Supplementation of ginger root extract into broiler chicken diet: effects on growth performance and immunocompetence.

Ginger contains bioactive compounds that possess anti-inflammatory and antimicrobial properties. In this study, 432-day-old Ross 708 broiler male chicks were randomly allocated to 6 dietary treatments to investigate the effect of ginger root extract (GRE) on immunocompetence and growth performance to 6 wk of age. Treatment 1 (CON) consisted of chicks fed a corn-soybean meal (SBM), a base diet without GRE. Treatment 2 (MX) chicks were given basal diets containing bacitracin methylene disalicylate (BMD) at 0.055 g/kg. Treatments 3 (GRE-0.375%), 4 (GRE-0.75%), 5 (GRE-1.5%), and 6 (GRE-3%) were fed similar diet to control with GRE supplemented at 0.375%, 0.75%, 1.5%, and 3%, respectively. Moreover, HPLC analysis of GRE was carried out to determine the concentration of bioactive compounds found in GRE. Each treatment consisted of 6 replicate pens with 12 chicks/pen. Bodyweight (BW) and feed conversion ratio (FCR) were recorded. Results show that the concentration of bioactive compounds increased with increasing GRE supplementation. Likewise, dietary GRE supplementation did not have any detrimental effect on growth performance parameters up to 1.5%, as values for BWG was not different from CON and MX; however, 3% GRE had the poorest FCR and a lower BWG as compared to other treatments. On d 27 and d 41, fecal and cecal concentrations of total bacteria count (TBC), Escherichia coli, Lactobacillus spp., and Bifidobacterium spp enumerated using selective plating media showed that GRE supplementation significantly reduced (P < 0.05) the amount of TBC and E. coli but increased the number of beneficial microorganisms such as Lactobacillus spp. and Bifidobacterium spp. On d 20, no significant differences were observed (P > 0.05) among all treatments for antibody titer against Newcastle disease virus and total IgY antibodies; however, on d 27, GRE-0.75% had the highest value for both immune indicators and was not different from MX. Dietary supplementation of GRE up to 1.5% enhanced the immune system and suppressed E. coli while promoting the growth of healthy bacteria, without any detrimental effect on growth performance.

Impacts of Biotransformation on the Health Benefits of Tea Polyphenols.

Consumption of tea has been associated with many health benefits including the prevention of cardiovascular disease, cancer, and obesity. These effects are attributed to the polyphenol compounds in tea with catechins being the major components in green tea and theaflavins (TFs) and thearubigins (TRs) as the unique compounds in black tea. Tea polyphenols are extensively metabolized in vivo and have poor systematic bioavailability. It is generally believed that the metabolites of tea polyphenols retain their bioactivities and some of the microbial metabolites are more bioavailable than the parent compounds. This manuscript summarizes the recent progress on the identification of novel metabolic pathways of tea polyphenols and their contributions to the health benefits of tea.

Pharmacokinetics of Gingerols, Shogaols, and Their Metabolites in Asthma Patients.

6-Gingerol and 6-shogaol are the most abundant gingerols and shogaols in ginger root and have been shown to reduce the asthmatic phenotype in murine models of asthma. Several studies have described the pharmacokinetics of gingerols and shogaols in humans following the oral ingestion of ginger, while little was known about the metabolism of these components in humans, particularly in patients with asthma. In this study, a dietary supplement of 1.0 g of ginger root extract was administered to asthma patients twice daily for 56 days and serum samples were drawn at 0.5-8 h on days 0, 28, and 56. The metabolic profiles of gingerols and shogaols in human plasma and the kinetic changes of gingerols, shogaols, and their metabolites in asthma patients collected on the three different visits were analyzed using liquid chromatography-mass spectrometry (LC-MS). Ketone reduction was the major metabolic pathway of both gingerols and shogaols. Gingerdiols were identified as the major metabolites of 6-, 8-, and 10-gingerols. M11 and M9 were identified as the double-bond reduction and both the double-bond and ketone reduction metabolites of 6-shogaol, respectively. Cysteine conjugation was another major metabolic pathway of 6-shogaol in asthma patients, and two cysteine-conjugated 6-shogaol, M1 and M2, were identified as the major metabolites of 6-shogaol. Furthermore, gingerols, shogaols, and their metabolites were quantitated in the human serum collected at different time points during each of the three visits using a very sensitive high-resolution LC-MS method. The results showed that one-third of 6-gingerol was metabolized to produce its reduction metabolites, 6-gingerdiols, and more than 90% of 6-shogaol was metabolized to its phase I and cysteine-conjugated metabolites, suggesting the importance of considering the contribution of these metabolites to the bioavailability and health beneficial effects of gingerols and shogaols. All gingerols, shogaols, and their metabolites reached their peak concentrations in less than 2 h, and their half-lives (t1/2) were from 0.6 to 2.4 h. Furthermore, long-term treatment of ginger supplements, especially after 56 days of treatment, increases the absorption of ginger compounds and their metabolites in asthma patients.

