茶多酚生理机制及其保健食品研发进展

张文娟1,刘雪娜2,李丽维2,李建勋1,宋文军1*

(1.天津商业大学生物技术与食品科学学院,天津 300134;2.天士力研究院,天津 300410)

摘 要:茶多酚是茶叶中的主要活性成分。现代研究表明,茶多酚具有抗菌、抗炎、抗氧化、抗肿瘤、护肝、保护肠道、保护心血管等众多生理功能。深入研究茶多酚生理机制对其在保健食品领域的研发应用至关重要。该文以近年来国内外关于茶多酚的研究为基础,对其生理机制及保健食品研究现状进行归纳,以期为此类化合物的深度开发与应用提供参考。

关键词:茶多酚;生理机制;保健食品;生物利用度;剂型

茶是世界上畅销的饮品之一,它起源于中国西南部的云贵高原,迄今已在中国、日本等亚洲国家种植了几千年。因具有独特的风味、香气和保健作用,使其在世界范围内受到高度重视[1]。随着分析方法的发展,茶叶中的主要化学成分,包括多酚、多糖、氨基酸、生物碱、有机酸、蛋白质和挥发性成分已被成功分离和鉴定。在现有的茶叶成分研究中,发现茶多酚所占比例最高,是茶叶的主要生物活性成分。研究表明,茶多酚在生物体内具有多种生物活性,如抗菌、抗炎、抗氧化、抗肿瘤等。本文就茶多酚的组成、生理机制及其在保健食品应用等方面的研究进行综述,梳理茶多酚的化学活性成分和已明确的生理功能,为茶多酚的进一步开发研究和应用提供参考。

1 不同茶叶茶多酚组成

茶叶通常根据氧化程度分为6种类型,即未发酵的绿茶、微发酵的白茶、部分发酵的黄茶、半发酵的乌龙茶、完全发酵的红茶和后发酵的黑茶。不同种类的茶在制作过程中各有特色。在绿茶生产过程中,热处理可以防止茶多酚的酶促氧化,最大限度地减少活性物质的降解。对于白茶,刚采收的鲜叶和新芽立即进行干燥处理,不会导致叶和芽中的酶失活和化合物的氧化。与绿茶生产相比,黄茶的生产涉及一种独特的工艺,称为“闷黄”,这是促进氧化反应和去除绿茶独特的青草香味的关键步骤,同时仍能保持绿茶的功效成分。乌龙茶是一种半发酵的茶叶产品,具有较低的酶促氧化速率,具有多种生理功效,香气口感良好。在生产红茶的过程中,新鲜的茶叶被彻底碾压,以增加多酚氧化酶的释放,随后与儿茶素反应,导致其他多酚的产生,如茶黄素和茶红素。黑茶是通过微生物发酵生产的后发酵茶,其化学成分会发生变化,例如多酚、多糖和咖啡因。不同的加工方法会导致茶叶中酚类成分的变化,不同茶制品的酚类含量见表1[2-8]

表1 不同茶制品的酚类含量
Table 1 Phenolic content of different tea products

注:-表示没有相关数据。

mg/g酚类化合物 绿茶 白茶 黄茶 乌龙茶 红茶 黑茶儿茶素(C) 0~1.315 - 0~2.040 0~0.775 - 0~4.930表儿茶素(EC) 5.380~8.700 0~1.311 0.968~10.062 1.579~13.723 0~0.796 0~10.357没食子儿茶素(GC) 1.824~4.002 - 2.736~11.858 2.509~11.528 0~1.098 0~5.535表没食子儿茶素(EGC) 13.094~100.684 0~8.419 13.661~45.484 31.253~139.854 0~8.479 0~23.430儿茶素没食子酸酯(CG) 0~0.645 - 0~1.608 0~0.981 - -表儿茶素没食子酸酯(ECG) 7.599~35.395 2.270~3.841 0~30.491 3.683~8.435 0~2.583 0.455~10.881没食子儿茶素没食子酸酯(GCG) 0~5.844 - 1.388~24.710 0~2.261 0~0.510 0~0.933表没食子儿茶素没食子酸酯(EGCG) 33.102~59.354 3.537~8.539 17.209~57.230 20.211~36.704 0.539~3.795 0.584~10.885

