Gut microbiota protects from triptolide-induced hepatotoxicity: Key role of propionate and its downstream signalling events.

As a potential drug for treating inflammatory, autoimmune diseases and cancers, triptolide (TP) is greatly limited in clinical practice due to its severe toxicity, particularly for liver injury. Recently, metabolic homeostasis was vitally linked to drug-induced liver injury and gut microbiota was established to play an important role. In this study, we aimed to investigate the functions of gut microbiota on TP-induced hepatotoxicity using metabolomics in mice. Here, predepletion of gut microbiota by antibiotic treatment strikingly aggravated liver injury and caused mortality after treated with a relatively safe dosage of TP at 0.5 mg/kg, which could be reversed by gut microbial transplantation. The loss of gut microbiota prior to TP treatment dramatically elevated long chain fatty acids and bile acids in plasma and liver. Further study suggested that gut microbiota-derived propionate contributed to the protective effect of gut microbiota against TP evidenced by ameliorative inflammatory level (Tnfa, Il6 and Cox2), ATP, malondialdehyde and hepatic histology. Supplementing with propionate significantly decreased the mRNA levels of genes involved in fatty acid biosynthesis (Srebp1c, Fasn and Elovl6), resulting in the decreased long chain fatty acids in liver. Moreover, TP restricted the growth of Firmicutes and led to the deficiency of short chain fatty acids in cecum content. In conclusion, our study warns the risk for TP and its preparations when antibiotics are co-administrated. Intervening by foods, prebiotics and probiotics toward gut microbiota or supplementing with propionate may be a clinical strategy to improve toxicity induced by TP.

Synthesis of glucosamine-selenium compound and evaluation of its oral toxicity and in vitro anti-hepatitis B virus activity.

Selenium supplements are beneficial to human health, however, concerns regarding the toxicity of inorganic selenium have stimulated research on safer organic compounds. The main objective of this study was to develop a novel glucosamine-selenium compound (Se-GlcN), clarify its structure, and subsequently investigate its oral toxicity and in vitro anti-hepatitis B virus (HBV) activity. Electron microscopy, infrared, ultraviolet spectroscopy, nuclear magnetic resonance and thermogravimetric analyses revealed a unique binding mode of Se-GlcN, with the introduction of the Se-O bond at the C6 position, resulting in the formation of two carboxyl groups. In acute toxicity studies, the median lethal dose (LD50) of Se-GlcN in ICR mice was 92.31 mg/kg body weight (BW), with a 95 % confidence interval of 81.88-104.07 mg/kg BW. A 30-day subchronic toxicity study showed that 46.16 mg/kg BW Se-GlcN caused livers and kidneys damage in mice, whereas doses of 9.23 mg/kg BW and lower were safe for the livers and kidneys. In vitro studies, Se-GlcN at 1.25 µg/mL exhibited good anti-HBV activity, significantly reducing HBsAg, HBeAg, 3.5 kb HBV RNA and total HBV RNA by 45 %, 54 %, 84 %, 87 %, respectively. In conclusion, the Se-GlcN synthesized in this study provides potential possibilities and theoretical references for its use as an organic selenium supplement.

Insights into the interaction mechanism of acid phosphatase from Lateolabrax japonicus livers and rosmarinic acid using multispectroscopy and molecular docking.

Acid phosphatase (ACP) is a key enzyme that hydrolyzes inosinic acid. The mechanisms underlying the interaction between rosmarinic acid (RA) and ACP and the inhibition of the enzyme were investigated using inhibition kinetics, UV-visible and fluorescence spectroscopy, circular dichroism, and molecular docking. The results showed that RA was a reversible inhibitor of ACP and that the inhibition mechanism was uncompetitive. The ACP fluorescence was quenched by RA, and the quenching mode was static. The interaction of ACP with RA was driven by H bonds and van der Waals forces. The addition of RA increased the α-helix content and decreased the ß-sheet, ß-turn, and random coil contents in ACP, thereby altering the secondary structure of the enzyme. This study enriched our understanding of inhibitory and interaction mechanisms involving ACP and RA.

