Research Progress of γ-Aminobutyric Acid (GABA)
-
摘要: γ-氨基丁酸(GABA)是一种广泛分布于动、植物和微生物体内的非蛋白氨基酸,于2009年被我国卫健委批准为“新资源食品”,在食品、医药、饲料等领域具有十分广阔的应用前景,近年来有关GABA的研究也逐渐成为热点。本文阐述了GABA的生物合成与代谢途径,归纳了GABA的化学合成、植物富集方法及目前常用的GABA检测技术,并对比分析其优缺点。此外,本文对GABA的主要生理功能及其作用机制进行总结,并对GABA的未来研究和发展趋势进行展望,以期为今后GABA的研究与应用提供参考。Abstract: γ-aminobutyric acid (GABA) is a non-protein amino acid discovered in animals, plants, and microorganisms that was approved as the "new resource food" by the National Health Commission of the People's Republic of China (NHC) in 2009. It has a wide range of applications in food, medicine, feed, and other industries, and the research has grown increasingly popular in recent years. The paper reviews the bio-synthesis and metabolic processes of GABA, summarizes the methods of chemical synthesis, plant enrichment, and present GABA detection techniques, and discusses their advantages and limitations. Furthermore, the main physiological functions and mechanism of GABA are summarized, and GABA’s research and development trend is also presented, in order to provide reference for future research and application of GABA.
-
Keywords:
- γ-aminobutyric acid /
- metabolic pathways /
- enrichment /
- detection method /
- bioactivity
-
γ-氨基丁酸(GABA)又称4-氨基丁酸,氨基取代基位于C-4位置,分子式为NH2(CH2)3COOH,结构式如图1,其相对分子量为103.12,熔点202 ℃,白色至浅黄色结晶物质,易溶于水,不溶于或难溶于有机溶剂[1]。
GABA广泛分布于动、植物和微生物体内,在植物体内可参与调节植物的代谢,同时作为一种应激反应信号,与其他途径相互作用共同调节植物的抗逆能力[2]。1950年,研究发现哺乳动物的中枢神经系统中存在GABA,随后的研究表明,GABA是中枢神经系统的主要抑制性神经递质,也是具有不同功能的多功能分子[3],具有降血压、降血糖、抗肿瘤、抗抑郁、镇静止痛、提高脑活力及改善脂质代谢等多种生理功能,目前已应用于食品、保健品和饲料等领域,研发出GABA胶囊、GABA茶、GABA软糖等一系列产品。
研究人员在GABA的合成制备、提取纯化、功能作用等方面开展了大量的研究,但有关GABA的研究起步较晚,同时由于其在生物体内作用的复杂性,目前仍有大量争议。因此,本文从生物合成与代谢途径、化学合成与富集方法、检测方法以及生物活性等方面对GABA进行全面的综述,以期为GABA的研究与应用提供理论参考。
1. γ-氨基丁酸的生物合成与代谢途径
1.1 GABA支路
GABA支路(GABA Shunt)是动植物体内GABA合成与代谢的主要途径,也是目前已知唯一能降低胞质GABA水平的途径[4],主要涉及三种酶,谷氨酸脱羧酶(GAD)、γ-氨基丁酸转氨酶(GABA-T)和琥珀酸半醛脱氢酶(SSADH)(图2)。谷氨酸脱羧酶是催化谷氨酸(Glu)脱羧合成GABA反应中的限速酶,受Ca2+/钙调蛋白调节[5],当植物处于胁迫环境(冷、热、干旱等)时,H+或Ca2+的累积上调钙调蛋白水平,进而激活谷氨酸脱羧酶并催化谷氨酸转化为GABA[6]。GABA的分解代谢是在线粒体内经GABA-T和SSADH催化转化生成琥珀酸进入三羧酸(TCA)循环,最终由α-酮戊二酸转化为谷氨酸从而维持线粒体内GABA/Glu平衡[7]。GABA积累过多时会诱导氧化还原电位增加,抑制SSADH活性,导致GABA在谷氨酸脱氢酶的作用下转化为γ-羟基丁酸[4]。
图 2 GABA在生物体内的代谢途径注:Glu:谷氨酸;GAD:谷氨酸脱羧酶;GABA:γ-氨基丁酸;GABA-T:γ-氨基丁酸转氨酶;SSA:琥珀酸;SSADH:琥珀酸脱氢酶;Succ:琥珀酸;GHB:γ-羟基丁酸;Acetyl-CoA:乙酰辅酶A;Citrate:柠檬酸;αKG:α-酮戊二酸;GDH:谷氨酸脱氢酶;Succ-CoA:琥珀酰辅酶A;P5C: Δ1-吡咯啉-5-羧酸;P5CR:Δ1-吡咯啉-5-羧酸还原酶;P5CDH:Δ1-吡咯啉-5-羧酸脱氢酶;Pro:脯氨酸;ProDH:脯氨酸脱氢酶;Asp:天冬氨酸;Arg:精氨酸;Orn:鸟氨酸;OAT:鸟氨酸转氨酶;ODC:鸟氨酸脱羧酶;ADC:精氨酸脱羧酶;Put:腐胺;DAO:二胺氧化酶;SPDS:亚精胺合酶;PAO:多胺氧化酶;Spd:亚精胺;Spm:精胺;SPMS:精胺合酶;ABAL:4-氨基丁醛;AMADH:氨基醛脱氢酶。Figure 2. Metabolic pathway of GABA in organismsGABA支路的生物学功能因不同生物体而异,同时参与各种生理过程,包括调节胞质pH、维持TCA循环、介导C:N平衡等,还参与植物体内的激素代谢、多胺代谢途径[6,8]。Studart-Guimarães等[9]的研究表明,抑制番茄植株琥珀酰CoA活性对其生长影响不大,因为细胞可以通过增强GABA支路的活性,弥补TCA循环中因无法合成琥珀酸造成的损失,维持细胞呼吸作用的正常功能。Michaeli等[5]对拟南芥线粒体GABA转运蛋白突变植株的研究也证实了这一点。另外,该突变植株体内部分氨基酸水平上调,海藻糖和蔗糖含量明显降低,且在碳源限制性培养条件下生长异常,表明GABA支路在介导碳氮代谢方面具有十分重要的作用,可以作为植物中的氮储存代谢物。GABA支路与生物体内的各种生理功能也有密切联系,如在糖酵解途径受损时为TCA循环提供羧酸和能量来源[9];阿尔茨海默症发病早期阶段GABA支路被激活等[10]。
1.2 多胺降解途径
多胺降解途径是另一条GABA合成途径(图2),在该途径中,GABA主要通过4-氨基丁醛中间体自发环化形成1-吡咯啉,随后在吡咯啉脱氢酶的作用下转化生成。二胺氧化酶(DAO)是代谢途径中的关键酶,与铜胺氧化酶和单胺氧化酶等酶共同参与催化腐胺降解为4-氨基丁醛[6]。植物中腐胺生物合成的主要途径是由精氨酸脱羧酶催化精氨酸生成胍丁胺再转化为腐胺,鸟氨酸或亚精胺也可以作为腐胺合成的前体物质。4-氨基丁醛也可以通过亚精胺转化生成,反应由多胺氧化酶催化,该酶同样可以催化亚精胺转化为腐胺和精胺[6,11]。
在正常或胁迫条件下,植物体内多胺降解途径对GABA富集的贡献率并不高,在氨基胍(AG,DAO酶抑制剂)真空渗透条件下,龙眼和蚕豆GABA合成的贡献率分别约20%~25%和30%[7,12]。而在动物体部分组织内,GABA的主要合成途径并不是GABA支路,如肾上腺。采用氨基胍抑制腐胺降解,24 h后GABA浓度几乎降至零,表明大鼠肾上腺中的GABA几乎完全来自于多胺降解途径[13]。Sequerra等[14]同样报道了大鼠脑室下区(SVZ)GABA的合成依赖于腐胺的降解且没有明显检测到GAD的免疫标记。
