Lonicera japonica polysaccharides alleviate D-galactose-induced oxidative stress and restore gut microbiota in ICR mice.

Lonicera japonica polysaccharides (LJPs) exhibit anti-aging effect in nematodes. Here, we further studied the function of LJPs on aging-related disorders in D-galactose (D-gal)-induced ICR mice. Four groups of mice including the control group, the D-gal-treated group, the intervening groups with low and high dose of LJPs (50 and 100 mg/kg/day) were raised for 8 weeks. The results showed that intragastric administration with LJPs improved the organ indexes of D-gal-treated mice. Moreover, LJPs improved the activity of superoxide dismutase (SOD), catalase (CAT) as well as glutathione peroxidase (GSH-Px) and decreased the malondialdehyde (MDA) level in serum, liver and brain. Meanwhile, LJPs restored the content of acetylcholinesterase (AChE) in the brain. Further, LJPs reversed the liver tissue damages in aging mice. Mechanistically, LJPs alleviate oxidative stress at least partially through regulating Nrf2 signaling. Additionally, LJPs restored the gut microbiota composition of D-gal-treated mice by adjusting the Firmicutes/Bacteroidetes ratio at the phylum level and upregulating the relative abundances of Lactobacillaceae and Bifidobacteriacesa. Notably, the KEGG pathways involved in hazardous substances degradation and flavone and flavonol biosynthesis were significantly enhanced by LJPs treatment. Overall, our study uncovers the role of LJPs in modulating oxidative stress and gut microbiota in the D-gal-induced aging mice.

Intracellular Polysaccharides of Aspergillus cristatus from Fuzhuan Brick Tea Leverage the Gut Microbiota and Repair the Intestinal Barrier to Ameliorate DSS-Induced Colitis in Mice.

The intracellular polysaccharides of Aspergillus cristatus (IPSs) from Fuzhuan brick tea have been demonstrated to improve immune function linked to modulating the gut microbiota. Herein, to further investigate the efficacy of IPSs to maintain gut homeostasis, the protection of the purified fraction of IPSs (IPSs-2) on the mice with colitis induced by dextran sulfate sodium (DSS) and the underlying mechanisms were explored in this study. The results revealed that IPSs-2 alleviated the typical symptoms of colitis and suppressed the excessive inflammatory mediators, regulating the genes related to inflammatory responses in the colon at the mRNA level. Meanwhile, IPSs-2 treatment reinforced the intestinal barrier function by ameliorating the DSS-induced histological injury, facilitating the differentiation of goblet cells to enhance Mucin-2 generation, and enhancing the expression of tight junction proteins to alleviate colitis. In addition, IPSs protected against colitis by promoting the production of short-chain fatty acids (SCFAs), the activation of SCFAs receptors, and the leverage of the gut microbiota via the enrichment of Bacteroides, Parabacteroides, Faecalibacterium, Flavonifractor_plautii, and Butyricicoccus, linking with reducing inflammation and repairing intestinal barrier function. Overall, our research revealed the therapeutic potential of IPSs-2 as a prebiotic for attenuating inflammatory bowel disease and provided a rationale for future investigation.

A critical review of Fuzhuan brick tea: processing, chemical constituents, health benefits and potential risk.

Fuzhuan brick tea (FBT) is a traditional popular beverage in the border regions of China. Nowadays, FBT has been attracted great attention due to its uniquely flavor and various health-promoting functions. An increasing number of efforts have been devoted to the studies on health benefits and chemistry of FBT over the last decades. However, FBT was still received much less attention than green tea, oolong tea and black tea. Therefore, it is necessary to review the current encouraging findings about processing, microorganisms, chemical constituents, health benefits and potential risk of FBT. The fungus fermentation is the key stage for processing of FBT, which is involved in a complex and unique microbial fermentation process. The fungal community in FBT is mainly dominated by "golden flower" fungi, which is identified as Aspergillus cristatus. A great diversity of novel compounds is formed and identified after a series of biochemical reactions during the fermentation process of FBT. FBT shows various biological activities, such as antioxidant, anti-inflammatory, anti-obesity, anti-bacterial, and anti-tumor activities. Furthermore, the potential risk of FBT was also discussed. It is expected that this review could be useful for stimulating further research of FBT.

