味觉受体及其对食品功能评价的应用潜力

Odorant and Taste Receptors and Their Potential Applications in Evaluation of Functional Foods

哺乳动物味觉系统传统分类为五味:鲜、甜、咸、酸、苦。这些味觉让我们能够大概了解食物的组成成分。味觉的传感受体经鉴定属于最大的基因家族——G蛋白偶联受体的主要成员T1R和T2R。有研究表明,还有一种和脂肪传感有关的受体,可以介导游离脂肪酸(free fatty acid,FFA)的味道,也属于G蛋白偶联受体(G protein-coupled receptors,GPCR)家族成员。越来越多的研究显示,味觉受体不仅在味觉器官中表达,也广泛表达于其他组织和器官中。但是大多数研究结果都是通过反转录聚合酶链式反应(reverse transcriptionpolymerase chain reaction,RT-PCR)和微阵列方法得到,尚未对其蛋白表达和生理功能进行系统研究。近年来,一些文章报道了关于胃肠道味觉受体的生理功能。这些研究结果进一步证明嗅觉和味觉受体绝不仅仅局限于味觉和嗅觉传感,可能还有其他潜在的重要功能。本文首先整理和总结了嗅觉和味觉受体在嗅觉和味觉器官以外的组织中的表达情况,而后深入探讨其潜在的多种生理功能,从营养传感、吸收控制及对代谢平衡、能量吸收与控制的影响,到代谢紊乱所引起的疾病。最后,预期这些受体及其检测技术的发展方向和应用前景,特别是在食品性味评价和主要功能性成分,如:白藜芦醇、多酚类、黄酮类和其他植物化合物的功能性评价中的应用。

The mammalian gustatory system is classified into five primary tastes： umami, sweet, salty, sour and bitter, which enable us to evaluate food constituents. The tastes have been identif ied as the major members of the G protein-coupled receptor（GPCR） family, the largest family of receptor proteins in mammals（referred to as taste receptor type 1（T1R） and type 2（T2R））. Another taste quality related to lipid sensing is mediated by free fatty acid（FFA） GPCR family. An increasing number of reports on the expression of odorant and taste receptors in tissues beyond the nose and mouth started to appear in the literature. But most literatures have been relied on reverse transcription PCR（RT-PCR） and microarray data without demonstrating either protein expression or function. Recently, some publications are appearing on the function of odorant and taste receptors in the gastrointestinal tract. These studies reinforce the broader potential and even more important roles beyond the odorant and taste receptors. In this review, the prevailing evidence for the expression of odorant and taste GPCRs in cells and tissues beyond the nose and mouth is summarized, and then the putative function for these receptors in diverse physiological functions, ranging from nutrient sensing, regulation of nutrient uptake, metabolic balance, energy control and metabolic disorder is highlighted. Finally, the future trends and potential applications of detection technologies for these GPCRs are expected for the evaluation of functional ingredients such as resveratrol, polyphenols, f lavonoids and other phytochemicals.