Aqueous preparation of arginyl-fructosyl-glucose (a maltose-arginine AC) and determination of Amadori compounds (ACs) in red ginseng by ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS).

Amadori compounds (ACs) are key Maillard intermediates in various foods after thermal processing, and are also important non-saponin components in red ginseng. Currently, due to the difficulty in obtaining AC standards, the determination of multiple ACs is limited and far from optimal. In this study, an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated. A green synthetic method was developed for arginyl-fructosyl-glucose (AFG), the major AC in red ginseng with potential health benefits. The UPLC-MS/MS method was then applied in identification and quantification of ACs in red ginseng samples, which showed for the first time that 12 other ACs also exist in red ginseng in addition to AFG and arginyl-fructose (total 98.88 % of all ACs). Contents of AFG and arginyl-fructose in whole red ginseng were 36.23 and 10.80 mg/g dry weight, respectively. Raw ginseng can be steamed and then dried whole to obtain whole red ginseng, or sliced before drying to obtain sliced red ginseng. Slicing before drying was found to reduce ACs content. Results of the present study will help to reveal the biological functions of red ginseng and related products associated with ACs and promote the standardization of red ginseng manufacture.

Green Pea (Pisum sativum L.) Hull Polyphenol Extract Alleviates NAFLD through VB6/TLR4/NF-κB and PPAR Pathways.

Green pea hull is a processing byproduct of green pea and rich in polyphenols. Nonalcoholic fatty liver disease (NAFLD) is a chronic metabolic disease characterized by accumulation of lipids in the liver for which there are no effective treatment strategies. Here, a mouse model of NAFLD induced by a DSS+high-fat diet (HFD) was established to investigate the effect of green pea hull polyphenol extract (EGPH). The results show that EGPH relief of NAFLD was a combined effect, including reducing hepatic fat accumulation, improving antioxidant activity and blood lipid metabolism, and maintaining glucose homeostasis. Increased intestinal permeability aggravated NAFLD. Combined metabolomics and transcriptomic analysis showed that vitamin B6 is the key target substance for EGPH to alleviate NAFLD, and it may be the intestinal flora metabolite. After EGPH intervention, the level of vitamin B6 in mice was significantly increased, and more than 60% in the blood enters the liver, which activated or inhibited PPAR and TLR4/NF-κB signaling pathways to relieve NAFLD. Our research could be a win-win for expanding the use of green pea hull and the search for NAFLD prophylactic drugs.

Anthocyanin-Rich Butterfly Pea Flower Extract Ameliorating Low-Grade Inflammation in a High-Fat-Diet and Lipopolysaccharide-Induced Mouse Model.

This study aimed to explore the enhancive effects of butterfly pea flower (BF) extracts on metabolic and immune homeostasis in a low-grade inflammation mouse model. The BF extract was found to contain mainly anthocyanins among other flavonoids. BF supplementation alleviated metabolic endotoxemia by lowering the plasma glucose, lipopolysaccharide (LPS), and tumor necrosis factor-α (TNF-α) levels and restored lipid metabolism and the balance between Treg and Th17 cells, thereby inhibiting the dysfunctional liver and abdominal white adipose tissues. BF extract increased the tight junction protein expression and reduced the expression of proinflammatory cytokines, therefore sustaining the colonic mucosa structure. Furthermore, BF extracts reshaped the gut microbiota structure characterized by significantly promoted SCFA-producing gut microbiota such as Akkermansia and Butyricicoccaceae. Additionally, BF extracts enhanced fecal primary bile acid (BA) levels and modulated bile acid signaling in the liver and ileum to facilitate BA synthesis for the restoration of lipid metabolism. In summary, anthocyanin-enriched BF extracts alleviated the profound negative dietary alterations and helped maintain the metabolic health by modulating the various aspects of the gut microenvironment and enhancing hepatic bile acid synthesis.

Multi-omics reveals that green pea (Pisum sativum L.) hull supplementation ameliorates non-alcoholic fatty liver disease via the SHMT2/glycine/mTOR/PPAR-γ signaling pathway.