Zeaxanthin Dipalmitate-Enriched Emulsion Stabilized with Whey Protein Isolate-Gum Arabic Maillard Conjugate Improves Gut Microbiota and Inflammation of Colitis Mice.

In the present study, protein-polysaccharide Maillard conjugates were used as novel emulsifiers and bioactive carriers. Effects and potential mechanisms of zeaxanthin dipalmitate (ZD)-enriched emulsion stabilized with whey protein isolate (WPI)-gum Arabic (GA) conjugate (WPI-GA-ZD) and ZD-free emulsion (WPI-GA) on gut microbiota and inflammation were investigated using a model of dextran sulfate sodium (DSS)-induced colitis in mice. As a result, supplementation with WPI-GA and WPI-GA-ZD improved the serum physiological and biochemical indicators, decreased the expression of pro-inflammatory cytokines and related mRNA, as well as increased the tight junction proteins to a certain extent. 16S rDNA sequencing analyses showed that supplementation with WPI-GA and WPI-GA-ZD presented differential modulation of gut microbiota and played regulatory roles in different metabolic pathways to promote health. Compared with WPI-GA, the relative abundances of Akkermansia, Lactobacillus and Clostridium_IV genera were enriched by the intervention of WPI-GA-ZD. Overall, the designed carotenoid-enriched emulsion stabilized with protein-polysaccharide conjugates showed potential roles in promoting health.

Study on the Interaction between Four Typical Carotenoids and Human Gut Microflora Using an in Vitro Fermentation Model.

Recent studies indicated a strong relationship between carotenoids and gut microflora. However, their structure-activity relationship remains unclear. This study evaluated the interaction between four typical carotenoids (ß-carotene, lutein, lycopene, and astaxanthin) and gut microflora using an in vitro fermentation model. After 24 h of fermentation, the retention rates of the four carotenoids were 1.40, 1.38, 1.46, and 5.63 times lower than those of their without gut microflora control groups, respectively. All four carotenoid treated groups significantly increased total short-chain fatty acids (SCFAs) production. All carotenoid supplements significantly promoted the abundance of Roseburia and Parasutterella and inhibited the abundance of Collinsella, while ß-carotene, lutein, lycopene, and astaxanthin significantly promoted the abundance of Ruminococcus, Sutterella, Subdoligranulum, and Megamonas, respectively. Furthermore, xanthophylls have a more significant impact on gut microflora than carotenes. This study provides a new way to understand how carotenoids work in the human body with the existing gut microflora.

Dendrobium officinale polysaccharide attenuates cognitive impairment in circadian rhythm disruption mice model by modulating gut microbiota.

Dendrobium officinale polysaccharide (DOP) has received an increasing amount of attention as it could alleviate AD-related cognitive impairment via the regulation of microglial activation. However, the modulatory mechanism of DOP on circadian rhythm disruption (CRD) and related cognitive impairment needs further investigation. In our study, the circadian rhythm disruption mice showed a deficit in recognition and spatial memory. DOP treatment reshaped the perturbation of gut microbiota caused by CRD, including up-regulated the abundance of Akkermansia and Alistipes, down-regulated the abundance of Clostridia. In addition, DOP restored histopathological changes, reduced inflammatory cells infiltration and strengthened mucosal integrity. Mechanistically, DOP ameliorated intestinal barrier dysfunction by up-regulating tight junction protein expression, which in turn improved the invasion of lipopolysaccharide to blood and brain. The change of these contributes to inhibiting the NF-κB activation and neuroinflammation, and thus attenuating hippocampus neuronal damage and the deposition of Aß. Meanwhile, our results revealed that DOP could reverse the levels of metabolites derived related to cognitive function improvement, and these metabolites were closely associated with the key microbiota. Therefore, we speculated that DOP has the potential to provide neuroprotection against cognitive impairment by modulating the gut microbiota.

Fuzhuan brick tea polysaccharides serve as a promising candidate for remodeling the gut microbiota from colitis subjects in vitro: Fermentation characteristic and anti-inflammatory activity.

