥、改善脂类代谢、抗炎、提高免疫力、降低血糖等。石榴酸(Punicic acid, PA)是一种omega-5脂肪酸,是共轭亚麻酸的一个重要异构体,结构式为9c,11t,13c-18:3。PA可以在体内部分代谢为9c,11t-共轭亚油酸(9c,11t-conjugated linoleic acid,9c,11t-CLA)。本学位论文主要包括以下3个部分：第一部分共轭亚麻酸(石榴酸)油脂载体的选择——安全性评价本部分对不同成分(C18：1或C18：2n-6)或不同结构(甘油三酯或甘油二酯)的油脂和石榴酸的摄入进行安全性评价,比较选择较佳的石榴酸的油脂载体。研究结果表明,无论是与不同成分的油脂,还是与不同结构的油脂联合摄入,富含石榴酸的石榴籽油的摄入均可以改善肝肾功能,调节或恢复由油脂摄入造成的组织脂肪酸的变化,降低肝脏中总甘油三酯(TG, Totaltriglyceride)和总胆固醇(TC, Totalcholesterol)的含量。综合考虑,橄榄油是石榴酸代谢或功能研究的较佳的油脂载体。第二部分共轭亚麻酸(石榴酸)的抗糖尿病功能和可能的机制研究以富含PA的石榴籽油和富含CLA的共轭亚油酸甘油酯油作为研究材料,研究膳食摄入PA和CLA对糖尿病大鼠的影响。结果表明,PA和CLA (120mL/只/d)显著的降低DM大鼠的空腹血糖(p<0.01),且PA摄入可以显著降低胰岛素抵抗(HOMA-IR)(p<0.01)和显著提高胰岛素敏感性(HOMA-ISI)(p<0.01),而CLA则没有此效果。DM大鼠肝脏总饱和脂肪酸(Total saturated fatty acids, Total SFA)显著高于正常对照大鼠(p<0.01),且Total n-3PUFA显著低于正常对照大鼠(p<0.01)。膳食补充CLA和PA均可以显著提高或恢复肝脏DHA和Total n-3PUFA的组成(p<0.01),且PA组优于CLA组,且PA摄入可显著降低并恢复Total SFA的组成(p<0.05)。与糖尿病模型组相比,富含PA的石榴籽油可以显著抑制NF-kB、PI3k、和Gsk-3β mRNA的表达(p<0.01),表达量分别是模型对照组的0.5倍、0.26倍和0.37倍；PA可以显著上调AKT1、Adipoq、PPARa和PPARy mRNA的表达(p<0.01),表达量分别是DM模型对照组的2.01倍、7.16倍、1.65倍和2.98倍,且PA摄入可以显著升高GLUT4mRNA的表达(p<0.05),表达量为DM模型对照组的2.69倍。而CLA仅可以上调PPARy基因的表达(1.77倍)。第三部分共轭亚麻酸(PA和α-ESA)对人恶性皮肤癌A375细胞增殖和脂肪酸组成的影响选用PA和α-ESA的纯品单体,0、5、10、20、40和80μM的剂量处理A375细胞24h,研究PA和a-ESA对A375细胞的毒害作用以及对脂肪酸的影响。研究结果表明,PA和a-ESA都可以抑制A375细胞的增殖,降低存活率,且PA比a-ESA的作用更强(在剂量为10μM存活率分别为41.5%(PA)和60.1%(a-ESA))。PA和a-ESA都可以抑制A375细胞增殖,且PA优于a-ESA。PA和a-ESA对人恶性皮肤癌A375的影响是不同的,PA可以在细胞内可以代谢为9c,11t-CLA,显著降低细胞膜中MUFA的组成,提高n-6PUFA、DHA和n-3PUFA的组成,提高n-3/n-6的比例,从而引起细胞的凋亡。而a-ESA对细胞膜脂肪酸组成的影响较小,它的凋亡作用可能主要是通过在细胞内代谢转化为9c,11t-CLA.第四部分地理环境和生态条件对栝楼籽中的石榴酸含量的影响四个不同地区(浙江长兴,亚热带季风气候区；河北安国,半干旱大陆性季风气候区；山西晋城,暖温带半湿润大陆性季风气候区；山东滨州,温带大陆性季风气候区)的栝楼籽油中的脂肪酸成分存在显著性差异。温带的,大陆性季风气候区,纬度越高,年平均温度越低,年降雨量越低的地区的栝楼籽中石榴酸和PUFA的含量越高。更多还原

【Abstract】 Animal and cell culture studies found that conjugated linolenic acids (CLN) have many physiological functions, such as anticancer, anti-obesity, improve lipid metabolism, anti-inflammatory, enhance immunity, and reduce fasting blood glucose level etc. Punicic acid (9c,11t,13c-18:3) is an important CLN isomers belonging to an omega-5fatty acids family, and PA can be partly converted into9c,11t-conjugated linoleic acid (9c,11t-CLA) in vivo. This thesis mainly includes the following4parts:Part I Oil vehicle selection for Conjugated linolenic acid (PA) Effects of oil vehicle with different fatty acid composition (C18:1and C18:2n-6) or different form (triglyceride-form and diglyceride-form) on the metabolism and function study of PA were studied in this part.The result showed that, olive oil is a better suitable oil vehicle or placebo for metabolism and functions study of PA after taking liver and renal functions, serum and liver lipids composition, fatty acids composition of liver, kidney, brain and heart, and the related protein expression into consideration.Part II Anti-diabete