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

Theabrownin from Pu-erh Tea Improves DSS-Induced Colitis via Restoring Gut Homeostasis and Inhibiting TLR2&4 Signaling Pathway

BACKGROUND

Theabrownin (TB) is a dark brown pigment from Pu-erh tea or other dark teas. It is formed by further oxidization of theaflavins and thearubigins, in combination with proteins, polysaccharides, and caffeine etc. TB is a characteristic ingredient and bioactive substance of Pu-erh tea. However, the effects of TB on ulcerative colitis (UC) remains unclear.

PURPOSE

This study aims to elucidate the mechanism of TB on UC in terms of recovery of intestinal homeostasis and regulation of toll-like receptor (TLR) 2&4 signaling pathway.

METHODS

The colitis models were established by administering 5% dextran sulfate sodium (DSS) to C57BL/6 mice for 5 days to evaluate the therapeutic and preventive effects of TB on UC. Mesalazine was used as a positive control. H&E staining, complete blood count, enzyme-linked immunosorbent assay, immunohistochemistry, flow cytometry, and 16S rRNA sequencing were employed to assess histological changes, blood cells analysis, content of cytokines, expression and distribution of mucin (MUC)2 and TLR2&4, differentiation of CD4+T cells in lamina propria, and changes in intestinal microbiota, respectively. Western blot was utilized to study the relative expression of tight junction proteins and the key proteins in TLR2&4-mediated MyD88-dependent MAPK, NF-κB, and AKT signaling pathways.

RESULTS

TB outstanding alleviated colitis, inhibited the release of pro-inflammatory cytokines, reduced white blood cells while increasing red blood cells, hemoglobin, and platelets. TB increased the expression of occludin, claudin-1 and MUC2, effectively restored intestinal barrier function. TB also suppressed differentiation of Th1 and Th17 cells in the colon's lamina propria, increased the fraction of Treg cells, and promoted the balance of Treg/Th17 to tilt towards Tregs. Moreover, TB increased the Firmicutes to Bacteroides (F/B) ratio, as well as the abundance of Akkermansia, Muribaculaceae, and Eubacterium_coprostanoligenes_group at the genus level. In addition, TB inhibited the activation of TLR2&4-mediated MAPK, NF-κB, and AKT signaling pathways in intestinal epithelial cells of DSS-induced mice.

CONCLUSION

TB acts in restoring intestinal homeostasis and anti-inflammatory in DSS-induced UC, and exhibiting a preventive effect after long-term use. In a word, TB is a promising beverage, health product and food additive for UC.

Theabrownin from Fu Brick tea ameliorates high-fat induced insulin resistance, hepatic steatosis, and inflammation in mice by altering the composition and metabolites of gut microbiota

Fu Brick tea belongs to fermented dark tea, which is one of the six categories of tea. Fu Brick tea has been reported to reduce adiposity and has beneficial effects in the treatment of hypercholesterolemia and cardiovascular disease. Theabrownin (TB) is one of the pigments with the most abundant content in Fu Brick tea. TB has also been reported to have lipid-lowering effects, but its mechanism remains unclear. We found that TB could effectively reduce the insulin resistance and fat deposition induced by a high fat diet (HFD), decrease inflammation in the liver, improve intestinal integrity, and reduce endotoxins in circulation. Further studies showed that TB increased the abundance of Verrucomicrobiota and reduced the abundance of Firmicutes and Desulfobacterota in the intestinal tract of obese mice. The alteration of gut microbiota is closely linked to the metabolic phenotype after TB treatment through correlation analysis. Moreover, TB changed the gut microbial metabolites including L-ornithine, α-ketoglutarate, and glutamine, which have also been found to be upregulated in the liver after TB intervention. In vitro, L-ornithine, α-ketoglutarate, or glutamine significantly reduced lipopolysaccharide (LPS)-induced inflammation in macrophages. Therefore, our results suggest that TB can reduce adiposity, systemic insulin resistance, and liver inflammation induced by a HFD through altering gut microbiota and improving the intestinal tight junction integrity. The metabolites of gut microbiota might also play a role in ameliorating the HFD-induced phenotype by TB.