2. γ-氨基丁酸的制备方法
2.1 化学合成
化学合成法是早期比较经典的制备GABA的一种方法,主要方法有两种,一种是以γ-丁内酯为起始原料,与氯化亚砜反应,先后经开环、氯代反应后得到4-氯丁酰氯,其酯化后可生成4-氯丁酸甲酯,在催化剂的作用下能够与氨水发生胺化、水解反应后生成GABA[15]。
另有报道以2-吡咯烷酮为起始原料制备GABA(图3),采用NaOH或Ca(OH)2作为开环试剂水解2-吡咯烷酮生成γ-氨基丁酸钠,再加入碳酸氢铵沉降钙离子制备而成[16],或是利用弱酸型阳离子交换树脂柱酸化处理γ-氨基丁酸钠生成γ-氨基丁酸水溶液[17]。该法生产所用吡咯烷酮、NaOH等为腐蚀性物质,会影响人体健康,特别是吡咯烷酮,在高温条件下具有燃爆性,且会产生有毒的氧化氮烟气。这些化学合成制备的GABA与自然产生的相比,成本高昂,且在生产过程中通常用到危险溶剂,并伴随有毒副产物的生成,因此其产品主要应用于生化研究,而不能应用于食品领域[18]。近十年来有关化学合成GABA的研究报道逐渐减少,安全性更高的生物转化法成为研究热点。
2.2 微生物发酵法
化学合成法安全性较低,而植物提取法产量不高,相较而言,微生物发酵法生产成本低廉,工艺简单,并且产量可观,可满足食品和制药等行业具有高附加值应用的复杂需求。发酵法生产GABA是利用微生物体内含有的谷氨酸脱羧酶,将谷氨酸脱羧转化为GABA。目前用于发酵生产GABA的菌种主要有细菌、真菌和酵母菌,包括短乳杆菌、蜡样芽孢杆菌、红曲霉、酵母菌、大肠杆菌等,菌种来源多从发酵食品中分离得到,不同菌种发酵GABA产量如表1。
表 1 不同菌种发酵产GABA含量Table 1. Content of GABA produced by fermentation of different strains发酵菌种 菌种来源 营养来源 GABA产量(g/L) 参考文献 Lactobacillus Paracasei NFRI 7415 发酵鱼 MRS肉汤 21.66 [22] Lactobacillus rhamnosus YS9 腌菜 MRS肉汤 19.28 [23] Lactobacillus brevis BJ20 发酵鳕鱼肠 MRS肉汤 0.47 [24] Lactobacillus plantarum LMG6907 酸菜 豆浆 0.86 [25] Bacillus cereus KBC 酱油 MRS肉汤 3.39 [26] Lactobacillus brevis CRL 2013 发酵面团 MRS-GF 27.33 [18] Lactobacillus plantarum FNCC 260 发酵木薯 MRS肉汤 1.23 [27] Lactobacillus brevis L2
Brettanomycescustersii ZSM-001− 发芽糙米 33.25 [20] Enterococcus faecium AB157
Lactobacillus plantarum BC112泡菜 MRS肉汤 6.35 [19] Aspergillus oryzae NSK 酱油 优化培养基 3.28 [28] Lactobacillus brevis JCM 1059T − 枣渣制备液 2.89 [29] 许多文献报道了采用单一菌种发酵产GABA,但根据张恕铭等[19]的研究,屎肠球菌AB157与植物乳杆菌BC112两种菌株共培养较屎肠球菌AB157单菌株发酵产生的GABA提高3.9倍。诱变选育高产GABA菌株也可以进一步提高GABA产量,粪肠乳酸球菌经7轮室温常压等离子体(ARTP)诱变与2轮微生物微液滴培养系统(MMC)适应性进化后所产生的突变株EM05的GABA产量最高可达64.233 g/L[20]。经UV和60Co-γ射线反复诱变处理得到的短乳杆菌hjxj-08119 GABA产量也可达到76.36 g/L[21]。除此之外,还有大量学者针对培养基组成、pH、发酵时间等培养条件进行优化以提高GABA产量,可见微生物发酵产GABA具有进一步深入挖掘的潜力和十分良好的发展前景。
2.3 植物富集法
随着人们对饮食健康的重视,天然食品逐渐受到消费者的青睐。GABA广泛分布于高等植物体内,这种自然来源的GABA仅需水提即可,可以减少危险试剂残留的风险[27],同时具有操作简单、成本低廉等优点,且其安全性较高,可广泛适用于食品、医药等领域。但GABA在植物体内的含量较低,目前已报道的新鲜红枣中GABA含量为5.12~14.02 mg/100 g FW[30],糙米为13.89 mg/100 g DW[31],桑叶和荔枝中的GABA含量相对较高,分别为60 mg/100 g FW[59] 和60~130 mg/100 g FW[32−34],但其含量也远低于微生物发酵所产生的GABA。
大量文献报道了利用各种环境压力使植物产生应激反应以提高GABA含量的方法。周沫霖[12]报道了低温驯化结合冰温贮藏可以激活龙眼果肉GABA支路代谢,进而引起GABA积累,含量由7.49 mmol/kg FW上升至17.35 mmol/kg FW。超声辅助盐胁迫处理新鲜荸荠也能使其GABA含量提高5.04倍[35]。采后水果需要消耗大量营养物质维持正常的生理代谢,采用胁迫手段内源代谢富集GABA往往仅能提高2~5倍,而种子中含有丰富的蛋白质,发芽过程中内源性蛋白酶被激活,可将蛋白质水解成氨基酸,是GABA积累的良好来源。采用水分胁迫处理即可使小麦种子的GABA含量提高12倍,先后经水分胁迫、厌氧和热处理发芽后的小麦GABA含量可提高40倍[36]。另一项研究采用低氧联合酸胁迫发芽工艺优化富集大麦芽GABA也使其含量提高了33.6倍[37],可见,不同植物体GABA的富集效果具有极大的差异。
3. γ-氨基丁酸的检测方法
由于GABA的结构特点,其在紫外光区、可见光区以及荧光区均没有显著吸收[38],难以直接进行测定,目前报道的GABA测定方法有比色法、氨基酸分析仪法、薄层色谱法、(超)高效液相色谱法、(超)高效液相色谱法串联质谱法等。由于薄层层析仅用于定性测定,氨基酸分析仪适用范围较窄,对糖组分和脂肪含量较高的样品不适用,因此,目前多采用比色法、(超)高效液相色谱法和(超)高效液相色谱串联质谱法。
3.1 比色法
Berthelot比色法是一种简单、快速且成本较低的GABA测定方法,利用苯酚和次氯酸钠与GABA的游离氨发生显色反应来检测GABA的含量。利用ω-氨基酸响应灵敏而α-氨基酸响应值较低的差别来减少部分常规氨基酸对反应体系的干扰[39],但样液中其他游离氨、色素以及显色液稳定性等不良因素对测定结果的影响也限制了其应用范围[40],万蓝婷等[40]针对该问题建立一个优化体系,在显色之前先后采用甲醇和氯化铝除去叶绿素和水溶性色素,并对显色剂比例、显色时间和温度进行优化以进一步提高Berthelot法测定植物叶片GABA含量的精准度和灵敏度。此外,Jinnarak等[41]报道了一种基于银纳米粒子的比色方法,利用GABA在酸性环境下带正电荷,由于静电相互作用导致柠檬酸盐溶液中银纳米粒子的聚集,溶液在390 nm处的表面等离子体共振偏移且颜色发生变化。该法灵敏度较高,检测限为57.7 mg/L,但由于制备的粒子粒径差异大,且生产成本较高而限制其应用。
3.2 高效液相色谱法
高效液相色谱法是目前测定GABA含量最常用的方法,相较于比色法,具有较高的精密度和广泛的适用性,可用于测定植物组织、发酵液等多种样品,但对血浆、脑脊液等微量GABA样品无法灵敏检测,同时该法操作较为繁琐,需结合各种衍生化技术,包括柱前/柱后衍生和在线衍生[42](表2),目前报道的衍生化试剂主要有邻苯二醛(OPA)、2,4-二硝基氯苯(FDCB)、2,4-二硝基氟苯(FDNB)、异硫氰酸苯酯(PITC)以及丹酰氯(Dansyl-Cl)等。其中OPA反应灵敏迅速、衍生时间短,且试剂本身不发荧光,可避免试剂干扰,因此成为目前应用最广泛的衍生化方法,采用OPA法测定GABA也可以有效分离Glu和GABA,避免Glu对检测结果的干扰[45],但其衍生产物半衰期较短,通常需要在3 min内上样[43]。Dansyl-Cl和FMOC容易生成多级衍生产物干扰检测结果,AQC衍生试剂昂贵,而PITC毒性较大,容易对柱子的寿命产生影响[44]。王能凤[42]对Dansyl-CI、FDCB、FDNB和PITC等4种柱前衍生化法进行对比分析,发现其对红枣GABA的测定结果之间无显著性差异(P>0.05)。HPLC柱后衍生-荧光检测法也有报道,该法在高效液相色谱与荧光检测器间加装柱后衍生装置,同样采用OPA作为衍生剂,GABA保留时间为3.8 min,且能实现程序化在线柱后衍生[46],减少柱前预处理时间和因OPA衍生化法衍生物稳定性差带来的误差。