Diets rich in various active ingredients may be an effective intervention strategy for non-alcoholic fatty liver disease (NAFLD). The green pea hull (GPH) is a processing by-product of green peas rich in dietary fiber and polyphenols. Here, a mouse model of NAFLD induced by DSS + high-fat diet (HFD) was established to explore the intervention effect of the GPH. The results showed that dietary supplements with the GPH can inhibit obesity and reduce lipid accumulation in the mouse liver to prevent liver fibrosis. GPH intervention can improve liver antioxidant capacity, reduce blood lipid deposition and maintain glucose homeostasis. DSS-induced disruption of the intestinal barrier aggravates NAFLD, which may be caused by the influx of large amounts of LPS. A multi-omics approach combining metabolomics and transcriptomic analysis indicated that glycine was the key target and its content was decreased in the liver after GPH intervention, and that dietary supplements with the GPH can relieve NAFLD via the SHMT2/glycine/mTOR/PPAR-γ signaling pathway, which was further supported by liver-associated protein expression. In conclusion, our study demonstrated that dietary GPH can significantly ameliorate NAFLD, and the future development of related food products can enhance the economic value of the GPH.

Substrate specificity of polyphenol oxidase and its selectivity towards polyphenols: Unlocking the browning mechanism of fresh lotus root (Nelumbo nucifera Gaertn.).

Polyphenol oxidase (PPO) causes the browning of lotus roots (LR), negatively affecting their nutrition and shelf-life. This study aimed to explore the specific selectivity of PPO toward polyphenol substrates, thus unlocking the browning mechanism of fresh LR. Results showed that two highly homologous PPOs were identified in LR and exhibited the highest catalytic activity at 35 ℃ and pH 6.5. Furthermore, the substrate specificity study revealed (-)-epigallocatechin had the lowest Km among the polyphenols identified in LR, while (+)-catechin showed the highest Vmax. The molecular docking further clarified that (-)-epigallocatechin exhibited lower docking energy and formed more hydrogen bonds and Pi-Alkyl interactions with LR PPO than (+)-catechin, while (+)-catechin entered the active cavity of PPO more quickly due to its smaller structure, both of which enhance their affinity to PPO. Thus, (+)-catechin and (-)-epigallocatechin are the most specific substrates responsible for the browning mechanism of fresh LR.

Bioaccessibility and transport of lentil hull polyphenols in vitro, and their bioavailability and metabolism in rats.

Polyphenol-rich lentil hulls are a valuable by-product. In this study, lentil hulls were subjected to simulated in vitro digestion and caco-2 cell monolayer models to assess the bioaccessibility, transmembrane transport, and a rat model to examine the bioavailability and metabolism in vivo. Polyphenols were increasingly released during the in vitro digestion, and were found to contribute to the increased antioxidant activity. Among the bioaccessible polyphenols, catechin glucoside, kaempferol tetraglucoside, procyanidin dimer and dihydroxybenzoic acid-O-dipentoside were most efficiently transported across the caco-2 membrane, and responsible for promoting intestinal integrity as a result of enhanced expression of tight junction proteins. When ingested by rats, lentil hull polyphenols underwent extensive I and II phase metabolic reactions in vivo, including hydroxylation, methylation, glucuronidation and sulfation. Overall, results of this study showed that lentil hull polyphenols are bioaccessible and bioavailable, and lentil hulls as a by-product can be a valuable ingredient for future functional foods.

Effect of honey on cardiometabolic risk factors: a systematic review and meta-analysis.

