Effect of pu-erh tea on body fat and lipid profiles in rats with diet-induced obesity

The inhibitory activity of Flos Sophorae Immaturus extract and its major flavonoid components on pancreatic lipase

Inhibition of pancreatic lipase (PL) is a strategy to prevent obesity. The inhibitory effects of Flos Sophorae Immaturus (FSI) extract and its main flavonoid components, rutin and quercetin, on PL were investigated. The contents of rutin and quercetin in FSI extract were 44.10 ± 1.33 % and 6.07 ± 1.62 %, respectively. The IC50 values of FSI extract, rutin and quercetin on PL were 322, 258 and 71 μg/mL, respectively. Rutin and quercetin inhibited PL in a reversible and noncompetitive manner. The combination of rutin and quercetin exhibited synergistic inhibitory effects at low concentration. The binding of rutin/quercetin with PL caused the fluorescence quenching of protein. Fluorescence titration showed the binding affinity of quercetin with PL protein was stronger than that of rutin. Circular dichroism analysis showed the binding changed the secondary structure of PL with an increase in random coil and a decrease in α-Helix and β-Sheet. Molecular docking revealed that rutin and quercetin could interact with the amino acid residues around the catalytic site through multiple secondary interactions. In vivo studies showed that FSI extract can reduce fat absorption and promote fecal fat excretion through inhibition of PL activity, and the effects were mainly due to rutin and quercetin.

Theabrownin from Dark Tea Ameliorates Insulin Resistance via Attenuating Oxidative Stress and Modulating IRS-1/PI3K/Akt Pathway in HepG2 Cells

Dark tea has great potential in regulating glycolipid metabolism, and theabrownin (TB) is considered to be the characteristic and bioactive constituent of dark tea. This study evaluated the ability of TB1 (fermented for 7 days) and TB2 (fermented for 14 days) isolated from dark tea to reverse insulin resistance (IR) in HepG2 cells. The results indicated that TB significantly ameliorated oxidative stress by improving mitochondrial function. In addition, TB improved glycogen synthesis and glucose consumption, and inhibited gluconeogenesis and fatty acid synthesis, by regulating GSK3β (Glycogen synthase kinase 3β), G6Pase (Glucose-6-phosphatase), GCK (Glucokinase), PEPCK1 (Phosphoenolpyruvate carboxy kinase 1), SREBP-1C (sterol regulatory element-binding protein 1C), FASN (fatty acid synthase), and ACC (Acetyl-CoA carboxylase). Additionally, the results of Western blot and real-time PCR experiments demonstrated that TB modulated glucolipid metabolism through the IRS-1 (Insulin receptor substrate 1)/PI3K (phosphatidylinositol-3 kinase)/Akt (protein kinase B) signaling pathway. Treatment with the PI3K inhibitor demonstrated a favorable correlation between PI3K activation and TB action on glycolipid metabolism. Notably, we observed that TB2 had a greater effect on improving insulin resistance compared with TB1, which, due to its prolonged fermentation time, increased the degree of oxidative polymerization of TB.

Theabrownin of raw and ripened pu-erh tea varies in the alleviation of HFD-induced obesity via the regulation of gut microbiota

PURPOSE

Pu-erh tea can be classified into raw pu-erh tea and ripened pu-erh tea. Theabrownin (TB) is one of the major components of pu-erh tea. The difference of the anti-obesity activity between raw pu-erh tea TB (R-TB) and ripened pu-erh tea TB (F-TB) has not been comprehensively investigated yet. Therefore, this article aimed to systemically study the anti-obesity activity and the underlying mechanism of R-TB and F-TB.

METHOD

High-fat diet (HFD)-induced C57BL/6J mice with obesity were gavaged with R-TB or F-TB to assess the effect of R-TB and F-TB on the amelioration of obesity, the expression of lipid metabolism-related genes, and the regulation of gut flora imbalance.

RESULTS

Administration of both R-TB and F-TB could suppress body weight gain, improve insulin sensitivity and glucose homeostasis, regulate the lipid level and reduce the chronic inflammation in obese mice. The underlying anti-obesity mechanism of R-TB and F-TB might involve the regulation of lipogenesis and lipolysis, amelioration of the gut microbiota disorder and promotion of microbial metabolism. Interestingly, R-TB was more efficient in the regulation of blood glucose, reduction of inflammation and suppression of partial adipogenesis-related genes and protein, while F-TB was more effective in the inhibition of lipolysis-related genes and protein. In addition, F-TB might be more effective in adjusting the dysbacteria caused by HFD back to normal by promoting the proliferation of the beneficial microbiota, such as Lactobacillus and Lachnospiraceae_NK4A136_group.

CONCLUSION

Taken together, both R-TB and F-TB had the potential to be developed as beneficial dietary supplements or functional foods for ameliorating obesity and obesity-related metabolic disorders, but their effects and the ability to regulate the intestinal flora varied.

Dietary Theabrownin Supplementation Improves Production Performance and Egg Quality by Promoting Intestinal Health and Antioxidant Capacity in Laying Hens

Theabrownin, an activated and ample pigment in Pu-erh tea, is known to exert antiobesity and antihyperlipidemic effects in humans, mice, and rats. In this study, we aimed to explore the effects of theabrownin (TB) dietary supplementation on production performance, egg quality, intestinal health, and antioxidant capacities in laying hens. In total, 160 Lohmann laying hens (25 weeks old) were randomly split into four groups (each group 40 hens), namely the CONT (control, basal diet + 0 mg/kg TB), TB1 (basal diet + 100 mg/kg TB), TB2 (basal diet + 200 mg/kg TB), and TB4 (basal diet + 400 mg/kg TB) groups, respectively. These were supplemented with TB for 12 weeks. The results showed that the TB1 group exhibited a significantly higher laying rate during 9 to 12 weeks and higher egg weight and feed conversion efficiency (lower FCR) during 5 to 8 weeks and in the overall period (1 to 12 weeks) than the CONT group (p < 0.05). Compared with the CONT group, the eggs from the TB4 group had higher albumen height and Haugh unit than those from the other treatment groups after the 8th and 12th week; notably, the same was also observed in the TB1 and TB2 groups but only after the 12th week (p < 0.05). The albumen quality (albumen height and Haugh unit) after 3 weeks of storage was significantly higher in the TB1, TB2 and TB4 groups than in the CONT group (p < 0.05). Furthermore, TB supplementation lowered the serum levels of total cholesterol and total triglyceride (p < 0.05). Expression analysis revealed that TB2 and TB4 groups had reduced expression of tumor necrosis factor-α (p < 0.05), while TB1, TB2, and TB4 had significantly decreased expression of interleukin-1β and IL-6 (p < 0.05). Conversely, zonula occludens-1, claudin-1, and mucin-2 were upregulated in the TB2 and TB4 groups (p < 0.05). Meanwhile, dietary TB supplementation ameliorated the antioxidant status of the ovary and the magnum, showing a significant reduction in malondialdehyde and 8-hydroxydeoxyguanosine levels in the magnum, the upregulation of glutathione in the ovary, and superoxide dismutase and catalase in the magnum (p < 0.05). Overall, dietary supplementation with TB (>100 mg/kg) improved production performance and egg storage quality by improving the intestinal health and antioxidant capacities of the reproductive system in laying hens.