表 2 HPLC衍生化法测定样品中GABATable 2. Determination of GABA in samples by HPLC derivatization测定样品 衍生方法 衍生时间(min) 色谱柱 保留时间(min) 线性范围
(mg/L)检出限
(μg/mL)文献 保健食品 OPA柱后衍生 − Agela C18 3.80 3×10−5~1.4×10−4 0.01 [46] 发芽糙米 OPA柱后衍生 − Hypercarb column 7.80 0.2~50 − [47] 红枣 Dansyl-Cl柱前衍生 30 ZORBAX SB C18 9.11 1.4~55 1.36 [42] 红枣 OPA柱前衍生 2 Inertsil ODS-3 C18 11.57 0.1~657 169.62 [45] 茶叶 DNFB柱前衍生 10 Hypersil ODS C18 43.99 0.03~0.21 − [48] 发芽糙米 DABS-Cl柱前衍生 20 Agilent C18 4.64 20~100 5×10−3 [49] 三七 PITC柱前衍生 120 Hypersil GOLD C18 8.80 10~1030 0.10 [50] 乳酸菌发酵液 OPA柱前衍生 5 XBridgeR C18 11.20 50~500 0.02 [51] 黑莓果汁/啤酒 AQC柱前衍生 30 Waters AccQ Tag 22.59 1~1000 700 [52] 3.3 液相色谱-串联质谱法
液相色谱-串联质谱法兼具液相色谱(LC)的高分离能力和质谱(MS)的高选择性和灵敏度等优点[53]。相较于HPLC法和比色法,液相色谱-串联质谱法测定GABA含量无需复杂的柱前衍生化操作,且能显著缩短分析时间和提高检测灵敏度,适用于动物组织、血浆以及脑脊液等基质中微量GABA的定量检测。Dai等[53]采用高效液相色谱串联质谱法(HPLC-MS/MS)快速检测脑组织中神经递质,GABA在1 min左右即可出峰,检出限为1.47 ng/mL。反相超高效液相色谱串联质谱法(UHPLC-MS/MS)的应用也有报道,该法测定的脑组织和细胞外液的GABA分别在8~4000 nmol/L和10~1000 nmol/L范围内线性关系良好,且仅需150 μg的脑组织即可上样,远低于其他方法的上样量[54]。液相色谱串联质谱法同样适用于植物组织,采用UPLC-MS/MS对南瓜GABA进行定性定量分析,4 min内即可完成[55],且分离效果良好,操作简单方便,结果准确可靠,但由于其成本较高,目前对于植物样本普遍采用高效液相色谱法。
4. γ-氨基丁酸主要生理功能
4.1 促睡眠作用
睡眠行为由基底前脑、丘脑和脑干中的不同神经元核团调控,而GABA作为一种抑制性神经递质,在调控中枢神经系统神经元兴奋和抑制的平衡中起着关键作用,其三种受体(GABAA、GABAB和GABAC)上的变构位点可以高精度地调节大脑相关区域中神经元的抑制水平,这些位点同时也是催眠药物的分子靶点[56−58]。研究表明,外源摄入的GABA可以进入血液,人体口服GABA 30 min后血液中的GABA即达到最高水平,但有关GABA能否穿透血脑屏障仍是一个具有争议的问题,目前没有直接证据表明GABA可在人体中穿透血脑屏障并对大脑产生作用[59−60]。但GABA可通过肠-脑轴中迷走神经途径对中枢神经系统中的GABA含量水平及受体表达产生影响,小鼠口服GABA后,其GABA能神经递质的mRNA和蛋白质表达水平明显上调,特别是肠道和大脑,GABAA水平分别提高7倍和5倍[61]。除此之外,GABA还能通过神经内分泌途径、免疫途径等肠-脑轴双向交流途径改善睡眠[62]。有关外源摄入GABA发挥促睡眠作用的研究也多有报道,口服短乳杆菌发酵产生的γ-氨基丁酸(100 mg/kg)能使小鼠入睡时间缩短32.2%,睡眠时长延长59%;在咖啡因诱导的失眠条件下,可以增加大鼠非快速眼动睡眠时间(NREM)[61]。此外,口服GABA也可以影响人体睡眠的早期阶段,显著缩短睡眠潜伏期,增加非快速眼动睡眠时间[59]。
4.2 抗焦虑、抗抑郁
病理生理学认为与焦虑症和抑郁症的产生与GABA中枢神经系统的功能紊乱有显著关联,抑郁症患者的血浆、脑脊液以及枕叶皮层中GABA浓度低于正常人群,而经电惊厥疗法(ECT)治疗后,相关部位GABA浓度有所增加也证实了这一点[63−64,67]。参与调控焦虑的神经回路主要是由GABA能中间神经元组成的抑制性网络,神经元的抑制水平受到GABAA受体上的异生作用位点的调控,这些特异性结合位点也是通常作为抗惊厥、抗焦虑和抗抑郁药物的分子靶点[65−66]。而GABA能通过与GABAA受体结合而打开特定氯离子通道以及导致神经元的超极化和分路抑制,使神经元处于保护性抑制状态,阻止与焦虑相关的信号抵达大脑指示中枢[65]。此外,GABA对焦虑/抑郁的调控也涉及神经内分泌系统,口服低剂量(0.75 mg/g/d)或高剂量(1.5 mg/g/d)酪蛋白水解物和GABA复合物可上调小鼠下丘脑-垂体-肾上腺(HPA)轴的激素分泌,缓解海马体CA3区域的组织病变,显著改善小鼠焦虑/抑郁行为[66]。尽管目前的研究显示GABA具有很好的改善焦虑和抑郁症状的效果,仅食用富含GABA的淡豆豉即可使小鼠快感缺失、行为绝望等抑郁症状得到改善[68],但关于其在体内复杂的作用机制、药代动力学、最佳给药方案和临床效果等相关研究仍有待深入探讨。
4.3 降血糖
GABA在其他外周组织中也有分布,如肾上腺髓质、胰腺和子宫等[69]。胰腺β细胞所产生的GABA是胰腺激素释放的功能性调节剂[70],可引起胰腺α细胞超极化和β细胞的去极化,从而抑制胰高血糖素和促进胰岛素的分泌来调节血糖[69]。同时,GABA受体的激活可以抑制免疫激活和巨噬细胞炎症细胞因子的分泌,调节葡萄糖稳态、减少糖尿病并发症的发生[71]。此外,胰腺等外周器官对葡萄糖的调节活动受到中枢神经系统的协调,通过自主神经系统调控包括GABA在内的神经递质和神经肽的释放来控制激素分泌、糖原合成和代谢[72]。GABA给药(1.5 g/kg/d)可通过影响Ⅱ型糖尿病大鼠及其后代的胰岛素信号传导和糖异生途径来降低胰岛素抵抗(IR)[70]。除此之外,负载了GABA的壳聚糖纳米颗粒也可通过保护胰腺β细胞改善链脲佐菌素诱导的糖尿病小鼠的血糖指数[73]。临床数据同样显示口服GABA可改善健康受试者的胰岛素和C肽水平,静脉注射GABA也可以降低糖尿病患者的血糖,但不能降低正常受试者的血糖[69],同时,由于GABA可在机体内代谢分解,具有较高的安全性,在目前许多降糖药物易引发低血糖、过敏反应或其他不良反应的情况下,GABA作为新型降糖药在预防和治疗糖尿病方面具有极大的潜力。
4.4 降血压
中枢神经系统在调节心血管稳态中发挥重要作用,主要涉及下丘脑室旁核(PVN)、延髓头端腹外侧区(RVLM)、延髓孤束核(NTS)和延髓尾端腹外侧区(CVLM)等[74]。延髓孤束核(NTS)是压力感受器传入纤维的一个终止位点,压力感受器介导的孤束核神经元的激活可进一步激活延髓头端腹外侧区的GABA能神经元释放大量GABA,最终导致交感神经传出减少,血压降低[75]。在下丘脑室旁核和延髓头端腹外侧区中注射GABA受体拮抗剂可引发不同程度的交感神经兴奋的研究结果也证实了这一点[76]。大量研究表明GABA具有良好的降血压效果,对大鼠十二指肠内给予GABA(0.3~300 mg/kg)在30~50 min内能够引起剂量依赖性的血压降低[77];轻度高血压成年患者补充适量GABA也可降低血压,且没有出现身体不适的状况[78]。食用高GABA含量的食物同样可以达到降压效果,自发性高血压大鼠口服富含GABA的酸奶(0.1 mg GABA/kg)8 h后收缩压降低65.22 mmHg[79],这种通过日常饮食摄入富含GABA的食物来调节血压的方法或可为预防高血压提供新途径。
