Efficacy of Probiotic Compounds in Relieving Constipation and Their Colonization in Gut Microbiota

A number of studies have confirmed the relationship between constipation and gut microbiota. Additionally, many human and animal experiments have identified probiotics as effectors for the relief of constipation symptoms. In this study, probiotic compounds, including Lactobacillus acidophilus LA11-Onlly, Lacticaseibacillus rhamnosus LR22, Limosilactobacillus reuteri LE16, Lactiplantibacillus plantarum LP-Onlly, and Bifidobacterium animalis subsp. lactis BI516, were administered to mice with loperamide-induced constipation, and the impacts of these strains on constipation-related indicators and gut microbiota were evaluated. The effects of probiotic compounds on constipation relief were associated with various aspects, including gastrointestinal transit rate, number and weight of stools, serum and intestinal gastrointestinal regulatory hormones, and serum cytokines. Some of the probiotic compounds, including Limosilactobacillus reuteri, Lactiplantibacillus plantarum, and Lacticaseibacillus rhamnosus, were found to colonize the intestinal tract. Furthermore, higher dosages promoted the colonization of specific strains. This study yields a new perspective for the clinical use of probiotics to improve constipation symptoms by combining strains with different mechanisms for the alleviation of constipation.     

Honeysuckle Berry (Lonicera caerulea L.) Inhibits Lipase Activity and Modulates the Gut Microbiota in High-Fat Diet-Fed Mice

Honeysuckle berry (HB, Lonicera caerulea L.) is an oriental herbal medicine reported to have beneficial effects on metabolic disorders, such as obesity and non-alcoholic fatty liver disease. The fruit part of HB is rich in anthocyanin, a type of polyphenol. Most studies credit the antioxidant and anti-inflammatory properties of HB as the mechanisms of its effectiveness. This study investigated the inhibitory effects of HB on lipase using an in vitro assay and the modulatory effect of HB on gut microbiota in high-fat diet (HFD)-fed mice. HB inhibited pancreatic lipase activity with IC₅₀ values of approximately 0.47 mg/mL. The fecal triglyceride (TG) levels were higher from the HFD of the HB-fed mice than they were for the control mice. Moreover, the fecal microbiota from the HFD of the HB-fed mice had relatively lower Firmicutes and higher Bacteroidetes than that from the HFD-only mice. These results suggest that HB modulates gut microbiota composition, which may contribute to body fat reduction. Hence, HB could present a useful agent for treating metabolic diseases through lower TG uptake and the regulation of gut microflora.     

Characteristics of evodiamine-exerted stimulatory effects on rat jejunal contractility

This study was designed to characterise the effects of evodiamine on intestinal contractility and reveal the correlated mechanisms. Evodiamine (2.5–80.0 μM) increased normal jejunal contractility and jejunal hypocontractility established under a variety of experimental conditions. Evodiamine-exerted stimulatory effects were blocked by the L-type Ca²⁺ channel blocker nifedipine or abolished in the Ca²⁺-free assay condition. The stimulatory effects of evodiamine on jejunal contractility were partially blocked in the presence of neurotoxin tetrodotoxin or endogenous acetylcholine synthesis blocker hemicholinium-3 or muscarinic receptor antagonist atropine, respectively. Evodiamine-exerted stimulatory effects were blocked by c-kit receptor tyrosine kinase inhibitor imatinib. Evodiamine increased myosin phosphorylation in jejunal smooth muscle of constipation-prominent rats. These results showed that evodiamine-exerted stimulatory effects on jejunal segments are Ca²⁺-dependent, need the presence of interstitial cell of Cajal, requirement of cholinergic neuron and correlate with increased myosin phosphorylation, implicating the potential value of evodiamine in relieving hypo-motility disorders.     