2 茶多酚的生理机制

流行病学研究发现,茶多酚对人体健康有益。现代研究表明,其具有抗菌、抗炎、抗氧化、抗肿瘤、保肝、保护肠道、保护心血管等多种生理活性。

2.1 抗菌

茶多酚具有广谱的抗菌活性,对革兰氏阴性杆菌、普通变性杆菌、金黄色葡萄球菌和肠道致病菌均有抑制作用[9-12]。研究显示,白细胞毒素(leukotoxin,LtxA)与表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)质量比为 4∶0.1、4 ∶1、4∶10 时,EGCG 均能起到抑制LtxA活性的作用,其机理是通过改变LtxA结构,抑制毒素与宿主细胞表面必需的分子结合,从而降低放线菌的致病性[13]。1 024 μg/mL绿茶多酚可显著下调毒力相关因子猪链球菌溶血素(suilysin,SLY)的表达,从而抑制SC19细胞的生长,降低其溶血活性,起到降低猪链球菌致病性的作用[14]。50 μL EGCG可干扰肺炎克雷伯菌DNA代谢和生物蛋白的形成,同时下调其能量代谢,起到抗菌的效果[15]。Kitichaler mkiat等[16]发现,经500 mg/L EGCG处理的金黄色葡萄球菌,膜转运相关基因转录增加,与毒素产生和应激反应相关基因转录降低,并且细胞膜电位显著降低,表明EGCG对金黄色葡萄球菌细胞膜有损伤作用。Schneider-Rayman等[17]研究表明,2.2 mg/mL~4.4 mg/mL EGCG对变形链球菌牙科生物膜形成、DNA含量和胞外多糖(exopoly saccharides,EPS)产量均有显著的抑制作用,可能是一种潜在的防龋药。Ye等[18]以果胶和纤维素(pectin and cellulose,PC)基础,添加茶多酚,开发了一种新的生物活性薄膜。不负载茶多酚(tea polyphenols,TP)的PC膜不具备任何真菌和细菌的抑制能力,而负载TP的PC膜对大肠杆菌、白色念珠菌和金黄色葡萄球菌具有良好的抗菌活性。没有TP负载的PC膜具有33%的DPPH自由基清除率。随着TP在PC膜中的负载量增加,DPPH自由基的清除率从92%增加到97%。基于上述结果,负载TP的PC膜可广泛应用于食品保鲜。与此同时,已有研究证实,茶多酚对家禽疾病有积极的作用,包括禽流感和球虫病[19]

2.2 抗炎

炎症是宿主抵抗有害刺激的防御机制的一部分。然而,未能维持免疫稳态会导致慢性炎症,从而导致组织损伤。

细胞试验显示,茶多酚通过抑制脂多糖刺激的RAW 264.7巨噬细胞Toll样受体 4(toll-like receptor 4,TLR4)、丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)和核因子-κB(nuclear factor-kappa B,NF-κB)信号通路表达来发挥抗炎作用,且具有剂量依赖性[20-21]。在肝炎小鼠模型中,绿茶多酚通过抑制核苷酸结合寡聚化结构域样受体蛋白3(nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3,NLRP3)炎症小体的表达,增加核因子E2相关因子 2(nuclear factor erythroid 2-related factor2,Nrf2)通路,减轻肝炎对机体造成的损伤[22]。动物实验研究表明,茶多酚可使模型动物的环氧化酶-2(cyclooxygenase-2,COX-2)、白细胞介素-6(interleukin-6,IL-6)、白细胞介素-1β(interleukin-1β,IL-1β)、肿瘤坏死因子-α(tumor necrosis factor,TNF-α)和血浆单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)表达水平降低,白细胞介素-10(interleukin-10,IL-10)和血红素氧合酶1(heme oxygenase-1,HO-1)蛋白水平升高[23-28],从而起到抗炎作用。