Gut Microbiota as a Novel Tool to Dissect the Complex Structures of Black Tea Polymers.

Thearubigins, polymers of tea catechins, account for more than 20% of the black tea polyphenols and have been reported to be the active components in black tea. However, the chemical structures and underlying mechanisms regarding how the thearubigins, being poorly bioavailable, generate in vivo health benefits are still largely unknown. Using germ-free and specific pathogen-free husbandry conditions combined with LC/MS-based nontargeted and targeted metabolomic analyses, we investigated the role of intestinal bacteria in thearubigin metabolism. Theaflavins and theasinensins were identified as the major microbial metabolites of thearubigins, suggesting that these molecules are the building units for the complex thearubigins. To further confirm this, thearubigin depolymerization was done using menthofuran in an acidic condition. Menthofuran-conjugated theaflavins, theasinensins, and catechins as well as their free forms were detected as the major degradation products of thearubigins. This indicated that theaflavins and theasinensins could be further polymerized through B-type proanthocyanidin linkages. Furthermore, four microbial degradation products were able to be detected in urine samples, suggesting that they can be absorbed into the circulatory system. Using the combination of microbial degradation, metabolomics, and chemical degradation, our results demonstrate that thearubigins are the complex polymers of theaflavins, theasinensins, and catechins and can be metabolized by gut microbiota to their corresponding bioactive and bioavailable smaller molecular metabolites.

Dietary supplementation of gingerols- and shogaols-enriched ginger root extract attenuate pain-associated behaviors while modulating gut microbiota and metabolites in rats with spinal nerve ligation.

Neuroinflammation is a central factor in neuropathic pain (NP). Ginger is a promising bioactive compound in NP management due to its anti-inflammatory property. Emerging evidence suggests that gut microbiome and gut-derived metabolites play a key role in NP. We evaluated the effects of two ginger root extracts rich in gingerols (GEG) and shogaols (SEG) on pain sensitivity, anxiety-like behaviors, circulating cell-free mitochondrial DNA (ccf-mtDNA), gut microbiome composition, and fecal metabolites in rats with NP. Sixteen male rats were divided into four groups: sham, spinal nerve ligation (SNL), SNL+0.75%GEG in diet, and SNL+0.75%SEG in diet groups for 30 days. Compared to SNL group, both SNL+GEG and SNL+SEG groups showed a significant reduction in pain- and anxiety-like behaviors, and ccf-mtDNA level. Relative to the SNL group, both SNL+GEG and SNL+SEG groups increased the relative abundance of Lactococcus, Sellimonas, Blautia, Erysipelatoclostridiaceae, and Anaerovoracaceae, but decreased that of Prevotellaceae UCG-001, Rikenellaceae RC9 gut group, Mucispirillum and Desulfovibrio, Desulfovibrio, Anaerofilum, Eubacterium siraeum group, RF39, UCG-005, Lachnospiraceae NK4A136 group, Acetatifactor, Eubacterium ruminantium group, Clostridia UCG-014, and an uncultured Anaerovoracaceae. GEG and SEG had differential effects on gut-derived metabolites. Compared to SNL group, SNL+GEG group had higher level of 1'-acetoxychavicol acetate, (4E)-1,7-Bis(4-hydroxyphenyl)-4-hepten-3-one, NP-000629, 7,8-Dimethoxy-3-(2-methyl-3-buten-2-yl)-2H-chromen-2-one, 3-{[4-(2-Pyrimidinyl)piperazino]carbonyl}-2-pyrazinecarboxylic acid, 920863, and (1R,3R,7R,13S)-13-Methyl-6-methylene-4,14,16-trioxatetracyclo[11.2.1.0∼1,10∼.0∼3,7∼]hexadec-9-en-5-one, while SNL+SEG group had higher level for (±)-5-[(tert-Butylamino)-2'-hydroxypropoxy]-1_2_3_4-tetrahydro-1-naphthol and dehydroepiandrosteronesulfate. In conclusion, ginger is a promising functional food in the management of NP, and further investigations are necessary to assess the role of ginger on gut-brain axis in pain management.

