Core-shell Au@MIL-100 (Fe) as an enhanced substrate for flunixin meglumine ultra-sensitive detection.

This study aimed to develop and validate a simple and efficient surface-enhanced Raman spectroscopy (SERS) method to determine flunixin meglumine (FM) residues in animal tissues through using core-shell Au@MIL-100 (Fe) as enhanced substrate. Au@MIL-100 (Fe) composite material was synthesized by coating metal-organic framework materials (MOFs) on the surface of gold nanoparticles using the solvothermal method. Transmission electron microscopy (TEM), UV-vis spectrum, SERS spectrum, X-ray diffraction (XRD), Infrared spectrum (FT-IR), and EDX elemental mapping results revealed that the structural composition of the compound has good properties with localized surface plasmon resonance (LSPR) properties, high adsorption capacity, excellent SERS sensitivity and stability. When it was used as SERS substrate, the results of quantitative analysis of FM in pork showed a linear range of 0.10-50 mg·L-1 with a correlation coefficient (R2) of 0.9819, the limit of detection (LOD) of 0.15 mg·g-1, the recovery rate of 88.94%∼104.77%, the intra- and inter- batch relative standard deviation (RSD) of 3.57%∼14.22% and 0.18%∼3.44% respectively. Further verification results of the existing standard methods showed no significant difference between the SERS and UV methods (P < 0.05), as well as demonstrating that the SERS method has optimal precision, accuracy, and practicality. These results exposed that Au@MIL-100 (Fe) as a SERS substrate has great potential in rapid and on-site detection analysis.

Development of UPLC-MS/MS method for determining hainanmycin in foods of animal origin.

Hainanmycin is a polyether antibiotic. Toxicological studies have shown the adverse effects of hainanmycin on animals and humans. At present, no study is available on the detection of hainanmycin in edible tissues of animals. Hence, a fast and accurate detection method for hainanmycin is essential. This study aimed to develop a new analytical method based on ultra-high-performance liquid chromatography-tandem mass spectrometry to detect hainanmycin in 10 matrices, including milk, eggs, fat, kidney, muscles and livers of chicken, beef and sheep. The limit of detection and the limit of quantitation of the 10 matrices were 0.1-0.4 µg/kg and 0.25-1 µg/kg, respectively, and were far below the maximum residue limits of other polyether anticoccidial drugs (1-150 µg/kg). The recoveries of hainanmycin ranged from 79% to 105%, and the relative standard deviation ranged from 2.8% to 12.0%. The research results prove that the proposed method is operational and simple in detecting hainanmycin, and has high precision and accuracy in a variety of matrices.

Neuroprotection of chicoric acid in a mouse model of Parkinson's disease involves gut microbiota and TLR4 signaling pathway.

Chicoric acid (CA), a polyphenolic acid obtained from chicory and purple coneflower (Echinacea purpurea), has been regarded as a nutraceutical to combat inflammation, viruses and obesity. Parkinson's disease (PD) is a common neurodegenerative disorder, and the microbiota-gut-brain axis might be the potential mechanism in the pathogenesis and development of PD. The results obtained in this study demonstrated that oral pretreatments of CA significantly prevented the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced motor dysfunctions and death of nigrostriatal dopaminergic neurons along with the inhibition of glial hyperactivation and the increment in striatal neurotrophins. 16S rRNA sequence results showed that CA significantly reduced MPTP-induced microbial dysbiosis and partially restored the composition of the gut microbiota to normal, including decreased phylum Bacteroidetes and genera Parabacteroide, as well as increased phylum Firmicutes, genera Lactobacillus and Ruminiclostridium. Besides, CA promoted colonic epithelial integrity and restored normal SCFA production. We also observed that proinflammatory cytokines such as TNF-α and IL-1ß in the serum, striatum and colon were reduced by CA, indicating that CA prevented neuroinflammation and gut inflammation, in which the suppression of the TLR4/MyD88/NF-κB signaling pathway might be the underlying molecular mechanism. These findings demonstrated that CA had neuroprotective effects on MPTP-induced PD mice possibly via modulating the gut microbiota and inhibiting inflammation throughout the brain-gut axis.

Synergistic combination of Sapindoside A and B: A novel antibiofilm agent against Cutibacterium acnes.