Electrochemical quartz crystal microbalance study on Au-supported Pt adlayers for electrocatalytic oxidation of methanol in alkaline solution

Underpotential deposition (UPD) of Cu on an Au electrode followed by redox replacement reaction (RRR) of Cu_UPD with a Pt source (H₂PtCl₆ or K₂PtCl₄) yielded Au-supported Pt adlayers (for short, Pt(CuUPD-Pt⁴⁺)n/Au for H₂PtCl₆, or Pt(CuUPD-Pt²⁺)n/Au for K₂PtCl₄, where n denotes the number of UPD-redox replacement cycles). The electrochemical quartz crystal microbalance (EQCM) technique was used for the first time to quantitatively study the fabricated electrodes and estimate their mass-normalized specific electrocatalytic activity (SECA) for methanol oxidation in alkaline solution. In comparison with Pt(CuUPD-Pt²⁺)n/Au, Pt(CuUPD-Pt⁴⁺)n/Au exhibited a higher electrocatalytic activity, and the maximum SECA was obtained to be as high as 35.7 mA μg^?1 at Pt(CuUPD-Pt⁴⁺)3/Au. The layer-by-layer architecture of Pt atoms on Au is briefly discussed based on the EQCM-revealed redox replacement efficiency, and the calculated distribution percentages of bare Au sites agree with the experimental results deduced from the charge under the AuO _x -reduction peaks. The EQCM is highly recommended as an efficient technique to quantitatively examine various electrode-supported catalyst adlayers, and the highly efficient catalyst adlayers of noble metals are promising in electrocatalysis relevant to biological, energy and environmental sciences and technologies.     

Synthesis and characterization of some trans-hydridomethylbis(phosphine)-platinum(II) and -palladium(II) complexes

Several trans-hydridomethylbis(phosphine)-platinum(II) and -palladium(II) complexes have been made by the reaction: trans-M(H)Cl(PR₃)₂ + CH₃MgBr → trans-M(CH₃)(PR₃)₂ + MgClBr and their structures determined by ¹H NMR and IR spectroscopy. The complexes in which M  Pt and R  Cy (cyclohexyl) or i-Pr (isopropyl) are very stable in the solid state and in solution, while the compounds in which M  Pt, R  Et (ethyl) and M  Pd, R  i-Pr slowly decompose either in the solid state or in solution. The compound in which M  Pd and R  Cy was not isolated but was identified in solution.     

Impact of Targeted Specific Antibiotic Delivery for Gut Microbiota Modulation on High-Fructose-Fed Rats

The objective of present investigation was to study the effect of gut microbiota alteration by oral administration of targeted delivery of pH sensitive cefdinir microspheres to high-fructose-fed (HFD) rats. Rats were fed with a high-fructose diet with or without cefdinir microsphere administration for 30 days. The fecal microbiota community, oral glucose tolerance, the markers of liver injury, plasma and hepatic lipids profile, and histological evaluation were investigated. The levels of blood glucose, liver injury markers, lipid profile in plasma and liver, and fat tissue were significantly increased in high-fructose-fed rats. However, after pH-sensitive cefdinir microsphere administration, the elevation of these parameters was significantly suppressed. Cef EL significantly lowered the increased AST (p?<?0.05) and ALT (p?<?0.001) levels in HFD group. There is a significant lower (p?<?0.01) AUC_glucose level in Cef EL group than HFD group The histological changes in the liver and the small and large intestines were more profound in HFD group as compared to cefdinir-treated HFD and control groups. Feeding of cefdinir microsphere sustained lactobacilli and bifidobacteria and significantly decreased (p?<?0.05) the number of Enterobacteriaceae induced by HFD. Experimental evidences demonstrated that the effectiveness of pH-specific cefdinir microsphere on reducing insulin resistance and development of metabolic changes in high-fructose-fed rats and suggested that it may be a promising therapeutic agent in treating type 2 diabetes. Intestinal-targeted antibiotic delivery needs to be further explored for its therapeutic applications.     