Peanut Shell Extract and Luteolin Regulate Lipid Metabolism and Induce Browning in 3T3-L1 Adipocytes

Peanut shells are agricultural waste products that require utilization. The freeze-dried ethanolic peanut shell extract (PSE) contained 10.01 ± 0.55 mg/g of luteolin (LUT) with a total polyphenol content of 18.11 ± 0.88 mg GAE/g. Thus, LUT is one of the major polyphenolic components in PSE. Although PSE displays antibacterial and neurotrophic activities, minimal research is available addressing its potential role in lipid metabolism. This study investigated the role of PSE in terms of inhibiting adipogenesis, accelerating lipolysis, and promoting lipid browning using the 3T3-L1 cell line. Without affecting cell viability, high concentrations of PSE and LUT prevented adipogenesis by reducing the mRNA levels of C/EBPα, PPARγ, and SREBP1-c, and increasing the protein levels of pACC and pAMPK. Moreover, PSE and LUT induced lipolysis by activating lipolytic proteins, and enhanced the protein expressions of the brown adipocyte-specific markers, UCP1, PGC-1α, and SIRT1 in fully differentiated 3T3-L1 adipocytes. Increased mitochondrial biosynthesis provided additional evidence in favor of these findings. Due to their anti-obesity properties, it is proposed that PSE and LUT could be used as potential dietary supplements.

The Anti-Obesity Effect of Traditional Chinese Medicine on Lipid Metabolism

With the improvement of living conditions and the popularity of unhealthy eating and living habits, obesity is becoming a global epidemic. Obesity is now recognized as a disease that not only increases the risk of metabolic diseases such as type 2 diabetes (T2D), non-alcoholic fatty liver disease (NAFLD), cardiovascular disease (CVD), and cancer but also negatively affects longevity and the quality of life. The traditional Chinese medicines (TCMs) are highly enriched in bioactive compounds and have been used for the treatment of obesity and obesity-related metabolic diseases over a long period of time. In this review, we selected the most commonly used anti-obesity or anti-hyperlipidemia TCMs and, where known, their major bioactive compounds. We then summarized their multi-target molecular mechanisms, specifically focusing on lipid metabolism, including the modulation of lipid absorption, reduction of lipid synthesis, and increase of lipid decomposition and lipid transportation, as well as the regulation of appetite. This review produces a current and comprehensive understanding of integrative and systematic mechanisms for the use of TCMs for anti-obesity. We also advocate taking advantage of TCMs as another therapy for interventions on obesity-related diseases, as well as stressing the fact that more is needed to be done, scientifically, to determine the active compounds and modes of action of the TCMs.

Effects of several tea extracts on nonalcoholic fatty liver disease in mice fed with a high-fat diet

Nonalcoholic fatty liver disease (NAFLD) is considered as a severe threat to human health. It has been reported that tea has abundant bioactive compounds and beneficial effects. In our study, the effects of 12 tea extracts on NAFLD were assessed and compared at the dose of 200 mg/kg body weight in mice fed with a high-fat diet (HFD) for 15 weeks. Enshi Yulu Tea, Fenghuang Narcissus Tea, and Yihong Tea showed strong effects in suppressing the accumulation of epididymal and perirenal adipose tissue as well as the increases of body weight and liver weight. The histopathological analysis revealed that hepatic steatosis and adipocyte hypertrophy induced by a HFD could be ameliorated by tea supplementation. In addition, Enshi Yulu Tea and Qing Brick Tea exerted more remarkable functions on decreasing the level of serum triglyceride and preventing hepatic fat accumulation, respectively. Furthermore, Fenghuang Narcissus Tea, Enshi Yulu Tea, and Qing Brick Tea could reverse the abnormal change in the levels of glutathione and superoxide dismutase. Moreover, 13 phytoconstituents were detected and quantified in these teas with high-performance liquid chromatography (HPLC) method. The correlation analysis demonstrated that gallic acid might decrease MDA level, and the reduction of liver weight might be attributed to ellagic acid. However, it should be paid attention to some teas that showed hepatotoxicity with elevated levels of aspartate transaminase and alanine aminotransferase. Several teas showed strong effects in the prevention of NAFLD, which could be developed into functional foods against NAFLD.

Regulation of Apolipoprotein B by Natural Products and Nutraceuticals: A Comprehensive Review

Cardiovascular Disease (CVD) is the most important and the number one cause of mortality in both developing and industrialized nations. The co-morbidities associated with CVD are observed from infancy to old age. Apolipoprotein B100 (Apo B) is the primary apolipoprotein and structural protein of all major atherogenic particles derived from the liver including Very-Low- Density Lipoproteins (VLDL), Intermediate-density Lipoprotein (IDL), and Low-density Lipoprotein (LDL) particles. It has been suggested that measurement of the Apo B concentration is a superior and more reliable index for the prediction of CVD risk than is the measurement of LDL-C. Nutraceuticals and medicinal plants have attracted significant attention as it pertains to the treatment of non-communicable diseases, particularly CVD, diabetes mellitus, hypertension, and Nonalcoholic Fatty Liver Disease (NAFLD). The effect of nutraceuticals and herbal products on CVD, as well as some of its risk factors such as dyslipidemia, have been investigated previously. However, to the best of our knowledge, the effect of these natural products, including herbal supplements and functional foods (e.g. fruits and vegetables as either dry materials, or their extracts) on Apo B has not yet been investigated. Therefore, the primary objective of this paper was to review the effect of bioactive natural compounds on plasma Apo B concentrations. It is concluded that, in general, medicinal plants and nutraceuticals can be used as complementary medicine to reduce plasma Apo B levels in a safe, accessible, and inexpensive manner in an attempt to prevent and treat CVD.