The purified fraction 3 of polysaccharides from Fuzhuan brick tea (FBTPS-3) could attenuate the colitis and modulate the gut microbiota. However, the relationship between anti-inflammatory effect of FBTPS-3 and the gut microbiota is still unknown. Thus, the anaerobic fermentation in vitro was used to investigate the potential mechanism. FBTPS-3 could be utilized and degraded by gut microbiota from inflammatory bowel disease (IBD) subjects. Furthermore, FBTPS-3 could modulate the composition and structure of IBD gut microbiota toward to that of healthy group. FBTPS-3 showed a superior modulated effect on IBD gut microbiota by increasing Bacteroides and decreasing Escherichia/Shigella. Furthermore, the fermentation solution rather than FBTPS-3 itself showed anti-inflammatory effects on lipopolysaccharide-treated RAW264.7 macrophages, which might be due to the metabolites such as short-chain fatty acids (SCFAs). Thus, FBTPS-3 can be expected as novel prebiotics for treatment of IBD via modulating gut microbiota, and promoting the production of SCFAs.

Immunomodulatory activity of polysaccharides from the mycelium of Aspergillus cristatus, isolated from Fuzhuan brick tea, associated with the regulation of intestinal barrier function and gut microbiota.

Aspergillus cristatus is the dominant fungus involved in the fermentation of Fuzhuan brick tea (FBT). The intracellular polysaccharides (IPSs) from A. cristatus (MK346334, NCBI), isolated from FBT, exhibited immunomodulatory activity in vitro while the effects in vivo on immune system and gut microbiota remain unclear. In this study, IPSs and the purified fraction (IPSs-2) from IPSs were prepared and their immunomodulatory activities were investigated with cyclophosphamide (Cy)-induced immunosuppressive mice. As results, IPSs strengthened the immune function, manifesting in the improvement of body weight, daily intake, immune organ indices, cytokines and immunoglobulin. Meanwhile, IPSs attenuated Cy-induced intestinal barrier injury and promoted the expression of tight junction proteins and mucin, reinforcing the intestinal barrier function. Moreover, IPSs not only promoted the production of short-chain fatty acids and the expression of G protein-coupled receptor (GPR), but also balanced dysbiosis of gut microbiota through elevating the growth of beneficial bacteria while reducing pathobionts to maintain the homeostasis of the microbial ecology. These results suggested that IPSs exerted immunomodulatory activity linking with the restoration of intestinal barrier function and regulation of gut microbiota, which contributes to the development of novel probiotics and effective immunomodulators for strengthening host immunity and gut health.

Effects of polysaccharides from Fuzhuan brick tea on immune function and gut microbiota of cyclophosphamide-treated mice.

In this study, cyclophosphamide (Cy) was used to treat mice to establish an immunosuppressant model in mice, and the regulatory effects of polysaccharides from Fuzhuan brick tea (FBTPSs) including crude FBTPSs (CFBTPSs) and the purified fraction (FBTPSs-3) on the immune function and gut microbiota of mice were investigated. The results showed that CFBTPSs and FBTPSs-3 restored the levels of body weight, feed intake, immune organ index, cytokine and immunoglobulin A in mice. The Cy-induced injury of gut including intestinal morphology and expression of tight junction proteins were also restored. Furthermore, CFBTPSs and FBTPSs-3 could significantly modulate gut microbiota by increasing the relative abundance of Muribaculaceae and reduceing the relative abundances of Lachnospiraceae, Helicobacteraceae, Clostridaceae, Desulfovibrionaceae and Deferribacteraceae. Moreover, the gut microbiota derived short-chain fatty acids might play an important role in improvement of immune function by FBTPSs. Our results showed that FBTPSs could regulate the immune function of mice, which provided evidences for the development of FBTPSs as potentially functional foods to improve human health.

Anti-inflammatory and gut microbiota modulatory effects of polysaccharides from Fuzhuan brick tea on colitis in mice induced by dextran sulfate sodium.