Co-electrospun-electrosprayed ethyl cellulose-gelatin nanocomposite pH-sensitive membrane for food quality applications.

Anthocyanin from red cabbage is an important biomolecule suitable for pH sensing due to its oxidoreduction potential that leads to a color change at various pH conditions. The pH-sensitive anthocyanin compound was extracted from red cabbage (1785 ± 235 mg/L) and encapsulated with gelatin as the wall material at the nanoscale (350 nm) through electrospraying. By using a simultaneous electrospraying and spinning process at 20 kV, nanoencapsulated anthocyanin was immobilized on ethyl cellulose (EC) nanofibers and formed as a nanocomposite membrane. The surface morphology of developed nanocomposites has shown complex nonwoven nanofiber formation and the immobilized nano encapsulates captured inside the nanofibrous membrane. The pH sensitivity was significantly stable up to 7 days of storage at room temperature. Total color difference has been observed to be statistically significant at different pH conditions of 2 to 12. Also, the application of the nanocomposite strips in pH sensing during milk spoilage was studied and reported.

Impact of molar absorbance on anthocyanin content of the foods.

Anthocyanins are present in bright colored fruit and vegetables with growing evidence for their health benefits. Several methods exist in the literature to measure the total monomeric anthocyanin content in foods. Although the simplest method uses UV-Vis spectrophotometry, it requires the use of anthocyanin molar absorption coefficients (Ɛ). While commonly reported for some compounds, these values vary substantially between studies. This study collated and compared existing Ɛ values for a range of anthocyanin-3-glucosides, measured new Ɛ values for these compounds and underwent an inter-laboratory validation of spectrometry methods. The Ɛ values used for the determination of anthocyanin content in Australian blueberries, were shown to greatly affect the estimated total anthocyanin. Significant differences in the Ɛ values were observed when measured at 520 nm, or their absorbance maximum and substantial difference in the estimated total anthocyanins were observed when expressed as equivalent of cya-3-glu or mal-3-glu.

The palladacycle, BTC2, exhibits anti-breast cancer and breast cancer stem cell activity.

In women globally, breast cancer is responsible for most cancer-related deaths and thus, new effective therapeutic strategies are required to treat this malignancy. Platinum-based compounds like cisplatin are widely used to treat breast cancer, however, they come with limitations such as poor solubility, adverse effects, and drug resistance. To overcome these limitations, complexes containing other platinum group metals such as palladium have been studied and some have already entered clinical trials. Here we investigated the anti-cancer activity of a palladium complex, BTC2, in MCF-7 oestrogen receptor positive (ER+) and MDA-MB-231 triple negative (TN) human breast cancer cells as well as in a human breast cancer xenograft chick embryo model. BTC2 exhibited an average IC50 value of 0.54 µM, a desirable selectivity index of >2, inhibited the migration of ER+ and TN breast cancer cells, and displayed anti-cancer stem cell activity. We demonstrate that BTC2 induced DNA double strand breaks (increased levels of γ-H2AX) and activated the p-ATM/p-CHK2 and p-p38/MAPK pathways resulting in S- and G2/M-phase cell cycle arrests. Importantly, BTC2 sensitised breast cancer cells by triggering the intrinsic (cleaved caspase 9) and extrinsic (cleaved caspase 8) apoptotic as well as necroptotic (p-RIP3 and p-MLKL) cell death pathways and inhibiting autophagy and its pro-survival role. Furthermore, in the xenograft in vivo model, BTC2 displayed limited toxicity and arrested the tumour growth of breast cancer cells over a 9-day period in a manner comparable to that of the positive control drug, paclitaxel. BTC2 thus displayed promising anti-breast cancer activity.

Co-pigmentation of anthocyanins extracted from sour cherry (Prunus cerasus L.) with some organic acids: Color intensity, thermal stability, and thermodynamic parameters.

