Inhibitory effects of ß-type glycosidic polysaccharide from Pleurotus eryngii on dextran sodium sulfate-induced colitis in mice.

The aim of the present study was to determine the inhibitory effects and the potential underlying mechanisms of a novel Pleurotus eryngii ß-type glycosidic polysaccharide (WPEP) on colitis. To achieve this, sixty CD-1 (ICR) mice were divided into six groups including healthy and colitic mice treated with or without WPEP at two different doses (n = 10). The results showed that WPEP displayed a significant inhibitory effect on colitis as indicated by the lowered disease activity index in the treated colitic mice compared to the untreated colitic mice (2.78 ± 0.50 to 1.80 ± 0.17). A decrease in pro-inflammatory cytokine concentrations and pro-inflammatory protein expressions and an increase in the colon length (9.31 ± 0.59 cm to 10.89 ± 1.20 cm) along with histological improvements were also observed in the treated colitic mice compared to the untreated colitic mice in the present study. Flow cytometry and western blotting analysis revealed that these anti-colitis effects were associated with decreased accumulation of CD45+ immune cells, CD45 + F4/80+ macrophages and CD45 + Gr1+ neutrophils. Moreover, the 16s rRNA sequencing analysis of the gut microbiota revealed that WPEP partially reversed gut microbiota dysbiosis in the colitic mice including the decreased abundance of Akkermansia muciniphila (35.80 ± 9.10% to 18.24 ± 6.23%) and Clostridium cocleatum (2.34 ± 1.78% to 0.011 ± 0.003%) and the increased abundance of Bifidobacterium pseudolongum (3.48 ± 2.72% to 9.65 ± 3.74%), Lactobacillus reuteri (0.007 ± 0.002% to 0.21 ± 0.12%), Lactobacillus salivarius (1.23 ± 0.87% to 2.22 ± 1.53%) and Ruminococcus bromii (0.009 ± 0.001% to 3.83 ± 1.98%). In summary, our results demonstrated that WPEP could be utilized as a functional food component in colitis management as well as a potential prebiotic agent to improve inflammation-related disorders.

Foodborne Titanium Dioxide Nanoparticles Induce Stronger Adverse Effects in Obese Mice than Non-Obese Mice: Gut Microbiota Dysbiosis, Colonic Inflammation, and Proteome Alterations.

The recent ban of titanium dioxide (TiO2 ) as a food additive (E171) in France intensified the controversy on safety of foodborne-TiO2 nanoparticles (NPs). This study determines the biological effects of TiO2 NPs and TiO2 (E171) in obese and non-obese mice. Oral consumption (0.1 wt% in diet for 8 weeks) of TiO2 (E171, 112 nm) and TiO2 NPs (33 nm) does not cause severe toxicity in mice, but significantly alters composition of gut microbiota, for example, increased abundance of Firmicutes phylum and decreased abundance of Bacteroidetes phylum and Bifidobacterium and Lactobacillus genera, which are accompanied by decreased cecal levels of short-chain fatty acids. Both TiO2 (E171) and TiO2 NPs increase abundance of pro-inflammatory immune cells and cytokines in the colonic mucosa, indicating an inflammatory state. Importantly, TiO2 NPs cause stronger colonic inflammation than TiO2 (E171), and obese mice are more susceptible to the effects. A microbiota transplant study demonstrates that altered fecal microbiota by TiO2 NPs directly mediate inflammatory responses in the mouse colon. Furthermore, proteomic analysis shows that TiO2 NPs cause more alterations in multiple pathways in the liver and colon of obese mice than non-obese mice. This study provides important information on the health effects of foodborne inorganic nanoparticles.

Identification of a new benzophenone from Psidium guajava L. leaves and its antineoplastic effects on human colon cancer cells.