Sapindus saponins extracted from Sapindus mukorossi Gaertn. have been reported to exert antibacterial activity against Cutibacterium acnes (C. acnes). However, there are no reports about their potentials against its biofilm, which is a major contributor to the antibiotic resistance of C. acnes. This study aimed to investigate the synergistic antibiofilm activity and action of the combination of Sapindoside A and B (SAB) against C. acnes. SAB with sub-MICs significantly inhibited the early-formed and mature biofilm of C. acnes and decreased the adhesion and cell surface hydrophobicity (p < 0.05). Also, SAB greatly reduced the production of exopolysaccharide and lipase (p < 0.05), and the binding mode of SAB and lipase was predicted by molecular docking, via hydrogen bonds and hydrophobic interactions. Biofilm observed with electron microscopies further confirmed the high antibiofilm activity of SAB against C. acnes. Furthermore, a significant down-regulation of biofilm biosynthesis-associated genes was observed. The combination index explained the synergistic effects of SAB leading to the above results, and the contribution of SA was greater than that of SB. The current results showed that SAB had synergistic antibiofilm activity against C. acnes, and the Sapindoside A played a major role, indicating that SAB could be a natural antiacne additive against C. acnes biofilm-associated infections.

Synergistic antibacterial combination of Sapindoside A and B changes the fatty acid compositions and membrane properties of Cutibacterium acnes.

Sapindus saponins extracted from S. mukorossi have been reported to exert antibacterial activities against skin pathogenic bacteria, but their antibacterial mechanism is still at an exploratory stage. The objective of this study was to explore the synergistic antibacterial mechanism of the combination of two Sapindus saponins, namely Sapindoside A and B (SAB) against Cutibacterium acnes (C. acnes) 6919 via targeting the fatty acid compositions and membrane properties. After exposure to SAB, C. acnes cells increased the cell surface hydrophobicity and reduced the cell membrane fluidity by changing the composition of membrane fatty acids. In the fatty acid compositions, the content of two main fatty acids 12-methyl-tetradecanoic acid (isoC15:0) and octadecanoic acid (C18:0) reduced and improved respectively with the addition of SAB, and fatty acid biosynthesis-related genes were significantly down-regulated (p < 0.05). Further, molecular docking demonstrated that SAB interacted with FabD, which is an essential enzyme for bacterial type II fatty acid synthesis, via hydrogen bonds and hydrophobic interactions. In the above results, the contribution of SA to SAB was greater than that of SB. In summary, the results revealed that SAB changed the fatty acid compositions of C. acnes, further disrupting the cell membrane properties, and SA played a major role, suggesting that SAB could be a natural antiacne additive against C. acnes-associated infections.

Potent in vitro synergistic antibacterial activity of natural amphiphilic Sapindoside A and B against Cutibacterium acnes with destructive effect on bacterial membrane.

Sapindus saponins are obtained from the outer bark of Sapindus mukorossi Gaertn. (S. mukorossi), and they have become an interesting subject in the search for new anti-acne agents without resistance. This study aimed to screen the synergistic antibacterial combination from Sapindus saponins and investigated the synergistic antibacterial action via targeting the cell membrane of Cutibacterium acnes (C. acnes) to reduce the effective dose. The combination of Sapindoside A and B (SAB) was obtained with synergistic activity against C. acnes. SAB led to the leakage of ions and disturbed the membrane morphology of C. acnes. The spectral features of cell membrane composition showed obvious changes based on Raman spectroscopy, and changes in membrane protein microenvironment were also observed by fluorescence spectroscopy. Among the above results, the contribution of Sapindoside A was greater than that of Sapindoside B to the synergistic combination of SAB. Furthermore, molecular docking demonstrated that Sapindoside A interacted with penicillin-binding protein 2, playing an important role in peptidoglycan synthesis for the cross wall, and showed a higher binding score than Sapindoside B, further indicating that the greater contribution in the synergistic action of SAB on membrane proteins. Collectively, these results showed that the synergistic antibacterial action of SAB against C. acnes could be achieved by attacking cell membrane, and Sapindoside A played a major role, suggesting that SAB has the potential to be the natural anti-acne agent additive in the cosmetic industry.

Design and synthesis of 7-O-1,2,3-triazole hesperetin derivatives to relieve inflammation of acute liver injury in mice.