The co-pigmentation reactions involving anthocyanins of sour cherry (Prunus cerasusL.) were investigated with tannic, caffeic, 4-hydroxybenzoic, gallic, and malic acids at pH 3.5. The influence of the co-pigments with different concentrations (120, 240, 480, and 960 mg/L), and temperatures (20, 40, 60, 80 and 100 ℃), on the co-pigmentation effects, stoichiometric ratio (n), the equilibrium constant (K) and thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were determined.The strongest immediate co-pigmentation reactions were observed at 960 mg/L, being significantly highest using tannic acid; also,the greatest bathochromic and hyperchromic effects were reasonable for itsn,K, and ΔG° values of 0.64, 56.55, and -10.00 kJ/mol, respectively. Furthermore, tannic and caffeic acids, with the highest negative values ofΔH°(-11.74 kJ/mol) andΔS°(-8.08 J/K.mol) led to the most excellent stability at 100 ℃.The presence of anthocyanins in the sour cherry extract was confirmed with the Fourier-transform infrared spectroscopy technique.

Physicochemical properties, antioxidant activities, and binding behavior of 3,5-di-O-caffeoylquinic acid with beta-lactoglobulin colloidal particles.

Milk proteins and polyphenols are increasingly being studied as functional ingredients due to the epidemiologically-proved health benefits. In this study, composite ß-lactoglobulin (ß-lg) or ß-lactoglobulin nanoparticles (ß-lgNPs)-3,5-di-O-caffeoylquinic acid (3,5diCQA) with superior physicochemical and antioxidant activity (AA) were produced using ß-lg and 3,5-di-O-caffeoylquinic acid. The main interactions between ß-lg or ß-lgNPs with 3,5diCQA were hydrogen bonding and hydrophobic effects. The 3,5diCQA caused a decrease in α-helix and ß-sheet structure with a corresponding increase in unordered structure. Compared to ß-lg alone, composite ß-lg or ß-lgNPs-3,5diCQA slightly decreased the particle size but increased their negative surface potentials especially for ß-lg or ß-lgNPs at a molar ratio of 5:1. The addition of 3,5diCQA appreciably improved the AA in a dose-dependent manner. These results shed light on the structural, physicochemical, and AA of composite ß-lg or ß-lgNPs-3,5diCQA non-covalent complexes, important for application as functional ingredients in food solutions as well as in the pharmaceutical industry.

Photo-stability of lutein in surfactant-free lutein-zein composite colloidal particles.

The ability of nanoparticles from the plant protein zein to protect lutein from light degradation was studied under various conditions. Lutein-zein nanoparticles were synthesized, after zein purification, by anti-solvent precipitation. Particle sizes, ranging from 25 to 75 nm, measured by dynamic light scattering, were tuned by varying zein concentrations in the solvent phase (before anti-solvent precipitation), which was linked to the encapsulation efficiency. However, changes in particle sizes did not result in significant changes in photo-stability. Zein-lutein nanoparticles showed increased photo-stability of lutein when compared to lutein dispersions in water. To further promote the lutein stability, ascorbic acid was used as an antioxidant in the aqueous dispersion. The addition of ascorbic acid to lutein-zein particles resulted in dispersions with similar properties. However, the photo-stability of lutein in dispersions stabilized with ascorbic acid improved significantly compared to samples without ascorbic acid or to pure lutein dispersions (about 25% increased relative stability).

Effects of fructans and probiotics on the inhibition of Klebsiella oxytoca and the production of short-chain fatty acids assessed by NMR spectroscopy.