Theacrine and strictinin, two major ingredients for the anti-influenza activity of Yunnan Kucha tea

ETHNOPHARMACOLOGICAL RELEVANCE

Kucha tea plant (Camellia assamica var. kucha Chang et Wang) is regarded as a mutant variety of wild Pu'er tea plant found in few mountain areas of Yunnan, China. Its fresh young leaves and shoots are picked by the indigenous aborigines in these local areas to prepare an herbal tea for the treatment of common cold empirically.

MATERIALS AND METHODS

Two extra compounds of relative abundance were detected in Kucha tea in comparison with Pu'er tea, and their chemical structures were identified as chlorogenic acid and theacrine. These two compounds as well as two major compounds, strictinin and caffeine, in Kucha tea were evaluated for their cytotoxicity and inhibitory effects on human influenza virus A/Puerto Rico/8/34 by analyzing viral protein expression and progeny production.

RESULTS

No or low cytotoxicity was detected for the four Kucha compounds when their concentrations were below 100 μM. Expression of viral NS1 protein was significantly inhibited by chlorogenic acid, theacrine or strictinin, but not caffeine at a concentration of 100 μM. The relative inhibitory potency was detected as chlorogenic acid < theacrine < strictinin, and both theacrine and strictinin displayed significant inhibition at a concentration of 50 μM. According to a plaque assay, viral progeny production was significantly reduced by theacrine or strictinin, but not by chlorogenic acid or caffeine under the same concentration of 100 μM.

CONCLUSION

It is suggested that theacrine and strictinin are two major ingredients responsible for the anti-influenza activity of Yunnan Kucha tea traditionally used for the treatment of common cold.

Lipase Inhibitors for Obesity: A Review

With the rapid increase in the population of obese individuals, obesity has become a global problem. Many kinds of chronic metabolic diseases easily caused by obesity have received increasing attention from researchers. People are also striving to find various safe and effective treatment methods as well as anti-obesity medicines. Pancreatic lipase (PL) inhibitors have received substantial attention from researchers in recent years, and PL inhibitors from natural products have attracted much attention due to their structural diversity, low toxicity and wide range of sources. They have been used in the intestinal tract, blood, and the central nervous system with no side effects, and these advantages could lead to a new generation of diet pills or health care products with great development potential. This article is mainly aimed at discussing the research of obesity drug treatment with PL inhibitors and offers a brief review of related properties and the use of PL inhibitors in the field of weight loss.

Oral gallic acid improve liver steatosis and metabolism modulating hepatic lipogenic markers in obese mice

INTRODUCTION

Gallic acid (GA) is a natural endogenous polyphenol found in a variety of fruits, vegetables and wines, with beneficial effects on the energetic homeostasis.

AIM

The present study aimed to investigate oral gallic acid effects on liver steatosis and hepatic lipogenesis markers in obese mice evaluating new possible molecular related mechanisms.

METHODS

Twenty-four Swiss male mice were divided into four groups and fed for 60 days with standard diet (ST), standard diet plus gallic acid (ST + GA), high-fat diet (HFD), and high-fat diet plus gallic acid (HFD + GA). We evaluated the relationship between body weight, food intake and serum levels of total cholesterol, triglycerides, insulin, aspartate and alanine transaminases. Liver histology was analyzed by hematoxylin and eosin staining. These results were accompanied by bioinformatics analyses. The acetyl-CoA carboxylase (ACC), sterol regulatory element binding protein-1 (SREBP-1) and fatty acid synthase (FAS) expression was assessed by quantitative real-time reverse transcriptase PCR (qRT-PCR).

RESULTS

The main findings of the present study showed that GA reduced liver steatosis, body weight and plasma insulin levels. Analyzes of hepatic steatosis related genes expression showed that ACC and FAS mRNA were significantly suppressed in liver of HFD + GA mice. These data was corroborated by bioinformatics analysis.

CONCLUSION

These data suggest an important clinical application of GA in the prevention and treatment of liver diseases.

Theabrownin from Pu-erh tea attenuates hypercholesterolemia via modulation of gut microbiota and bile acid metabolism

Pu-erh tea displays cholesterol-lowering properties, but the underlying mechanism has not been elucidated. Theabrownin is one of the most active and abundant pigments in Pu-erh tea. Here, we show that theabrownin alters the gut microbiota in mice and humans, predominantly suppressing microbes associated with bile-salt hydrolase (BSH) activity. Theabrownin increases the levels of ileal conjugated bile acids (BAs) which, in turn, inhibit the intestinal FXR-FGF15 signaling pathway, resulting in increased hepatic production and fecal excretion of BAs, reduced hepatic cholesterol, and decreased lipogenesis. The inhibition of intestinal FXR-FGF15 signaling is accompanied by increased gene expression of enzymes in the alternative BA synthetic pathway, production of hepatic chenodeoxycholic acid, activation of hepatic FXR, and hepatic lipolysis. Our results shed light into the mechanisms behind the cholesterol- and lipid-lowering effects of Pu-erh tea, and suggest that decreased intestinal BSH microbes and/or decreased FXR-FGF15 signaling may be potential anti-hypercholesterolemia and anti-hyperlipidemia therapies.

Theabrownin from Pu-erh tea together with swinging exercise synergistically ameliorates obesity and insulin resistance in rats

PURPOSE

Theabrownin (TB)-containing Pu-erh tea has been shown to be hypolipidemic in rats fed a high-fat diet. Physical exercise such as swinging is also known to reduce obesity. We hypothesized that TB in combination with swinging can synergistically ameliorate obesity and insulin resistance in rats with metabolic syndrome.

METHODS

TB, rosiglitazone, or lovastatin (controls) was administered by gavage to rats fed a diet high in fat, sugar, and salt. A subgroup of the rats was subjected to a 30-min daily swinging exercise regimen, whereas the other rats did not exercise.