Gut microbiota restoration through fecal microbiota transplantation: a new atopic dermatitis therapy

The pathogenesis of atopic dermatitis (AD) involves complex factors, including gut microbiota and immune modulation, which remain poorly understood. The aim of this study was to restore gut microbiota via fecal microbiota transplantation (FMT) to ameliorate AD in mice. FMT was performed using stool from donor mice. The gut microbiota was characterized via 16S rRNA sequencing and analyzed using Quantitative Insights into Microbial Ecology 2 with the DADA2 plugin. Gut metabolite levels were determined by measuring fecal short-chain fatty acid (SCFA) contents. AD-induced allergic responses were evaluated by analyzing blood parameters (IgE levels and eosinophil percentage, eosinophil count, basophil percentage, and monocyte percentage), the levels of Th1 and Th2 cytokines, dermatitis score, and the number of mast cells in the ileum and skin tissues. Calprotectin level was measured to assess gut inflammation after FMT. FMT resulted in the restoration of gut microbiota to the donor state and increases in the levels of SCFAs as gut metabolites. In addition, FMT restored the Th1/Th2 balance, modulated Tregs through gut microbiota, and reduced IgE levels and the numbers of mast cells, eosinophils, and basophils. FMT is associated with restoration of gut microbiota and immunologic balance (Th1/Th2) along with suppression of AD-induced allergic responses and is thus a potential new therapy for AD.Subject terms: Experimental models of disease, Biological therapy     

Preparation of carbon nanotubes supported platinum nanoparticles by an organic colloidal process for nonenzymatic glucose sensing

Multi-walled carbon nanotubes (MWNTs) supported platinum nanoparticles with narrow size distribution were prepared by an organic colloidal process with sodium citrate as the coordination reagent and stabilizer, and ethylene glycol as the reduction reagent. A nonenzymatic glucose sensor with high sensitivity based on the Pt/MWNTs electrode was demonstrated. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were employed to investigate the size distributions and the crystal structure of Pt nanoparticles on the MWNTs. The TEM images show that the Pt nanoparticles with about 2–4 nm in diameter are well dispersed on the MWNTs. The Pt/MWNTs shows high electrocatalytic activity towards the oxidation of glucose in 0.1 M NaOH solution. At +0.5 V, the Pt/MWNTs nanocomposite electrode exhibits linearity in the range of 1 mM to 23 mM (R > 0.998) glucose with a response time of 11.6 s. The detection limit is 50 μM (S/N = 3). It was demonstrated that the Pt/MWNTs electrode with high electrocatalytic activity to glucose oxidation could find application in nonenzymatic detection of glucose.     

Spectral and electro-chemical characterization of transition metal complexes of a modified [N<Subscript>6</Subscript>] macrocycle. A mimic to cyclic hexapeptide

The 16-membered modified [N₆] macrocylic ligand (L), a mimic to cyclic, hexapeptide is reacted with MCl₂ and MCl₃ resulting in complexes with stoichiometrices [MLCl₂] (M = Cr, Mn, Co, Ni, Cu), [MLCl₃] (M = Pt, Pd) and [MLCl₂]Cl (M = Fe, Ru). Its reactions with the precursors [M(Ph₃P)₂Cl₂] (M = Co, Ni, Pt, Pd) follow a ligand displacement path affording the final products which do not contain coordinated Ph₃P. Complexes have been characterized from results of elemental analyses, conductometric, magnetic susceptibility, i.r. and u.v.–vis (ligand field) spectral studies. Magnetic susceptibility and ligand field spectral data are consistent with a hexacoordinate geometry for Cr²⁺, Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺ and Cu²⁺ and four coordinate square-planar geometry for Pt²⁺ and Pd²⁺. Molecular orbital computations using CSChem ultra MOPAC software for an optimized minimum energy plot of the structure shows that the ligand binds metal ions as a tetradentate (N,N,N,N) chelating agent. Cyclic voltammetric studies indicate formation of stable reversible or quasi-reversible redox couples in solutions, which corroborates a kinetic stability of these complexes in their variable oxidation states.     