Generally, the selection of fructans prebiotics and probiotics for the formulation of a symbiotic has been based on arbitrary considerations and in vitro tests that fail to take into account competitiveness and other interactions with autochthonous members of the intestinal microbiota. However, such analyzes may be a valuable step in the development of the symbiotic. The present study, therefore, aims to investigate the effect of lactobacilli strains and fructans (prebiotic compounds) on the growth of the intestinal competitor Klebsiella oxytoca, and to assess the correlation with short-chain fatty acids production. The short-chain fatty acids formed in the fermentation of the probiotic/prebiotic combination were investigated using NMR spectroscopy, and the inhibitory activities were assessed by agar diffusion and co-culture methods. The results showed that Lactobacillus strains can inhibit K. oxytoca, and that this antagonism is influenced by the fructans source and probably associated with organic acid production.

A novel pH-sensing indicator based on bacterial cellulose nanofibers and black carrot anthocyanins for monitoring fish freshness.

A novel intelligent pH-sensing indicator based on bacterial nanocellulose (BC) and black carrot anthocyanins (CA) was developed and characterized to monitor the freshness/spoilage of rainbow trout and common carp fillet during the storage at 4 °C. The indicator displayed wide color differences from red to gray over the 2-11 pH range, which was clearly discerned by the naked eye. The fabricated pH-sensing indicator showed distinguishable color changes during fresh (deep carmine color), best to eat (charm pink color), and spoiled (jelly bean blue and khaki colors) stages of both fish fillets. Moreover, a strong and positive correlation was obtained between the total color differences values of the indicator and bacterial count (R = 0.952 and 0.991) and total volatile basic nitrogen (R = 0.815 and 0.92) in rainbow trout and common carp samples. The results of this work demonstrated a significant correspondence of fish shelf life and color changes of a nanocellulose-based pH-sensing indicator.

Lipophilization of EGCG and effects on antioxidant activities.

A green, fast, and efficient method for synthesizing lipophilic epigallocatechin gallate (EGCG) derivatives was set up for the first time. EGCG was lipophilized by esterification in order to promote its application in lipid products and to possibly enhance its bioactivity. A high conversion of EGCG was achieved. Three monoesters of the EGCG derivatives were confirmed by high performance liquid chromatography-mass spectrometry, and the predominant one was identified as 4'-O-palmitoyl EGCG by nuclear magnetic resonance. The EGCG derivatives exhibited good radical scavenging capacities. In lard the solubility of EGCG derivatives was enhanced 470 times compared to EGCG, and they exhibited excellent antioxidative activity in the oil. These results indicate that the palmitoylated EGCG derivatives may be used as potent antioxidants in lipophilic medium, such as edible oils and fatty foods. In addition, this method can be applied to commercial application, producing antioxidants to substitute for synthetic ones like tert-butylhydroquinone.

Low cost in situ digital image method, based on spot testing and smartphone images, for determination of ascorbic acid in Brazilian Amazon native and exotic fruits.

In this work, we propose a method that employed a smartphone to capture images obtained from a colorimetric spot test to determine ascorbic acid (AA) in Brazilian Amazon native and exotic fruits. The spot test reaction was based on reduction of Fe(III) by AA and further complexation with 1,10-phenanthroline. After optimization, the limit of detection was 8.5 × 10-7 mol L-1. Brazilian Amazon native fruits such as bacuri, cupuaçu, muruci, yellow mombin, as well as others as cashew, mango, orange and passion fruit, were analyzed. In order to determine the accuracy of this method, iodometric titration was used; results were in close agreement with a confidence level of 95% (paired t-test). Moreover, recoveries ranged from 87.1 to 116%. The method is economic, environmentally friendly, and portable, and might useful for small producers and family agriculture businesses unable to afford specialized laboratory analysis in the north region of Brazilian Amazon.

Interaction characterization of preheated soy protein isolate with cyanidin-3-O-glucoside and their effects on the stability of black soybean seed coat anthocyanins extracts.