Untargeted metabolomics and quantification analysis reveal the shift of chemical constituents between instant dark teas individually liquid-state fermented by Aspergillus cristatus, Aspergillus niger, and Aspergillus tubingensis

Instant dark teas (IDTs) were individually liquid-state fermented using the fungi Aspergillus cristatus, Aspergillus niger, and Aspergillus tubingensis. To understand how the chemical constituents of IDTs were affected by the fungi, samples were collected and measured by liquid chromatography-tandem mass-tandem mass spectrometry (LC-MS/MS). Untargeted metabolomics analysis revealed that 1,380 chemical constituents were identified in positive and negative ion modes, and 858 kinds of chemical components were differential metabolites. Through cluster analysis, IDTs were different from the blank control, and their chemical constituents mostly included carboxylic acids and their derivatives, flavonoids, organooxygen compounds, and fatty acyls. And the metabolites of IDTs fermented by A. niger and A. tubingensis had a high degree of similarity and were classified into one category, which showed that the fungus used to ferment is critical to the formation of certain qualities of IDTs. The biosynthesis of flavonoids and phenylpropanoid, which involved nine different metabolites such as p-coumarate, p-coumaroyl-CoA, caffeate, ferulate, naringenin, kaempferol, leucocyanidin, cyanidin, and (-)-epicatechin, were significant pathways influencing the quality formation of IDTs. Quantification analysis indicated that the A. tubingensis fermented-IDT had the highest content of theaflavin, theabrownin, and caffeine, while the A. cristatus fermented-IDT had the lowest content of theabrownin, and caffeine. Overall, the results provided new insights into the relationship between the quality formation of IDTs and the microorganisms used in liquid-state fermentation.

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.

Anti-Obesity Effect of Theabrownin from Dark Tea in C57BL/6J Mice Fed a High-Fat Diet by Metabolic Profiles through Gut Microbiota Using Untargeted Metabolomics

The epidemic of obesity is a serious public health problem. In this study, the effect of theabrownin from dark tea on obesity was evaluated by biochemical tests and nuclear magnetic resonance in C57BL/6J mice fed a high-fat diet. A mixture of antibiotics was used to deplete gut microbiota and then fecal microbiota transplant was used to restore gut microbiota. Untargeted metabolomics was used to reveal the effects of theabrownin on metabolic profiles through gut microbiota. The results showed that theabrownin significantly reduced body weight gain (83.0%) and body fat accumulation (30.29%) without affecting appetite. Also, theabrownin promoted lipid clearance with a hepatoprotective effect. The extra antibiotics disrupted the regulation of theabrownin on weight control while fecal microbiota transplant restored the beneficial regulation. That is, gut microbiota was important for theabrownin to reduce body weight gain. The untargeted metabolomics indicated that 18 metabolites were related to the anti-obesity effect of theabrownin mediated by gut microbiota. Furthermore, phenylalanine metabolism, histidine metabolism, as well as protein digestion and absorption pathway played a role in the anti-obesity of theabrownin. Our findings suggested that theabrownin significantly alleviated obesity via gut microbiota-related metabolic pathways, and theabrownin could be used for the prevention and treatment of obesity.

Theabrownin isolated from Pu-erh tea regulates Bacteroidetes to improve metabolic syndrome of rats induced by high-fat, high-sugar and high-salt diet

BACKGROUND

Theabrownin (TB), a high macromolecular compound and a characteristic component of Pu-erh tea, is able to markedly regulate blood lipid and glucose metabolism. We hypothesized that TB could ameliorate metabolic syndrome induced by high-fat, high-sugar and high-salt diet (HFSSD).