Ginger metabolites and metabolite-inspired synthetic products modulate intracellular calcium and relax airway smooth muscle.

Asthma affects millions of people worldwide and its prevalence is increasing. It is characterized by chronic airway inflammation, airway remodeling, and pathologic bronchoconstriction, and it poses a continuous treatment challenge with very few new therapeutics available. Thus, many asthmatics turn to plant-based complementary products, including ginger, for better symptom control, indicating an unmet need for novel therapies. Previously, we demonstrated that 6-shogaol (6S), the primary bioactive component of ginger, relaxes human airway smooth muscle (hASM) likely by inhibition of phosphodiesterases (PDEs) in the ß-adrenergic (cyclic nucleotide PDEs), and muscarinic (phospholipase C, PLC) receptor pathways. However, oral 6S is extensively metabolized and it is unknown if the resulting metabolites remain bioactive. Here, we screened all the known human metabolites of 6S and several metabolite-based synthetic derivatives to better understand their mechanism of action and structure-function relationships. We demonstrate that several metabolites and metabolite-based synthetic derivatives are able to prevent Gq-coupled stimulation of intracellular calcium [Ca2+]i and inositol trisphosphate (IP3) synthesis by inhibiting PLC, similar to the parent compound 6S. We also show that these compounds prevent recontraction of ASM after ß-agonist relaxation likely by inhibiting PDEs. Furthermore, they potentiate isoproterenol-induced relaxation. Importantly, moving beyond cell-based assays, metabolites also retain the functional ability to relax Gq-coupled-contractions in upper (human) and lower (murine) airways. The current study indicates that, although oral ginger may be metabolized rapidly, it retains physiological activity through its metabolites. Moreover, we are able to use naturally occurring metabolites as inspiration to develop novel therapeutics for brochoconstrictive diseases.

Novel Steroidal Saponins in Oat Identified by Molecular Networking Analysis and Their Levels in Commercial Oat Products.

Through the use of the Global Natural Product Social (GNPS) feature-based networking system, a series of newly identified steroidal saponins were discovered in oat. The structures of the three new major steroidal saponins, sativacosides A-C (1-3), were characterized by analyzing their high-resolution MS, 1D and 2D NMR spectra, and an additional eight new steroidal saponins were also tentatively identified (4-11) based on their tandem mass spectra and typical fragments. Using ultrahigh-performance liquid chromatography with tandem mass spectrometry techniques, a complete profile of the new sativacoside series was established, and the contents of sativacosides A-C were quantified in 18 different commercial oat products. The total levels of sativacosides A-C varied from 62.2 to 192.9 µg/g in these 18 products, in which oat bran (11 samples) and oatmeal (3 samples) had higher levels than cold oat cereal (4 samples).

Simultaneous Determination of Multiple Reactive Carbonyl Species in High Fat Diet-Induced Metabolic Disordered Mice and the Inhibitory Effects of Rosemary on Carbonyl Stress.

As potential endogenous biomarkers, reactive carbonyl species (RCS) have gained abundant attention for monitoring oxidative and carbonyl stress. However, there is no accurate method to evaluate multiple RCS in biological samples. In this study, a 2,4-dinitrophenylhydrazine (DNPH) derivatization-based LC-MS method was developed and validated to quantitate eight RCS: malondialdehyde (MDA), acrolein (ACR), 4-hydroxy-2-nonenal (4-HNE), 4-oxo-2-nonenal (4-ONE), methylglyoxal (MGO), glyoxal (GO), 3-deoxyglucosone (3-DG), and 2-keto-d-glucose (2-Keto). Subsequently, the method was applied to assess the RCS in low fat (LF), high fat (HF), and HF plus rosemary extract (RE) diet-fed mouse samples. The quantitative results on RCS levels indicated that the HF diet significantly increased the total RCS levels in mouse urine, plasma, and kidney with an average rate of 280.69%, 153.87%, and 61.30%, respectively. The RE administration significantly inhibited the elevated RCS levels induced by the HF diet, especially for MDA, 4-ONE, 4-HNE, and 2-Keto in mouse plasma, and ACR and 2-Keto in mouse kidney. This is the first study to simultaneously measure eight RCS in biological samples and demonstrate that RE was able to eliminate the accumulation of the HF diet-induced RCS.