CONTEXT: Excess calories from free sugars are implicated in the epidemics of obesity and type 2 diabetes. Honey is a free sugar but is generally regarded as healthy. OBJECTIVE: The effect of honey on cardiometabolic risk factors was assessed via a systematic review and meta-analysis of controlled trials using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. DATA SOURCES: MEDLINE, Embase, and the Cochrane Library databases were searched up to January 4, 2021, for controlled trials ≥1 week in duration that assessed the effect of oral honey intake on adiposity, glycemic control, lipids, blood pressure, uric acid, inflammatory markers, and markers of nonalcoholic fatty liver disease. DATA EXTRACTION: Independent reviewers extracted data and assessed risk of bias. Data were pooled using the inverse variance method and expressed as mean differences (MDs) with 95%CIs. Certainty of evidence was assessed using GRADE. DATA ANALYSIS: A total of 18 controlled trials (33 trial comparisons, N = 1105 participants) were included. Overall, honey reduced fasting glucose (MD = -0.20 mmol/L, 95%CI, -0.37 to -0.04 mmol/L; low certainty of evidence), total cholesterol (MD = -0.18 mmol/L, 95%CI, -0.33 to -0.04 mmol/L; low certainty), low-density lipoprotein cholesterol (MD = -0.16 mmol/L, 95%CI, -0.30 to -0.02 mmol/L; low certainty), fasting triglycerides (MD = -0.13 mmol/L, 95%CI, -0.20 to -0.07 mmol/L; low certainty), and alanine aminotransferase (MD = -9.75 U/L, 95%CI, -18.29 to -1.21 U/L; low certainty) and increased high-density lipoprotein cholesterol (MD = 0.07 mmol/L, 95%CI, 0.04-0.10 mmol/L; high certainty). There were significant subgroup differences by floral source and by honey processing, with robinia honey, clover honey, and raw honey showing beneficial effects on fasting glucose and total cholesterol. CONCLUSION: Honey, especially robinia, clover, and unprocessed raw honey, may improve glycemic control and lipid levels when consumed within a healthy dietary pattern. More studies focusing on the floral source and the processing of honey are required to increase certainty of the evidence. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42015023580.

Impact of solid-state fermentation on factors and mechanisms influencing the bioactive compounds of grains and processing by-products.

Cereal and legume grains and their processing by-products are rich sources of bioactives such as phenolics with considerable health potential, but these bioactives suffer from low bioaccessibility and bioavailability, resulting in limited use. Several studies have demonstrated that solid-state fermentation (SSF) with food-grade microorganisms is effective in releasing bound phenolic compounds in cereal and legume products. In this review, we discuss the effect of SSF on cereal and legume grains and their by-products by examining the role of specific microorganisms, their hydrolytic enzymes, fermentability of agri-food substrates, and the potential health benefits of SSF-enhanced bioactive compounds. SSF with fungi (Aspergillus spp. and Rhizopus spp.), bacteria (Bacillus subtilis and lactic acid bacteria (LAB) spp.) and yeast (Saccharomyces cerevisiae) significantly increased the bioactive phenolics and antioxidant capacities in cereal and legume grains and by-products, mainly through carbohydrate-cleaving enzymes. Increased bioactive phenolic and peptide contents of SSF-bioprocessed cereal and legume grains have been implicated for improved antioxidant, anti-inflammatory, anti-carcinogenic, anti-diabetic, and angiotensin-converting-enzyme (ACE) inhibitory effects in fermented agri-food products, but these remain as preliminary results. Future research should focus on the microbial mechanisms, suitability of substrates, and the physiological health benefits of SSF-treated grains and by-products.

Free and Bound Phenolics of Laird Lentil (Lens culinaris) Hulls and the Anti-inflammatory Activity of their Digestive Products via Crosstalk between NF-κB and Keap1-Nrf2 Signaling Pathways in HT-29 Cells.

Polyphenol-rich Laird lentil hulls are a byproduct of lentil processing. In the present study, free and bound polyphenols in lentil hulls were analyzed with UHPLC-LTQ-OrbiTrap-MS2, and the anti-inflammatory mechanism of their digestive products was explored based on the NF-κB and Keap1-Nrf2 signaling pathways in the HT-29 cell model. In summary, a total of 27 polyphenols and 5 nonphenolic constituents were identified in free and bound fractions, and among them, catechin glucoside, kaempferol tetraglucoside, procyanidin dimer, and dihydroxybenzoic acid-O-dipentoside were the main polyphenols in the digestive products. These digestive products could reduce inflammatory mediators and exert anti-inflammatory activity by inhibiting NF-κB and activating Keap1-Nrf2 signaling pathways, and there was crosstalk between them, which was a mutual inhibition effect. The results show that polyphenols in lentil hulls are a good source of anti-inflammatory ingredients and have a promising development potential.