In this study, the effects of crude Fuzhuan brick tea polysaccharides (CFBTPS) and their purified fraction (FBTPS-3) on colitis induced by dextran sulfate sodium (DSS) in mice were investigated. Both CFBTPS and FBTPS-3 exhibited intestinal anti-inflammatory activities, including restoring body weight, colon length and solid fecal weight, and decreasing the disease activity index score in mice. Moreover, the expression of lipocalin-2 in colitis could be significantly reduced. The inflammatory cytokines (IL-6, IL-1ß, IFN-γ and TNF-α) and lipopolysaccharides in the serum and the expression of inflammation-related mRNA in the colon tissue were decreased. Both CFBTPS and FBTPS-3 could increase tight junction proteins (Occludin, Claudin-1 and ZO-1), promoting the intestinal barrier function. For gut microbiota, DSS treatment resulted in abnormal proliferation of Bifidobacteria, while FBTPS-3 could restore this disorder to a certain extent. In addition, FBPTS-3 promoted the growth of probiotics such as Bacteroides, Parasutterella and Collinsella. Both CFBTPS and FBTPS-3 could attenuate colitis; what's more, FBTPS-3 exhibited a better anti-inflammatory effect than CFBTPS.

Structural Characterization and Immunostimulatory Activity of Heteropolysaccharides from Fuzhuan Brick Tea.

Fuzhuan brick tea (FBT), one of the unique dark teas, has various health-promoting functions. In the present study, one polysaccharide fraction, namely FBTPS-2-1, was extracted and purified from FBT, and its structure and potential immunostimulatory activity were investigated. The results showed that FBTPS-2-1,one of typical heteropolysaccharides, was mainly composed of Gal, Ara, and Glc with little molar content of Man, Rha, GalA, and GlcA in molar ratio of 46.59:22.13:13.57:8.20:6.02:2.12:1.38 and molecular weight of 748 kDa. The backbone of FBTPS-2-1 contained →4)-ß-d-Galp-(1→4)-ß-d-Galp-(1→, →4)-ß-d-Galp-(1→4)-α-d-Glcp-(1→, →4)-α-d-Glcp-(1→4)-α-d-Glcp-(1→, →4)-α-d-Glcp-(1→4)-ß-d-Galp-(1→, →3)-ß-d-Galp-(1→4)-ß-d-Galp-(1→, →3,6)-ß-d-Galp-(1→3)-ß-d-Galp-(1→ and →3,6)-ß-d-Galp-(1→3,6)-ß-d-Galp-(1→. The linkages of branches in FBTPS-2-1 were mainly composed of α-l-Araf-(1→3,6)-ß-d-Galp-(1→, →5)-α-l-Araf-(1→3,6)-ß-d-Galp-(1→, →6)-ß-d-Galp-(1→3,6)-ß-d-Galp-(1→, α-l-Araf-(1→3,5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→5)-α-l-Araf-(1→, α-d-Galp-(1→3,5)-α-l-Araf-(1→ and →5)-α-l-Araf-(1→6)-ß-d-Galp-(1→. Furthermore, FBTPS-2-1 could increase the phagocytosis of macrophages and promote the secretion of NO and a variety of inflammatory cytokines, including TNF-α, IL-1ß, and IL-6, indicating noticeable immune enhancement activity. Thus, FBTPS-2-1 could serve as a potentially functional food to improve human health by modulating the host immunoreaction.

Effects of long-term consumption of polysaccharides from the fruit of Lycium barbarum on host's health.

Polysaccharides from the fruit of Lycium barbarum (LBPs) are functional molecules with diverse biological functions in vivo and in vitro. This study investigated the long-term consumption of LBPs on host's health in BALB/c mice. Six-week-old male mice (n = 10 each group) were fed either a normal control (NC) diet or supplemented with 200 mg/kg (body weight)/d of LBPs for 14 weeks. Compared with the NC diet, the LBPs diet enhanced the expression of mucin 2 and Claudin5, improved the intestinal barrier morphologically, moreover, promoted the growth of Lactobacillus and strongly increased the production of short-chain fatty acids and IgA (p < 0.05). Feeding LBPs increased the levels of superoxide dismutase and reduced glutathione in the serum, liver and spleen while decreased the levels of alanine aminotransferase and lysozyme in serum and spleen. Besides, the LBPs diet increased the expression of cytokines including tumor necrosis factor α and interleukin-6 and related mRNA but decreased the level of lysozyme. To sum up, chronic intake of LBPs in BALB/c mice improved the oxidation resistance, changed the immune status especially promoted the intestinal immunity. These results may have important implications for LBPs as functional food supplement and for realizing the potential value of LBPs for host's health.