Black Tea Theaflavin Detoxifies Metabolic Toxins in the Intestinal Tract of Mice.

SCOPE: This study is to determine the in vivo efficacy of black tea theaflavin (TF) to detoxify two metabolic toxins, ammonia and methylglyoxal (MGO), in mice METHODS AND RESULTS: Under in vitro conditions, TF is able to react with ammonia, MGO, and hydrogen peroxide to produce its aminated, MGO conjugated, and oxidized products, respectively. In TF-treated mice, the aminated TF, the MGO conjugates of TF and aminated TF, and the oxidized TF are searched using LC-MS/MS. The results provide the first in vivo evidence that the unabsorbed TF is able to trap ammonia to form the aminated TF; furthermore, both TF and the aminated TF have the capacity to trap MGO to generate the corresponding mono-MGO conjugates. Moreover, TF is oxidized to dehydrotheaflavin, which underwent further amination in the gut. By exposing TF to germ-free (GF) mice and conventionalized mice (GF mice colonized with specific-pathogen-free microbiota), the gut microbiota is demonstrated to facilitate the amination and MGO conjugation of TF. CONCLUSION: TF has the capacity to remove the endogenous metabolic toxins through oxidation, amination, and MGO conjugation in the intestinal tract, which can potentially explain why TF still generates in vivo efficacy while showing a poor systematic bioavailability.

Precision Research on Ginger: The Type of Ginger Matters.

Ginger is a widely consumed spice and possesses numerous pharmacological properties. However, studies addressing the efficacy of ginger in humans have been inconsistent. Many confounding factors need to be considered when evaluating the health effects from ginger against chronic diseases, especially the levels of bioactive components in the ginger formulations used in human trials. Gingerols, the major compounds in fresh ginger, are liable to dehydrate and convert to shogaols, the major compounds in dried ginger, as a result of the instability of ß-hydroxyl ketone when exposed to heat and/or acidic conditions. As a result of various heating and processing methods, the concentrations of gingerols and shogaols in ginger products vary significantly. Increasing evidence has shown that gingerols and shogaols have different bioactivities, molecular targets, and metabolic pathways, suggesting the importance of identifying the optimal oral ginger composition for a specific disease. In this perspective, we highlighted differences in the composition between fresh ginger and dry ginger, bioactivities, molecular targets, and metabolic pathways of gingerols and shogaols as well as future perspectives regarding precision research on ginger.

Dietary Genistein Reduces Methylglyoxal and Advanced Glycation End Product Accumulation in Obese Mice Treated with High-Fat Diet.

Our previous study has found that dietary genistein could ameliorate high-fat diet (HFD)-induced obesity and especially lower methylglyoxal (MGO) and advanced glycation end product (AGE) accumulation in healthy mice exposed to genistein and HFD. However, it is still unclear whether dietary genistein intervention has a similar beneficial effect in obese mice. In this study, the mice were induced with obesity after being fed a HFD for nine weeks before being administered with two doses of genistein, 0.1% (G 0.1) and 0.2% (G 0.2), in the HFD for additional 19 weeks. After 19 week treatment, genistein supplementation reduced body and liver weights, plasma and liver MGO levels, and kidney AGE levels in mice. Mechanistically, genistein upregulated the expressions of glyoxalase I and II and aldose reductase to detoxify MGO, and genistein and its microbial metabolites, dihydrogenistein and 6'-hydroxy-O-demethylangolensin, were able to trap endogenous MGO via formation of MGO conjugates. Taken together, our results provide novel insights into the antiobesity and antiglycation roles of dietary genistein in obese subjects.

Triterpenoid Saponins in Oat Bran and Their Levels in Commercial Oat Products.