RESULTS

To test these hypotheses, we fed rats with HFSSD and administered a gavage of TB. HFSSD successfully induced metabolic syndrome in rats. TB significantly improved serum lipid status, prevented obesity and fasting blood glucose (FBG) and glycosylated hemoglobin (GHbAIc) in rats. After TB intervention, Firmicutes/Bacteroides (F/B) ratio was greatly reduced and showed a dose-effect relationship. TB promoted the reproduction of Bacteroidetes such as prevotella_sp._CAG:1031, prevotella_sp._MGM2 and Bacteroides_sartorii, and inhibited the reproduction of Firmicutes such as roseburia_sp._1XD42-69 and roseburia_sp._831b.

CONCLUSION

In HFSSD mode, prevotella_sp._CAG:1031 was one of the main dominant characteristic bacteria of TB targeting regulation, while roseburia_sp._1XD42-69 mainly inhibitory intestinal bacteria, which help to reduce body weight, TG and blood sugar levels of HFSSD rats. Glycerophospholipid metabolism, arachidonic acid metabolism, glycolysis/gluconeogenesis and insulin resistance were the critical pathway. TB has a high application potential in reducing the risk of metabolic diseases. © 2022 Society of Chemical Industry.

Theabrownin-targeted regulation of intestinal microorganisms to improve glucose and lipid metabolism in Goto-Kakizaki rats

Diabetes is a disease that is characterized by a disturbance of glucose metabolism. Theabrownin (TB) is one of the most active and abundant pigments in Pu-erh tea, and it is a brown pigment with multiple aromatic rings and attached residues of polysaccharides and proteins. TB has been shown to be hypolipidemic and displays fasting blood glucose (FBG)-lowering properties in rats fed a high-fat diet, but the underlying mechanism has not been elucidated. This study aimed to determine the effect of TB in treating diabetes and explore the underlying mechanism of action of intestinal microbes by using Goto-Kakizaki (GK) rats. Diabetic GK rats were treated up to 8 weeks with TB (GK-TB). Following treatment, the body weight, triglyceride (TG) content, fasting blood glucose (FBG) content, and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) were significantly lower in the GK-TB group than in the GK control group (P < 0.05). Meanwhile, the circulating adiponectin (ADPN), leptin, and glucokinase levels in the serum of the GK-TB group were significantly higher than those in the GK group, while there was little difference in hepatic lipase (HL) and hormone-sensitive triglyceride lipase (HSL) enzyme activities (P > 0.05). Furthermore, with the extension of treatment time, the number of unique intestinal microorganisms in GK rats greatly increased and an interaction among intestinal microorganisms was observed. The Firmicutes/Bacteroides ratio was decreased significantly, and the composition of Actinobacteria and Proteobacteria was increased. The use of multiple omics technologies showed that TB is involved in the targeted regulation of the core characteristic intestinal flora including Bacteroides thetaiotaomicron (BT), Lactobacillus murinus (LM), Parabacteroides distasonis (PD), and Bacteroides_acidifaciens (BA) which improved the glucose and lipid metabolism of GK rats via the AMP-activated protein kinase signaling pathway, insulin signaling pathway, bile secretion and glycerophospholipid metabolism. Intragastric administration of BT, LM, PD, or BA led to a significantly reduced HOMA-IR in GK rats. Furthermore, BT significantly reduced serum lipid TG and total cholesterol (TC) and BA significantly reduced the serum lipid TC and low-density lipoprotein (LDL). PD significantly reduced serum LDL, while the effect of LM was not significant. However, LM and PD significantly increased the content of ADPN in serum. Taken together, our results indicated that the effect of TB on diabetic rats mainly depends on the targeted regulation of intestinal microorganisms and that TB is a functional food component with great potential to treat or prevent diabetes.