RESULTS

Theabrownin in combination with swinging was found to significantly improve serum lipid status and prevent development of obesity and insulin resistance in rats. Liver transcriptomics data suggested that theabrownin activated circadian rhythm, protein kinase A, the adenosine monophosphate-activated protein kinase, and insulin signaling pathways by enhancing cyclic adenosine monophosphate levels and, hence, accelerating nutrient metabolism and the consumption of sugar and fat. The serum dopamine levels in rats increased significantly after exercise. In parallel work, intraperitoneal dopamine injections were shown to significantly reduce weight gain and prevent the elevation in triglyceride levels that would otherwise be induced by the high fat-sugar-salt diet. Theabrownin prevented obesity and insulin resistance mainly by affecting the circadian rhythm, while swinging exercise stimulated the overproduction of dopamine to accelerate metabolism of glucose and lipid.

CONCLUSIONS

Theabrownin and exercise synergistically ameliorated metabolic syndrome in rats and effectively prevented obesity.

Aqueous raw and ripe Pu-erh tea extracts alleviate obesity and alter cecal microbiota composition and function in diet-induced obese rats

Pu-erh tea is attracting increased attention worldwide because of its unique flavor and health effects, but its impact on the composition and function of the gut microbiota remains unclear. The aim of this study was to investigate the effects of aqueous extracts of fermented (ripe) and non-fermented (raw) Pu-erh teas on the composition and function of the intestinal microbiota of rats with diet-induced obesity. We conducted a comparative metagenomic and meta-proteomic investigation of the microbial communities in cecal samples taken from obese rats treated with or without extracts of raw or ripe Pu-erh teas. By analyzing the composition and diversity of 16S rRNA amplicons and expression profiles of 814 distinct proteins, we found that despite differences in the chemical compositions of raw and ripe Pu-erh teas, administration of either tea at two doses (0.15- and 0.40-g/kg body weight) significantly (P < 0.05) increased microbial diversity and changed the composition of cecal microbiota by increasing the relative abundances of Firmicutes and decreasing those of Bacteroidetes. Community metabolic processes, including sucrose metabolism, glycolysis, and syntheses of proteins, rRNAs, and antibiotics were significantly (P < 0.05) promoted or had a tendency (0.10 < P < 0.05) to be promoted due to the enrichment of relevant enzymes. Furthermore, evidence at population, molecular, and metabolic levels indicated that polyphenols of raw Pu-erh tea and their metabolites potentially promote Akkermansia muciniphila growth by stimulating a type II and III secretion system protein, the elongation factor Tu, and a glyceraldehyde-3-phosphate dehydrogenase. This study provides new evidence for the prebiotic effects of Pu-erh tea.

Inflammation and Oxidative Stress in an Obese State and the Protective Effects of Gallic Acid

Metabolic complications in an obese state can be aggravated by an abnormal inflammatory response and enhanced production of reactive oxygen species. Pro-inflammatory response is known to be associated with the formation of toxic reactive oxygen species and subsequent generation of oxidative stress. Indeed, adipocytes from obese individuals display an altered adipokine profile, with upregulated expression and secretion of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin (IL-6). Interestingly, natural compounds, including phenolic enriched foods are increasingly explored for their ameliorative effects against various metabolic diseases. Of interest is gallic acid, a trihydroxybenzoic acid that has progressively demonstrated robust anti-obesity capabilities in various experimental models. In addition to reducing excessive lipid storage in obese subjects, gallic acid has been shown to specifically target the adipose tissue to suppress lipogenesis, improve insulin signaling, and concomitantly combat raised pro-inflammatory response and oxidative stress. This review will revise mechanisms involved in the pathophysiological effects of inflammation and oxidative stress in an obese state. To better inform on its therapeutic potential and improvement of human health, available evidence reporting on the anti-obesity properties of gallic acid and its derivatives will be discussed, with emphases on its modulatory effect on molecular mechanisms involved in insulin signaling, inflammation and oxidative stress.

Pu-erh Tea Ameliorates Atherosclerosis Associated with Promoting Macrophage Apoptosis by Reducing NF-κB Activation in ApoE Knockout Mice

We explored whether pu-erh tea consumption ameliorates atherosclerosis and the possible mechanism for its effects in apolipoprotein E-deficient (ApoE^−/−) mice. Our data showed that pu-erh tea consumption markedly reduced early fatty streak formation and the advanced fibrofatty plaque sizes. Additionally, the mean proportion of inflammatory macrophages in the plaque decreased, and the number of apoptotic macrophages increased significantly. NF-κB activity in peritoneal macrophages decreased by 75.6% compared to the controls, similar with the levels of IL-6, IL-12, and TNF-α expression. The tea extract increased the apoptosis of RAW264.7 cells by decreasing NF-κB activation and reducing the inflammatory cytokine expression. In conclusion, pu-erh tea ameliorates atherosclerosis progress by alleviating the chronic inflammatory state by reducing NF-κB activation and promoting macrophage apoptosis in atherosclerotic plaques.

Molecular mechanisms of the anti-obesity effect of bioactive compounds in tea and coffee

Obesity is a serious health problem in adults and children worldwide. However, the basic strategies for the management of obesity (diet, exercise, drugs and surgery) have limitations and side effects. Therefore, many researchers have sought to identify bioactive components in food. Tea and coffee are the most frequently consumed beverages in the whole world. Their health benefits have been studied for decades, especially those of green tea. The anti-obesity effect of tea and coffee has been studied for at least ten years. The results have shown decreased lipid accumulation in cells via the regulation of the cell cycle during adipogenesis, changes in transcription factors and lipogenesis-related proteins in the adipose tissue of animal models, and decreased body weight and visceral fat in humans. Tea and coffee also influence the gut microbiota in obese animals and humans. Although the anti-obesity mechanism of tea and coffee still needs further clarification, they may have potential as a new strategy to prevent or treat obesity.

The Potential Effects of Caffeinated Beverages on Insulin Sensitivity

Caffeinated beverages, most commonly tea and coffee, may have important effects on insulin regulation that may give their consumption an important role among nutritional factors in the development of diseases of glucose and insulin metabolism, such as diabetes and atherosclerotic vascular diseases. These beverages include compounds that may have contradictory effects on insulin and glucose: Caffeine impairs insulin sensitivity, but polyphenolic molecules within tea, coffee, and cocoa augment the effects of insulin. In addition, epidemiologic associations exist between greater consumption of such beverages and lower risk of diabetes. The beneficial effects of such beverages might be enhanced by changing the process of their preparation and substitution of other substances commonly added to caffeinated beverages that impair the effect of insulin, such as sugar or milk.