Based on the previous research results of our research group, to further improve the anti-inflammatory activity of hesperetin, we substituted triazole at the 7-OH branch of hesperetin. We also evaluated the anti-inflammatory activity of 39 new hesperetin derivatives. All compounds showed inhibitory effects on nitric oxide (NO) and inflammatory factors in lipopolysaccharide-induced RAW264.7 cells. Compound d5 showed a strong inhibitory effect on NO (half maximal inhibitory concentration = 2.34 ± 0.7 µM) and tumor necrosis factor-α, interleukin (IL)-1ß, and (IL-6). Structure-activity relationships indicate that 7-O-triazole is buried in a medium-sized hydrophobic cavity that binds to the receptor. Compound d5 can also reduce the reactive oxygen species production and significantly inhibit the expression of inducible NO synthase and cyclooxygenase-2 through the nuclear factor-κB signaling pathway. In vivo results indicate that d5 can reduce liver inflammation in mice with acute liver injury (ALI) induced by CCI4. In conclusion, d5 may be a candidate drug for treating inflammation associated with ALI.

The chemical profile and biological activity of different extracts of Sapindus mukorossi Gaertn. against Cutibacterium acnes.

This study evaluated the antibacterial activities of different extracts of Sapindus mukorossi Gaertn. (S. mukorossi) on Cutibacterium acnes (C. acnes). The extract solvent and procedure were screened, based on the yield of saponins and minimum inhibitory concentration (MIC). The results showed that the optimized product, fermentation and ethyl acetate extract by adding isoamyl alcohol from water extract of S. mukorossi (SWFEAI), had the highest yield of saponins (7.83 ± 0.26%) and the best antibacterial activity (MIC = 0.125 mg/mL) on C. acnes. The destroyed bacterial cell membrane and wall were observed by transmission electron microscopy, which then resulted in cell lysis and death. Furthermore, 20 compounds of SWFEAI were detected, among which oleanane-type triterpenoid saponins with molecular weights of 734, 750, 882, 924 and 966 were speculated to contribute to the antibacterial activities of SWFEAI. The results showed that SWFEAI could be a natural anti-acne agent.

Isolation of two sesquiterpene glycosides from Sapindus mukorossi Gaertn. with cytotoxic properties and analysis of their mechanism based on network pharmacology.

The anti-tumor effects of two compounds purified from Sapindus mukorossi Gaertn. (S. mukorossi.) on breast cancer in vitro were observed. Their chemical structures were identified as sesquiterpene glycosides, namely, Mukurozioside IIa and Mukurozioside IIb. The results of XTT assay indicated that their inhibition rates against three cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB-435s) reached approximately 80% at a concentration of 200 µg/mL, which were higher than that of cyclophosphamide (below 40% at 200 µg/mL), and their 50% inhibiting concentrations were ranged from 120.73 to 154.01 µg/mL, indicating their inhibition were weaker than their parent fraction. Furthermore, the mechanism on breast cancer was predicted, and 22 targets including PTPN1, IL2 and VEGFA were relatively important. These results illustrated the anti-breast cancer activity of S. mukorossi was related to the two compounds with the structure of sesquiterpene glycosides, but they did not represent the full activity of their parent fraction.

Saponin fraction from Sapindus mukorossi Gaertn as a novel cosmetic additive: Extraction, biological evaluation, analysis of anti-acne mechanism and toxicity prediction.