Psidium guajava L. leaves have a long history of being consumed as herbal teas in many countries. The aim of this study was to identify compounds with anticancer potentials from Psidium guajava L. leaves. Utilizing various extraction and chromatographical techniques, we have isolated one new (2) and two known compounds (1, 3). Structural analyses by the spectroscopic methods of TOF-MS, 1H NMR, 13C NMR, HSQC, and HMBC identified these three compounds as guavinoside E (1), 3,5-dihydroxy-2,4-dimethyl-1-O-(6'-O-galloyl-ß-d-glucopyranosyl)-benzophenone (2), and guavinoside B (3). Cell viability assays showed that compounds 2 and 3 inhibited the growth of HCT116 human colon cancer cells in a dose-dependent manner, where compound 2 was more potent than compound 3. Based on flow cytometry analysis, compound 2 showed stronger activity in inducing cellular apoptosis in cancer cells than compound 3. Furthermore, compounds 2 and 3 modulated expression levels of key proteins involved in cell proliferation and apoptotic signaling. Specifically, compound 2 increased the levels of p53, p-ERK1/2, p-JNK, and cleaved caspases 8 and 9, and compound 3 increased the levels of p53 and cleaved caspase 8. Overall, this study provided identities of three bioactive compounds from P. guajava L. leaves and their anti-cancer effects against human colon cancer cells, which could facilitate the utilization of these compounds and P. guajava L. leaves as potential chemoprevention agents against colon carcinogenesis.

Inhibitory effects of 7,7'-bromo-curcumin on 12-O-tetradecanoylphorbol-13-acetate-induced skin inflammation.

This study aimed to determine the capacity of 7,7'-bromo-curcumin (CUR-Br), a curcumin analogue with higher chemical stability than curcumin (CUR), in the suppression of mouse ear edema. Male CD-1 mice were topically pre-treated with either CUR or CUR-Br for 30 min prior to an application of 12-O-tetradecanoylphorbol-13-acetate. After 6 h, mice were killed, and ear punches were measured for their weight and thickness as a marker of edema and inflammation. CUR-Br demonstrated a higher anti-inflammatory efficacy compared to CUR. CUR and CUR-Br at 1.0 µmol suppressed the TPA-induced increase in the ear weight by 26.0% and 57.2%, and decreased TPA-induced increase in the ear thickness by 22.2% and 84.7%, respectively. The inhibitory effects of Cur-Br were associated with decreased levels of inflammatory cytokines (IL-1ß, IL-2, IL-6, KC/GRO, IL-10, IL-17, and IL-23). In addition, CUR-Br significantly downregulated expression of pro-inflammatory signaling proteins such as p-STAT3, STAT3, PI3K, AKT, p-p65, and COX-2. Overall, our results demonstrated that the curcumin analogue, CUR-Br, showed stronger anti-inflammatory properties than CUR in inhibiting TPA-induced inflammatory response in mouse skin.

Uncovering the potential of novel micromonosporae isolated from an extreme hyper-arid Atacama Desert soil.

The taxonomic status, biotechnological and ecological potential of several Micromonospora strains isolated from an extreme hyper arid Atacama Desert soil were determined. Initially, a polyphasic study was undertaken to clarify the taxonomic status of five micromonosporae, strains LB4, LB19, LB32T, LB39T and LB41, isolated from an extreme hyper-arid soil collected from one of the driest regions of the Atacama Desert. All of the isolates were found to have chemotaxonomic, cultural and morphological properties consistent with their classification in the genus Micromonospora. Isolates LB32T and LB39T were distinguished from their nearest phylogenetic neighbours and proposed as new species, namely as Micromonospora arida sp. nov. and Micromonospora inaquosa sp. nov., respectively. Eluted methanol extracts of all of the isolates showed activity against a panel of bacterial and fungal indicator strains, notably against multi-drug resistant Klebsiella pneumoniae ATCC 700603 while isolates LB4 and LB41 showed pronounced anti-tumour activity against HepG2 cells. Draft genomes generated for the isolates revealed a rich source of novel biosynthetic gene clusters, some of which were unique to individual strains thereby opening up the prospect of selecting especially gifted micromonosporae for natural product discovery. Key stress-related genes detected in the genomes of all of the isolates provided an insight into how micromonosporae adapt to the harsh environmental conditions that prevail in extreme hyper-arid Atacama Desert soils.

UV-C Irradiation on the Quality of Green Tea: Effect on Catechins, Antioxidant Activity, and Cytotoxicity.