Theabrownin from Fu Brick Tea Exhibits the Thermogenic Function of Adipocytes in High-Fat-Diet-Induced Obesity

This study explored whether the antiobesity effect of theabrownin (TB) extracted from Fu brick tea (FBT) was associated with the activation of brown adipose tissue (BAT) or browning of the white adipose tissue (WAT) in mice fed a high-fat diet (HFD). Mice were divided into five groups, which received a normal diet, HFD, or HFD plus TB (200, 400, and 800 mg/kg), respectively. A 12-week administration of TB in a dose-dependent manner reduced the body weight and WAT weight and improved lipid and glucose disorders in the HFD-fed mice (p < 0.05). TB also promoted the expression of thermogenic and mitochondrial genes, whereas inflammation genes were reduced in interscapular BAT (iBAT), inguinal WAT (iWAT), and epididymis white adipose tissue (eWAT), accompanied by improvement in the intestinal homeostasis by improving SCFAs, especially butyric acid levels (p < 0.05), which was related to thermogenic and inflammatory factors of iBAT and iWAT. Mechanistically, TB was shown to efficiently promote thermogenesis by stimulating the AMPK-PGC1α pathway with an increase in uncoupling protein 1 (UCP1). Conclusively, these findings suggest that long-term consumption of TB can enhance BAT activity and WAT browning by activating the AMPK-PGC1α pathway and modulating SCFAs; meanwhile, SCFAs regulating TB improved inflammatory disorder in HFD-fed mice.

Structural Characteristics and Hypolipidemic Activity of Theabrownins from Dark Tea Fermented by Single Species Eurotium cristatum PW-1

Recently, studies on theabrownins (TBs), the main bioactive polymeric pigments found in dark tea, have received increasing attention for its health effects. Thus far, information on their structural characteristics is unclear. In the present study, theabrownins were isolated from single species Eurotium cristatum PW-1-fermented loose tea and their structural and hypolipidemic characteristics were studied for the first time. The theabrownins were fractionated by their molecular weights and were then analyzed. Ultraviolet–visible spectrophotometry (UV-Vis) and Flourier transformation infrared spectroscopy (FT-IR) showed that they were polymerized phenolic substances containing abundant hydroxy and carboxyl groups. All theabrownin samples exhibited hypolipidemic activity in high-fat zebrafish; among which TBs-10-30k sample, decreased lipid level in high-fat zebrafish to 51.57% at 1000 μg/mL, was most effective. It was found that TBs-10-30k was a type of amorphous and thermostable polymer with slice shape and smooth surface under scanning electron microscope (SEM). Atomic force microscope (AFM) analysis showed that it had island-like structure because of aggregation of theabrownin molecules. Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis further showed that the main pyrolytic products of TBs-10-30k were hexadecanoic acid (33.72%), phenol (14.90%), and eicosane (12.95%), indicating TBs-10-30k was mainly composed of phenols, lipids, saccharides, and proteins. These results not only facilitate subsequent identification of theabrownins, but also provide insights into the applications of theabrownins in functional foods.

Effects of theabrownin on serum metabolites and gut microbiome in rats with a high-sugar diet

Evidence has proven that the gut microbiota is an important environmental factor contributing to obesity by altering host energy harvest and storage. We performed a high-throughput 16S rDNA sequencing association study and serum metabolomics profiling in rats with a high-sugar diet. Our studies revealed that the high sugar diet reduced the diversity of cecal microorganisms, while the combination of theabrownin and the high sugar diet increased the diversity of cecal microorganisms and promoted reproduction of Alloprevotella, Coprostanoligenes_group, Bacteroides, Prevotellaceae_NK3B31_group, Desulfovibrio, Intestinimonas, Alistipes, Bifidobacterium, Phascolarctobacterium, Ruminococcaceae_UCG-010 and Staphylococcus. The combination also inhibited the growth of Lactobacillus, Prevotellaceae_Ga6A1_group and Tyzzerella. The Firmicutes/Bacteroidetes (F/B) ratio can be significantly reduced after the intervention of theabrownin in high sugar diet rats, and the reproduction of Bacteroides acidifaciens (BA) and Staphylococcus saprophyticus subsp. saprophyticus can be promoted. We found that the obesity-associated gut microbial species were linked to the changes in circulating metabolites. Serum levels of deoxycholic acid, cholic acid, 1H-indole-3-acetic acid, 3-indole acrylic acid and melatonin were negatively correlated with BA and Staphylococcus saprophyticus subsp. saprophyticus, but positively correlated with Lactobacillus murinus, Leptum and Gut_metagenome. 2-Hydroxy-6-methylpyridin-3-carboxylic acid, l-homoserine, and 1,7-dimethylxanthine were positively correlated with BA and Staphylococcus saprophyticus subsp. saprophyticus, but negatively correlated with Lactobacillus murinus, Leptum, and Gut_metagenome. In a high sugar diet mode, theabrownin reduced the body weight and triglycerides and improved insulin resistance mainly by targeting the reproduction of intestinal microorganisms such as BA, Staphylococcus saprophyticus subsp. saprophyticus, Lactobacillus murinus, Leptum, Gut_metagenome and so on. A strong correlation between cecal microorganisms and serum metabolites, obesity and insulin resistance was observed. Theabrownin has high potential in reducing the risk of cardiovascular diseases such as diabetes and obesity.