Regulatory Effect of Isomaltodextrin on a High-Fat Diet Mouse Model with LPS-Induced Low-Grade Chronic Inflammation.

This study aimed to identify the effects of isomaltodextrin (IMD) on sustaining the gut integrity and microbiota composition in a high-fat diet (HFD) with a lipopolysaccharide (LPS)-induced low-grade inflammation mouse model. The homeostasis of the immune response is important to reduce the risk of developing metabolic syndromes. The results of this study showed that pre-treatment of IMD at 5% (w/v) suppressed the concentration of endotoxin and pro-inflammatory mediators TNF-α, MCP-1, and IL-6 while increasing the adiponectin level in the plasma. Subsequently, IMD supplementation maintained the structural integrity and intestinal permeability by upregulating the tight junction protein expressions, leading to reducing D-mannitol concentration in the blood. In addition, dysbiosis was observed in mice induced by HFD plus LPS, suggesting that unhealthy dietary factors elicit metabolic endotoxemia and associated dysbiosis to impair the barrier function. However, IMD supplementation was shown to restore the microbial diversity, promote the growth of Bacteroides-Prevotella, and upregulate the related d-glucarate and d-galactarate degradation pathways, together demonstrating the benefits of IMD as a prebiotic able to promote energy homeostasis. Our results also showed that the blood lipid profile and glucose level in the low-grade inflammation mouse model were modulated by IMD. Moreover, IMD supplementation effectively prevented the metabolic disorder and modulated immune responses in inflamed white adipose tissues by inhibiting the macrophage infiltration and restoring the adiponectin, PPAR-γ, and IRS-1 expression. These findings provide strong evidence for IMD to be a potential prebiotic that acts to sustain a healthy gut microbiota composition and barrier function. By protecting against an unhealthy diet-impaired metabolic balance and maintaining immune homeostasis, IMD may affect the development of metabolic disorders.

Paradigm Shift in Phytochemicals Research: Evolution from Antioxidant Capacity to Anti-Inflammatory Effect and to Roles in Gut Health and Metabolic Syndrome.

Food bioactive components, particularly phytochemicals with antioxidant capacity, have been extensively studied over the past two decades. However, as new analytical and molecular biological tools advance, antioxidants related research has undergone significant paradigm shifts. This review is a high-level overview of the evolution of phytochemical antioxidants research. Early research used chemical models to assess the antioxidant capacity of different phytochemicals, which provided important information about the health potential, but the results were overused and misinterpreted despite the lack of biological relevance (Antioxidants v1.0). This led to findings in the anti-inflammatory properties and modulatory effects of cell signaling of phytochemicals (Antioxidants v2.0). Recent advances in the role of diet in modulating gut microbiota have suggested a new phase of food bioactives research along the phytochemicals-gut microbiota-intestinal metabolites-low-grade inflammation-metabolic syndrome axis (Antioxidants v3.0). Polyphenols and carotenoids were discussed in-depth, and future research directions were also provided.

Amelioratory Effect of Resistant Starch on Non-alcoholic Fatty Liver Disease via the Gut-Liver Axis.

