Cyanidin-3-O-glucoside impacts fecal discharge of polystyrene microplastics in mice: Potential role of microbiota-derived metabolites.

Microplastic particles degraded from plastic litters are recognized as a global environmental pollutant, which can be transferred and enriched via the food chain to impact ecosystems and human health. A balanced gut microbiota contributes to human health through host-gut interactions, environmentally-driven factors such as microplastic exposure would disturb the gut bacteria and affect its functionality. Dietary compounds can remodel the compositions of gut microbes, and interact with bacteria exerting profound effects on host physiology. This study explored the effects of bayberry-derived anthocyanin cyanidin-3-O-glucoside (C3G) and microplastic polystyrene (PS) on the gut microbiome in C57BL/6 mice, especially the alterations in gut bacteria and its metabolites. Using 16S rRNA high-throughput sequencing, variations in gut bacterial composition and enrichment of functional pathways were found upon PS and C3G administration. Meanwhile, the differential metabolites and metabolic pathways were identified by metabolomic analysis. Importantly, colonic and fecal PS levels were found to be strongly correlated with key microbiota-derived metabolites, which are associated with xenobiotic metabolism via regulation of xenobiotics-metabolizing enzymes and transporters. These results may offer new insights regarding the protective effects of C3G against xenobiotic PS exposure and the roles of gut bacterial metabolites.

Modulation of Gut Microbial Metabolism by Cyanidin-3-O-Glucoside in Mitigating Polystyrene-Induced Colonic Inflammation: Insights from 16S rRNA Sequencing and Metabolomics.

Microplastics derived from plastic waste have emerged as a pervasive environmental pollutant with potential transfer and accumulation through the food chain, thus posing risks to both ecosystems and human health. The gut microbiota, tightly intertwined with metabolic processes, exert substantial influences on host physiology by utilizing dietary compounds and generating bacterial metabolites such as tryptophan and bile acid. Our previous studies have demonstrated that exposure to microplastic polystyrene (PS) disrupts the gut microbiota and induces colonic inflammation. Meanwhile, intervention with cyanidin-3-O-glucoside (C3G), a natural anthocyanin derived from red bayberry, could mitigate colonic inflammation by reshaping the gut bacterial composition. Despite these findings, the specific influence of gut bacteria and their metabolites on alleviating colonic inflammation through C3G intervention remains incompletely elucidated. Therefore, employing a C57BL/6 mouse model, this study aims to investigate the mechanisms underlying how C3G modulates gut bacteria and their metabolites to alleviate colonic inflammation. Notably, our findings demonstrated the efficacy of C3G in reversing the elevated levels of pro-inflammatory cytokines (IL-6, IL-1ß, and TNF-α) and the upregulation of mRNA expression (Il-6, Il-1ß, and Tnf-α) induced by PS exposure. Meanwhile, C3G effectively inhibited the reduction in levels (IL-22, IL-10, and IL-4) and the downregulation of mRNA expression (Il-22, Il-10, and Il-4) of anti-inflammatory cytokines induced by PS exposure. Moreover, PS-induced phosphorylation of the transcription factor NF-κB in the nucleus, as well as the increased level of protein expression of iNOS and COX-2 in the colon, were inhibited by C3G. Metabolisms of gut bacterial tryptophan and bile acids have been extensively implicated in the regulation of inflammatory processes. The 16S rRNA high-throughput sequencing disclosed that PS treatment significantly increased the abundance of pro-inflammatory bacteria (Desulfovibrio, norank_f_Oscillospiraceae, Helicobacter, and Lachnoclostridium) while decreasing the abundance of anti-inflammatory bacteria (Dubosiella, Akkermansia, and Alistipes). Intriguingly, C3G intervention reversed these pro-inflammatory changes in bacterial abundances and augmented the enrichment of bacterial genes involved in tryptophan and bile acid metabolism pathways. Furthermore, untargeted metabolomic analysis revealed the notable upregulation of metabolites associated with tryptophan metabolism (shikimate, l-tryptophan, indole-3-lactic acid, and N-acetylserotonin) and bile acid metabolism (3b-hydroxy-5-cholenoic acid, chenodeoxycholate, taurine, and lithocholic acid) following C3G administration. Collectively, these findings shed new light on the protective effects of dietary C3G against PS exposure and underscore the involvement of specific gut bacterial metabolites in the amelioration of colonic inflammation.