Short-wavelength ultraviolet (UV-C) irradiation is a nonthermal processing technique that is a possible alternative to the heat-pasteurization of tea beverages. This study investigated the effect of UV-C irradiation on the polyphenolic and total phenolic contents of a green tea beverage and analyzed cytotoxicity of irradiated green tea using a novel continuous flow-through UV system. UV-C fluence levels ranging from 0 to 240 mJ/cm2 were delivered to green tea, and polyphenols were chemically profiled. Continuous-flow UV-C irradiation of the green tea beverage at a fluence of 68 mJ/cm2  induced a minor reduction in the concentration of the most abundant catechin in green tea, (-)-epigallocatechin gallate (EGCG), from 145 to 131.1 µg/mL. The total phenolic content of the green tea beverage was 0.19 µg GAE/uL and remained constant at all UV fluence levels. The UV-treated green tea beverage showed no cytotoxic effects on normal intestinal cells with healthy colonic cells (CCD-18Co) maintained at 90% viability for the UV-treated green tea beverages and the control. The treated and nontreated green tea have comparable inhibitory effects on the survival of human colon cancer cells. Overall, these results demonstrate that the UV-C irradiation did not significantly deplete catechins or produce cytotoxic byproducts. PRACTICAL APPLICATION: Short wavelength ultraviolet (UV-C) irradiation is a nonthermal processing technique that is a possible alternative to the heat pasteurization of tea beverages. This study investigated the effect of UV-C irradiation on the antioxidant concentration of green tea and analyzed cytotoxicity of irradiated a green tea beverage using a novel continuous flow-through UV system. The results demonstrated that the UV-C irradiation did not significantly deplete catechins or produce cytotoxic byproducts.

Hunting for cultivable Micromonospora strains in soils of the Atacama Desert.

Innovative procedures were used to selectively isolate small numbers of Micromonospora strains from extreme hyper-arid and high altitude Atacama Desert soils. Micromonosporae were recognised on isolation plates by their ability to produce filamentous microcolonies that were strongly attached to the agar. Most of the isolates formed characteristic orange colonies that lacked aerial hyphae and turned black on spore formation, whereas those from the high altitude soil were dry, blue-green and covered by white aerial hyphae. The isolates were assigned to seven multi- and eleven single-membered groups based on BOX-PCR profiles. Representatives of the groups were assigned to either multi-membered clades that also contained marker strains or formed distinct phyletic lines in the Micromonospora 16S rRNA gene tree; many of the isolates were considered to be putatively novel species of Micromonospora. Most of the isolates from the high altitude soils showed activity against wild type strains of Bacillus subtilis and Pseudomonas fluorescens while those from the rhizosphere of Parastrephia quadrangulares and from the Lomas Bayas hyper-arid soil showed resistance to UV radiation.

Microbial inactivation and cytotoxicity evaluation of UV irradiated coconut water in a novel continuous flow spiral reactor.

A continuous-flow UV reactor operating at 254nm wave-length was used to investigate inactivation of microorganisms including bacteriophage in coconut water, a highly opaque liquid food. UV-C inactivation kinetics of two surrogate viruses (MS2, T1UV) and three bacteria (E. coli ATCC 25922, Salmonella Typhimurium ATCC 13311, Listeria monocytogenes ATCC 19115) in buffer and coconut water were investigated (D10 values ranging from 2.82 to 4.54mJ·cm-2). A series of known UV-C doses were delivered to the samples. Inactivation levels of all organisms were linearly proportional to UV-C dose (r2>0.97). At the highest dose of 30mJ·cm-2, the three pathogenic organisms were inactivated by >5 log10 (p<0.05). Results clearly demonstrated that UV-C irradiation effectively inactivated bacteriophage and pathogenic microbes in coconut water. The inactivation kinetics of microorganisms were best described by log linear model with a low root mean square error (RMSE) and high coefficient of determination (r2>0.97). Models for predicting log reduction as a function of UV-C irradiation dose were found to be significant (p<0.05) with low RMSE and high r2. The irradiated coconut water showed no cytotoxic effects on normal human intestinal cells and normal mouse liver cells. Overall, these results indicated that UV-C treatment did not generate cytotoxic compounds in the coconut water. This study clearly demonstrated that high levels of inactivation of pathogens can be achieved in coconut water, and suggested potential method for UV-C treatment of other liquid foods. INDUSTRIAL RELEVANCE: This research paper provides scientific evidence of the potential benefits of UV-C irradiation in inactivating bacterial and viral surrogates at commercially relevant doses of 0-120mJ·cm-2. The irradiated coconut water showed no cytotoxic effects on normal intestinal and healthy mice liver cells. UV-C irradiation is an attractive food preservation technology and offers opportunities for horticultural and food processing industries to meet the growing demand from consumers for healthier and safe food products. This study would provide technical support for commercialization of UV-C treatment of beverages.