The interactions of soy protein isolate with cyanidin-3-O-glucoside were investigated to study the protective effect of protein on anthocyanin's stability by UV-Vis spectrophotometry, Fourier transform infrared spectroscopy, circular dichroism and fluorescence spectroscopy. Preheat treatment and binding of cyanidin-3-O-glucoside effectively changed the secondary structure of soy protein isolate, with a decrease in α-helix, random coil structure and an increase in ß-sheet and ß-turn. The soy protein isolate preheated at 121 °C exhibited a strong binding affinity towards cyanidin-3-O-glucoside with strong Ks of 147.40 × 104 M-1 and also effectively increased the thermal and oxidation stabilities of black soybean seed coat extract via decreasing the degradation rate by 67% and 23%, respectively. Soy protein isolate interacted with cyanidin-3-O-glucoside mainly through hydrophobic interactions and static quenching process. Altogether, the results suggested that preheated soy protein isolate-cyanidin-3-O-glucoside interaction could effectively protect anthocyanins' stability through strong binding affinity influenced by the systematic alterations in the secondary structure.

Multi-scale structural changes in lintnerized starches from three coloured potatoes.

Three kinds of potato starch were treated with 2.2 N HCl at 35 °C for 40 days, and their susceptibility to acid hydrolysis and the resulting structural changes were evaluated. Red potato starch was more susceptible to acid hydrolysis and presented highest rate of hydrolysis. Lintnerized starches had relatively low average molecular weights and z-average radius of gyration. HPAEC analyses showed three lintners presented different molecular size distributions. Lintnerized yellow potato starch had few chains of DP ≤ 12 (2.58 mol%) and more chains of DP ≥ 37 (8.16 mol%). Furthermore, the similarities of the branch-chain length distributions before and after debranching indicated the lintners consisted primarily of linear molecules. After lintnerization, most starch granules were degraded, and the birefringence disappeared from some granules. X-ray diffraction patterns revealed that the relative crystallinity significantly increased after lintnerization. DSC analyses showed that lintners displayed broader thermal-transitions.

Effects of starch from five different botanical sources on the rheological and structural properties of starch-gluten model doughs.

Wheat, corn, tapioca, sweet potato and potato starches were independently mixed into starch-gluten model doughs containing 15% (w/w) vital gluten. Rheological properties, including linear viscoelasticity region, frequency dependence and recovery capacity, were studied by strain sweep, frequency sweep, and creep and recovery measurements. Structural properties were also investigated by measuring the disulfide bonds (-SS-) content, SDS-PAGE and low-resolution 1H nuclear magnetic resonance. Wheat starch (WS)-gluten dough had the greatest linear viscoelasticity region (0.190%), lowest frequency dependence (0.128) and greatest recovery capacity (67.39%), while potato starch-gluten dough had the smallest linear viscoelasticity region (0.126%), greatest frequency dependence (0.195) and lowest recovery capacity (54.97%). Furthermore, WS-gluten dough showed the highest disulfide bonds (-SS-) content (3.47µmol/g), lowest intensity of extracted glutenin bands and highest bond water content (23.20%). This suggested that WS-gluten dough formed stronger starch-gluten interactions compared with those of the other four starch-gluten model doughs.

Peptides derived from tryptic hydrolysate of Bacillus subtilis culture suppress fungal spoilage of table grapes.

This study confirmed the anti-fungal effect of trypsin-treated Bacillus subtilis culture (BC) (tryptic hydrolysate, TH) on mold growth on Kyoho grapes. We examined the anti-fungal activity of TH by identifying TH peptides and performing a computational docking analysis. TH was more potent than untreated BC in suppressing fungal growth on grapes. Specifically, TH maintained grape freshness by inhibiting respiration and rachis browning, maintaining firmness, and preventing weight loss. Thirty-six inhibitory peptides against ß-1,3-glucan synthase (GS) were screened from 126 TH peptides identified through proteomic analysis. Among them, 13 peptides bound tightly to GS active pockets with lower binding energies than that of GppNHp. The most potent peptides, LFEIDEELNEK and FATSDLNDLYR, were synthesized, and further experiments showed that these peptides had a highly suppressive effect on GS activity and Aspergillus niger and Penicillium chrysogenum growth. Our results confirm that tryptic treatment is effective for improving the anti-fungal activity of BC.