总体而言,茶多酚具有良好的抗炎活性,主要作用机制包括抑制促炎因子的表达和调节相关信号途径的转导,这使得茶多酚具有预防和治疗炎症相关疾病的潜力。

2.3 抗氧化

氧化应激是指体内产生的活性氧和抗氧化能力之间的失衡,导致细胞内脂质、蛋白质和DNA的正常功能受损,从而导致许多慢性病的发生和发展[29]。茶及其具有的生物活性物质,特别是茶多酚,已被体外和体内实验证明是天然抗氧化剂的理想来源。

茶多酚由于具有酚羟基结构,使得氢离子的结合能力减弱,活性氢离子直接清除自由基和其他活性氧[30],其邻位二酚羟基还可以成为金属螯合物的反应位点,显著降低高浓度羰基的氧化应激[31]。细胞和动物实验结果显示,10 μg/mL茶多酚能使细胞和模型动物的超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽氧化物酶(selenium containing gluten oxide dismutase cysteine peroxidase,GSH-Px)、热休克蛋白(heat shock proteins,Hsps)和总抗氧化能力(total antioxidant capacity,T-AOC)显著上升[32-35]。研究者通过建立椎间盘髓核细胞体外退化模型和草鱼肾细胞模型,发现茶多酚可通过激活Kelch样环氧氯丙烷相关蛋白1/核因子样蛋白2/3′非翻译区基因序列(kelch-like ech-related protein 1/nuclear factor-like 2/the gene sequence in the 3′untranslated region of mRNA,Keap1/Nrf2/ARE)通路,发挥抗氧化应激作用,最终延缓椎间盘退变和肾细胞死亡[36-38]

茶多酚在体外和动物实验中都表现出抗氧化活性,其作用机制包括清除自由基、螯合金属离子、增强抗氧化酶活性和调节细胞信号通路。

2.4 抗肿瘤

茶多酚及其单体可通过诱导细胞凋亡和细胞周期停滞、阻断信号转导、抗肿瘤细胞生长、转移和侵袭、抗血管生成及抑制耐药细胞相关蛋白表达等多种途径防治癌症的发生发展[39]

Alam 等[40]发现 0.45 μmol/L~0.59 μmol/L EGCG 可以降低 B 淋巴细胞瘤-xL(B cell lymphoma-xL,Bcl-xL)和B淋巴细胞瘤2(B cell lymphoma 2 family protein,Bcl-2)的表达,诱导癌细胞凋亡。800 mg/L绿茶多酚可以调节DNA合成前期/DNA合成期(G1/S)和DNA合成/分裂期(G2/M)之间的转换,导致细胞周期停滞,并显著抑制人乳腺癌MCF-7细胞的生长[41]。由于EGCG生物利用度差,且需要大剂量才能表现出活性,限制了其临床应用[42]。Man等[43]合成了一种过乙酸盐保护的EGCG衍生物,被称为pro-EGCG,40 μmol/L~60 μmol/L pro-EGCG通过抑制外部调节信号酶(external signal-regulated kinases,ERK) 和蛋白激酶 B(protein kinase B,PKB)信号通路来调节血管内皮生长因子(vascular endothelial growth factor,VEGF) 的表达和促进子宫内膜癌细胞死亡,下调参与细胞增殖和细胞存活的机制途径。10 μmol/L EGCG可通过抑制基质金属蛋白酶2和9来抑制LL2-Lu3肿瘤细胞的侵袭[44]。大于10 μmol/L EGCG剂量依赖地抑制信号转导和转录激活剂3(STAT3)介导的人胃癌细胞血管内皮生长因子的表达和分泌[45]。活体检查表明,口服EGCG可以减少动物异种移植和同种移植模型的肿瘤生长、抗血管生成和抗转移作用[46]。已有研究表明,100 μg/mL EGCG可下调耐药细胞MDR-1、P-糖蛋白(P-glycoprotein,P-gp)等相关蛋白的表达,同时抑制mRNAs和蛋白的表达,从而逆转 5-氟尿嘧啶(5-fluorouracil,5-FU)的耐药性[47]

癌症是当今影响人类生命健康的一种重大疾病,茶多酚具有的抗肿瘤功效使其成为中医药保健食品开发利用的重要资源,可用于预防和辅助治疗癌症,同时也为研发和生产茶多酚相关功能产品带来了较大的市场需求和可观的经济价值。