Poly(2-hydroxyethyl methacrylate) brush surface for specific and oriented adsorption of glycosidases.

We present a detailed picture to screen general ligands from simple chemicals for fabricating affinity surface to glycosidase enzymes. The surface was constructed by grafting poly(2-hydroxyethyl methacrylate) (PHEMA) brush on SPR gold chip via surface-initiated atom-transfer radical polymerization, after which poly(methoxyethyl methacrylate) (PMEMA) and poly(oligo(ethylene glycol) methacrylate) (POEGMA) brushes were also prepared for comparison. SPR measurements were adopted to monitor the early-stage adsorption of two glycosidases and three other typical proteins. PHEMA resists the adsorption of lysozyme, bovine serum albumin, and fibrinogen, while it is capable of specifically adsorbing ß-glucosidase (GLU) and ß-galactosidase (GAL). These are quite different from the nonspecific adsorption of PMEMA and the anti-nonspecific adsorption of POEGMA to the studied proteins, because PHEMA is the acceptor substrate of the glycosidases. About 69.6 and 93.7 ng/cm(2) of GAL and GLU are adsorbed on the PHEMA brush surface, of which more than 49.6 ng/cm(2) is remained after washing with PBS. The specific adsorption process is appropriately described by Freundlich isothermal model rather than Langmuir one, and is also indicated to be spontaneous, endothermic, and entropy driven through thermodynamic studies. Taking into account all stated results above, we propose that molecular recognition takes place between the hydroxyl groups of PHEMA and the active sites of glycosidases, which subsequently enables the oriented adsorption of glycosidases on the brush surface. The adsorbed enzyme can be effectively eluted with 1.0 M aqueous solution of ethanol. Our findings open the door to the further development in the design of novel acceptor substrate-ligand affinity chromatography for enzyme purification.

Cyanidin-3-O-glucoside promotes stress tolerance and lifespan extension of Caenorhabditis elegans exposed to polystyrene via DAF-16 pathway.

Microplastic pollution has attracted growing attention due to its prevalent and persistent exposure to general population through the food chain, but few reports have focused on the toxicological prevention of polystyrene (PS). Using the wild-type and mutant strains, this study explored the impacts of PS and cyanidin-3-O-glucoside (C3G) on stress tolerance and lifespan of Caenorhabditis elegans (C. elegans). In N2 nematodes, PS exposure initiated the oxidative stress and subsequent lifespan reduction, while these adverse impacts could be positively improved by C3G treatment. Considering the pivotal role of DAF-16 pathway in stress tolerance and lifespan regulation, the expression of the daf-16 gene and its downstream antioxidant genes (clt-2, hsp-16.1, sod-3, sod-5) were examined, and found to be significantly enhanced by C3G. Since the sod-3 gene was up-regulated the most fold by C3G, the activity of SOD enzyme that encoded by the sod-3 was examined, and could be obviously enhanced upon C3G treatment. This explained the improved oxidative stress and delayed oxidation-associated aging after C3G intervention. Nevertheless, these positive effects of C3G were weakened in daf-16(-) mutant strain (with deleted DAF-16 gene), for which the beneficial effects of C3G in promoting stress resistance and lifespan extension were inhibited. These findings suggested that the DAF-16 gene and its downstream antioxidant genes, have participated in C3G's regulations on redox balance and lifespan that impacted by nano-polystyrene particles. This study highlighted the link between dietary components and environmentally driven disturbance.

Food-derived cyanidin-3-O-glucoside reverses microplastic toxicity via promoting discharge and modulating the gut microbiota in mice.