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome with a global prevalence. Impaired gut barrier function caused by an unhealthy diet plays a key role in disrupting the immune-metabolic homeostasis of the gut-liver axis (GLA), leading to NAFLD. Therefore, dietary interventions have been studied as feasible alternative therapeutic approaches to ameliorate NAFLD. Resistant starches (RSs) are prebiotics that reduce systemic inflammation in patients with metabolic syndrome. The present review aimed to elucidate the mechanisms of the GLA in alleviating NAFLD and provide insights into how dietary RSs counteract diet-induced inflammation in the GLA. Emerging evidence suggests that RS intake alters gut microbiota structure, enhances mucosal immune tolerance, and promotes the production of microbial metabolites such as short-chain fatty acids (SCFAs) and secondary bile acids. These metabolites directly stimulate the growth of intestinal epithelial cells and elicit GPR41/GPR43, FXR, and TGR5 signaling cascades to sustain immune-metabolic homeostasis in the GLA. The literature also revealed the dietary-immune-metabolic interplay by which RSs exert their regulatory effect on the immune-metabolic crosstalk of the GLA and the related molecular basis, suggesting that dietary intervention with RSs may be a promising alternative therapeutic strategy against diet-induced dysfunction of the GLA and, ultimately, the risk of developing NAFLD.

Polyphenol Content of Green Pea (Pisum sativum L.) Hull under In Vitro Digestion and Effects of Digestive Products on Anti-Inflammatory Activity and Intestinal Barrier in the Caco-2/Raw264.7 Coculture Model.

Green pea hulls are a byproduct of the processing of green pea and are rich in phenolic substances. In the present study, in vitro digestion, human colonic adenocarcinoma cell line (Caco-2) monolayer, and the Caco-2/macrophage cell lines of the murine origin (Raw264.7) coculture model were established to investigate the release of polyphenols, absorption, and transport of digestive products and their effects on inflammation and intestinal barrier. During the digestive process, polyphenols were constantly released from the pea hulls, reaching the maximum amount in the small intestine (total phenolic content (TPC): 5.41 ± 0.04 mg gallic acid (GAE)/g dry weight (DW)), and the digestive products (800 µg/mL) could reduce the secretion of NO (50.9%), IL-6 (50.6%), and TNF-α (24.6%) and inhibit the mRNA expression of cyclooxygenase-2 (COX-2) (37.2%) and inducible nitric oxide synthase (iNOS) (91.1%) compared with the lipopolysaccharide (LPS) group. A total of 12 phenolic components were quantified by ultraperformance liquid chromatography-linear ion trap orbitrap tandem mass spectrometry (UHPLC-LTQ-OrbiTrap-MS) technology. Kaempferol trihexoside in digestive products could be absorbed and transported (1.25 ± 0.13 ng quercetin/mL). The digestive products could promote the expression of claudin-1 (210.8%), occludin (64.9%), and zonulin occludin-1 (ZO-1) (52.0%) compared with the LPS group and exert anti-inflammatory effects after being absorbed. The results indicated that pea hull polyphenols could be continuously released and absorbed to play a positive role in protecting the intestinal barrier and anti-inflammatory activity.

Green Pea (Pisum sativum L.) Hull Polyphenol Extracts Ameliorate DSS-Induced Colitis through Keap1/Nrf2 Pathway and Gut Microbiota Modulation.

As a processing by-product, green pea hull (GPH) was found to be rich in phenolic components in our previous studies. In this study, UHPLC-LTQ-OrbiTrap-MS (Ultra performance liquid chromatography-linear ion trap orbitrap tandem mass spectrometry) technique was used to quantify polyphenols, and DSS (sodium dextran sulfate)-induced colitis mouse model was established to explore the effect of GPH extracts on colitis. The results showed that quercetin and its derivatives, kaempferol trihexanside and catechin and its derivatives were the main phenolic substances in the extract, reaching 2836.57, 1482.00 and 1339.91 µg quercetin/g GPH extract, respectively; GPH extracts can improved inflammatory status, repaired colonic function, regulated inflammatory factors, and restored oxidative balance in mice. Further, GPH extracts can activate Keap1-Nrf2-ARE signaling pathway, regulate downstream antioxidant protease and gut microbiota by increasing F/B value and promoting the growth of Lactobacillaceae and Lachnospiraceae, and improve the level of SCFAs (short-chain fatty acids) to relieve DSS-induced colitis in mice. Therefore, GPH may be a promising dietary resource for the treatment of ulcerative colitis.

