共轭亚油酸调节反刍动物脂肪代谢的研究进展

Research Progress on the Regulation of Conjugated Linoleic Acid on Ruminant Lipid Metabolism

摘要:

共轭亚油酸(Conjugated Linoleic Acids,CLA)是含有共轭双键的一类脂肪酸，由反刍动物瘤胃内微生物催化必需脂肪酸产生，主要储存于反刍动物的乳腺、脂肪及肉组织中。共轭亚油酸成员中cis9 trans11 CLA和trans10 cis 12 CLA的含量占比最高，其中，cis9 trans11 CLA具有抗炎、抗癌症作用，而trans10 cis 12 CLA具有抗肥胖作用。共轭亚油酸被认为是健康食品，FDA建议人类每天摄入3.4～6.0 g共轭亚油酸。反刍动物的肉类及奶类制品含有较高含量的共轭亚油酸。当机体摄入共轭亚油酸后，由于trans10 cis 12 CLA具有更高的生物活性，共轭亚油酸主要发挥抑制脂肪沉积的作用。有研究表明，共轭亚油酸补充能够降低奶牛的乳脂率，提高个体能量平衡，避免出现健康问题。因此共轭亚油酸补充已成为哺乳期奶牛饲养的常用策略。近年来，关于trans10 cis 12 CLA抑制脂肪沉积的研究层出不穷，但其调控脂代谢机制仍不清楚。本文综述近些年研究成果，并提供可能参与trans10 cis 12 CLA调节的候选基因，为深入探究trans10 cis 12 CLA作用机制及扩展其应用领域提供理论基础。

Abstract:

Conjugated linoleic acids（CLA）, a group of fatty acids with conjugated double bonds, are produced by rumen microbes and stored in mammary gland, adipose, and muscle tissues in ruminants. Among CLA isomers,cis9 trans11 CLA and trans10 cis 12 CLA account for the highest proportions: cis-9, trans-11 CLA exhibits antiinflammatory and anti-cancer activities, while trans-10, cis-12 CLA plays a role in fat reduction. CLA has been recognized as a functional food component, and the U.S. Food and Drug Administration（FDA） recommends a daily intake of 3.4-6.0 g CLA for humans. Ruminant meat and dairy products contain higher CLA concentrations than other food sources. CLA exerts a primary effect on reducing fat deposition, as trans-10, cis-12 CLA exhibits higher bioactivity in regulating lipid metabolism than cis-9, trans-11 CLA. Previous studies have demonstrated that CLA supplementation reduces milk fat content, improves energy balance, and decreases disease incidence in lactating cows. Consequently, CLA supplementation has been applied as a feeding strategy for lactating cows. Although numerous studies on CLA-mediated fat deposition reduction have been published in recent years, the regulatory mechanism underlying CLA-mediated lipid metabolism remains unclear. This study reviews relevant research findings, identifies candidate genes affected by CLA, and provides references for exploring the regulatory mechanisms of CLA and expanding its application fields.