Concurrent oxygen reduction and methanol oxidation in sulfuric acid solutions on platinized platinum electrodes

Steady-state polarization curves are compared in solutions of 0.5 M H₂SO₄ + O₂ (saturated), 0.5 M H₂SO₄ + (0.005–0.1) M CH₃OH, and 0.5 M H₂SO₄ + (0.005–0.1) M CH₃OH + O₂ (saturated) on a Pt/Pt electrode. A considerable difference is found between the currents in mixed solutions and those expected based on the principle of additivity of currents in CH₃OH and O₂ individual solutions. The surface coverages with the CH₃OH and O₂ adsorption products are determined in the potential range of 0.2–0.9 V (RHE). Open-circuit potentials are measured in mixed solutions. The obtained results suggest that the direct heterogeneous interaction between methanol and oxygen occurs alongside with faradaic reactions. This is assumed to lead to a decrease in methanol electrooxidation currents at E ≥ 0.8 V and their increase at E ≤ 0.65 V.     

The liquid—liquid extraction of platinum in the presence of tin(II) chloride from dilute hydrochloric acid into 4-methyl-2-pentanone

The distribution of complexes of type [Pt(SnCl₃)_nCl_4?n]^2? (n = 1–4) and [Pt(SnCl₃)₅]^3? between 1.5–3.5 M hydrochloric acid and 4-methyl-2-pentanone is discussed in detail. Platinum can be quantitatively extracted into the organic phase from hydrochloric acid solutions containing tin(II) chloride when the mole ratio Sn²⁺: Pt²⁺ > 5. In the presence of sufficient tin(II) chloride, the [Pt(SnCl₃)₅]^3? anion is the predominant species extracted into the organic phase. Similar results pertain to starting solutions of either Ptcl^2?₄ or PtCl^2?₆, although Pt⁴⁺ is rapidly reduced to Pt²⁺. Small amounts of Co²⁺, Ni²⁺, Fe³⁺ and Cu²⁺ do not interfere.     

Hydrolysis of platinum(II) phosphine complexes in aqueous 1.0 M NaNO3 medium

Hydrolysis of [Pt(PR₃)₂]²⁺ (R=Me, Et) have been investigated at 25.0°C in 1.000 M NaNO₃ by the combined emf–NMR method. Quantitative analysis of the emf and ³¹P NMR data revealed the formation of [{Pt(PR₃)₂(μ-OH)}₂]²⁺ as the only hydrolysis product in the range 1.5<−log h<5.7. Least-squares calculation gave log β_Me=−4.19±0.04 and log β_Et=−3.58±0.04, where β_Me and β_Et stand for the formation constants of the dimeric cations of methyl and ethyl derivatives, respectively. The ¹⁹⁵Pt NMR data were also consistent with this model.     

Determination of Trace Cholinergic Compounds and the Evaluation of Their Relative Receptor Activity with the Use of a Receptor Biosensor and an Ion-Selective Choline Electrode

A comparative assessment of the analytical capabilities of a tensoresistive biosensor based on muscarinic acetylcholine receptors and a potentiometric choline sensor was performed. It was found that the receptor biosensor is promising for the determination of ultratrace amounts of cholinergic agents with a detection limit of 10^–7–10^–10 M. The selectivity of the potentiometric choline sensor is equal to the selectivity of the receptor biosensor; however, the sensitivity of the former is lower by two orders of magnitude. Nevertheless, it can be successfully used for evaluating the relative receptor activity of cholinergic agents.     