Microplastics (MPs) ingested and accumulated by organisms would ultimately pose a threat to humans via the food chain. A balanced gut microbiota contributes to many health benefits, which is readily influenced by environmental chemicals such as MPs. Cyanidin-3-O-glucoside (C3G), a bioactive compound of the anthocyanin family, possesses a variety of functional effects including anti-oxidant and anti-inflammatory, as well as gut microbiota modulation. C3G has been demonstrated to prevent polystyrene (PS) induced toxicities in Caco-2 cells and Caenorhabditis elegans (C. elegans) via activating autophagy and promoting discharge. In the present study, we aimed to explore the alleviation effect of C3G on PS induced toxicities in C57BL/6 mice. Our results showed that the supplementation of C3G effectively reduced the tissue accumulation and promoted the fecal PS discharge, leading to alleviation of the PS-caused oxidative stress and inflammatory response. Meanwhile, C3G modulated PS-associated gut microbiome perturbations and regulated functional bacteria in inflammation such as Desulfovibrio, Helicobacter, Oscillospiraceae and Lachnoclostridium. Also, C3G administration initiated alterations in functional pathways in response to xenobiotic PS, and reduced bacterial functional genes related to inflammation and human diseases. These findings may offer evidence for the protective role of C3G in the intervention of PS-induced toxicity and gut dysbiosis.

Canidin-3-glucoside prevents nano-plastics induced toxicity via activating autophagy and promoting discharge.

Increasing attention has been brought to microplastics pollution recently, while emerging evidences indicate that nano-plastics degraded from microplastics are more of research significance owing to stronger toxicity. However, there is little study focused on the prevention of nano-plastics induced toxicity until now. Canidin-3-glucoside (C3G), a natural anthocyanin proved to possess multiple functions like antioxidant and intestinal tissue protection. Thus, we proposed whether C3G could act as a molecular weapon against nano-plastics induced toxicity. In Caco2 cell and Caenorhabditis elegans (C. elegans) models, we found that polystyrene (PS) nano-plastics exposure resulted in physiological toxicity and oxidative damage, which could be restored by C3G. More significantly in Caco2 cells, we observed that autophagy was activated via Sirt1-Foxo1 signaling pathway to attenuate PS induced toxicity after C3G intervention and further verified by adding autophagy inhibitor 3-Methyladenine (3-MA). Meanwhile, PS co-localization with lysosomes was observed, indicating the encapsulation and degradation of PS. In C. elegans, by detecting LGG-1/LC3 expression in GFP-targeted LGG-1 report gene (LGG-1:GFP) labeled transgenic DA2123 strain, the co-localization of LGG-1:GFP with PS was found as well, means that autophagy is involved in C3G's beneficial effects. Furthermore, we were surprised to find that C3G could promote the discharge of PS from N2 nematodes, which reduces PS toxicity more directly.

Preparation of A. succinogenes immobilized microfiber membrane for repeated production of succinic acid.

A new applicability of cell-immobilized system for biological production of target chemical was reported in this work. A. succinogenes CCTCC M2012036 was immobilized on positively charged polypropylene microfiber membrane by physical interaction and were used for converting glucose into succinic acid. Glucose consumption and succinic acid production kinetics were investigated for optimizing the operational parameters. The cell-immobilized membrane presented good reuse stability, and six cycles of fermentation without activity loss were realized with an average succinic acid yield of 0.83g/g. Importantly, a biofilm was formed which favored the production of succinic acid. A microfiber membrane bioreactor was further constructed with the cell-immobilized membrane to perform fermentation in a larger scale, and the yield and productivity of succinic acid were 0.82g/g and 1.04gL-1h-1 using a fed-batch strategy. By combining mesoporous support with biotechnological techniques, this work offered a prospect of adopting reusable cells feasible for industry.

Assessment of heavy metal pollution in surficial sediments from a tropical river-estuary-shelf system: A case study of Kelantan River, Malaysia.

To understand the source-to-sink of pollutants in the Kelantan River estuary and the adjacent shelf area in Malaysia, a total of 42 surface sediment samples were collected in the Kelantan River-estuary-shelf system to analyze for grain size, total organic carbon (TOC) content, Al and heavy metals (Cr, Ni, Cu, Zn, Cd and Pb). The surficial sediments were mainly composed of clayey silt and the TOC content in sediments decreased from the river to the shelf. The surficial sediments experienced Pb pollution; Cr only showed a certain level of pollution in the coastal area of the estuary but not in other areas, and Ni, Cu, Zn, and Cd showed no pollution. The heavy metals mainly originated from natural weathering and erosion of rocks and soils in the catchment and enriched near the river mouth. Total organic carbon can promote the enrichment of heavy metals in sediments.