ETHNOPHARMACOLOGICAL RELEVANCE: Sapindus mukorossi Gaertn. (S. mukorossi), known as 'mu huan zi' in Chinese folklore, belongs to the family Sapindaceae and it has been traditionally used for treating coughing and excessive salivation, removing freckle, whitening skin, etc. Evidence-based medicine also verified the antimicrobial, anti-tyrosinase and anti-acne activity of S. mukorossi extract, suggesting that it has the potential to be a pharmaceutical and cosmetic additive. AIM OF THE STUDY: The present study was intended to evaluate the freckle-removing and skin-whitening activities of S. mukorossi extracts, and further analyzing the potential anti-acne mechanism. METHODS: Saponin fractions were purified by using the semi-preparative high-performance liquid chromatography, and their antibacterial activity was detected against Propionibacterium acnes (P. acnes), which was the leading cause of inflamed lesions in acne vulgaris. The anti-lipase and anti-tyrosinase activities were assayed using a commercial kit, while the potential anti-acne mechanism was predicted on the basis of the network pharmacology. Active components of saponin fraction were identified by HPLC-MS analysis. Furthermore, the different toxicity level of compounds was predicted according to the quantitative structure-activity relationship, and the first application of crude extract and saponin fraction to facial masks was analyzed based on the comprehensive evaluation method. RESULTS: The saponin fraction (F4) purified from the fermentation liquid-based water extract (SWF) showed the best antibacterial activity against P. acnes ATCC 6919 with the MIC of 0.06 mg/mL, which was 33-fold of its parent SWF (with the MIC of 2.0 mg/mL). Compared with SWF, the application of F4 caused greater inhibition rates on lipase and tyrosinase. Chemical constituents of F4 were evaluated, from which four oleanane-type triterpenoid saponins were detected to contribute to the above biological activities of F4. The mechanism of the four compounds on anti-acne was predicted, and seven targets such as PTGS2 and F2RL1 were obtained to be important for the treatment of acne. The four compounds were also predicted to have different levels of toxicity to various species, and they were not harmful to rats. Besides, F4 and SWF were applied to facial masks and there was no significant influence on the physicochemical properties including pH, stability, and sensory characteristics. CONCLUSION: This work demonstrated that oleanane-type triterpenoid saponins were speculated to contribute to the skin-whitening, freckle-removing, and anti-acne activities of F4. These findings will facilitate the development of the S. mukorossi extract and the allied products as the new and natural anti-acne agent and cosmetic additives.

Three-Dimensional Cuprous Lead Bromide Framework with Highly Efficient and Stable Blue Photoluminescence Emission.

Considering the instability and low photoluminescence quantum yield (PLQY) of blue-emitting perovskites, it is still challenging and attractive to construct single crystalline hybrid lead halides with highly stable and efficient blue light emission. Herein, by rationally introducing d10 transition metal into single lead halide as new structural building unit and optical emitting center, we prepared a bimetallic halide of [(NH4 )2 ]CuPbBr5 with new type of three-dimensional (3D) anionic framework. [(NH4 )2 ]CuPbBr5 exhibits strong band-edge blue emission (441 nm) with a high PLQY of 32 % upon excitation with UV light. Detailed photophysical studies indicate [(NH4 )2 ]CuPbBr5 also displays broadband red light emissions derived from self-trapped states. Furthermore, the 3D framework features high structural and optical stabilities at extreme environments during at least three years. To our best knowledge, this work represents the first 3D non-perovskite bimetallic halide with highly efficient and stable blue light emission.

Broadband White-Light Emission in One-Dimensional Organic-Inorganic Hybrid Silver Halide.

In the past few decades, organic-inorganic hybrid metal halides acting as single-component white light emission diodes (LEDs) have attracted extensive attentions, but most of the studies concentrate on the low-dimensional lead perovskites. Here, by using the nontoxic silver as optically active metal center, a series of hybrid silver halides based on one-dimensional structures were constructed and realized broadband white light emission. Compounds [H2DABCO][Ag2X4(DABCO)] (X = Br (1), I (2)) feature one-dimensional [Ag2X4(DABCO)]2- structures charged balanced by [H2DABCO]2+ cations. Compound 1 exhibits an efficient broadband white-light emission with photoluminescence quantum efficiency (PLQE) of about 2.1% and excellent photochemical stability, while compound 2 gives a broadband yellow-white emission centered at 556 nm. [HDABCO]3Ag5Cl8 (3) gives a strong broadband yellow emission (585 nm) with high PLQE of 6.7%, which can be easily fabricated as a white light emitting device. Based on the temperature-dependent, particle-size-dependent, and time-resolved PL measurements as well as other detailed studies, the broadband white-light emissions are ascribed to the synergetic effects of the organic and inorganic components. Our work provides a unique structural assembly method to explore lead-free single-component white-light illuminants from molecular level.

Genome-wide DNA methylation changes associated with olfactory learning and memory in Apis mellifera.