4.5 其他生理功能
GABA对提高脑部活力也有具有明显作用,如改善记忆和认知功能,海马体神经元突触间隙释放的GABA通过激活GABA受体并介导强直抑制性传导来调节记忆和神经兴奋性疾病[80];刺激GABA能神经元也可以改善阿尔茨海默症小鼠大脑局部场电位节律和记忆的形成[81];此外,口服GABA能够上调小鼠海马体中与记忆功能相关的基因的表达从而对大脑功能产生影响[82]。GABA与可卡因成瘾行为也有密切关联,当特异性减少对中脑腹侧被盖区(VTA)GABA能神经元的强直性抑制可以减弱成瘾行为效应[83]。GABA还具有利尿排钠、调节血清中的脂质水平、改善肝肾等多种功能,以及作为潜在的癫痫治疗药物。值得一提的是,最近的研究结果突破了一直以来认为的GABA作为神经递质发挥作用的思维,GABA通过介导β-catenin的激活来刺激肿瘤细胞的增殖,并抑制CD8 T细胞的瘤内浸润,这或可在药理学上靶向逆转肿瘤免疫抑制,成为癌症治疗的新靶点[84−85]。
5. 结论与展望
γ-氨基丁酸作为动植物体内普遍存在的氨基酸,来源广泛,转化合成制备工艺简单,其物质本身稳定性高、水溶性极强且具有良好的复配性,同时由其具有特殊的生理活性,在改善睡眠、缓解焦虑和抑郁、降低血压血糖等方面具有良好功效。然而,由于GABA在生物体内作用的特殊性,目前尚有许多作用机理亟待深入探讨,结合目前国内外的研究成果,同时为进一步提高GABA的利用度,建议从以下方面着手:a.优化GABA合成方法。考虑到植物富集效果不强,传统发酵法创新性不足,应进一步优化植物胁迫富集方法,利用各种诱导手段筛选高产GABA菌种并扩大生产,降低生产成本、简化生产工艺。b.建立简单精准的GABA检测方法。现有GABA检测方法操作繁琐,部分方法检测精确度不高,可通过改进设备实现自动化检测以简化检测流程,同时探寻新兴检测技术,如利用纳米材料与氨基酸的相互作用来实现检测。c.进一步深入挖掘GABA生物活性。GABA在生物体内代谢错综复杂,有关GABA及其受体作用的机制也尚未明了,其生物活性和药理作用有待进一步挖掘。d.加强GABA新型产品和药物的开发。目前富含GABA的粮食制品和乳制品等已流通于市场,有关功能性调味品和茶饮、抗抑郁药物的研发也有报道,有针对性地开发适合不同人群的功能性产品是未来GABA资源开发的方向,也是未来研究的关键问题。
-
图 2 GABA在生物体内的代谢途径
注:Glu:谷氨酸;GAD:谷氨酸脱羧酶;GABA:γ-氨基丁酸;GABA-T:γ-氨基丁酸转氨酶;SSA:琥珀酸;SSADH:琥珀酸脱氢酶;Succ:琥珀酸;GHB:γ-羟基丁酸;Acetyl-CoA:乙酰辅酶A;Citrate:柠檬酸;αKG:α-酮戊二酸;GDH:谷氨酸脱氢酶;Succ-CoA:琥珀酰辅酶A;P5C: Δ1-吡咯啉-5-羧酸;P5CR:Δ1-吡咯啉-5-羧酸还原酶;P5CDH:Δ1-吡咯啉-5-羧酸脱氢酶;Pro:脯氨酸;ProDH:脯氨酸脱氢酶;Asp:天冬氨酸;Arg:精氨酸;Orn:鸟氨酸;OAT:鸟氨酸转氨酶;ODC:鸟氨酸脱羧酶;ADC:精氨酸脱羧酶;Put:腐胺;DAO:二胺氧化酶;SPDS:亚精胺合酶;PAO:多胺氧化酶;Spd:亚精胺;Spm:精胺;SPMS:精胺合酶;ABAL:4-氨基丁醛;AMADH:氨基醛脱氢酶。
Figure 2. Metabolic pathway of GABA in organisms
表 1 不同菌种发酵产GABA含量
Table 1 Content of GABA produced by fermentation of different strains
发酵菌种 菌种来源 营养来源 GABA产量(g/L) 参考文献 Lactobacillus Paracasei NFRI 7415 发酵鱼 MRS肉汤 21.66 [22] Lactobacillus rhamnosus YS9 腌菜 MRS肉汤 19.28 [23] Lactobacillus brevis BJ20 发酵鳕鱼肠 MRS肉汤 0.47 [24] Lactobacillus plantarum LMG6907 酸菜 豆浆 0.86 [25] Bacillus cereus KBC 酱油 MRS肉汤 3.39 [26] Lactobacillus brevis CRL 2013 发酵面团 MRS-GF 27.33 [18] Lactobacillus plantarum FNCC 260 发酵木薯 MRS肉汤 1.23 [27] Lactobacillus brevis L2
Brettanomycescustersii ZSM-001− 发芽糙米 33.25 [20] Enterococcus faecium AB157
Lactobacillus plantarum BC112泡菜 MRS肉汤 6.35 [19] Aspergillus oryzae NSK 酱油 优化培养基 3.28 [28] Lactobacillus brevis JCM 1059T − 枣渣制备液 2.89 [29] 表 2 HPLC衍生化法测定样品中GABA
Table 2 Determination of GABA in samples by HPLC derivatization
测定样品 衍生方法 衍生时间(min) 色谱柱 保留时间(min) 线性范围
(mg/L)检出限
(μg/mL)文献 保健食品 OPA柱后衍生 − Agela C18 3.80 3×10−5~1.4×10−4 0.01 [46] 发芽糙米 OPA柱后衍生 − Hypercarb column 7.80 0.2~50 − [47] 红枣 Dansyl-Cl柱前衍生 30 ZORBAX SB C18 9.11 1.4~55 1.36 [42] 红枣 OPA柱前衍生 2 Inertsil ODS-3 C18 11.57 0.1~657 169.62 [45] 茶叶 DNFB柱前衍生 10 Hypersil ODS C18 43.99 0.03~0.21 − [48] 发芽糙米 DABS-Cl柱前衍生 20 Agilent C18 4.64 20~100 5×10−3 [49] 三七 PITC柱前衍生 120 Hypersil GOLD C18 8.80 10~1030 0.10 [50] 乳酸菌发酵液 OPA柱前衍生 5 XBridgeR C18 11.20 50~500 0.02 [51] 黑莓果汁/啤酒 AQC柱前衍生 30 Waters AccQ Tag 22.59 1~1000 700 [52] -
[1] OKETCH-RABAH H A, MADDEN E F, ROE A L, et al. United States Pharmacopeia (USP) safety review of gamma-aminobutyric acid (GABA)[J]. Nutrients,2021,13(8):2742. doi: 10.3390/nu13082742
[2] RAMESH S A, TYERMAN S D, GILLIHAM M. γ-aminobutyric acid (GABA) signalling in plants[J]. Cellular and Molecular Life Sciences:CMLS,2017,74(9):1577−1603. doi: 10.1007/s00018-016-2415-7
[3] YANG W, LEI Z, HU Y. Investigations of the thermal properties, nucleation kinetics, and growth of γ-aminobutyric acid in aqueous ethanol solution[J]. Industrial & Engineering Chemistry Research,2010,49(22):11170−11175.