effect and possible mechanisms of PA and CLA Dietary PSO rich in PA can decrease the fasting glucose (p<0.01) and HOMA-IR (p<0.01), and increase the HOMA-ISI in DM rats (p<0.01), while CLA intake can only decrease the fasting glucose (p<0.05). Dietary PSO rich in PA can significantly restore the SFA composition. Both PA and CLA intake can significantly increase DHA and Total n-3PUFA composition, and PA is more effective than CLA (p<0.01).Compared with diabetic model group, pomegranate seed oil rich in PA can significantly inhibit the mRNA expression of NF-kB, PI3k and Gsk-3β(p<0.01), and the expression was0.5-fold,0.26-fold, and0.37-fold by diabete control group, respectively and PA can significantly downregulated IRSR mRNA of (p<0.05). PA can significantly upregulate the mRNA expression of Adipoq, PPARa and PPARy (p<0.01), and the expression level was2.01-fold,7.16-fold,1.65-fold and2.98-fold by diabete control group, respectively; PA also can significantly increase the GLUT4mRNA expression by1.77-fold than diabetes control group. Meanwhile, CLA intakes can only upregulate the PPARy expression in liver. In conclusion, dietary PSO rich in PA is more effectively in anti-diabetes than CLA, and the possible antidiabetic mechanism of PA may be partly induced by PA itself as a PPARa and PPARy and inhibit the expression the GSK-3, NF-kB and Adipoq mRNA, and activation of PI3k/p-AKT pathway, while CLA may be due to upregulate the PPARy mRNA expression.Part III Anti-cancer effect of PA and α-ESA Mono-PA and mono-a-ESA with97%+purity were used in this part. The result showed that, both PA and a-ESA can induce apoptosis in A375cells, and PA is more effective than a-ESA at a dose of10μM, the cell viability of PAis41.5%while a-ESA is60.1%.PA can significantly decrease the MUFA, and increase DHA, n-6PUFA, n-3PUFA, and n-3/n-6ratio of A375cells membrane, but not for a-ESA. Both PA and a-ESA can be converted to9c,11t-CLA in cells, the apoptic effect of PA may partly attribute to CLA, and PA itself, while the apoptic effect of a-ESA only attribute to CLA.Part Ⅳ The geographical and ecological environment may affect PA content in Trichosanthes kirilowii seeds Changxing belongs to a subtropical monsoon climate zone; Anguo, belongs to semi-arid continental monsoon climate zone; Jincheng, belongs to warm temperate semi-humid continental monsoon climate zone, and Binzhou belongs to temperate continental monsoon climate zone.Significant differences were found in the fatty acid composition of Trichosanthes kirilowii seeds from the four climate zones. In the temperate, continental monsoon climate zone, the higher the latitude, the lower the annual average temperature, the lessr annual rainfall, and the higher content of PA and PUFA in Trichosanthes kirilowii seeds.更多还原