Liberation of insoluble-bound phenolics from lentil hull matrices as affected by Rhizopus oryzae fermentation: Alteration in phenolic profiles and their inhibitory capacities against low-density lipoprotein (LDL) and DNA oxidation.

Fermentation is an effective non-thermal food processing operation used for enhancing the nutritional and functional properties of food. HPLC-ESI-MS/MS analysis and inhibitory capacity of the soluble- and insoluble-bound phenolics in lentil hulls in retarding the oxidation of LDL and DNA strand scission were determined following fermentation. In HPLC-ESI-MS/MS analysis, most insoluble-bound phenolics in lentil hulls were significantly decreased, indicating their liberation from the cell wall matrix upon fermentation. However, the released insoluble-bound phenolics did not show an efficient conversion into the bioavailable soluble phenolics as reflected in the inhibitory capacity against oxidation of LDL and DNA strands. The low efficiency in bioconversion from insoluble-bound to soluble phenolics might be due to the loss of the released bound phenolics during the fermentation process. Following the alterations of individual insoluble-bound phenolics in legumes upon fermentation in this work may fill the existing gap in the related areas.

LED-Induced Carotenoid Synthesis and Related Gene Expression in Brassica Microgreens.

In this study, various ratios of combined red, blue, and amber light-emitting diodes (rbaLEDs) were investigated for their effect on the expression of carotenoid biosynthetic genes and carotenoid accumulation in eight Brassica microgreens. Total and individual (ß-carotene, lutein, α-carotene, neoxanthin, and violaxanthin) carotenoids were increased 20-44 and 10-55%, respectively, under dose-dependent increasing amber-blue light and decreasing red in most microgreens. Lipophilic 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power antioxidant activities were significantly increased under higher amber and blue light fractions, while oxygen radical absorbance capacity was generally decreased. Under rbaLED in mizuna (B. rapa) microgreens, the lycopene epsilon cyclase (LYCε) expression was 10-15-fold higher, which resulted in downstream accumulation of α-carotene and lutein. Lycopene beta cyclase (LYCß) was not significantly changed, suggesting that ß-carotene, violaxanthin and neoxanthin were mainly controlled by upstream phytoene synthase and branch-point LYCε. Increased beta-ring carotenoid hydroxylase (CHXß) expression was also consistent with lutein accumulation. This study demonstrated for the first time that amber LED was involved in the regulatory mechanism of carotenoid biosynthesis, thus a potential novel approach to production of antioxidant-rich microgreens.

Phenolics of Yellow Pea (Pisum sativum L.) Hulls, Their Plasma and Urinary Metabolites, Organ Distribution, and In Vivo Antioxidant Activities.

As a byproduct, large amounts of yellow pea hull (YPH) are used as low-value or worthless feed worldwide each year, which is a major waste of these polyphenol-rich hulls. The metabolism, bioavailability, and in vivo activities of these polyphenols have not been reported. In the present study, the chemical profiles of YPH extract, their metabolites, and organ distribution were analyzed with UHPLC-LTQ-OrbiTrap-MS, and their in vivo antioxidant activities were studied using the d-gal model in rats. In summary, a total of 42 ingredients were identified in YPH extracts, and 54 metabolites were found in plasma or urine samples. The distribution of metabolites in plasma and organs may have a positive effect on SOD, GSH-Px, MDA, and T-AOC, and the liver and kidneys were the main distribution organs of these metabolites. Our results are of great significance for the development and utilization of the polyphenol-rich hull of yellow pea.

Role of dietary polyphenols on gut microbiota, their metabolites and health benefits.