Oats are commonly consumed as whole grains and generally considered as a healthy food. However, the bioactive compounds in oats have not been fully investigated. In this study, we reported for the first time the purification, structure elucidation, and chemical profile of the major triterpenoid saponins in oat bran as well as the quantification of the major triterpenoid saponins in commercial oat products. Thirteen triterpenoid saponins (1-13) were purified from oat bran. Their structures were characterized by analyzing their high-resolution mass spectrometry (MS), one-dimensional (1-D), and two-dimensional (2-D) NMR spectra. All of the purified triterpenoid saponins have been reported from oat bran for the first time, in which compounds (1-8) are newly discovered compounds and compound (9) is a new natural product. Using ultra-high-performance liquid chromatography with tandem mass spectrometry techniques, a complete profile of oat triterpenoid saponins was established, and the contents of the 13 purified triterpenoid saponins were quantitated in 19 different commercial oat products. The total levels of the 13 triterpenoid saponins varied from 1.77 to 18.20 µg/g in these 19 products, in which oat bran (11 samples) and oatmeal (three samples) had higher levels than cold oat cereal (five samples). Among the 11 commercial oat bran samples, the average total levels of the 13 triterpenoid saponins in the five sprouted oat samples are slightly higher than those in the regular oat bran products.

Translating In Vitro Acrolein-Trapping Capacities of Tea Polyphenol and Soy Genistein to In Vivo Situation is Mediated by the Bioavailability and Biotransformation of Individual Polyphenols.

SCOPE: Acrolein (ACR) is a highly toxic unsaturated aldehyde. Humans are both endogenously and exogenously exposed to ACR. Long-term exposure to ACR leads to various chronic diseases. Dietary polyphenols have been reported to be able to attenuate ACR-induced toxicity in vitro via formation of ACR-polyphenol conjugates. However, whether in vitro ACR-trapping abilities of polyphenols can be maintained under in vivo environments is still unknown. METHODS AND RESULTS: Two most commonly consumed dietary polyphenols, (-)-epigallocatechin-3-gallate (EGCG) from tea and genistein from soy, are evaluated for their anti-Acrolein behaviors both in vitro and in mice. Tea EGCG exerts a much higher capacity to capture ACR than soy genistein in vitro. But translation of in vitro anti-ACR activity into in vivo is mainly mediated by bioavailability and biotransformation of individual polyphenols. It is found that 1) both absorbed EGCG and genistein can trap endogenous ACR by forming mono-ACR adducts and eventually be excreted into mouse urine; 2) both absorbed EGCG and genistein can produce active metabolites, methyl-EGCG (MeEGCG) and orobol, to scavenge endogenous ACR; 3) both MeEGCG and non-absorbed EGCG show ability to trap ACR in the gut; 4) considerable amounts of microbial metabolites of genistein display enhanced anti-ACR capacity both in the body and in the gut, compared to genistein; and 5) biotransformation of genistein is able to boost its in vivo anti-ACR capacity, compared to EGCG. CONCLUSION: The findings demonstrate that in vivo anti-ACR ability of dietary polyphenols cannot be reflected solely based on their in vitro ability. The bioavailability and biotransformation of individual polyphenols, and especially the gut microbiome, contribute to in vivo anti-ACR ability of dietary polyphenols.

Dietary Genistein Inhibits Methylglyoxal-Induced Advanced Glycation End Product Formation in Mice Fed a High-Fat Diet.

BACKGROUND: Methylglyoxal (MGO), an important precursor of advanced glycation end products (AGEs), circulates at high concentrations in diabetic patients' blood and plays an important role in the pathogenesis of diabetes and other chronic diseases. OBJECTIVES: The aim of this study was to determine whether dietary genistein can prevent indicators of metabolic syndrome (MetS) induced by a very-high-fat (VHF) diet or a high-fat (HF) diet plus exogenous MGO, and the accumulation of MGO and AGEs in mice. METHODS: Male, 6-wk-old C57BL/6J mice (n = 15) were fed a low-fat (LF) diet (10% fat energy) or a VHF diet (60% fat energy) alone or including 0.25% genistein (VHF-G) for 16 wk in study 1. In study 2, 75 similar mice were fed the LF diet (LF) or the HF diet alone (HF) or in combination with up to 0.2% MGO in water (HFM) and 0.067% (HFM-GL) or 0.2% (HFM-GH) dietary genistein for 18 wk. Anthropometric and metabolic data were obtained in both studies to determine the effects of MGO and genistein on variables indicative of MetS. RESULTS: Body weight gain, fat deposits, dyslipidemia, hyperglycemia, and fatty liver were ameliorated by dietary genistein in both studies. The plasma MGO concentration in VHF-G mice was 52% lower than that in VHF mice. Moreover, the AGE concentrations in plasma, liver, and kidney of VHF-G mice were 73%, 52%, and 49%, respectively, lower than in the VHF group (study 1). Similarly, the concentrations of plasma MGO and AGE in plasma, liver, and kidney of HFM-GH mice were 33.5%, 49%, 69%, and 54% lower than in HFM mice (study 2). Genistein inhibited AGE formation by trapping MGO to form adducts and upregulating the expressions of glyoxalase I and II and aldose reductase in liver and kidney to detoxify MGO in both studies. CONCLUSIONS: Our data demonstrate for the first time that genistein significantly lowers MGO and AGE concentrations in 2 mouse MetS models via multiple pathways.