Modulation of gut homeostasis by exopolysaccharides from Aspergillus cristatus (MK346334), a strain of fungus isolated from Fuzhuan brick tea, contributes to immunomodulatory activity in cyclophosphamide-treated mice.

In this study, the crude exopolysaccharides (CEPSs) from fungus Aspergillus cristatus (MK346334, NCBI) isolated from Fuzhuan brick tea and its main purified fraction (EPSs-2) were investigated. Using the RAW264.7 cell model, EPSs-2 exhibited an excellent immunomodulatory effect in vitro. Then, the regulating effects of EPSs on immune function and gut microbiota were evaluated using a cyclophosphamide (Cy)-induced mice model. It was found that both CEPSs and EPSs-2 improved the body weight loss, immune organ indexes as well as the levels of TNF-α, IL-1ß, IFN-γ and IgA, exhibiting potent immunoregulatory activity. Moreover, CEPSs and EPSs-2 not only attenuated the intestinal tissue damage, but also promoted the production of short-chain fatty acids and modulated the microbial composition by increasing the growth of Muribaculaceae, Prevotellaceae_UCG-001, Bacteroides, Parabacteroides and Tidjanibacter, while decreasing the relative abundances of Helicobacter, Bilophila, Mucispirillum, Lachnospiraceae, Ruminococcaceae and Clostridiales. These results indicated that the EPSs, especially EPSs-2, exhibited immunomodulatory activity associated with the modulation of gut microbiota to maintain gut homeostasis, which provided evidence for the development of novel potential prebiotics and immunomodulators.

Physiological genetics, chemical composition, health benefits and toxicology of tea (Camellia sinensis L.) flower: A review.

The flower of tea (Camellia sinensis L.) plant has been paid an increasing attention in the last twenty years, since it was found that tea flowers contained representative constituents similar to those of tea leaves, such as catechins, caffeine and amino acids. Tea flower is theoretically valuable although it has been considered as an industrial waste over a long period of time. This review summarizes the research findings conducted until now on physiological genetics, chemical composition, health benefits and toxicology of tea flowers, aiming to foresee their future applications. A lot of genes are involved in flower development and the synthesis and transmission of various chemicals in tea flowers. The chemical composition of tea flower consists mainly of catechins, polysaccharides, proteins, amino acids and saponins and thus tea flower possesses various health benefits such as antioxidant, anti-inflammatory, immunostimulating, antitumor, hypoglycemic, anti-obesity and anti-allergic activities. Moreover, tea flower contains a protease that can elevate the free amino acids content in the tea infusion by almost two folds. More importantly, the enzymatic activity of the protease is much higher than that of the commercially available proteases. Additionally, aqueous extracts of tea flower are demonstrated to safe to animals. Thus, the potential uses of tea flowers in food and medical fields are warranted.

Long-Term Consumption of 2-O-ß-d-Glucopyranosyl-l-ascorbic Acid from the Fruits of Lycium barbarum Modulates Gut Microbiota in C57BL/6 Mice.