Utilization of an Active Site Mutant Receptor for the Identification of Potent and Selective Atypical 5-HT2C Receptor Agonists.

Agonism of the 5-HT2C receptor represents one of the most well-studied and clinically proven mechanisms for pharmacological weight reduction. Selectivity over the closely related 5-HT2A and 5-HT2B receptors is critical as their activation has been shown to lead to undesirable side effects and major safety concerns. In this communication, we report the development of a new screening paradigm that utilizes an active site mutant D134A (D3.32) 5-HT2C receptor to identify atypical agonist structures. We additionally report the discovery and optimization of a novel class of nonbasic heterocyclic amide agonists of 5-HT2C. SAR investigations around the screening hits provided a diverse set of potent agonists at 5-HT2C with high selectivity over the related 5-HT2A and 5-HT2B receptor subtypes. Further optimization through replacement of the amide with a variety of five- and six-membered heterocycles led to the identification of 6-(1-ethyl-3-(quinolin-8-yl)-1H-pyrazol-5-yl)pyridazin-3-amine (69). Oral administration of 69 to rats reduced food intake in an ad libitum feeding model, which could be completely reversed by a selective 5-HT2C antagonist.

Selective solid-phase extraction of cholesterol using molecularly imprinted polymers and its application in different biological samples.

Non-covalent molecularly imprinted polymers (MIPs) of cholesterol were prepared by UV initiated polymerization. A polymer that had the highest binding selectivity and capability was used as solid-phase extraction (SPE) sorbents for direct extraction of cholesterol from different biological samples (human serum, cow milk, yolk, shrimp, pork and beef). The extraction conditions of molecularly imprinted SPE (MISPE) were optimized and the optimum protocol was: conditioning MISPE cartridges with n-hexane, loading with n-hexane, washing with n-hexane and n-hexane:toluene=9:1, respectively, then eluting with chloroform:ethanol:acetic acid=3:1:1. Cholesterol MISPE selectively recognized, effectively trapped and pre-concentrated cholesterol over a concentration range of 10-80 microg/mL. Recoveries ranged from 80.6% to 92.7%, with R.S.D. lower than 9.8%. Under the optimal condition, MISPE recoveries of spiked human serum, yolk, cow milk, shrimp, pork and beef were 91.1%, 80.4%, 86.6%, 78.2%, 81.4% and 80.1%, respectively. Compared with C18 SPE, almost all of the matrix interferences were removed after MISPE, and better baselines and higher selectivity were achieved.

Effects of quaternization on the morphological stability and antibacterial activity of electrospun poly(DMAEMA-co-AMA) nanofibers.

Electrospun nanofibers with antibacterial activity are greatly promising for medical treatment and water purification. Herein we report antibacterial nanofibers electrospun from a series of poly(dimethylamino ethyl methacrylate-co-alkyl methacrylates) (poly(DMAEMA-co-AMA)) and to distinguish the effects of free and cross-linked cations derived from quanternization on the antibacterial activity. Poly(DMAEMA-co-AMA)s are simply synthesized by free radical polymerization from commercial monomers. DSC analysis indicates that they have Tg lower than room temperature and thus the electrospun nanofibers adhere to each other and evenly tend to form films, instead of keeping cylinderic shape. Benzyl chloride (BC) and p-xylylene dichloride (XDC) can quaternize DMAEMA units and to generate cations on the nanofiber surface. XPS analysis and colorimetric assay determine the quaternization degree and the surface accessible quaternary amines (N(+)), respectively. It is very promising that this quaternization endows the electrospun nanofibers with both stable morphology and antibacterial activity. The BC-quaternized fibers show better antibacterial behavior against Escherichia coli and Staphylococcus aureus than those of the XDC-quaternized/cross-linked ones, because cross-linking suppresses the chain mobility of cations. Our results confirm that antibacterial nanofibers can be facilely prepared and chain mobility of the formed cations is the necessary prerequisite for their antibacterial activity.