The platinum—carbon bond strength in Pt(PPh3)2(Cl)(CPhCHPh)

The enthalpies of the reactions 1 and 2 have been determined as ΔH = Pt(PPh₃)₂(CPhCPh)_cryst. + HCl_g → Pt(PPh₃)₂(Cl)(CPhCHPh)_cryst. (1) Pt(PPh₃)₂(CPhCPh)_cryst. + 2HCl_g → cis-Pt(PPh₃)₂Cl_2cryst. + trans-CHPhCHPh_g (2) ?90.2 ± 6 and ΔH = ?139.0 ± 16 kJ mol^?1, respectively; dissociation energies of bonds involving platinum are expressed by the relationship: 41 kJ mol^?1 + D(Pt-tolane) = 2D(PtCPhCHPh) = {D₁(PtCl) + D₂(PtCl)} ?350 kJ mol^?1     

A fast,fully validated GC-MS method using a simplified pretreatment for the quantification of short and branched chain fatty acids in human stool

The study of short (SCFAs) and branched chain fatty acids (BCFAs) in human stool related to gastrointestinal diseases, gut microbiota, metabolism, and diet has dramatically increased. As a result, a fast, reliable method with minimal pretreatment is needed for quantification of these metabolites (acetic, propionic, isobutyric, butyric, isovaleric, valeric, and caproic acid) in stool. Therefore, a GC-MS method meeting this criterion was developed. A bias sampling study showed no statistical difference (p > 0.05) in analyte means when comparing 100 mg subsamples of homogenized to non-homogenized samples (n = 6, p values 0.153–0.910). Stool samples were homogenized, diluted with 80:20 water:methanol (v/v), and adjusted to a pH of 1.5–2.5. Samples were vortexed, centrifuged, and directly injected into the GC-MS using pulsed splitless injection offering twofold-to-threefold signal enhancement over a 10:1 split injection. DB-FATWAX Ultra Inert Polyethylene Glycol (PEG) Column showed no peak tailing, reduced responses, or retention time shifts after 1,476 stool injections, while other columns failed before 361 injections. Intra- and inter-day accuracy for stool supernatant samples ranged from −10.21% to 8.88% and −13.25% to 9.91%, while intra- and inter-day precision ranged from 0.21% to 1.21% and 0.89% to 2.84% coefficient of variation (CV), respectively. This method demonstrates excellent linearity (0.9999–1.0000) and low limits of quantification (1.50–8.01 μM). Stool samples proved stable stored at −20°C up to 28 days, and recoveries ranged from 85.04% to 106.59%. Matrix effects in stool are non-significant determined by comparing standard and stool supernatant calibration curve slopes (p > 0.05).     

Synthesis of platinum-iodo-alkyl/aryl complexes in ligand-exchange reactions: Determination of the structure of Pt{(S,S)-bdpp}(X)I complexes (X = Me, I) by X-ray crystallography

Pt{(S,S)-bdpp}(R)I (bdpp = 2,4-bis(diphenylphosphino)pentane; R = Me, Ph, Bz, 2-Tioph) complexes were formed in alkyl/aryl ligand - iodide ligand-exchange reactions by reacting the corresponding Pt{(S,S)-bdpp}R₂ complexes with methyl iodide. The Pt{(S,S)-bdpp}(Me)I complex was isolated and fully characterised. The influence of the X ligand on the platinum-bdpp chelate conformation was investigated in Pt{(S,S)-bdpp}(X)I (X = I, SnCl₃, Me) complex series by means of X-ray crystallography.     

Theoretical study of the structure and water affinity of [M(18C6)(HFA)<Subscript>2</Subscript>] complexes for M = Zn,Cu, Hg,Co, Ni,and Pt