In Vitro Bioavailability, Cellular Antioxidant Activity, and Cytotoxicity of ß-Carotene-Loaded Emulsions Stabilized by Catechin-Egg White Protein Conjugates.

Previously, it was shown that catechin-egg white protein (CT-EWP) conjugates were effective antioxidant emulsifiers that could form and stabilize emulsions, and also inhibit the degradation of encapsulated carotenoids. The objective of the current study was to evaluate the impact of conjugation on the in vitro bioavailability, cellular antioxidant activity, and cytotoxicity of ß-carotene-loaded emulsions. Lipid droplets coated with EWP or with CT-EWP conjugates exhibited quite similar behavior when they were passed through a simulated gastrointestinal tract. The ß-carotene encapsulated in emulsions stabilized by CT-EWP conjugates exhibited a higher overall in vitro bioavailability, which was attributed to a greater stability of the carotenoids to chemical transformation. The emulsions stabilized by CT-EWP conjugates also exhibited greater ability in inhibiting oxidation in a cell-based assay (dichlorofluorescein diacetate). Cytotoxicity analysis suggested that ß-carotene emulsions stabilized by CT-EWP conjugates only exhibited a slight cytotoxicity when used at high concentrations. These results suggest that CT-EWP conjugates can be used to formulate emulsion-based delivery systems for chemically labile hydrophobic bioactives with enhanced antioxidant activity and bioavailability.

Effect of UV Irradiation on the Nutritional Quality and Cytotoxicity of Apple Juice.

UV-C irradiation operating at 254 nm wavelength on the polyphenolic and vitamin contents of apple juice including cytotoxicity analysis was studied. UV doses ranging from 0 to 150 mJ·cm-2 were selected for the treatments. Polyphenols (catechin, epicatechin, chlorogenic acid, and phloridzin) and vitamins (riboflavin, thiamine hydrochloride, pyridoxal hydrochloride, pyridoxine, pyridoxamine dihydrochloride, cyanocobalamin, choline chloride, biotin, niacin, and niacinamide) were chemically profiled. It was observed that UV treatment of apple juice at disinfection doses caused minor reductions (p < 0.05) in the concentrations of two main polyphenols (i.e., chlorogenic acid and epicatechin). In contrast, significant (p < 0.05) decreases in vitamin concentrations were observed (p < 0.05). The irradiated juice was evaluated for cytotoxic effects. The irradiated apple juice showed no cytotoxic effects on normal intestinal cells, and both irradiated and nonirradiated samples are significantly comparable in inhibiting the growth of human colon cancer cells. Overall, these results indicated that UV-C treatment of apple juice neither significantly degraded polyphenols nor generated cytotoxic compounds.

Identification of pinostilbene as a major colonic metabolite of pterostilbene and its inhibitory effects on colon cancer cells.

SCOPE: Pterostilbene (PTE) is a resveratrol derivative mainly found in blueberries, and it has been shown to inhibit colon carcinogenesis in multiple animal models. To shed light on the mechanism of PTE in inhibiting colon carcinogenesis, we investigated the PTE metabolites in the mouse colon and in the human colon cancer cells. METHODS AND RESULTS: CD-1 mice were fed PTE-containing diet for 3 weeks, and colonic content and colonic mucosa were collected and subjected to LC-MS analysis. Pinostilbene (PIN) was identified as a major metabolite of PTE in the mouse colon. Importantly, the level of PIN was found to be approximately equivalent to that of PTE in the colonic mucosa. PIN significantly inhibited the growth of human colon cancer cells, i.e., HCT116 and HT29. These inhibitory effects were similar to those produced by PTE. Moreover, under physiologically relevant conditions, 20 and 40 µM of PIN caused cell cycle arrest at S phase and induced apoptosis in colon cancer cells. These effects were associated with profound modulation of signaling proteins related with cell proliferation and programmed cell death. CONCLUSION: Our results demonstrated that PIN is a major metabolite of PTE in the colon of mice fed with PTE, and PIN may play important roles in the anti-colon cancer effects elicited by orally administered PTE.