[4] BOWN A W, SHELP B J. Does the GABA shunt regulate cytosolic GABA?[J]. Trends in Plant Science,2020,25(5):422−424. doi: 10.1016/j.tplants.2020.03.001
[5] MICHAELI S, FAIT A, LAGOR K, et al. A mitochondrial GABA permease connects the GABA shunt and the TCA cycle, and is essential for normal carbon metabolism[J]. The Plant Journal,2011,67(3):485−498. doi: 10.1111/j.1365-313X.2011.04612.x
[6] KATEŘINA P, LYDIA U, LUKÁŠ S, et al. Phytohormones and polyamines regulate plant stress responses by altering GABA pathway[J]. New Biotechnology,2018,48:53−65.
[7] YANG R, GUO Q, GU Z. GABA shunt and polyamine degradation pathway on γ-aminobutyric acid accumulation in germinating fava bean (Vicia faba L.) under hypoxia[J]. Food Chemistry, 2013, 136(1):152−159.
[8] CHE-OTHMAN M H, JACOBY R P, MILLAR A H, et al. Wheat mitochondrial respiration shifts from the tricarboxylic acid cycle to the GABA shunt under salt stress.[J]. The New Phytologist,2020,225(3):1166−1180. doi: 10.1111/nph.15713
[9] STUDART-GUIMARÃES C, FAIT A, NUNES-NESI A, et al. Reduced expression of succinyl-coenzyme a ligase can be compensated for by up-regulation of the γ-aminobutyrate shunt in illuminated tomato leaves[J]. Plant Physiology,2007,145(3):626−639. doi: 10.1104/pp.107.103101
[10] SALMINEN A, JOUHTEN P, SARAJÄRVI T, et al. Hypoxia and GABA shunt activation in the pathogenesis of alzheimer's disease[J]. Neurochemistry International,2016,92:13−24. doi: 10.1016/j.neuint.2015.11.005
[11] SHELP B J, BOZZO G G, TROBACHER C P, et al. Hypothesis/review:Contribution of putrescine to 4-aminobutyrate (GABA) production in response to abiotic stress[J]. Plant Science,2012,193:130−135.
[12] 周沫霖. 低温和二氧化碳胁迫下龙眼γ-氨基丁酸富集与机理研究[D]. 广州:华南农业大学, 2017. [ZHOU M L. Study on γ-aminobutyric acid (GABA) accumulation and regulation mechanism in longan (Dimocarpus longan Lour.) fruit in response to cold stress and CO2 stress[D]. Guangzhou:South China Agricultural University, 2017.] ZHOU M L. Study on γ-aminobutyric acid (GABA) accumulation and regulation mechanism in longan (Dimocarpus longan Lour.) fruit in response to cold stress and CO2 stress[D]. Guangzhou: South China Agricultural University, 2017.
[13] CARON P C, KREMZNER L T, COTE L J. GABA and its relationship to putrescine metabolism in the rat brain and pancreas[J]. Neurochemistry International,1987,10(2):219−229. doi: 10.1016/0197-0186(87)90131-8
[14] SEQUERRA E B, GARDINO P, HEDIN-PEREIRA C, et al. Putrescine as an important source of GABA in the postnatal rat subventricular zone[J]. Neuroscience,2007,146(2):489−493. doi: 10.1016/j.neuroscience.2007.01.062
[15] 杨东元, 陈开勋, 王亚红. γ-氨基丁酸的合成研究[J]. 中国饲料,2010(1):27−28. [YANG D Y, CHEN K X, WANG Y H. Study on synthesis of γ-aminobutanoic acid[J]. China Feed,2010(1):27−28.] YANG D Y, CHEN K X, WANG Y H . Study on synthesis of γ-aminobutanoic acid[J]. China Feed,2010 (1 ):27 −28 .[16] 王金玲, 袁军, 刘登才. γ-氨基丁酸的合成[J]. 化学与生物工程,2010,27(3):40−41. [WANG J L, YUAN J, LIU D C. Synthesis of γ-aminobutyric acid[J]. Chemistry & Bioengineering,2010,27(3):40−41.] WANG J L, YUAN J, LIU D C . Synthesis of γ-aminobutyric acid[J]. Chemistry & Bioengineering,2010 ,27 (3 ):40 −41 .[17] 董学君. 一种氨酪酸的制造方法:CN200710010078.1[P]. 2010-05-19. [DONG X J. A synthetic method of Aminobutyric acid:CN200710010078.1[P]. 2010-05-19.] DONG X J. A synthetic method of Aminobutyric acid: CN200710010078.1[P]. 2010-05-19.
[18] PABLO G C, JOSEFINA M V, GRACIELA S D G, et al. Enhancement of γ-aminobutyric acid (GABA) production by Lactobacillus brevis crl 2013 based on carbohydrate fermentation[J]. International Journal of Food Microbiology,2020,333:108792. doi: 10.1016/j.ijfoodmicro.2020.108792
[19] 张恕铭, 曾林, 孙向阳, 等. 屎肠球菌与植物乳杆菌共培养产 γ-氨基丁酸条件优化及关键酶活性研究[J]. 食品与发酵工业,2021,47(9):154−159. [ZHANG S M, ZENG L, SUN X Y, et al. Optimization of γ-aminobutyric acid produced by co-culturing Enterococcus faecium and Lactobacillus plantarum and the activities of key enzyme[J]. Food and Fermentation Industries,2021,47(9):154−159.] ZHANG S M, ZENG L, SUN X Y, et al . Optimization of γ-aminobutyric acid produced by co-culturing Enterococcus faecium and Lactobacillus plantarum and the activities of key enzyme[J]. Food and Fermentation Industries,2021 ,47 (9 ):154 −159 .[20] 张敏. γ-氨基丁酸乳酸菌诱变选育及其发酵条件优化[D]. 芜湖:安徽工程大学, 2020. [ZHANG M. Mutagenesis breeding of enterococcus faecalis producing GABA and optimization of fermentation conditions[D]. Wuhu:Anhui Polytechnic University, 2020.] ZHANG M. Mutagenesis breeding of enterococcus faecalis producing GABA and optimization of fermentation conditions[D]. Wuhu: Anhui Polytechnic University, 2020.
[21] 黄俊. 利用短乳杆菌制备γ-氨基丁酸相关过程研究[D]. 杭州:浙江大学, 2006. [HUANG J. Process study on the preparation of γ-aminobutyric acid by Lactobacillus brevis[D]. Hangzhou:Zhejiang University, 2006.] HUANG J. Process study on the preparation of γ-aminobutyric acid by Lactobacillus brevis[D]. Hangzhou: Zhejiang University, 2006.