Application of response surface methodology to acidified water extraction of black soybeans for improving anthocyanin content, total phenols content and antioxidant activity.

Acidified water extraction of total anthocyanin content, total phenol content and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity from black soybeans (Glycine max [L.] Merr. Cheongja4ho) was optimized using response surface methodology (RSM). A five-level, three-factor central composite design was employed to optimize the conditions for the maximum yields of these three components using19 different experiments. The HCl concentration (0.3-0.5%), solid-liquid ratio (1/30-1/50 g/mL) and extraction temperature (30-50 °C) significantly affected three components. The optimized conditions were HCl concentration of 0.359%, solid-liquid ratio of 1/54.2 g/mL and extraction temperature of 56.8 °C for total anthocyanin content (136.68 mg/100 g), total phenol content (1197.09 mg/100 g) and ABTS+ scavenging activity (211.65 mg/100 g). These experimental values fit well with the predicted values. Among three anthocyanins found in the black soybean extracts, cyanidin-3-O-glucoside was the major one (65-73% of the total), followed by petunidin-3-O-glucoside (17-23%) and delphinidin-3-O-glucoside (10-12%).

Understanding the fine structure of intermediate materials of maize starches.

Here we concern the molecular fine structure of intermediate material (IM) fraction in regular maize starch (RMS) and Starpro 40 maize starch (S40). IM had a branching degree and a molar mass (Mw) somewhere between amylopectin (AP) and amylose (AM). Compared with AP, IM had more extra-long (Fr I) and long (Fr II) chains and fb3-chains (degree of polymerization (DP)>36), with a higher average chain length (CL). Also, IM contained less A-chains but more B-chains (both BS-chains with DP 3-25 and BL-chains with DP≥26), accompanied by longer B- and BL-chains, total internal chains (TICL) and average internal chains (ICL), and a similar average external chain length (ECL). Furthermore, relative to RMS-IM, the IM of S40 (with higher apparent amylose content than RMS) showed increases in relatively-long chains, e.g., Fr II, fb3-chains and BL-chains, but reductions in Mw, relatively-short chains (those with DP 6-12, etc.).

Enhanced anticancer effect and reduced toxicity of doxorubicin in combination with thymoquinone released from poly-N-acetyl glucosamine nanomatrix in mice bearing solid Ehrlish carcinoma.

The incidence of breast cancer remarkably increases all over the world. Therefore, there is a great demand to introduce new approaches into cancer treatment field. The current study was designated to evaluate the role of doxorubicin (DOX) and/or thymoquinone (TQ) nanomatrix in potentiating the cytotoxicity of either drug, and to investigate the ability of TQ to reduce cardiotoxicity of DOX in solid Ehrlich carcinoma (SEC)-bearing mice. DOX and TQ were loaded into F2 gel, which is a fully-acetylated poly-N-acetyl glucosamine nanofiber. SEC was induced in female albino mice as a model for experimentally induced breast cancer. Mice were randomly divided into eight groups (n=10): normal control, tumor control, F2 gel, free DOX, DOX+F2 gel, free TQ, TQ+F2 gel, and DOX+TQ+F2 gel. On day 28th from tumor inoculation, mice were sacrificed and blood samples were collected for measurement of the cardiac markers; lactate dehydrogenase (LDH) and creatine kinase (CK-MB). In addition, cardiac tissue was utilized for determination of lipid peroxide, and tumor tissue was used for measurement of anti-apoptotic protein Bcl-2 as well as gene expression of the tumor suppressor gene P53. DOX and/or TQ showed a significant reduction in tumor volume, cardiac markers, tumor Bcl-2, and P53 upregulation compared to free conventional therapies. Co-treatment with DOX+TQ+F2 gel was superior to all other groups in exerting beneficial effects. Use of TQ as an adjuvant therapy with DOX could improve its cytotoxic effects and limit its cardiac toxicity. Furthermore, loading of DOX and/or TQ into F2 gel showed a remarkable anti-cancer activity.