The modulating effect of 2-O-ß-d-glucopyranosyl-l-ascorbic acid (AA-2ßG), a natural derivative of ascorbic acid from the fruits of Lycium barbarum, on mice gut microbiota was investigated in the present study. It was found that AA-2ßG was able to adjust the structure of mice gut microbiota, elevated the relative abundances of Verrucomicrobia, Porphyromonadaceae, Verrucomicrobiaceae, and Erysipelotrichaceae, and meanwhile reduced the relative abundances of Firmicutes, Lachnospiraceae, Rikenellaceae, Ruminococcaceae, Bdellovibrionaceae, Anaeroplasmataceae, and Peptococcaceae. Through the linear discriminant analysis effect size analysis, the key microbiota that were found to be significantly changed after long-term consumption of AA-2ßG were Ruminococcaceae, Porphyromonadaceae, Lachnospiraceae, and Rikenellaceae. In addition, AA-2ßG could upregulate pro-inflammatory cytokines, promote tight junctions between intestinal cells, facilitate the generation of short-chain fatty acids (SCFAs), and upregulate the mRNA expression level of SCFAs receptors, indicating that AA-2ßG might promote organism health. The results demonstrated that AA-2ßG might maintain organism health by modulating gut microbiota.

Antioxidant and immunomodulatory activities in vitro of polysaccharides from bee collected pollen of Chinese wolfberry.

China is a larger apiculture producer in the world and more than 120 million kg of bee collected pollens of Chinese wolfberry (WBP) are produced per year. However, the lack of knowledge of the nutritional benefits of WBP limits the use of this natural product in food industry. In the present study, three polysaccharides (WBPPS-1, WBPPS-2 and WBPPS-3) were obtained by ion-exchange chromatography, and their preliminary structures, antioxidant and immunomodulatory activities were investigated. The results showed that WBPPS-1, WBPPS-2 and WBPPS-3 were composed of mannose, rhamnose, galacturonic acid, glucose, galactose, xylose and arabinose with different ratio and their average molecular weights were 1016.3, 878.7 and 901.6 KDa, respectively. In addition, the contents of zinc were far higher than other trace elements in the three polysaccharides, suggesting these polysaccharides probably be polysaccharides­zinc complex. Moreover, WBPPS-3 exhibited stronger scavenging activities on 2,2'-azinobis-(3-ethyl-benzothiazolin-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radicals than WBPPS-1 and WBPPS-2. Likewise, WBPPS-3 exhibited a superior enhanced effect on secretion of nitric oxide, tumor necrosis factor-α, interleukin-1ß and interleukin-6 in RAW264.7 cells than other two polysaccharides. Overall, these results suggest that WBPPS-3 has potential to be developed as antioxidant and immunomodulatory ingredients in functional foods, but further animal or clinical studies are required.

Effect of long-term consumption of tea (Camellia sinensis L.) flower polysaccharides on maintaining intestinal health in BALB/c mice.

Polysaccharides have various health-promoting functions. However, dietary polysaccharides cannot be digested by the human alimentary tract, thus the gut is the most important location where polysaccharides play their role. The effect of polysaccharides from tea (Camellia sinensis L.) flower (TFPS) on intestinal health was investigated in the present study. TFPS with the molecular weight of 1,316.29 kDa was prepared, and twenty 6-week-old BALB/c male mice were randomly allotted to a chow diet (normal control group, NC group) or with 200 mg/kg (body weight)/day of TFPS for 13 weeks (n = 10 each). Histomorphology observation of jejunum and colons showed that TFPS maintained the adequate gut barrier. qPCR analysis revealed that the expression of colonic tight junction proteins of claudin1 (1.29 ± 0.15 compared with 1.00 ± 0.13, P < 0.05) and claudin5 (2.91 ± 0.44 compared with 1.00 ± 0.27, P < 0.01) at mRNA level with a significant difference between TFPS supplement or not, while the expression of TLR4 and TNF-α mRNA was not changed statistically. 16S rDNA amplicons sequencing was applied to measure the compositions of gut microbiota from feces of mice. TFPS treatment exhibited similar relative abundances in Bacteroidetes and Firmicutes; however, it decreased the relative abundance of Akkermansia and increased that of Lactobacillus compared with the NC group. The contents of short-chain fatty acids after TFPS supplementation, both in cecal contents and feces, were significantly higher than those of the NC group. Besides, TFPS significantly increased IgA production. These results suggest that TFPS is beneficial to intestinal health and can improve intestinal adaptive immune tolerance. PRACTICAL APPLICATION: Dietary polysaccharides improve human intestinal health. Understanding the effect of TFPS, safe and healthy food components, on gut health increases the likelihood that TFPS will be developed as a functional food.