[22] NORIKO K, JUN S, SHINICHI K, et al. Production of γ-aminobutyric acid (GABA) by Lactobacillus paracasei isolated from traditional fermented foods[J]. Food Microbiology,2005,22(6):497−504. doi: 10.1016/j.fm.2005.01.002
[23] LIN Q. Submerged fermentation of Lactobacillus rhamnosus ys9 for γ-aminobutyric acid (GABA) production[J]. Brazilian Journal of Microbiology,2013,44(1):183−187. doi: 10.1590/S1517-83822013000100028
[24] LEE B, KIM J, KANG Y M, et al. Antioxidant activity and γ-aminobutyric acid (GABA) content in sea tangle fermented by Lactobacillus brevis bj20 isolated from traditional fermented foods[J]. Food Chemistry,2010,122(1):271−276. doi: 10.1016/j.foodchem.2010.02.071
[25] LE H P, PARMENTIER N, LE T T, et al. Evaluation of using a combination of enzymatic hydrolysis and lactic acid fermentation for γ-aminobutyric acid production from soymilk[J]. LWT,2021,142:111044. doi: 10.1016/j.lwt.2021.111044
[26] WAN A A Q I, MOHAMAD N A S, MOHAMAD F I, et al. Isolation, identification, and optimization of γ-aminobutyric acid (GABA)-producing Bacillus cereus strain kbc from a commercial soy sauce moromi in submerged-liquid fermentation[J]. Processes,2020,8(6):652. doi: 10.3390/pr8060652
[27] YOGESWARA I B A, KITTIBUNCHAKUL S, RAHAYU E S, et al. Microbial production and enzymatic biosynthesis of γ-aminobutyric acid (GABA) using Lactobacillus plantarum fncc 260 isolated from indonesian fermented foods[J]. Processes,2020,9(1):22. doi: 10.3390/pr9010022
[28] AB KADIR S, WAN-MOHTAR W A A Q, MOHAMMAD R, et al. Evaluation of commercial soy sauce koji strains of Aspergillus oryzae for γ-aminobutyric acid (GABA) production[J]. Journal of Industrial Microbiology and Biotechnology,2016,43(10):1387−1395. doi: 10.1007/s10295-016-1828-5
[29] HASEGAWA M, YAMANE D, FUNATO K, et al. Gamma-aminobutyric acid fermentation with date residue by a lactic acid bacterium, Lactobacillus brevis[J]. Journal of Bioscience and Bioengineering,2018,125(3):316−319. doi: 10.1016/j.jbiosc.2017.10.003
[30] PU Y, SINCLAIR A J, ZHONG J, et al. Determination of γ-aminobutyric acid (GABA) in jujube fruit (Ziziphus jujuba mill.)[J]. CyTA-Journal of Food, 2019, 17(1):158-162.
[31] LI R, LI Z J, WU N N, et al. The effect of cold plasma pretreatment on GABA, γ-oryzanol, phytic acid, phenolics, and antioxidant capacity in brown rice during germination[J]. Cereal Chemistry,2023,2(100):321−332.
[32] TU J, LIU G, JIN Y, et al. Enrichment of γ-aminobutyric acid in mulberry leaves and the inhibitory effects of the water extract on ace and α-glucosidase activity[J]. Industrial Crops and Products,2022,177:114485. doi: 10.1016/j.indcrop.2021.114485
[33] 杨苞梅, 姚丽贤, 李国良, 等. 不同品种荔枝果肉游离氨基酸及香气组分分析[J]. 热带作物学报,2014,35(6):1228−1234. [YANG B M, YAO L X, LI G L, et al. Analysis of amino acids and aromatic components of pulps for different litchi variety[J]. Chinese Journal of Tropical Crops,2014,35(6):1228−1234.] YANG B M, YAO L X, LI G L, et al . Analysis of amino acids and aromatic components of pulps for different litchi variety[J]. Chinese Journal of Tropical Crops,2014 ,35 (6 ):1228 −1234 .[34] 陈卓慧, 胡卓炎, 吕恩利, 等. 不同贮藏方式对双肩玉荷包荔枝氨基酸变化的影响[J]. 现代食品科技,2013,29(8):1955−1960. [CHEN Z H, HU Z Y, LÜ E L, et al. Changes in amino acid contents of Shuangjianyuhebao litchi during different storage conditions[J]. Modern Food Science and Technology,2013,29(8):1955−1960.] CHEN Z H, HU Z Y, LÜ E L, et al . Changes in amino acid contents of Shuangjianyuhebao litchi during different storage conditions[J]. Modern Food Science and Technology,2013 ,29 (8 ):1955 −1960 .[35] 白青云, 高红侠, 陈佳雯, 等. 超声辅助盐胁迫对荸荠中 γ-氨基丁酸富集的影响[J]. 食品科技,2021,46(8):76−81. [BAI Q Y, GAO H X, CHEN J W, et al. Effects of ultrasonic assisted salt stress on γ-aminobutyric acid accumulation in water chestnut[J]. Food Science and Technology,2021,46(8):76−81.] BAI Q Y, GAO H X, CHEN J W, et al . Effects of ultrasonic assisted salt stress on γ-aminobutyric acid accumulation in water chestnut[J]. Food Science and Technology,2021 ,46 (8 ):76 −81 .[36] YOUN Y, PARK J, JANG H, et al. Sequential hydration with anaerobic and heat treatment increases GABA ( γ-aminobutyric acid) content in wheat[J]. Food Chemistry,2011,129(4):1631−1635. doi: 10.1016/j.foodchem.2011.06.020
[37] 周新勇, 陆燕婷, 尹永祺, 等. 低氧联合酸胁迫富集大麦芽中γ-氨基丁酸工艺优化[J]. 中国粮油学报,2020,35(6):144−150. [ZHOU X Y, LU Y T, YIN Y Q, et al. Optimization of hypoxia combined with acid stress processing conditionsfor enriching γ-aminobutyric acid (GABA) in malt[J]. Journal of the Chinese Cereals and Oils Association,2020,35(6):144−150.] ZHOU X Y, LU Y T, YIN Y Q, et al . Optimization of hypoxia combined with acid stress processing conditionsfor enriching γ-aminobutyric acid (GABA) in malt[J]. Journal of the Chinese Cereals and Oils Association,2020 ,35 (6 ):144 −150 .[38] 黄柳舒, 沈莲清, 王向阳. 改良比色法测桑叶中 γ-氨基丁酸含量及其热稳定性研究[J]. 食品科技,2010,35(8):328−331. [HUANG L S, SHEN L Q, WANG X Y. Spectrophotometry improvement determination of γ-aminobutyric acid inmulberry leaf and study on its thermal stability[J]. Food Science and Technology,2010,35(8):328−331.] HUANG L S, SHEN L Q, WANG X Y . Spectrophotometry improvement determination of γ-aminobutyric acid inmulberry leaf and study on its thermal stability[J]. Food Science and Technology,2010 ,35 (8 ):328 −331 .[39] 陈恩成, 张名位, 彭超英, 等. 比色法快速测定糙米中 γ-氨基丁酸含量研究[J]. 中国粮油学报,2006(1):125−128. [CHEN E C, ZHANG M W, PENG C Y, et al. Spectrophometric determination of γ-aminobutyric acid in brown rice[J]. Journal of the Chinese Cereals and Oils Association,2006(1):125−128.] CHEN E C, ZHANG M W, PENG C Y, et al . Spectrophometric determination of γ-aminobutyric acid in brown rice[J]. Journal of the Chinese Cereals and Oils Association,2006 (1 ):125 −128 .[40] 万蓝婷, 李暄妍, 程建峰, 等. Berthelot比色法测定植物叶片中 γ-氨基丁酸(GABA)含量的体系优化[J]. 植物生理学报,2021,57(7):1462−1472. [WAN L T, LI X Y, CHENG J F, et al. Systematic optimization of Berthelot colorimetry for determining γ-aminobutyric acid (GABA) content in plant leaves[J]. Plant Physiology Journal,2021,57(7):1462−1472.] WAN L T, LI X Y, CHENG J F, et al . Systematic optimization of Berthelot colorimetry for determining γ-aminobutyric acid (GABA) content in plant leaves[J]. Plant Physiology Journal,2021 ,57 (7 ):1462 −1472 .[41] JINNARAK A, TEERASONG S. A novel colorimetric method for detection of gamma-aminobutyric acid based on silver nanoparticles[J]. Sensors and Actuators B: Chemical,2016,229:315−320. doi: 10.1016/j.snb.2016.01.115
[42] 王能凤. 红枣γ-氨基丁酸测定方法的优化及应用研究[D]. 阿拉尔:塔里木大学, 2022. [WANG N F. Research on optimization and application of determination method of γ-aminobutyric acid in jujube[D]. Alaer:Tarim University, 2022.] WANG N F. Research on optimization and application of determination method of γ-aminobutyric acid in jujube[D]. Alaer: Tarim University, 2022.