Rescue of hematopoietic stem/progenitor cells formation in plcg1 zebrafish mutant.

Hematopoietic stem/progenitor cells (HSPC) in zebrafish emerge from the aortic hemogenic endothelium (HE) and migrate towards the caudal hematopoietic tissue (CHT), where they expand and differentiate during definitive hematopoiesis. Phospholipase C gamma 1 (Plcγ1) has been implicated for hematopoiesis in vivo and in vitro and is also required to drive arterial and HSPC formation. Genetic mutation in plcg1-/- (y10 allele) completely disrupts the aortic blood flow, specification of arterial fate, and HSPC formation in zebrafish embryos. We previously demonstrated that ginger treatment promoted definitive hematopoiesis via Bmp signaling. In this paper, we focus on HSPC development in plcg1-/- mutants and show that ginger/10-gingerol (10-G) can rescue the expression of arterial and HSPC markers in the HE and CHT in plcg1-/- mutant embryos. We demonstrate that ginger can induce scl/runx1 expression, and that rescued HE fate is dependent on Bmp and Notch. Bmp and Notch are known to regulate nitric oxide (NO) production and NO can induce hematopoietic stem cell fate. We show that ginger produces a robust up-regulation of NO. Taken together, we suggest in this paper that Bmp, Notch and NO are potential players that mediate the effect of ginger/10-G for rescuing the genetic defects in blood vessel specification and HSPC formation in plcg1-/- mutants. Understanding the molecular mechanisms of HSPC development in vivo is critical for understanding HSPC expansion, which will have a positive impact in regenerative medicine.

Importance of the Nucleophilic Property of Tea Polyphenols.

Tea is the second most popular beverage in the world after water. Vast accumulative evidence attest that tea consumption may promote human health, such as antioxidant, anti-obesity, and anticancer activities. Therefore, tea phytochemicals have drawn exceeding attention from researchers in structure confirmation, formation mechanism, component clarification, and bioactivity screening of interested constituents. Particularly, most investigations of chemical or biochemical reactions of catechins have concentrated on the B ring of the C6-C3-C6 skeleton. Hence, in this perspective, we reviewed the profound findings of the carbon-carbon (C-C) connection from the unambiguous characterization of novel A-ring addition derivatives of tea catechins, including catechin-carbonyl and catechin-theanine conjugates and the C-C formation mechanisms, and offered our view of the potential effects of catechin-carbonyl interactions on flavor generation and bioactive action in tea.

Microbiota facilitates the formation of the aminated metabolite of green tea polyphenol (-)-epigallocatechin-3-gallate which trap deleterious reactive endogenous metabolites.