Polypropylene non-woven meshes with conformal glycosylated layer for lectin affinity adsorption: the effect of side chain length.

The unique characteristics of polypropylene non-woven meshes (PPNWMs), like random network of overlapped fibers, multiple connected pores and overall high porosity, make them high potentials for use as separation or adsorption media. Meanwhile, carbohydrates can specifically recognize certain lectin through multivalent interactions. Therefore glycosylated PPNWMs, combing the merits of both, can be regarded as superior affinity membranes for lectin adsorption and purification. Here, we describe a versatile strategy for the glycosylation of PPNWMs. Two hydrophilic polymers with different side chain length, poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(oligo(ethylene glycol) methacrylate) (POEGMA), were first conformally tethered on the polypropylene fiber surface by a modified plasma pretreatment and benzophenone (BP) entrapment UV irradiation process. Then glucose ligands were bound through the reaction between the hydroxyl group and acetyl glucose. Chemical changes of the PPNWMs surface were monitored by FT-IR/ATR. SEM pictures show that conformal glucose ligands can be achieved through the modified process. After deprotection, the glycosylated PPNWMs became superhydrophilic and had high specific recognition capability toward Concanavalin A (Con A). Static Con A adsorption experiments were further performed and the results indicate that fast adsorption kinetics and high binding capacity can be accomplished at the same time. We also found that increasing the side chain length of polymer brushes had positive effect on protein binding capacity due to improved chain mobility. Model studies suggest a multilayer adsorption behavior of Con A.

Selective solid-phase extraction of bisphenol A using molecularly imprinted polymers and its application to biological and environmental samples.

Molecularly imprinted polymers (MIPs) were prepared using bisphenol A (BPA) as a template by precipitation polymerization. The polymer that had the highest binding selectivity and ability was used as solid-phase extraction (SPE) sorbents for direct extraction of BPA from different biological and environmental samples (human serum, pig urine, tap water and shrimp). The extraction protocol was optimized and the optimum conditions were as follows: conditioning with 5 mL methanol-acetic acid (3:1), 5 mL methanol, 5 mL acetonitrile and 5 mL water, respectively, loading with 5 mL aqueous samples, washing with 1 mL acetonitrile, and eluting with 3 mL methanol. MIPs can selectively recognize, effectively trap and preconcentrate BPA over a concentration range of 2-20 microM. Recoveries ranged from 94.03 to 105.3%, with a relative standard deviation lower than 7.9%. Under the optimal condition, molecularly imprinted SPE recoveries of spiked human serum, pig urine, tap water and shrimp were 65.80, 82.32, 76.00 and 75.97%, respectively, when aqueous samples were applied directly. Compared with C18 SPE, a better baseline, better high-performance liquid chromatography separation efficiency and higher recoveries were achieved after molecularly imprinted SPE.

[Histological changes on the stress side in orthodontic rapid tooth movement through distraction osteogenesis of the periodental ligament on dogs].

PURPOSE: To study histological changes under the conditions of orthodontic rapid tooth movement through distraction osteogenesis of the periodental ligament on dogs. METHODS: The experiment was carried out in 6 dogs, the left side of jaws of each one was set as test or control side, and the other side was control or test side. On the control side, the first premolar was moved using traditional methods while the third premolar as anchor, on the test side, using self-made distraction device. The periodental tissue of tooth moved were extracted at the end of the test, some of decalcified sections were stained with hematoxylin and eosin and others with modified Mallory's trichrome staining method, being examined by LM. RESULTS: Decalcified sections stained with hematoxylin and eosin showed the bone formed actively, and there were a large number of fibroblasts and osteoblasts as well as abundant vascularity. The modified Mallory's trichrome staining method showed the newly formed bone very clearly and distinctly. CONCLUSIONS: There was no difference in quality but in quantity on the histological reactions in tension side of the tooth moved by traditional method and by distraction osteogenesis through the peridental ligament and periodontal membrane, the latter could induce higher activity of histological synthesization than the former.