[43] 王能凤, 杨家荣, 蒲云峰, 等. 红枣中 γ-氨基丁酸的功能及检测方法的研究进展[J]. 农产品加工,2022(14):94−96. [WANG N F, YANG J R, PU Y F, et al. Research progress of function and detection methods of γ-aminobutyric acid in jujube fruit[J]. Farm Products Processing,2022(14):94−96.] WANG N F, YANG J R, PU Y F, et al . Research progress of function and detection methods of γ-aminobutyric acid in jujube fruit[J]. Farm Products Processing,2022 (14 ):94 −96 .[44] 刘红梅, 魏淘涛, 刘行丹, 等. 发芽糙米 γ-氨基丁酸的检测及研究进展[J]. 作物研究,2012,26(1):88−92. [LIU H M, WEI T T, LIU X D, et al. Determination methods and research progress of gamma aminobutyric acid in germinated brown rice[J]. Crop Research,2012,26(1):88−92.] LIU H M, WEI T T, LIU X D, et al . Determination methods and research progress of gamma aminobutyric acid in germinated brown rice[J]. Crop Research,2012 ,26 (1 ):88 −92 .[45] 李雁琴. 红枣中GABA检测方法优化及其变化规律的研究[D]. 阿拉尔:塔里木大学, 2020. [LI Y Q. Study on the optimization of γ-aminobutyric acid detection method andits variation rule in jujube[D]. Alaer:Tarim University, 2020.] LI Y Q. Study on the optimization of γ-aminobutyric acid detection method andits variation rule in jujube[D]. Alaer: Tarim University, 2020.
[46] 郭旭光, 尹玉云, 徐晓楠. 高效液相-柱后衍生-荧光检测法测定保健品中 γ-氨基丁酸的含量[J]. 河南预防医学杂志,2020,31(12):894−896. [GUO X G, YIN Y Y, XU X N. HPLC determination of gamma-aminobutyric acid in health care productswith post-column derivatization and fluorescence detection[J]. Henan Journal of Preventive Medicine,2020,31(12):894−896.] GUO X G, YIN Y Y, XU X N . HPLC determination of gamma-aminobutyric acid in health care productswith post-column derivatization and fluorescence detection[J]. Henan Journal of Preventive Medicine,2020 ,31 (12 ):894 −896 .[47] 王丽群, 潘媛媛, 孟庆虹, 等. 基于柱后衍生发芽糙米中 γ-氨基丁酸HPLC检测方法的建立及应用[J]. 中国酿造,2016,35(2):144−147. [WANG L Q, PAN Y Y, MENG Q H, et al. Establishment and application of the HPLC determination method for γ-aminobutyric acid in germinated brown rice based on postcolumn derivation[J]. China Brewing,2016,35(2):144−147.] WANG L Q, PAN Y Y, MENG Q H, et al . Establishment and application of the HPLC determination method for γ-aminobutyric acid in germinated brown rice based on postcolumn derivation[J]. China Brewing,2016 ,35 (2 ):144 −147 .[48] 邢志强. 茶叶γ-氨基丁酸富集方法及其检测方法的研究[D]. 合肥:安徽农业大学, 2009. [XING Z Q. Study of enriching ways and analytical method on the γ-aminobutyric acid in tea leaves[D]. Hefei:Anhui Agricultural University, 2009.] XING Z Q. Study of enriching ways and analytical method on the γ-aminobutyric acid in tea leaves[D]. Hefei: Anhui Agricultural University, 2009.
[49] 杜金凤, 郭航宏, 陶晓杰, 等. DABS-Cl柱前衍生HPLC测定发芽糙米粉中 γ-氨基丁酸[J]. 食品工业,2021,42(6):468−472. [DU J F, GUO H G, TAO X J, et al. Determine of γ-aminobuytric acid in germinated brown rice powder by HPLC with DABS-Cl precolumn derivatization[J]. The Food Industry,2021,42(6):468−472.] DU J F, GUO H G, TAO X J, et al . Determine of γ-aminobuytric acid in germinated brown rice powder by HPLC with DABS-Cl precolumn derivatization[J]. The Food Industry,2021 ,42 (6 ):468 −472 .[50] 杨晶晶, 刘英, 崔秀明, 等. 高效液相色谱法测定三七地上部分 γ-氨基丁酸的含量[J]. 中国中药杂志,2014,39(4):606−609. [YANG J J, LIU Y, CUI X M, et al. Determination of γ-aminobutyric acid in aerial part of panax notoginseng by HPLC[J]. China Journal of Chinese Materia Medica,2014,39(4):606−609.] YANG J J, LIU Y, CUI X M, et al . Determination of γ-aminobutyric acid in aerial part of panax notoginseng by HPLC[J]. China Journal of Chinese Materia Medica,2014 ,39 (4 ):606 −609 .[51] 刘宗乐, 高林森, 张东东, 等. 高效液相色谱法测定乳酸菌发酵液中 γ-氨基丁酸[J]. 中国酿造,2022,41(11):233−238. [LIU Z L, GAO L S, ZHANG D D, et al. Determination of γ-aminobutyric acid in lactic acid bacteria fermentationbroth by HPLC[J]. China Brewing,2022,41(11):233−238.] LIU Z L, GAO L S, ZHANG D D, et al . Determination of γ-aminobutyric acid in lactic acid bacteria fermentationbroth by HPLC[J]. China Brewing,2022 ,41 (11 ):233 −238 .[52] 胡雪莲, 王宏华, 王莉娜. 高效液相色谱法测定黑莓果汁及黑莓啤酒中的 γ-氨基丁酸[J]. 中国酿造,2015,34(3):150−153. [HU X L, WANG H H, WANG L N. Determination of γ-aminobutyric acid in blackberry juice and blackberry beer by HPLC[J]. China Brewing,2015,34(3):150−153.] HU X L, WANG H H, WANG L N . Determination of γ-aminobutyric acid in blackberry juice and blackberry beer by HPLC[J]. China Brewing,2015 ,34 (3 ):150 −153 .[53] DAI D, QIN Q, ZHU X, et al. A high performance liquid chromatography tandem mass spectrometry protocol for detection of neurotransmitters in the rat brain tissue[J]. MethodsX,2023,10:102083. doi: 10.1016/j.mex.2023.102083
[54] BERGH M S, BOGEN I L, LUNDANES E, et al. Validated methods for determination of neurotransmitters and metabolites in rodent brain tissue and extracellular fluid by reversed phase UHPLC-MS/MS[J]. Journal of Chromatography B,2016,1028:120−129. doi: 10.1016/j.jchromb.2016.06.011
[55] 秦宇, 侯蓓蓓, 张斌骏, 等. 超高效液相色谱-串联质谱法测定南瓜中 γ-氨基丁酸的含量[J]. 食品安全质量检测学报,2020,11(2):528−532. [QIN Y, HOU B B, ZHANG B J, et al. Simultaneous determination of γ-aminobutyric acid in pumpkin by ultraperformance liquid chromatography-tandem mass spectrometry[J]. Journal of Food Safety & Quality,2020,11(2):528−532.] QIN Y, HOU B B, ZHANG B J, et al . Simultaneous determination of γ-aminobutyric acid in pumpkin by ultraperformance liquid chromatography-tandem mass spectrometry[J]. Journal of Food Safety & Quality,2020 ,11 (2 ):528 −532 .[56] ZHAO M, TUO H, WANG S, et al. The effects of dietary nutrition on sleep and sleep disorders[J]. Mediators of Inflammation,2020(25):3142874.