2.5 保肝

肝病包括非病毒性肝病,如药物或污染物引起的肝损伤、酒精性肝病(alcoholic liver disease,ALD)、非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)和病毒性肝病。

2.5.1 对药物和污染物所致肝损伤的保护作用

药物或污染物所致的肝损伤是最常见的肝病之一。绿茶多酚可明显减轻对乙酰氨基酚(acetaminophen,APAP)诱导的小鼠肝损伤,包括提高存活率,减轻肝细胞坏死,降低丙氨酸氨基转移酶(alanine aminotransferase,ALT)和天冬氨酸氨基转移酶(aspartate aminotransferase,AST)水平,升高谷胱甘肽(glutathione,GSH)水平,其机制可能与调节代谢酶和转运体有关[48]。EGCG显著降低了二乙基亚硝胺诱导的大鼠肝毒性和细胞凋亡,其作用机制是降低血清中肝功能酶的水平,增强抗氧化能力,防止细胞周期停滞[49]。然而在一项动物研究中,治疗性剂量(8.5 mg/kg,持续1个月)的绿茶提取物对大鼠产生了肝毒性,这表明在临床过量APAP的情况下,给予绿茶提取物可能会增强APAP引起的肝毒性[50]。因此,茶多酚及其单体临床应用的安全剂量仍需进一步探讨。

2.5.2 酒精性肝病保护作用

长期过量饮酒可导致酒精性脂肪肝(alcoholic fatty liver disease,AFLD),其特征是甘油三酯在肝细胞中异常堆积。此外,AFLD可发展为酒精性肝炎、纤维化、肝硬变和肝癌。在酒精诱导的大鼠肝损伤动物模型中,茶多酚干预组大鼠内脏脂肪含量、SOD/MDA比值、TAOC和GSH-Px活力显著增加,肝体比、脂肪酸转位酶(fatty acid translocase,FAT/CD36)蛋白水平显著下降,肝细胞中脂滴减少,表明茶多酚干预能改善慢性酒精中毒大鼠肝脏的脂质沉积和氧化应激状态,并伴有肝细胞膜上FAT/CD36表达的减少[51]。在一项研究中,Li等[52]发现,炒绿茶、凤凰水仙茶和普洱茶提取物中的儿茶素对亚急性饮酒所致的肝脏脂质积累有较强的抑制作用。此外,3种茶叶提取物还能显著降低ALT和AST的活性,抑制细胞色素P4502E1的表达,明显提高超氧化物歧化酶、谷胱甘肽过氧化物酶活性和GSH水平,显著降低丙二醛水平,起到保护肝脏的作用。因此,这些茶有很大潜力被开发成预防AFLD的功能食品。

2.5.3 非酒精性肝病保护作用

许多研究表明,茶多酚通过不同机制对NAFLD产生积极影响。基于高脂肪膳食喂养的小鼠模型,茯苓速溶茶使小鼠短链脂肪酸总量增加,促进肠上皮细胞的生长,有利于预防脂肪肝[53]。另一项研究表明,生沱茶可以改善血清和肝组织脂代谢失衡,从而达到预防非酒精性脂肪肝的效果[54]。Xia等[55]的研究表明,绿茶多酚对肝硬化和肝癌也有治疗作用,绿茶多酚可以降低高脂肪饮食引起的胰岛素抵抗,表明绿茶多酚可以防止肝脏中的脂质积累和脂肪变性。EGCG通过下调胆汁酸的重吸收来降低肠道胆汁酸的水平,进而减少脂肪的吸收,从而减轻高脂饲料喂养的小鼠的脂肪肝[56]

2.5.4 病毒性肝病

病毒感染是全球肝炎的主要原因。肝炎病毒有5种类型:甲型、乙型、丙型、丁型和戊型。乙型和丙型是导致肝纤维化、肝硬化和肝细胞癌等慢性肝病的主要原因。据报道,红茶中的3种茶黄素在人肝癌Huh-7细胞感染的早期阶段抑制了丙型肝炎病毒的感染,它们直接作用于病毒颗粒并能抑制细胞间的传播[57]。此外,EGCG能在细胞中发挥抗乙肝病毒的作用,有效抑制乙肝病毒的RNA和DNA合成及抗原表达[58]