Insights into the microbial diversity and community dynamics of Chinese traditional fermented foods from using high-throughput sequencing approaches

Chinese traditional fermented foods have a very long history dating back thousands of years and have become an indispensable part of Chinese dietary culture. A plethora of research has been conducted to unravel the composition and dynamics of microbial consortia associated with Chinese traditional fermented foods using culture-dependent as well as culture-independent methods, like different high-throughput sequencing (HTS) techniques. These HTS techniques enable us to understand the relationship between a food product and its microbes to a greater extent than ever before. Considering the importance of Chinese traditional fermented products, the objective of this paper is to review the diversity and dynamics of microbiota in Chinese traditional fermented foods revealed by HTS approaches.

Flavanols from the Camellia sinensis var. assamica and their hypoglycemic and hypolipidemic activities

α-Glucosidase and lipase inhibitors play important roles in the treatment of hyperglycaemia and dyslipidemia. To identify novel naturally occurring inhibitors, a bioactivity-guided phytochemical research was performed on the pu-erh tea. One new flavanol, named (–)-epicatechin-3-O-(Z)-coumarate (1), and 16 known analogs (2—17) were isolated from the aqueous extract of the pu-erh tea. Their structures were determined by spectroscopic and chemical methods. Furthermore, the water extract of pu-erh tea and its fractions exhibited inhibitory activities against α-glucosidases and lipases in vitro; compound 15 showed moderate inhibitory effect against sucrase with an IC₅₀ value of 32.5 μmol/L and significant inhibitory effect against maltase with an IC₅₀ value of 1.3 μmol/L. Compounds 8, 10, 11 and 15 displayed moderate activity against a lipase with IC₅₀ values of 16.0, 13.6, 19.8, and 13.3 μmol/L, respectively.

Fermented green tea extract exhibits hypolipidaemic effects through the inhibition of pancreatic lipase and promotion of energy expenditure

Hyperlipidaemia is a major cause of atherosclerosis and related CVD and can be prevented with natural substances. Previously, we reported that a novel Bacillus-fermented green tea (FGT) exerts anti-obesity and hypolipidaemic effects. This study further investigated the hypotriglyceridaemic and anti-obesogenic effects of FGT and its underlying mechanisms. FGT effectively inhibited pancreatic lipase activity in vitro (IC50, 0·48 mg/ml) and ameliorated postprandial lipaemia in rats (26 % reduction with 500 mg/kg FGT). In hypertriglyceridaemic hamsters, FGT administration significantly reduced plasma TAG levels. In mice, FGT administration (500 mg/kg) for 2 weeks augmented energy expenditure by 22 % through the induction of plasma serotonin, a neurotransmitter that modulates energy expenditure and mRNA expressions of lipid metabolism genes in peripheral tissues. Analysis of the gut microbiota showed that FGT reduced the proportion of the phylum Firmicutes in hamsters, which could further contribute to its anti-obesity effects. Collectively, these data demonstrate that FGT decreases plasma TAG levels via multiple mechanisms including inhibition of pancreatic lipase, augmentation of energy expenditure, induction of serotonin secretion and alteration of gut microbiota. These results suggest that FGT may be a useful natural agent for preventing hypertriglyceridaemia and obesity.

Preventive effect of Silibinin in combination with Pu-erh tea extract on non-alcoholic fatty liver disease in ob/ob mice

This study investigates the synergistic effect of Silibinin combined with Pu-erh tea extract against NAFLD.

Transcriptome Profile Reveals that Pu-Erh Tea Represses the Expression of Vitellogenin Family to Reduce Fat Accumulation in Caenorhabditis elegans

Due to misbalanced energy surplus and expenditure, obesity has become a common chronic disorder that is highly associated with many metabolic diseases. Pu-erh tea, a traditional Chinese beverage, has been believed to have numerous health benefits, such as anti-obesity. However, the underlying mechanisms of its anti-obesity effect are yet to be understood. Here, we take the advantages of transcriptional profile by RNA sequencing (RNA-Seq) to view the global gene expression of Pu-erh tea. The model organism Caenorhabditis elegans was treated with different concentrations of Pu-erh tea water extract (PTE, 0 g/mL, 0.025 g/mL, and 0.05 g/mL). Compared with the control, PTE indeed decreases lipid droplets size and fat accumulation. The high-throughput RNA-Sequence technique detected 18073 and 18105 genes expressed in 0.025 g/mL and 0.05 g/mL PTE treated groups, respectively. Interestingly, the expression of the vitellogenin family (vit-1, vit-2, vit-3, vit-4 and vit-5) was significantly decreased by PTE, which was validated by qPCR analysis. Furthermore, vit-1(ok2616), vit-3(ok2348) and vit-5(ok3239) mutants are insensitive to PTE triggered fat reduction. In conclusion, our transcriptional profile by RNA-Sequence suggests that Pu-erh tea lowers the fat accumulation primarily through repression of the expression of vit(vitellogenin) family, in addition to our previously reported (sterol regulatory element binding protein) SREBP-SCD (stearoyl-CoA desaturase) axis.

Serum metabolomics analysis of rat after intragastric infusion of Pu-erh theabrownin

BACKGROUND

The aim was to study the effects of Pu-erh theabrownin (TB) (Mw  > 50 kDa) on the metabolism of rat serum by nuclear magnetic resonance (NMR)-based metabolomics and identify candidate marker metabolites associated with Pu-erh TB, and thus provide fundamental information for a better understanding of the metabolism of Pu-erh tea in animals.

RESULTS

TB infusion induced different changes in endogenous serum metabolites depending on the type of diet. Compared with the control group, the TB infusion group showed significantly reduced serum glycine and choline levels, as well as significantly increased taurine, carnitine and high-density lipoprotein (all P < 0.05). Compared with the high-lipid group, the high-lipid TB infusion group exhibited significantly reduced low-density lipoprotein and acetate levels, as well as significantly increased inositol, carnitine and glycine levels (all P < 0.05).

