Triggering Akkermansia with dietary polyphenols: A new weapon to combat the metabolic syndrome?

The gut and its bacterial colonizers are now well characterized as key players in whole-body metabolism, opening new avenues of research and generating great expectation for new treatments against obesity and its cardiometabolic complications. As diet is the main environmental factor affecting the gut microbiota, it has been suggested that fruits and vegetables, whose consumption is strongly associated with a healthy lifestyle, may carry phytochemicals that could help maintain intestinal homeostasis and metabolic health. We recently demonstrated that oral administration of a cranberry extract rich in polyphenols prevented diet-induced obesity and several detrimental features of the metabolic syndrome in association with a remarkable increase in the abundance of the mucin-degrading bacterium Akkermansia in the gut microbiota of mice. This addendum provides an extended discussion in light of recent discoveries suggesting a mechanistic link between polyphenols and Akkermansia, also contemplating how this unique microorganism may be exploited to fight the metabolic syndrome.     

茶多酚治疗骨质疏松症的研究进展

茶多酚是茶叶中所含有的多酚类化合物的总称,是一种具有多种生物学活性的高效抗氧化剂,研究发现茶多酚具有抗氧化、抗炎、抗肿瘤、抗辐射、抗高血脂、延缓衰老等药理和保健作用,有关茶多酚的研究目前已成为药学领域的研究热点。近年来有研究认为茶多酚的抗氧化、抗炎功效使其在骨质疏松的预防及治疗方面起着重要的作用。本文就近年来国内外对茶多酚抗骨质疏松的作用及相关机制的研究进展作一综述。     

帕金森病模型大鼠的氧化应激反应及绿茶多酚的干预作用

目的:探讨帕金森病大鼠氧化应激反应及绿茶多酚的干预作用。方法:采用6-羟基多巴胺(6-OHDA)偏侧损毁纹状体制备帕金森病大鼠模型,并随机分为模型组、绿茶多酚组,另取正常对照组、假手术组大鼠,每组10只。分别在6周后进行神经行为学检测后,取纹状体,应用比色法分别测定各组大鼠纹状体内超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)的含量。结果:帕金森病模型组大鼠纹状体内SOD、GSH、GSH-Px的含量均明显减少,MDA含量呈增加趋势;而绿茶多酚组大鼠纹状体内SOD、GSH、GSH-Px的含量均呈现增加趋势,MDA含量呈减少趋势。结论:绿茶多酚能较好地改善帕金森病大鼠的氧化应激反应,可能通过清除自由基,减轻对细胞的损伤,从而缓解帕金森病的症状。     

香椿果抗补体活性成分

目的:研究香椿果抗补体活性成分。方法:采用溶血法进行抗补体活性筛选,然后利用溶剂萃取和多种色谱技术分离纯化,以1H-NMR,13C-NMR波谱方法,结合文献数据,鉴定化合物结构。结果:香椿果提取物具有显著抗补体活性,经溶剂萃取,其中乙酸乙酯部位为活性部位,从中分离得到14个化合物,分别鉴定为没食子酸(1),没食子酸甲酯(2),6-O-没食子酰基-葡萄糖(3),1,2,3-三-O-没食子酰基-β-D-葡萄糖(4),1,2,6-三-O-没食子酰基-β-D-葡萄糖(5),1,2,3,6-四-O-没食子酰基-β-D-葡萄糖(6),1,2,3,4,6-五-O-没食子酰基-β-D-葡萄糖(7),槲皮素-3-O-α-L-鼠李糖苷(8),芦丁(9),异鼠李素-3-O-β-半乳糖苷(10),槲皮素-3-O-β-半乳糖苷(11),山柰酚-3-O-β-D-葡萄糖苷(12),山柰酚-3-O-α-L-鼠李糖苷(13),槲皮素(14)。其中化合物3~14为首次从香椿果中分离得到,化合物5,10,11为首次从香椿中分离得到。化合物4~7有显著抗补体活性,半数抑制浓度(IC_(50))分别为88.3,76.2,13.9,9.6μmol·L~(-1)。结论:香椿果活性部位为乙酸乙酯萃取部位,活性成分为其中没食子酰基葡萄糖苷衍生物和黄酮苷,前者抗补体活性显著强于后者,并且其抗补体活性随着与葡萄糖羟基相连接的没食子酰基数目的增加而增强。     

Does the consumption of green tea reduce the risk of lung cancer among smokers?

Experimental and epidemiological studies were reviewed to assess whether the consumption of green tea could reduce the risk of lung cancer in smokers. Articles published since 1990 were located by searching electronic databases PubMed, Ovid and Science Direct, using keywords 'lung cancer', 'tea' and 'smoking' without any restriction on language. After relevant articles had been located, further papers were obtained from their reference lists. Evidence from experimental studies (in vitro animal and human trials) suggested that regular intake of green tea may be protective against tobacco carcinogens. However, the mechanism behind the protective effect is only partly understood. In most of the epidemiological studies reviewed, the green tea exposure was within 5 years of the interview or follow-up, which would coincide with the induction period and latent period of lung cancer. Longer term studies are thus needed to further quantify the cancer risk. There is some evidence suggesting regular intake of green tea at high level (>3 cups per day) may reduce the risk of smokers developing lung cancer. Improvement in measuring green tea intake is required in order to confirm the evidence from epidemiological studies.     