The honeybee is a model organism for studying learning and memory formation and its underlying molecular mechanisms. While DNA methylation is well studied in caste differentiation, its role in learning and memory is not clear in honeybees. Here, we analyzed genome-wide DNA methylation changes during olfactory learning and memory process in A. mellifera using whole genome bisulfite sequencing (WGBS) method. A total of 853 significantly differentially methylated regions (DMRs) and 963 differentially methylated genes (DMGs) were identified. We discovered that 440 DMRs of 648 genes were hypermethylated and 274 DMRs of 336 genes were hypomethylated in trained group compared to untrained group. Of these DMGs, many are critical genes involved in learning and memory, such as Creb, GABA B R and Ip3k, indicating extensive involvement of DNA methylation in honeybee olfactory learning and memory process. Furthermore, key enzymes for histone methylation, RNA editing and miRNA processing also showed methylation changes during this process, implying that DNA methylation can affect learning and memory of honeybees by regulating other epigenetic modification processes.

E3 ubiquitin ligase Cbl-b negatively regulates C-type lectin receptor-mediated antifungal innate immunity.

Activation of various C-type lectin receptors (CLRs) initiates potent proinflammatory responses against various microbial infections. However, how activated CLRs are negatively regulated remains unknown. In this study, we report that activation of CLRs Dectin-2 and Dectin-3 by fungi infections triggers them for ubiquitination and degradation in a Syk-dependent manner. Furthermore, we found that E3 ubiquitin ligase Casitas B-lineage lymphoma protein b (Cbl-b) mediates the ubiquitination of these activated CLRs through associating with each other via adapter protein FcR-γ and tyrosine kinase Syk, and then the ubiquitinated CLRs are sorted into lysosomes for degradation by an endosomal sorting complex required for transport (ESCRT) system. Therefore, the deficiency of either Cbl-b or ESCRT subunits significantly decreases the degradation of activated CLRs, thereby resulting in the higher expression of proinflammatory cytokines and inflammation. Consistently, Cbl-b-deficient mice are more resistant to fungi infections compared with wild-type controls. Together, our study indicates that Cbl-b negatively regulates CLR-mediated antifungal innate immunity, which provides molecular insight for designing antifungal therapeutic agents.

Transcription factors WRKY70 and WRKY11 served as regulators in rhizobacterium Bacillus cereus AR156-induced systemic resistance to Pseudomonas syringae pv. tomato DC3000 in Arabidopsis.

The activation of both the SA and JA/ETsignalling pathways may lead to more efficient general and broad resistance to Pst DC3000 by non-pathogenic rhizobacteria. However, the mechanisms that govern this simultaneous activation are unclear. Using Arabidopsis as a model system, two transcription factors, WRKY11 and WRKY70, were identified as important regulators involved in Induced Systemic Resistance (ISR) triggered by Bacillus cereus AR156. The results revealed that AR156 treatment significantly stimulated the transcription of WRKY70, but suppressed that of WRKY11 in Arabidopsis leaves. Furthermore, they were shown to be required for AR156 enhancing the activation of cellular defence responses and the transcription level of the plant defence response gene. Overexpression of the two transcription factors in Arabidopsis also showed that they were essential for AR156 to elicit ISR. AR156-triggered ISR was completely abolished in the double mutant of the two transcription factors, but still partially retained in the single mutants, indicating that the regulation of the two transcription factors depend on two different pathways. The target genes of the two transcription factors and epistasis analysis suggested that WRKY11 regulated AR156-triggered ISR through activating the JA signalling pathway, and WRKY70 regulated the ISR through activating the SA signalling pathway. In addition, both WRKY11 and WRKY70 modulated AR156-triggered ISR in a NPR1-dependent manner. In conclusion, WRKY11 and WRKY70 played an important role in regulating the signalling transduction pathways involved in AR156-triggered ISR. This study is the first to illustrate the mechanism by which a single rhizobacterium elicits ISR by simultaneously activating both the SA and JA/ET signalling pathways.

Differential protein expression analysis following olfactory learning in Apis cerana.

Studies of olfactory learning in honeybees have helped to elucidate the neurobiological basis of learning and memory. In this study, protein expression changes following olfactory learning in Apis cerana were investigated using isobaric tags for relative and absolute quantification (iTRAQ) technology. A total of 2406 proteins were identified from the trained and untrained groups. Among these proteins, 147 were differentially expressed, with 87 up-regulated and 60 down-regulated in the trained group compared with the untrained group. These results suggest that the differentially expressed proteins may be involved in the regulation of olfactory learning and memory in A. cerana. The iTRAQ data can provide information on the global protein expression patterns associated with olfactory learning, which will facilitate our understanding of the molecular mechanisms of learning and memory of honeybees.