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.

Comparison of two types of vinegar with different aging times by NMR-based metabolomic approach

Shanxi vinegar (SV) is well known as the most famous vinegar for its distinctive processing technique in China. Aging is the most important process for SV, and we call the vinegar aging more than 1-year Shanxi aged vinegar (SAV) and less than 1-year Shanxi mature vinegar (SMV). In this study, the chemical compositions and in vivo difference between SAV and SMV were compared by NMR based metabolomic profiling technique and multivariate statistical analysis. The results indicated that most of the metabolites exhibited higher concentrations in SAV than those in SMV¸ and the amino acids showed higher concentration ratio than the other compounds. The changes of endogenous metabolites after treatment with SMV and SAV were also investigated. Compared with the chemical differences, the differences of metabolomic changes between SAV and SMV were relatively minor. This study provides a valuable approach for accurately evaluating the differences of food products. PRACTICAL APPLICATIONS: Vinegar is commonly consumed as the important seasoning. SV, which is made from several kinds of cereal by solid-state fermentation techniques, is one of the famous vinegars in China. Aging is the most important process for SV which dividing vinegar into SAV and SMV according to the aging time. Due to the long aging process, the price of SAV is much higher than that of SMV in the market place. However, no investigation was conducted to compare their differences in vivo.

Theabrownin suppresses in vitro osteoclastogenesis and prevents bone loss in ovariectomized rats

Drinking tea exhibits beneficial effects on bone health and may protect against osteoporosis, particularly in postmenopausal women. Theabrownin (TB) is the main component responsible for the biological activities of Pu-erh tea, but whether it possesses anti-osteoporotic potential remains unknown. Here we investigated the in vitro and in vivo anti-osteoporotic effects of TB in the RAW 264.7 cell line and ovariectomized (OVX) rats, respectively. Our in vitro studies showed that TB significantly suppressed RANKL-induced osteoclastogenesis and the expression of related marker proteins, including NFATc1, TRAP, c-Fos, and cathepsin K. In vivo studies showed that TB treatment effectively ameliorated blood biochemical parameters, organ weights and organ coefficients in OVX rats. In addition, TB treatment significantly improved femoral bone mineral density (BMD) and biomechanical properties. What's more, TB treatment strikingly ameliorated bone microarchitecture in OVX rats because of increased cortical bone thickness and trabecular bone area in the femur. Our study therefore demonstrated that TB can inhibit RANKL-induced osteoclastogenesis in vitro and prevent bone loss in ovariectomized rats. Consequently, TB has a promising potential in postmenopausal osteoporosis treatment.