[57] BRUNI O, FERINI-STRAMBI L, GIACOMONI E, et al. Herbal remedies and their possible effect on the GABAergic system and sleep[J]. Nutrients,2021,13(2):530. doi: 10.3390/nu13020530
[58] GOTTESMANN C. GABA mechanisms and sleep[J]. Neuroscience,2002,111(2):231−239. doi: 10.1016/S0306-4522(02)00034-9
[59] YAMATSU A, YAMASHITA Y, PANDHARIPANDE T, et al. Effect of oral γ-aminobutyric acid (GABA) administration on sleep and its absorption in humans[J]. Food Science and Biotechnology,2016,25(2):547−551. doi: 10.1007/s10068-016-0076-9
[60] HEPSOMALI P, GROEGER J A, NISHIHIRA J, et al. Effects of oral gamma-aminobutyric acid (GABA) administration on stress and sleep in humans:A systematic review[J]. Frontiers in Neuroscience,2020,14:923. doi: 10.3389/fnins.2020.00923
[61] JEONG A, HWANG J, JO K, et al. Fermented gamma aminobutyric acid improves sleep behaviors in fruit flies and rodent models[J]. International Journal of Molecular Sciences,2021,22(7):3537. doi: 10.3390/ijms22073537
[62] 李科, 俞兰秀, 刘小雨, 等. γ-氨基丁酸改善睡眠作用机制的研究进展[J]. 食品工业科技,2019,40(14):353−358. [LI K, YU L X, LIU X Y, et al. Research progress on improving sleep mechanism of γ-aminobutyric acid[J]. Science and Technology of Food Industry,2019,40(14):353−358.] LI K, YU L X, LIU X Y, et al . Research progress on improving sleep mechanism of γ-aminobutyric acid[J]. Science and Technology of Food Industry,2019 ,40 (14 ):353 −358 .[63] WANG H, WANG Z, CHEN N. The receptor hypothesis and the pathogenesis of depression:Genetic bases and biological correlates[J]. Pharmacological Research,2021,167:105542. doi: 10.1016/j.phrs.2021.105542
[64] FARAJDOKHT F, VOSOUGHI A, ZIAEE M, et al. The role of hippocampal GABA a receptors on anxiolytic effects of echium amoenum extract in a mice model of restraint stress[J]. Molecular Biology Reports,2020,47(9):6487−6496. doi: 10.1007/s11033-020-05699-7
[65] TAFET G E, NEMEROFF C B. Pharmacological treatment of anxiety disorders:The role of the hpa axis[J]. Frontiers in Psychiatry,2020,11:443. doi: 10.3389/fpsyt.2020.00443
[66] CAI L, TAO Q, LI W, et al. The anti-anxiety/depression effect of a combined complex of casein hydrolysate and γ-aminobutyric acid on C57BL/6 mice[J]. Frontiers in Nutrition,2022,9:971853. doi: 10.3389/fnut.2022.971853
[67] SANACORA G, MASON G F, ROTHMAN D L, et al. Increased cortical GABA concentrations in depressed patients receiving ect[J]. American Journal of Psychiatry,2003,160(3):577−579. doi: 10.1176/appi.ajp.160.3.577
[68] 陈青峰, 贺婧, 谢小梅, 等. 淡豆豉炮制中 γ-氨基丁酸含量测定及其抗抑郁作用研究[J]. 药物评价研究,2021,44(4):688−694. [CHEN Q F, HE J, XIE X M, et al. Determination of content of γ-aminobutyric acid and its antidepressant effect at different time points during processing of sojae semen praeparatum[J]. Drug Evaluation Research,2021,44(4):688−694.] CHEN Q F, HE J, XIE X M, et al . Determination of content of γ-aminobutyric acid and its antidepressant effect at different time points during processing of sojae semen praeparatum[J]. Drug Evaluation Research,2021 ,44 (4 ):688 −694 .[69] AL-KURAISHY H M, HUSSIAN N R, AL-NAIMI M S, et al. The potential role of pancreatic γ-aminobutyric acid (GABA) in diabetes mellitus:A critical reappraisal[J]. International Journal of Preventive Medicine,2021,12(1):19.
[70] HOSSEINI DASTGERDI A, SHARIFI M, SOLTANI N. GABA administration improves liver function and insulin resistance in offspring of type 2 diabetic rats[J]. Scientific Reports,2021,11(1):23155. doi: 10.1038/s41598-021-02324-w
[71] PRUD'HOMME G J, GLINKA Y, KURT M, et al. The anti-aging protein klotho is induced by GABA therapy and exerts protective and stimulatory effects on pancreatic beta cells[J]. Biochemical and Biophysical Research Communications,2017,493(4):1542−1547. doi: 10.1016/j.bbrc.2017.10.029
[72] LIN E E, SCOTT-SOLOMON E, KURUVILLA R. Peripheral innervation in the regulation of glucose homeostasis[J]. Trends in Neurosciences,2021,44(3):189−202. doi: 10.1016/j.tins.2020.10.015
[73] LIU Y, WENG W, WANG S, et al. Effect of γ-aminobutyric acid-chitosan nanoparticles on glucose homeostasis in mice[J]. ACS Omega,2018,3(3):2492−2497. doi: 10.1021/acsomega.7b01988
[74] DUPONT A G, LÉGAT L. GABA is a mediator of brain at 1 and at 2 receptor-mediated blood pressure responses[J]. Hypertension Research,2020,43(10):995−1005. doi: 10.1038/s41440-020-0470-9
[75] LÉGAT L, SMOLDERS I, DUPONT A G. At 1 receptor mediated hypertensive response to ang ii in the nucleus tractus solitarii of normotensive rats involves no dependent local GABA release[J]. Frontiers in Pharmacology,2019,10:460. doi: 10.3389/fphar.2019.00460
[76] MILANEZ M I, SILVA A M, PERRY J C, et al. Pattern of sympathetic vasomotor activity induced by GABAergic inhibition in the brain and spinal cord[J]. Pharmacological Reports,2020,72:67−79. doi: 10.1007/s43440-019-00025-w
[77] KIMURA M, HAYAKAWA K, SANSAWA H. Involvement of γ-aminobutyric acid (GABA) b receptors in the hypotensive effect of systemically administered GABA in spontaneously hypertensive rats[J]. Japanese Journal of Pharmacology,2002,89(4):388−394. doi: 10.1254/jjp.89.388
[78] AKAMA K, KANETOU J, SHIMOSAKI S, et al. Seed-specific expression of truncated osgad 2 produces GABA-enriched rice grains that influence a decrease in blood pressure in spontaneously hypertensive rats[J]. Transgenic Research,2009,18:865−876. doi: 10.1007/s11248-009-9272-1
[79] HUSSIN F S, CHAY S Y, ZAREI M, et al. Potentiality of self-cloned Lactobacillus plantarum taj-apis362 for enhancing GABA production in yogurt under glucose induction:optimization and its cardiovascular effect on spontaneous hypertensive rats[J]. Foods,2020,9(12):1826. doi: 10.3390/foods9121826
[80] XU Y, ZHAO M, HAN Y, et al. GABAergic inhibitory interneuron deficits in alzheimer's disease:Implications for treatment[J]. Frontiers in Neuroscience,2020,14:660. doi: 10.3389/fnins.2020.00660
[81] ZHANG Z, JING Y, MA Y, et al. Driving GABAergic neurons optogenetically improves learning, reduces amyloid load and enhances autophagy in a mouse model of alzheimer's disease[J]. Biochemical and Biophysical Research Communications,2020,525(4):928−935. doi: 10.1016/j.bbrc.2020.03.004
[82] INOTSUKA R, UDONO M, YAMATSU A, et al. Exosome-mediated activation of neuronal cells triggered by γ-aminobutyric acid (GABA)[J]. Nutrients,2021,13(8):2544. doi: 10.3390/nu13082544
[83] YANG J, CHEN J, LIU Y, et al. Ventral tegmental area astrocytes modulate cocaine reward by tonically releasing GABA[J]. Neuron,2023,111(7):1104−1117. doi: 10.1016/j.neuron.2022.12.033
[84] HUANG D, WANG Y, THOMPSON J W, et al. Cancer-cell-derived GABA promotes β-catenin-mediated tumour growth and immunosuppression[J]. Nature cell Biology,2022,24(2):230−241. doi: 10.1038/s41556-021-00820-9
[85] HUANG D, ALEXANDER P B, LI Q, et al. GABAergic signaling beyond synapses:An emerging target for cancer therapy[J]. Trends in Cell Biology, 2022. doi: 10.1016/j.tcb.2022.08.004.