The in vivo mechanism of tea polyphenol-mediated prevention of many chronic diseases is still largely unknown. Studies have shown that accumulation of toxic reactive cellular metabolites, such as ammonia and reactive carbonyl species (RCS), is one of the causing factors to the development of many chronic diseases. In this study, we investigated the in vivo interaction between (-)-epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in tea leaves, and ammonia and RCS. We found that EGCG could be oxidized to EGCG quinone in mice, and then rapidly react with ammonia to generate the aminated EGCG metabolite, 4'-NH2-EGCG. Both EGCG and its aminated metabolite could further scavenge RCS, such as methylglyoxal (MGO), malondialdehyde (MDA), and trans-4-hydroxy-2-nonenal (4-HNE), to produce the RCS conjugates of EGCG and the aminated EGCG. Both the aminated and the RCS conjugated metabolites of EGCG were detected in human after drinking four cups of green tea per day. By comparing the levels of the aminated and the RCS conjugated metabolites in EGCG exposed germ-free (GF) mice and specific-pathogen-free (SPF) mice, we demonstrated that gut microbiota facilitate the formation of the aminated metabolite of EGCG, the RCS conjugates of EGCG, and the RCS conjugates of the aminated EGCG. By comparing the trapping capacities of EGCG and its aminated metabolite under aerobic and anaerobic conditions, we found that oxygen is not essential for the trapping of reactive species by EGCG and 4'-NH2-EGCG suggesting that EGCG and its aminated metabolite could scavenge RCS in the GI track and in the circulation system. Altogether, this study provides in vivo evidences that EGCG has the capacity to scavenge toxic reactive metabolic wastes. This finding opens a new window to understand the underlying mechanisms by which drinking tea could prevent the development of chronic diseases.

Induction of Apoptosis and Cell-Cycle Arrest in Human Colon-Cancer Cells by Whole-Grain Alkylresorcinols via Activation of the p53 Pathway.

Colon cancer, one of the leading causes of cancer-associated deaths, is the target of choice for nutrition-based-prevention approaches because of the direct and early contact between the active compounds and the cancerous tissues. We previously reported alkylresorcinols (ARs) as the major active components in wheat bran against human colon cancer. Here, we further investigate the anticancer mechanisms of action of ARs. Our mechanistic studies indicated that AR C15 and AR C17 exert their anticancer activities in colon-cancer cells by inducing apoptosis through PUMA upregulation and mitochondrial-pathway activation, inducing cell-cycle arrest through p21 upregulation, and inhibiting proteasome activity and Mdm2 expression. This cascade of distinct mechanisms was linked to the consequent activation and accumulation of p53. The results of treatment with p53 inhibitor further confirmed that the p53 pathway might play a very important role in AR-induced apoptosis in colon-cancer cells. Altogether these results show that AR C15 and AR C17 can specifically activate the mitochondrial pathway of apoptosis and cause cell-cycle arrest and that inhibition of p53 greatly reduces the activation of this pathway.

Avenanthramide Aglycones and Glucosides in Oat Bran: Chemical Profile, Levels in Commercial Oat Products, and Cytotoxicity to Human Colon Cancer Cells.

Avenanthramides (AVAs), unique phytochemicals in oat, have attracted an increasing amount of attention due to their outstanding health benefits. However, the chemical profile and the levels of AVAs in commercial oat products as well as their health benefits have not been examined in detail. In the present study, a total of 29 AVA aglycones and AVA glucosides were identified and characterized from oat bran using NMR (1D and 2D NMR) and LC-MS techniques. Among them, 17 novel AVA glucosides were reported in oat bran for the first time. The most abundant AVA glucoside, 2c-3'- O-glc, had a similar growth inhibitory activity with the major AVA, 2c, against HCT-116 and HT-29 human colon cancer cells, indicating glucosylation does not affect the growth inhibitory effects of AVAs. Furthermore, the levels of all individual AVAs in 13 commercial oat products were analyzed using HPLC-MS/MS. The total AVAs contents in various oat products ranged from 9.22 to 61.77 mg/kg (fresh weight).

A new method to prepare and redefine black tea thearubigins.

Thearubigins (TRs) are the major components of black tea, which are formed during the fermentation reactions. Although anti-inflammatory and anti-cancer activities of TRs have been reported, the prepared TRs according to the literature methods still contain many floating peaks. It is puzzling whether the observed activities are from TRs or these floating peaks. Thus, it is urgent to develop a method to prepare pure TRs and redefine them. In the present study, we developed a new method, the combination of caffeine precipitation and Sephadex LH-20 column chromatography, to prepare pure TRs. The floating peaks on the hump of the crude TRs were removed, and pure TRs were prepared. The chemical profile of the floating peaks was established using LC/MS, and the major compounds in this fraction were identified as apigenin glycosides, quercetin glycosides, kaempferol glycosides, theaflavins, theasinensin, and galloylglucoses based on the analysis of their tandem mass spectra and in comparison with literature data. This study will pave the way to further study the chemistry and biological activities of TRs and the health effects of black tea consumption.