Theabrownin triggers DNA damage to suppress human osteosarcoma U2OS cells by activating p53 signalling pathway

Osteosarcoma becomes the second leading cause of cancer death in the younger population. Current outcomes of chemotherapy on osteosarcoma were unsatisfactory to date, demanding development of effective therapies. Tea is a commonly used beverage beneficial to human health. As a major component of tea, theabrownin has been reported to possess anti‐cancer activity. To evaluate its anti‐osteosarcoma effect, we established a xenograft model of zebrafish and employed U2OS cells for in vivo and in vitro assays. The animal data showed that TB significantly inhibited the tumour growth with stronger effect than that of chemotherapy. The cellular data confirmed that TB‐triggered DNA damage and induced apoptosis of U2OS cells by regulation of Mki67, PARP, caspase 3 and H2AX, and Western blot assay showed an activation of p53 signalling pathway. When P53 was knocked down by siRNA, the subsequent downstream signalling was blocked, indicating a p53‐dependent mechanism of TB on U2OS cells (p53 wt). Using osteosarcoma cell lines with p53 mutations (HOS, SAOS‐2 and MG63), we found that TB exerted stronger inhibitory effect on U2OS cells than that on p53‐mut cell lines, but it also exerted obvious effect on SAOS‐2 cells (p53 null), suggesting an activation of p53‐independent pathway in the p53‐null cells. Interestingly, theabrownin was found to have no toxicity on normal tissue in vivo and could even increase the viability of p53‐wt normal cells. In sum, theabrownin could trigger DNA damage and induce apoptosis on U2OS cells via a p53‐dependent mechanism, being a promising candidate for osteosarcoma therapy.

Comparison of the serum metabolic signatures based on 1H NMR between patients and a rat model of deep vein thrombosis

Deep vein thrombosis (DVT) and pulmonary embolism (PE) have high morbidity, reduce quality of life, and can cause death. Biomarkers or genetic risk factors have not been identified in patients with DVT. In present study, serum of 61 patients suffering from DVT and a rat DVT model (n = 10) were assayed by a proton nuclear magnetic resonance (¹H NMR) metabolomics technique combing with multivariate statistical analysis to identify the metabolites. The MetPA platform was used to identify differences in the metabolic pathways between the rat model and patients. The metabolomics results discovered that 11 different metabolites in rats and 20 different metabolites in DVT patients. Seven metabolites both altered in the rats and patients. Moreover, we observed changes in the metabolic pathways, including carbohydrate metabolism, lipid metabolism, and amino acid metabolism that were induced immediately by the thrombosis. Pathway of aminoacyl-tRNA biosynthesis perturbed only in the patients which was associated with the genetic risk factor of DVT. The study demonstrated that serum ¹H NMR metabolomics can be used to diagnose DVT in the clinic. The altered pathways related to thrombosis and genetics will provide a foundation and new strategies for understanding the pathological mechanism and pharmacological targets of DVT.

High-theabrownins instant dark tea product by Aspergillus niger via submerged fermentation: α-glucosidase and pancreatic lipase inhibition and antioxidant activity

BACKGROUND

Theabrownins (TB) are bioactive components that are usually extracted from Chinese dark tea, in which they are present at low concentrations. The present study aimed to produce an instant dark tea high in theabrownins via submerged fermentation by the fungus Aspergillus niger. Three fermentation parameters that affect theabrownins content (i.e. inoculum size, liquid-solid ratio and rotation speed) were optimized using response surface methodology.

RESULT

Optimum fermentation conditions were modeled to be an inoculum of 5.40% (v/v), a liquid-solid ratio of 27.45 mL g^-1 and a rotation speed of 184 rpm and were predicted to yield 292.99 g kg^-1 TB. Under these experimentally conditions, the TB content of the instant dark tea was 291.93 g kg^-1 . The antioxidant capacity and α-glucosidase and pancreatic lipase inhibitory activities of the high-TB instant black tea were higher than four other typical instant dark tea products.

CONCLUSION

The results of the present study show that careful management of culture conditions can produce a dark tea high in theabrownins. Furthermore, high-theabrownins instant dark tea could serve as a source of bioactive products and be used in functional foods as an ingredient imparting antioxidant properties and the ability to inhibit pancreatic lipase and α-glucosidase. © 2017 Society of Chemical Industry.