CONCLUSION

Examination of the variations of these differential expressed metabolites and their individual functions revealed that the TB extract accelerated lipid catabolism in rats and might affect glucose metabolism. Of these, carnitine level significantly increased after intragastric infusion of TB regardless of the type of diet, and activities of carnitine palmitoyltransferases I and II changed significantly, suggesting carnitine may be a candidate serum marker for tracking the metabolism of TB in rats. © 2015 Society of Chemical Industry.

Oxidized tea polyphenols prevent lipid accumulation in liver and visceral white adipose tissue in rats

BACKGROUND

Tea polyphenols are the prominent component in tea. After the fermentation process, tea polyphenols are oxidized by polyphenol oxidase to form oxidized tea polyphenols (OTPs). OTPs contain a significant amount of hydrophobic phenyl groups that can bind with non-aqueous materials. Here, we determined whether OTPs can bind with lipids and reduce fat uptake and assessed the effect of OTPs on decreasing obesity and alleviating hyperlipidaemia and other metabolic syndromes.

METHODS

Rats were divided into three groups: control, high-fat diet (HFD) and OTP groups. The control and HFD groups were fed a chow diet and a high-fat diet, respectively, for 12 weeks; the OTP group was fed a high-fat diet for 6 weeks and then a high-fat diet containing 2 % OTP for 6 weeks. The serum and excrement triglyceride (TAG) and total cholesterol (CHOL) concentrations were determined, and liver tissue and white adipose tissue were collected to detect the expression levels of genes involved in lipid metabolism.

RESULTS

Our results revealed that OTPs failed to decrease the serum concentrations of TAG and CHOL. OTPs alleviated the accumulation of lipids in the liver tissue and changed the expression levels of the regulators of lipid metabolism, i.e., peroxisome proliferation-activated receptors (ppars), compared with the rats fed a high-fat diet alone. We also observed a significantly decreased reduction of weight in the visceral white adipose, enhanced regulation of fatty acid β-oxidation by PPARα and enhanced biosynthesis of mitochondria in the visceral white adipose of the OTP rats compared with the HFD rats. Additionally, OTPs promoted the excretion of lipids.

CONCLUSION

Our results suggest that OTPs alleviate the accumulation of lipids in liver and visceral white adipose tissue and promote lipid excretion in rats in vivo.

Safety evaluation and antihyperlipidemia effect of aqueous extracts from fermented puerh tea

Fermented puerh tea, having undergone a long period of secondary oxidization and fermentation, has become more and more popular in recent years. In the present paper, a safety evaluation of aqueous extracts from fermented puerh tea (EFPT) was performed, including an oral acute toxicity study in rats and mice, mutation tests, a mouse micronucleus test, mouse sperm abnormality test and a 30 day feeding study in rats. Meanwhile, the antihyperlipidemia effect of EFPT was investigated as well. It was found that the oral maximum tolerated dose of EFPT was more than 10.0 g per kg body weight both in rats and mice. And it had no mutagenicity as judged by negative experimental results of the mutation test. No abnormal symptoms, clinical signs or deaths have been found in rats in each group throughout the experiments. In addition, EFPT in this study showed certain effects on hyperlipidemia.

Reduction of body fat and improved lipid profile associated with daily consumption of a Puer tea extract in a hyperlipidemic population: a randomized placebo-controlled trial

OBJECTIVE

The goal for this study was to evaluate the effects of daily consumption of Puer tea extract (PTE) on body weight, body-fat composition, and lipid profile in a non-Asian population in the absence of dietary restrictions.

MATERIALS AND METHODS

A randomized, double-blind, placebo-controlled study design was used. A total of 59 overweight or mildly obese subjects were enrolled upon screening to confirm fasting cholesterol level at or above 220 mg/dL (5.7 mmol/dL). After giving informed consent, subjects were randomized to consume PTE (3 g/day) or placebo for 20 weeks. At baseline and at 4-week intervals, blood lipids, C-reactive protein, and fasting blood glucose were evaluated. A dual-energy X-ray absorptiometry scan was performed at baseline and at study exit to evaluate changes to body composition. Appetite and physical and mental energy were scored at each visit using visual analog scales (0-100).

RESULTS

Consumption of PTE was associated with statistically significant weight loss when compared to placebo (P<0.05). Fat loss was seen for arms, legs, and the gynoid region (hip/belly), as well as for total fat mass. The fat reduction reached significance on within-group analysis, but did not reach between-group significance. Consumption of PTE was associated with improvements to lipid profile, including a mild reduction in cholesterol and the cholesterol:high-density lipoprotein ratio after only 4 weeks, as well as a reduction in triglycerides and very small-density lipoproteins, where average blood levels reached normal range at 8 weeks and remained within normal range for the duration of the study (P<0.08). No significant changes between the PTE group and the placebo group were seen for fasting glucose or C-reactive protein. A transient reduction in appetite was seen in the PTE group when compared to placebo (P<0.1).

CONCLUSION

The results from this clinical study showed that the daily consumption of PTE was associated with significant weight loss, reduced body mass index, and an improved lipid profile.

Deepure Tea Improves High Fat Diet-Induced Insulin Resistance and Nonalcoholic Fatty Liver Disease

This study was to explore the protective effects of Deepure tea against insulin resistance and hepatic steatosis and elucidate the potential underlying molecular mechanisms. C57BL/6 mice were fed with a high fat diet (HFD) for 8 weeks to induce the metabolic syndrome. In the Deepure tea group, HFD mice were administrated with Deepure tea at 160 mg/kg/day by gavage for 14 days. The mice in HFD group received water in the same way over the same period. The age-matched C57BL/6 mice fed with standard chow were used as normal control. Compared to the mice in HFD group, mice that received Deepure tea showed significantly reduced plasma insulin and improved insulin sensitivity. Deepure tea increased the expression of insulin receptor substrate 2 (IRS-2), which plays an important role in hepatic insulin signaling pathway. Deepure tea also led to a decrease in hepatic fatty acid synthesis and lipid accumulation, which were mediated by the downregulation of sterol regulatory element binding protein 1c (SREBP-1c), fatty acid synthesis (FAS), and acetyl-CoA carboxylase (ACC) proteins that are involved in liver lipogenesis. These results suggest that Deepure tea may be effective for protecting against insulin resistance and hepatic steatosis via modulating IRS-2 and downstream signaling SREBP-1c, FAS, and ACC.