2.6 保护肠道

肠道菌群是动物机体消化、代谢和维生素合成等生理功能的重要组成部分。茶多酚对肠道菌群具有调节作用,并影响肠道微生物代谢物的产生。一方面,茶和茶多酚为肠道微生物提供代谢底物,促进肠道有益菌群的生长和繁殖;另一方面,它们的抗菌活性使它们能够抑制有害肠道细菌的生长,并降低致病菌的毒性。

TLR2介导的信号转导可以避免肠上皮细胞的凋亡,减缓肠黏膜损伤,维护肠屏障功能的完整性。一项研究发现,茶多酚可显著抑制ETEC K88攻击诱导的细胞TLR2 mRNA表达下调,茶多酚可能通过TLR2介导的信号转导维持肠上皮细胞屏障功能的完整性[59]。Li等[60]通过使用抗生素造成小鼠肠道菌群失调,通过口服茶多酚可显著缓解肠道菌群丰富度和多样性的下降,提高益生菌如真杆菌、罗斯拜瑞士菌和乳酸菌的相对丰度。然而,目前茶多酚的口服生物利用度较低,在改善肠道疾病和维护肠道健康方面的应用也很少。因此,茶多酚对肠黏膜屏障的具体调控机制和信号转导途径仍需进一步研究。

2.7 保护心血管系统

心血管疾病是一种多因素的慢性健康并发症,直接或间接与病理生理机制有关,包括动脉粥样硬化、脂质代谢和高血压等。心血管疾病的发病机制因疾病而异。例如,冠状动脉疾病、中风、外周动脉疾病都涉及动脉硬化,可能与高血压、吸烟、饮食因素、肥胖、糖尿病、缺乏体育锻炼等因素有关。茶多酚通过抑制动脉粥样硬化、调节脂质代谢、降血压等机制,抑制心血管炎症的发展,对心血管疾病具有预防和治疗作用。

2.7.1 抑制动脉粥样硬化

动脉粥样硬化是心血管疾病的危险因素之一。茶多酚能有效缓解动脉粥样硬化。普洱茶可减少ApoE-/-小鼠早期脂肪条纹的形成和晚期纤维脂肪斑块的大小,并通过下调NF-κB的激活和促进动脉粥样硬化斑块中巨噬细胞的凋亡来减轻慢性炎症,从而改善动脉粥样硬化[61]。有证据表明,茶多酚通过增加高密度脂蛋白水平和减少巨噬细胞中低密度脂蛋白的积聚,减少泡沫细胞的形成,从而减缓动脉粥样硬化的进展[62]

2.7.2 调节脂质代谢

血脂异常是指脂蛋白代谢异常,包括总胆固醇、甘油三酯、低密度脂蛋白胆固醇升高,高密度脂蛋白胆固醇降低。绿茶、红茶、白茶对高脂饲料喂养低密度脂蛋白受体基因敲除小鼠的高脂血症、抑制血清高密度脂蛋白、胰岛素抵抗和C反应蛋白升高以及防止左室肥厚有一定的作用[63]。Guan等[64]研究发现,EGCG可以通过激活腺苷酸活化蛋白激酶(adenylate activated protein kinase,AMPK)抑制过氧化物酶体增殖物激活受体(peroxisome proliferators-activated receptors,PPAR)的表达,显著降低脂代谢、转运和吸收相关基因的mRNA表达水平,从而减少脂滴在3T3L1成熟脂肪细胞中的积累。

2.7.3 降血压

高血压仍然是心血管疾病的主要危险因素。胡晓凤等[65]以家兔为对象研究,表明静脉注射茶多酚具有一定的降压作用,且呈剂量相关性。绿茶渣蛋白水解物对与高血压密切相关的血管紧张素转换酶有体外抑制作用[66]。绿茶多酚还可以改善动脉压力感受器功能,从而改善心血管功能,这可能是由于绿茶具有抗氧化活性[67]

虽然已有大量研究表明茶多酚对心血管疾病有一定的预防和治疗作用,但茶多酚预防和治疗心血管疾病的有效剂量、副作用、作用时间、作用机制等仍需进一步探索,具体的生物活性化合物也有待研究。