Components identification and nutritional value exploration of tea (Camellia sinensis L.) flower extract: Evidence for functional food.

Camellia sinensis L., its fresh leaves and buds are used to make tea, is an important industrial crop with a long history. However, less attention has been paid to tea flowers. Indeed, tea flower extract (TFE) is a rich source of functional molecules, but its nutritional value remains unclear. This study, from the perspective of "whole food", aimed to investigate the composition of TFE and further explore its possible health-promoting effects on cyclophosphamide-induced mice. It was found that TFE was mainly composed of carbohydrates (34.02 ± 1.42%), phenolic compounds (11.57 ± 0.14%), crude proteins (27.72 ± 3.07%) and saponins (2.81 ± 0.00%). Supplementation of TFE at 200 mg/kg·BW/d regulated intestinal homeostasis by improving the intestinal barrier, alleviating dysbacteriosis (reverse 44 of 68 disordered genera), stimulated immunoreactions with significant enhancement of serum TNF-α, IFN-γ, IL-1ß, IL-2 and IL-6. Furthermore, TFE could improve the liver function through decreasing the hepatic malondialdehyde and aminotransferase levels and increasing the levels of catalase, myeloperoxidase, superoxide dismutase and reduced glutathione. Notably, the ameliorating effects of TFE on cyclophosphamide-induced immunosuppression and the hepatic injury were associated with its modulation of gut microbiota. The results provide the evidence for the application of tea flower as potential functional food.

Preparation of theasinensin A and theasinensin B and exploration of their inhibitory mechanism on α-glucosidase.

Theasinensin A (TSA) and theasinensin B (TSB), dimers of tea catechins produced during the processing of oolong tea and black tea, had superior inhibitory effects on α-glucosidase. However, the potential inhibitory mechanisms on α-glucosidase are still unclear. In the present study, TSA and TSB were chemically synthesized and purified, and their inhibitory effects on α-glucosidase and potential mechanisms were investigated. The results showed that TSA and TSB could inhibit the activity of α-glucosidase in a reversible and noncompetitive manner with IC50 values of 6.342 and 24.464 µg mL-1, respectively, which were much lower than that of acarbose. The fluorescence and circular dichroism spectra revealed that TSA and TSB could alter the microenvironment and the secondary structure of α-glucosidase, thereby decreasing the α-glucosidase activity. Molecular docking results indicated that both TSA and TSB had a strong binding affinity to α-glucosidase by hydrophobic interactions and hydrogen bonds. Moreover, the stronger inhibition of TSA on α-glucosidase might be related to the closer binding site to the active site pocket of α-glucosidase.

Phenolics and Carbohydrates in Buckwheat Honey Regulate the Human Intestinal Microbiota.

Intestinal microbiota plays an important role in human health. The aim of this paper is to determine the impact of the phenolics and carbohydrate in buckwheat honey on human intestinal microbiota. We investigated the phenolics and carbohydrate compositions of eight buckwheat honey samples using high-performance liquid chromatography and ion chromatography. The human intestinal microbes were cultured in a medium supplemented with eight buckwheat honey samples or the same concentration of fructooligosaccharides. The bacterial 16S rDNA V4 region sequence of DNA extraction was determined by the Illumina MiSeq platform. 12 phenolics and 4 oligosaccharides were identified in almost all buckwheat honey samples, namely, protocatechuic acid, 4-hydroxy benzoic acid, vanillin, gallic acid, p-coumaric acid, benzoic acid, isoferulic acid, methyl syringate, trans,trans-abscisic acid, cis,trans-abscisic acid, ferulic acid, 4-hydroxybenzaldehyde, kestose, isomaltose, isomaltotriose, and panose. Most notably, this is the first study to reveal the presence of 4-hydroxybenzaldehyde in buckwheat honey. 4-Hydroxybenzaldehyde seems to be a land marker of buckwheat honey. Our results indicate that buckwheat honey can provide health benefits to the human gut by selectively supporting the growth of indigenous Bifidobacteria and restraining the pathogenic bacterium in the gut tract. We infer that buckwheat honey may be a type of natural intestinal-health products.