Pu-erh tea down-regulates sterol regulatory element-binding protein and stearyol-CoA desaturase to reduce fat storage in Caenorhaditis elegans

Consumption of Pu-erh has been reported to result in numerous health benefits, but the mechanisms underlying purported weight-loss and lowering of lipid are poorly understood. Here, we used the nematode Caenorhaditis elegans to explore the water extract of Pu-erh tea (PTE) functions to reduce fat storage. We found that PTE down-regulates the expression of the master fat regulator SBP-1, a homologue of sterol regulatory element binding protein (SREBP) and its target stearoyl-CoA desaturase (SCD), a key enzyme in fat biosynthesis, leading to an increased ratio of stearic acid (C18:0) to oleic acid (C18:1n-9), and subsequently decreased fat storage. We also found that both the pharyngeal pumping rate and food uptake of C. elegans decreased with exposure to PTE. Collectively, these results provide an experimental basis for explaining the ability of Pu-erh tea in promoting inhibition of food uptake and the biosynthesis of fat via SBP-1 and SCD, thereby reducing fat storage.

New Phenylpropanoid-Substituted Flavan-3-ols from Pu-er Ripe Tea

Pu-er ripe tea is a special microbial post-fermented tea made from Pu-er raw tea, a kind of green tea produced from the leaves of Camellia sinensis var. assamica. It is one of the most consumed teas in the past two decades in China, due to its special flavor, taste, and beneficial effects. This work aimed to obtain diverse catechin structures from Pu-er ripe tea, which led to the isolation of four new phenylpropanoid-substituted flavan-3-ols, puerins C-F (1-4), together with four known flavan-3-ols, (+)-catechin (5), (-)-epicatechin (6), (±)-gallocatechin (7), and (-)-epigallocatechin (8). Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR, mass and CD spectra. Compounds 1-4, which could be formed in the post-fermentative process of Pu-er tea, were isolated for the first time from tea and Theaceae plant.

8-C N-ethyl-2-pyrrolidinone substituted flavan-3-ols as the marker compounds of Chinese dark teas formed in the post-fermentation process provide significant antioxidative activity

Phytochemical investigation of the aqueous extract of pu-erh tea afforded eight novel 8-C N-ethyl-2-pyrrolidinone substituted flavan-3-ols (puerins I-VIII) by (1)H, (13)C, two-dimensional nuclear magnetic resonance (NMR) and high-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESI/MS) analysis. Comparative chemical analysis of green tea, black tea and Chinese dark teas confirmed that these compounds were the marker compounds of Chinese dark teas. Furthermore, fungal fermentation was indispensable for the biosynthesis of these novel compounds. Through single fungal fermentation, it was proved that catechins and theanine were the precursors of puerins I-VIII. HPLC-DAD-ESI/MS analysis elucidated the biosynthetic pathway for puerins I-VIII. Puerins I-IV have potential protective effects for the human micro-vascular endothelial cells (HMEC) injury induced by hydrogen dioxide compared to other tea polyphenols. 8-C N-ethyl-2-pyrrolidinone substituted flavan-3-ols could be used in the quality control and authentication of Chinese dark teas.

Pu-erh tea suppresses diet-induced body fat accumulation in C57BL/6J mice by down-regulating SREBP-1c and related molecules

Although pu-erh tea has been shown to suppress hyperlipidemia, it is unclear how it modulates fatty acid synthase expression in mice fed on a high-fat diet. We investigated the effects of a pu-erh tea extract (PTE) on diet-induced body fat accumulation. C57BL/6J mice were fed a control diet, a high-fat diet (HFD), and HFD supplemented with 0.225% or 0.45% PTE for 70 d. Supplementation with PTE reduced the body weight gain, and the abdominal and liver fat accumulation. A significant difference in the triglyceride level were observed between the HFD control and HFD+0.45% PTE groups. A PTE intake tended to decrease sterol regulatory element-binding protein (SREBP)-1c and fatty acid synthase (FAS) mRNA expression in the liver of the mice. These findings indicate that PTE reduced lipogenesis by down-regulating SREBP-1c and related molecules, leading to the suppression of body fat accumulation.

Anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extract in high-fat diet-induced obese rats

BACKGROUND

Fuzhuan brick tea is a kind of microbial fermented tea, which has received increasing attention in recent years owing to its benefits for human health. In this study, the anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extracts (FTEs) were investigated.

RESULTS

FTEs consisted of 204.07 ± 3.38 mg g(-1) polyphenol, 109.20 ± 1.36 mg g(-1) flavonoids, and others. The FTEs significantly suppressed the increase of body weight and accumulation of adipose tissue, and reduced the level of serum triacylglycerol, total cholesterol and low-density lipoprotein (LDL) cholesterol in obese rats fed a high-fat diet. Moreover, FTEs attenuated the gene expression of sterol regulatory element binding protein-1c, fatty acid synthase and CCAAT/enhancer binding protein α, which is related to lipogenic metabolism. In contrast, the gene expressions of enzymes involved in energy expenditure and lipodieresis including hepatic peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1a and LDL receptor gene expression were increased by FTE treatment.

CONCLUSIONS

Our study demonstrates that FTEs have anti-obesity and hypolipidemic functions, suggesting that it might be effective for treatment of obesity and hyperlipemia.