2.8 其他作用

除上述药理作用外,茶多酚还具有降血糖、抗抑郁、抗高尿酸血症、神经保护等药理作用。流行病学和临床试验表明,茶多酚通过抑制α-淀粉酶、α-葡萄糖苷酶和β-葡萄糖苷酶的活性来刺激胰岛素的分泌,从而预防氧化应激和炎症相关的高血糖,并重塑肠道菌群以改善血糖[68]。据报道,在所有主要茶类中发现的成分,主要是茶多酚和多酚代谢物,能够同时通过多种途径发挥作用,以降低患抑郁症的风险[69]。EGCG在体内和体外均有明显的抗高尿酸血症作用,其机制可能与抑制黄嘌呤氧化酶(xanthine oxidase,XOD)活性和葡萄糖转运蛋白 9(glucose transporter 9,GLUT9)表达,促进有机阴离子转运蛋白1(organic anion transporters 1,OAT 1)表达有关[70]。从安化黑茶中分离得到的一种新的儿茶素衍生物MCGE通过调节N-甲基-D-天冬氨酸受体亚型2B的表达来抑制N-甲基-D-天冬氨酸诱导的兴奋性脑损伤和细胞凋亡,从而显示出神经保护作用并刺激SH-SY5Y细胞中的PI3K/Akt信号传导和半胱天冬酶依赖性途径[71]

3 茶多酚在保健食品领域中的应用

通过检索国家市场监督管理总局特殊食品信息查询平台和药智网,可以获知已有368种茶多酚相关保健食品获得批准文号,其中涵盖了有助于增强免疫力、维持血脂健康水平、控制体内脂肪、抗氧化、缓解体力疲劳等多种保健功能产品,它们多以胶囊、片剂、茶等剂型出现。已申报的国产茶多酚保健食品的保健功能现状见表2。目前茶多酚类保健食品侧重于增强免疫力、维持血脂健康水平和控制体内脂肪等保健功能。

表2 已申报的国产茶多酚保健食品的保健功能现状
Table 2 Status of health functions of declared domestic tea polyphenols health food

保健功能 产品数量 占比/%有助于维持血脂健康水平 100 27.17有助于控制体内脂肪 79 21.47有助于增强免疫力 57 15.49

续表2 已申报的国产茶多酚保健食品的保健功能现状
Continue table 2 Status of health functions of declared domestic tea polyphenols health food

保健功能 产品数量 占比/%有助于抗氧化 45 12.23有助于维持血糖健康水平 21 5.71缓解体力疲劳 20 5.43有助于维持血压健康水平 14 3.80对化学性肝损伤有辅助保护作用 13 3.53有助于改善祛黄褐斑 12 3.26耐缺氧 7 1.90辅助改善记忆 4 1.10清咽润喉 3 0.82有助于改善骨密度 2 0.54

迄今为止,我国已注册的有助于维持血脂健康水平的保健食品中总黄酮、茶多酚的使用频率较高,分别为45.12%、15.55%,其根本原因在于总黄酮、茶多酚的降脂功能比较好。茶多酚有助于维持血脂健康水平的保健产品剂型丰富,包括胶囊、片剂和冲剂等。刘勇[72]以黄芪、灵芝、银杏叶、山楂、茶多酚为主要原料,设计了一款有助于增强免疫力、有助于维持血脂健康水平的保健品,经动物实验和人体试食,得出该品具有服用简单、安全可靠、易被人体吸收、疗效显著持久、提高免疫力整体调节功能,兼顾辅助降血脂功能。黄锡奇等[73]以莱菔子、香橼、茶多酚为主要原料制成一款保健饮料,在产品的功效性和安全性上进行了动物实验和体内实验,均证明能有效提高人体免疫力,有利于改善使用者免疫力低下的状况,效果显著,且所用原料为药食同源的中药成分,无毒副作用,更易被广大消费者所接受。陈少波[74]开发了一种以决明子提取物、荷叶提取物、茶多酚和左旋肉碱为原料制成的保健食品,所用原料属药食同源,其性平缓不含能量营养素,该减肥保健食品安全系数大、减肥效果好、无毒副作用等特点,由于转变身体新陈代谢方式,体重下降后不反弹,从而达到减肥效果。