The beneficial health roles of dietary polyphenols in preventing oxidative stress related chronic diseases have been subjected to intense investigation over the last two decades. As our understanding of the role of gut microbiota advances our knowledge of the antioxidant and anti-inflammatory functions of polyphenols accumulates, there emerges a need to examine the prebiotic role of dietary polyphenols. This review focused onthe role of different types and sources of dietary polyphenols on the modulation of the gut microbiota, their metabolites and how they impact on host health benefits. Inter-dependence between the gut microbiota and polyphenol metabolites and the vital balance between the two in maintaining the host gut homeostasis were discussed with reference to different types and sources of dietary polyphenols. Similarly, the mechanisms behind the health benefits by various polyphenolic metabolites bio-transformed by gut microbiota were also explained. However, further research should focus on the importance of human trials and profound links of polyphenols-gut microbiota-nerve-brain as they provide the key to unlock the mechanisms behind the observed benefits of dietary polyphenols found in vitro and in vivo studies.

Development of ultrasound-assisted mixture extraction and online extraction solution concentration coupled with countercurrent chromatography for the preparation of pure phytochemicals from Phellinus vaninii.

Herein, ultrasound-assisted mixture extraction (UAME) and online extraction solution concentration (OESC) were conducted to extract products from crops and plants. These techniques were coupled with parallel countercurrent chromatography (PCCC) and applied for continuous extraction and online isolation of chemical constituents from Phellinus vaninii. The UAME instrument comprises extraction and solution separation chambers. It provides higher extraction efficiency and fewer impurities and is suitable for processing various sample matrices. The OESC device comprises a spray nozzle, concentrating cylinder, and hot-blast air nozzle. The mechanical parameters for UAME and OESC were optimized, and the operation of online UAME and OESC coupled with PCCC was described. Raw plant materials were extracted using a two-phase extractant comprising petroleum-ethyl acetate-ethanol-water (0.5:2.0:0.5:2.0, v/v/v/v). The aqueous and organic phases were then concentrated using the OESC technique. Two CCC runs were conducted for preparatory work. After extraction and online concentration, the concentrate was pumped into the CCC for separation. During PCCC separation, continuous automated extraction and concentration were still conducted. When the first cycle of the UAME/OESC/PCCC was completed, followed by the initiation of the second cycle, and the process was continued. Six target compounds with purities exceeding 97.22% were successfully separated using the CCC solvent systems comprising n-hexane-ethyl acetate-acetonitrile-water (5.5:2.5:5.0:0.4, v/v/v/v) and n-butanol-ethanol-water (4.5:1.3:6.5, v/v/v). Compared with conventional extraction methods, the proposed UAME/OESC/PCCC method has higher efficiency, facilitates high-purity separation of analytes, and offers opportunity for automation and systematic preparation of natural products.

Do short chain fatty acids and phenolic metabolites of the gut have synergistic anti-inflammatory effects? - New insights from a TNF-α-induced Caco-2 cell model.

Fermentation of dietary fiber and metabolism of polyphenols by the gut microbiota produce short chain fatty acids (SCFAs) and some simple phenolic acids, both of which have been independently shown to have anti-inflammatory effects and to improve gut health. While synergistic interactions between the two colonic metabolite groups have been speculated, direct evidence on whether and how these compounds work together towards collective anti-inflammatory effect and gut health remain unclear. In this study, the most important SCFA butyric acid (BtA) and three phenolic metabolites benzoic acid (BzA), phenylacetic acid (PAA) and phenylpropionic acid (PPA) were selected and assessed for the anti-inflammatory effects and the underlying mechanisms in a TNF-α-induced Caco-2 cell model. Significantly stronger inhibition of TNF-α-induced IL-8 production was found in cells pre-treated with different concentrations of mixtures of BtA and the phenolic metabolites than individual compounds. Further study showed that the synergistic effect was via significant down-regulation of the gene expressions of IL-8, TNF-α and VCAM-1, and of phosphorylation of JNK, p38 and IĸBα, cellular signaling mediators of the MAPK and NF-κB pathways. Although these are results of a cell model, they do provide significant insights into the synergistic anti-inflammatory effects between SCFAs and phenolic metabolites. As both metabolite groups are simultaneously present in the gut, our findings therefore also suggest a potential synergistic effect between the two colonic metabolite groups in maintaining gut health.