Aged garlic extract enhances exercise-mediated improvement of metabolic parameters in high fat diet-induced obese rats

Aged garlic extract (AGE) is known to have a protective effect against immune system, endothelial function, oxidative stress and inflammation. We examined the effects of exercise with and without aged garlic extract administration on body weight, lipid profiles, inflammatory cytokines, and oxidative stress marker in high-fat diet (HFD)-induced obese rats. Forty-five Sprague-Dawley rats were fed either a HFD (HFD, n = 40) or a normal diet (ND, n = 5) for 6 weeks and thereafter randomized into ND (n = 5), HFD (n = 10), HFD with AGE (n = 10), HFD with Exercise (n = 10), or HFD with Exercise+AGE (n = 10) for 4 weeks. AGE groups were administered at a dose of 2.86 g/kg·body weight, orally. Exercise consisted of running 15-60 min 5 days/week with gradually increasing intensity. AGE (P < 0.01), Exercise, and Exercise+AGE (P < 0.001) attenuated body weight gain and food efficiency ratio compared to HFD. Visceral fat and liver weight gain were attenuated (P < 0.05) with all three interventions with a greater effect on visceral fat in the Exercise+AGE than AGE (P < 0.001). In reducing visceral fat (P < 0.001), epididymal fat (P < 0.01) and liver weight (P < 0.001), Exercise+AGE was effective, but exercise showed a stronger suppressive effect than AGE. Exercise+AGE showed further additive effects on reducing visceral fat and liver weight (P < 0.001). AGE significantly attenuated the increase in total cholesterol and low-density lipoprotein-cholesterol compared with HFD (P < 0.05). Exercise+AGE attenuated the increase in triglycerides compared with HFD (P < 0.05). Exercise group significantly decrease in C-reactive protein (P < 0.001). These results suggest that AGE supplementation and exercise alone have anti-obesity, cholesterol lowering, and anti-inflammatory effects, but the combined intervention is more effective in reducing weight gain and triglycerides levels than either intervention alone.

Hypoglycemic effect of the water extract of Pu-erh tea

The water extraction and composition of pu-erh tea, as well as the hypoglycemic effect of the water extract of pu-erh tea (WEPT) in vivo and in vitro, are reported to investigate its hypoglycemic effect on diabetes. High-performance liquid chromatography and colorimetric methods are used to analyze the tea catechins, caffeine, polyphenols, amino acids, and polysaccharides of the WEPT. The effect of the WEPT on glucose uptake by cultured HepG2 cells and the inhibition effect of rat intestinal sucrase, maltase, and porcine pancreatic amylase are determined in vitro. Then, the blood glucose and insulin levels of intragastrically administered WEPT on fasting and oral glucose tolerance test (OGTT) using type 2 diabetic db/db (BKS.Cg-m +/+ Lepr(db)/J) mice are determined in vivo. The results showed that the WEPT dose-dependently and significantly increased glucose uptake by HepG2 cells and inhibited rat intestinal sucrase, maltase, and porcine pancreatic amylase activity. The WEPT intragastrically given for 4 weeks suppressed the increase in blood insulin and glucose levels of db/db mice fasted overnight. In OGTT, the WEPT improved impaired glucose tolerance and ameliorated retarded insulin response at 60 and 120 min in db/db mice. These results suggest that the WEPT has beneficial effects on glucose homeostasis in type 2 diabetes and in amendment of insulin resistance.

Effects of aqueous extracts of raw pu-erh tea and ripened pu-erh tea on proliferation and differentiation of 3T3-L1 preadipocytes

Pu-erh tea has shown anti-obesity effects but little is known about its effect on proliferation and differentiation of preadipocytes. This study investigated the effects of the aqueous extracts of raw pu-erh tea and ripened pu-erh tea on proliferation and differentiation of murine 3T3-L1 preadiopocytes. We examined dose and time effects of both aqueous extracts on proliferation of 3T3-L1 preadipocytes. The contents of triglycerides in cytoplasm and the mRNA expression of critical transcriptional factors involved in differentiation were determined. Cytotoxicity and apoptosis rate of preadipocytes by pu-erh tea extracts treatment were test for toxic and pro-apoptotic effects. Both aqueous extracts of pu-erh tea inhibited the proliferation of 3T3-L1 preadipocytes at the selected time points. At lower concentration of raw pu-erh tea extracts (less than 300 µg/ml) and ripened pu-erh tea extracts (less than 350 µg/ml), no significant cytotoxic and pro-apoptotic were observed. Ripened pu-erh tea was more effective with lower IC50 than raw pu-erh tea. Both extracts suppressed the differentiation and down-regulated the gene expression of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer binding proteins-α. Therefore, these results indicate that both aqueous extracts of pu-erh tea can inhibit proliferation and differentiation with ripened pu-erh tea more potent. Polyphenol rich in both extracts may play a role in the inhibition of proliferation and differentiation of 3T3-L1 preadipocytes.

Pu-erh tea reduces nitric oxide levels in rats by inhibiting inducible nitric oxide synthase expression through toll-like receptor 4

Pu-erh tea undergoes a unique fermentation process and contains theabrownins, polysaccharides and caffeine; although it is unclear about which component is associated with the down regulation of nitric oxide levels or how this process is mediated. To address this question we examined the effects of pu-erh tea on nitric oxide synthase (NOS) genes. Cohorts of rats were separately given four-week treatments of water as control, pu-erh tea, or the tea components: theabrownins, caffeine or polysaccharides. Five experimental groups were injected with lipopolysaccharides (LPS) to induce nitric oxide (NO) production, while the corresponding five control groups were injected with saline as a negative control. The serum and liver NO concentrations were examined and the NOS expression of both mRNA and protein was measured in liver. The results showed that the rats which were fed pu-erh tea or polysaccharides had lower levels of NO which corresponded with the down-regulation of inducible nitric oxide synthase (iNOS) expression. We further demonstrate that this effect is mediated through reduction of Toll-like receptor 4 (TLR4) signaling. Thus we find that the polysaccharide components in pu-erh tea reduce NO levels in an animal model by inhibiting the iNOS expression via signaling through TLR4.

Inhibition of advanced glycation end product formation by Pu-erh tea ameliorates progression of experimental diabetic nephropathy

Accumulation of advanced glycation end products (AGEs) has been implicated in the development of diabetic nephropathy. We investigated the effects of Pu-erh tea on AGE accumulation associated with diabetic nephropathy. Although it did not affect blood glucose levels and insulin sensitivy, Pu-erh tea treatment for 8 weeks attenuated the increases in urinary albumin, serum creatinine, and mesangial matrix in db/db mice. We found that Pu-erh tea prevented diabetes-induced accumulation of AGEs and led to a decreased level of receptor for AGE expression in glomeruli. Both production and clearance of carbonyl compounds, the main precursor of AGE formation, were probably attenuated by Pu-erh tea in vivo independent of glyoxalase I expression. In vitro, HPLC assay demonstrated Pu-erh tea could trap methylglyoxal in a dose-dependent manner. Our study raises the possibility that inhibition of AGE formation by carbonyl trapping is a promising approach to prevent or arrest the progression of diabetic complications.