The structures of the [M(18C6)]²⁺ cations, where M = Zn, Cu, Hg, Ni, Co, and Pt, and cis- and trans-[M(18C6)(HFA)₂]/[M(18C6)(NO₃)₂] molecules in the gas phase have been calculated by the density functional theory method in the B3LYP/6-31G*//6-311++G** + LanL2Dz approximation. Geometry optimization has been performed, and the strength of binding of the central cation to the crown ether (18C6) and the degree of structural similarity of the [M(18C6)(HFA)₂] compounds for different central atoms M have been evaluated. For all [M(18C6)(NO₃)₂]/[M(18C6)(HFA)₂] molecules (M = Zn, Cu, Hg, Ni, Co, Pt), the vertical ionization potential and the vertical electron affinity have been calculated. These parameters are of interest for analysis of the stability of volatile compounds [M(18C6)(HFA)₂] to donor–acceptor interactions with other components of the gas phase, for example, with water vapor, which is usually a Lewis base with respect to the systems in question and can donate electron density in the course of complexation with the central atom. The propensity of the [M(18C6)(NO₃)₂]/[M(18C6)(HFA)₂] molecules to react with water is considered for a wider range of metals M²⁺ = Ba²⁺, Sr²⁺, Pb²⁺, Mn²⁺, Cd²⁺, Zn²⁺, Cu²⁺, Hg²⁺, Co²⁺, Ni²⁺, and Pt²⁺, with taking into account the degree of matching between the ionic radii of M²⁺ cations and the 18C6 cavity size.     

Synthesis and characterization of palladium(II) and platinum(II) metal complexes with iminophosphine ligands: X-ray crystal structures of platinum(II) complexes and use of palladium(II) complexes as pre-catalysts in Heck and Suzuki cross-coupling reactions

The reactions of N-(2(diphenylphosphino) benzylidene) (phenyl) methanamine, Ph₂PPhNHCH₂-C₅H₄N, 1 and N-(2-(diphenylphosphino) (benzylidene) (thiophen-2-yl) methanamine, Ph₂PPhNHCH₂-C₄H₃S, 2 with MCl₂(cod) and MCl(cod)Me (M = Pd, Pt; cod = 1,5-cyclooctadiene) yield the new complexes [M(Ph₂PPhNHCH₂-C₅H₄N)Cl₂], M = Pd1a, Pt1b, [M(Ph₂PPhNHCH₂-C₅H₄N)ClMe], M = Pd1c, Pt 1d, [M(Ph₂PPhNHCH₂-C₄H₃S)Cl₂], M = Pd2a, Pt 2b, and [M(Ph₂PPhNHCH₂-C₄H₃S)ClMe], M = Pd2c, Pt 2d, respectively. The new compounds were isolated as analytically pure crystalline solids and characterized by ³¹P-, ¹H-NMR, IR spectroscopy, electro spray ionization-mass spectrometry (ESI-MS) and elemental analysis. The representative solid-state molecular structures of the platinum complexes 1b and 2b were determined using single crystal X-ray diffraction analysis and revealed that the complexes exhibit a slightly distorted square-planar geometry. Furthermore, the palladium complexes were tested as potential catalysts in the Heck and Suzuki cross-coupling reactions.     

Carbene complexes : IV. Far infrared and 31P NMR spectra of palladium and platinum carbene complexes

Infrared bands mainly associated with v(M—X₂) stretching modes (M = Pd or Pt, and X = Cl, Br, or P) have been identified in the spectra of 35 carbene complexes. Based on these results and on |¹J| (³¹ P—¹⁹⁵ Pt) the trans-influence of the carbene ligands is assessed.     

Density functional theory study of the structures,electronic states and stabilities of Al n Pt (n = 1–15) clusters

The binding energy, dissociation energy, ionization potentials, electron affinities, gap and stability of small Al _n Pt (n = 1–15) clusters, in comparison with pure aluminum clusters have been systematically investigated by means of density functional calculations at the B3LYP level. The growth patten for Al _n Pt clusters is that the Pt atom substituted the surface atom of the Al _{n + 1} clusters for n < 13. Starting from n = 13, the Pt atom completely falls into the center of the Al-frame. The Pt atom substituted the center atom of the Al _{n + 1} clusters to form the Pt-encapsulated Aln geometries for n > 13. We also find that the impurity Pt atom causes local structural distortion due to different atomic radii and different bonding characteristics. The clusters with total atom numbers of 2, 7, and 11 exhibit high stability.