葡茶多酚对尿酸诱导的肾小管上皮细胞TGF-β1表达的影响

目的研究葡茶多酚对尿酸诱导的肾小管上皮细胞TGF-β1表达的影响。方法培养分离肾小管上皮细胞,分对照组、尿酸组、葡茶多酚组（在尿酸干预基础上,分别加入终浓度为0．2、0．4、0．8mg／L的葡茶多酚）共5组,MTT法测细胞增生率、TUNEI。测凋亡率、ELISA测TGF-β1分泌,RT-PCR测TGF-β1mRNA表达。结果与尿酸组相比,加入葡茶多酚干预后,肾小管上皮细胞增生率明显增高（P〈0．01）,葡茶多酚干预浓度愈高,肾小管上皮细胞增生率则愈高;葡茶多酚各浓度组在任一时间点凋亡率均明显低于尿酸组,差异有显著意义;葡茶多酚各浓度组之间相比,浓度愈高,则培养细胞凋亡率愈低,差异有显著意义,尿酸作用时间愈长,则培养细胞凋亡率愈高;葡茶多酚各浓度组在任一时间点培养上清TGF-β1浓度均明显降低,差异有显著意义;葡茶多酚各浓度组之间相比,浓度愈高,则培养上清TGF-β1浓度愈低,差异有显著意义,尿酸作用时间愈长,则培养上清TGF-β1浓度愈高;葡茶多酚各浓度组在任一时间点培养上清TGF-β1mRNA表达均明显降低,差异有显著意义;葡茶多酚各浓度组之间相比,浓度愈高,则培养上清TGF-β1mRNA表达愈低,但0．2mg／L葡茶多酚组与0．4mg／L葡茶多酚组、0．4mg／L葡茶多酚组与0．8mg／L葡茶多酚组差异无显著意义,0．2mg／L葡茶多酚组与0．8mg／L葡茶多酚组之间差异有显著意义,尿酸作用时间愈长,则TGF-β1mRNA表达愈高。结论高尿酸能抑制肾小管上皮细胞的增生,减少肾小管上皮细胞的凋亡及TGF-β1的表达与分泌。     

Effect of mate tea (Ilex paraguariensis) on the expression of the leukocyte NADPH oxidase subunit p47phox and on circulating inflammatory cytokines in healthy men: a pilot study

Increased superoxide production by phagocytic NADPH oxidase has been associated with inflammatory conditions. Growing evidences suggest that dietary polyphenols may modulate the expression of NADPH oxidase subunits. Herein, we examined whether soluble mate tea (SMT) consumption – a polyphenol-rich beverage – affects the expression of the leukocyte NADPH oxidase protein p47^phox and/or circulating biomarkers of inflammation and antioxidant biomarkers in humans. In a two-phase study, nine men were requested to drink water (control) for 8 d and then follow a second 8-d period drinking SMT. Blood samples were analysed for p47^phox protein in CD16⁺/CD14^? cells, interleukin (IL)-1β (IL-1β), tumour necrosis factor-alpha (TNF-α), IL-6, total phenols, and reduced and oxidised glutathione (GSH and GSSG, respectively) after each study phase. After SMT intake, CD16⁺/CD14^? cells' p47^phox protein and serum TNF-α and IL-6 levels were significantly attenuated (P?<?.05) while plasma phenolic compounds and blood GSH:GSSG ratio were significantly enhanced (P?<?.05). Consumption of SMT favourably affected leukocytes' p47^phox expression and inflammatory cytokine and antioxidants levels in peripheral blood, which may help decrease oxidative stress and low-grade inflammation.     

Association of Polyphenols from Oranges and Apples with Specific Intestinal Microorganisms in Systemic Lupus Erythematosus Patients

Our group has recently shown the existence of a gut microbial dysbiosis in systemic lupus erythematosus (SLE), supporting previous evidence involving intestinal bacteria in the initiation and amplification of autoimmune diseases. While several studies have addressed the use of dietary fibres to modify intestinal microbiota, information about other correlated components, such as polyphenols, is scarce. The aim of this work was to identify dietary components able to influence this altered microbiota in 20 SLE women and 20 age-matched controls. Food intake was recorded by means of a food frequency questionnaire. The intake of fibres was calculated from Marlett tables, and Phenol-Explorer was used for polyphenol consumption. Results showed positive associations between flavone intake and Blautia, flavanones and Lactobacillus, and dihydrochalcones and Bifidobacterium in the SLE group. Regarding the controls, dihydroflavonols were directly associated with Faecalibacterium, whereas flavonol intake was inversely associated with Bifidobacterium. From the food sources of these polyphenols related to microbiota, orange intake was directly associated with Lactobacillus and apple with Bifidobacterium in SLE, whilst red wine was the best contributor to Faecalibacterium variation. The association between common foods and particular microbial genera, reported to be decreased in SLE, could be of great importance for these patients.