茶多酚与大健康理念的落脚点最终还是要取决于在药品和保健食品的开发上,茶多酚保健食品相对于茶多酚药品开发周期短,成本相对低。因此,保健食品开发将是茶多酚生理机制得以具体发挥的一个有效途径,尤其是随着国内保健食品管理体系的不断完善,市场的不断推进,将茶多酚与中医理念相结合开发新型保健食品将是未来的一种发展趋势。

4 结语

流行病学调查表明,茶多酚对多种疾病有一定的预防和减轻作用,包括心血管疾病、癌症、肝病等。根据体外和体内实验,茶多酚具有多种生物活性,如抗菌、抗炎、护肝、抗氧化、抗肿瘤、保护肠道、保护心血管等。首先,茶多酚可以改变细菌基因的表达,特异性结合细菌蛋白,破坏细菌细胞膜结构,从而改变细菌的生理特性,抑制细菌的生长繁殖。其次,通过调节细胞信号或作为信号转导因子影响信号转导过程,从而减轻炎症反应。第三,降低甲羟戊酸途径相关酶的活性,减少脂肪积累对人体的影响。第四,增强抗氧化酶活性和调节细胞信号通路,从而起到抗氧化的作用。第五,通过阻断细胞周期抑制癌细胞生长,阻止癌细胞突变和增殖。第六,促进肠道有益菌增殖和抑制肠道有害菌生长。第七,抑制动脉粥样硬化、调节脂质代谢、降血压等机制,抑制心血管炎症的发展。茶多酚生理机制所涉及的分子机制多种多样,其中较为突出的是NF-κB、AMPK、MAPK、PI3K/Akt和 Keap/Nrf2/ARE 信号通路。

目前,茶多酚保健食品仍存在一些不足之处,茶多酚的多羟基结构影响了化合物在人体脏器中的溶解度、降解率、吸收率和进入血液的比例,从而影响茶多酚在机体中的生物可利用性。茶多酚的结构修饰、剂型改善是未来提高其生物利用度的有效途径。此外,茶多酚及其单体对人体的一些保健作用已在临床研究中得到证实,但临床试验证据尚不充分,具体安全用量、副作用、作用时间、作用机制等仍需进一步探索,具体的生物活性化合物也有待研究。未来可开展更多研究,促进茶多酚在保健食品中的综合利用。

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Physiological Mechanism of Tea Polyphenols and Development of Their Health Food

ZHANG Wen-juan1,LIU Xue-na2,LI Li-wei2,LI Jian-xun1,SONG Wen-jun1*
(1.School of Biotechnology and Food Science,Tianjin University of Commerce,Tianjin 300134,China;2.Tasly Research Institute,Tianjin 300410,China)

Abstract:Tea polyphenols are the main active ingredients in tea.Modern pharmacological studies show that tea polyphenols have antibacterial,anti-inflammatory,anti-oxidative,anti-tumor,liver-protecting,intestinalprotecting,cardiovascular-protecting,and other extensive physiological mechanism.Therefore,it is essential to study the physiological mechanism of tea polyphenols and their application in health food.Based on the research of tea polyphenols in China and foreign countries in recent years,this paper summarized the research status of their physiological mechanism and health food,hoping to provide references for the in-depth development and clinical application of tea polyphenols.

Key words:tea polyphenols;physiological mechanism;health food;bioavailability;dosage form

DOI:10.12161/j.issn.1005-6521.2023.05.031

作者简介:张文娟(1998—),女(汉),硕士研究生,研究方向:现代食品生物技术。

*通信作者:宋文军(1967—),男(汉),教授,研究方向:现代食品生物技术。

引文格式:

张文娟,刘雪娜,李丽维,等.茶多酚生理机制及其保健食品研发进展[J].食品研究与开发,2023,44(5):217-224.

ZHANG Wenjuan,LIU Xuena,LI Liwei,et al.Physiological Mechanism of Tea Polyphenols and Development of Their Health Food[J].Food Research and Development,2023,44(5):217-224.

加工编辑:张璐

收稿日期:2022-06-30