Effects of folate-chicory acid liposome on macrophage polarization and TLR4/NF-κB signaling pathway in ulcerative colitis mouse

BACKGROUND

Chichoric acid (CA) is a major active ingredient found in chicory and Echinacea. As a derivative of caffeic acid, it has various pharmacological effects.

PURPOSE

Due to the unclear etiology and disease mechanisms, effective treatment methods for ulcerative colitis (UC) are currently lacking. The study investigated the therapeutic effects of the folate-chicory acid liposome on both LPS-induced macrophage inflammation models and dextran sulfate sodium (DSS)-induced mouse UC models.

METHODS

Folate-chicory acid liposome was prepared using the double emulsion ultrasonic method with the aim of targeting folate receptors specifically expressed on macrophages. The study investigated the therapeutic effects of the folate-chicory acid liposome on both LPS-induced macrophage inflammation models and DSS -induced mouse UC models. Furthermore, the effects of the liposomes on macrophage polarization and their underlying mechanisms in UC were explored.

RESULTS

The average particle size of folate-chicory acid liposome was 120.4 ± 0.46 nm, with an encapsulation efficiency of 77.32 ± 3.19 %. The folate-chicory acid liposome could alleviate macrophage apoptosis induced by LPS, decrease the expression of inflammatory factors in macrophages, enhance the expression of anti-inflammatory factors, inhibit macrophage polarization towards the M1 phenotype, and mitigate cellular inflammation in vetro. In vivo test, folate-chicory acid liposome could attenuate clinical symptoms, increased colon length, reduced DAI scores, CMDI scores, and alleviated the severity of colonic histopathological damage in UC mice. Furthermore, it inhibited the polarization of macrophages towards the M1 phenotype in the colon and downregulated the TLR4/NF-κB signaling pathway, thereby ameliorating UC in mice.

CONCLUSION

Folate-chicory acid liposome exhibited a uniform particle size distribution and high encapsulation efficiency. It effectively treated UC mice by inhibiting the polarization of macrophages towards the M1 phenotype in the colon and downregulating the TLR4/NF-κB signaling pathway.

High performance poly(L-lactic acid)-based film by one-step synthesis of poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) for efficient preservation of yogurt storage

Biodegradable poly(L-lactic acid) (PLLA) has seldom used for dairy packaging due to medium permeability and brittleness. Novel PLLA copolymers, poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) (PLBIGA), were developed by integrating glycolic acid (GA) and poly(butylene itaconate) (PBI) into PLLA's structure using low molecular weight PLLA as a key initiator. Then, packaging materials with better barrier and mechanical properties were obtained by blended PLBIGA with PLLA. Both PLLA/PLBIGA films and polyethylene nylon composite film (PE/NY) were used for stirred yogurt packaging and storage at 4 °C for 25 days. Results revealed that yogurt packed by PLLA/PLBIGA films maintained stabler water-holding capacity, color, and viscosity over the storage period. Moreover, the integrity of the gel structure and the total viable count of lactic acid bacteria in yogurt packaged in PLLA/40-PLBIGA8 were also found to be superior to those in PE/NY packages, highlighting its eco-friendly advantages in dairy packaging.

Fabrication of D-α-tocopheryl polyethylene glycol 1000 succinates and human serum albumin conjugated chitosan nanoparticles of bosutinib for colon targeting application; in vitro-in vivo investigation

For more effective chemotherapy and targeted treatment of colorectal cancer, this study seeks to develop chitosan (CH)-human serum albumin (HAS)-D-α-tocopheryl polyethylene glycol 1000 (TPGS) nanoparticles (BOS-CH-HSA-TPGS-NPs) coated with Bosutinib (BOS). Nuclear magnetic resonance (NMR) indicated that chitosan's structure was modified by carbodiimide coupling with HSA. We used a Box-Behnken design to find the ideal region for particle size, zeta potential, and entrapment efficiency, eventually emerging at a formulation with these values: 187.14 ± 3.2 nm, 76.2 ± 0.96 %, and 21.1 ± 2.3 mV. Differential scanning calorimetry (DSC), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), High-performance liquid chromatography (HPLC) were all used to characterize the sample in detail. At a phosphate buffer pH of 7.4, in vitro drug release tests showed both Higuchi model release (0.954) and Fickian diffusion (n = 0.5). Compared to free BOS, HCT116 cell lines showed considerably higher cytotoxicity in in vitro cytotoxicity assays. In male albino Wistar rats, the BOS-CH-HSA-TPGS-NPs also showed enhanced pharmacokinetics, targeting efficiency, and biocompatibility. When used to the treatment of colorectal cancer, the BOS-CH-HSA-TPGS NPs show promise as a sustained-release therapy with improved therapeutic effects by addressing the challenges of poor solubility, poor permeability, and toxic side effects.

Development of poly(butylene adipate-co-butylene succinate-co-ethylene adipate-co-ethylene succinate) (PBEAS) net twine as biodegradable fishing gear

Nylon fishing nets have excellent strength and durability, but when lost at sea, their insufficient decomposition destroys habitats and spawning grounds, and pollutes the marine environment. This led to the development of poly(butylene succinate) (PBS) resin for biodegradable fishing gear based on aliphatic fibers. Prompted by the low stiffness and elastic recovery of PBS, we introduced two additional components into the molecular structure of PBS: adipic acid and ethylene glycol. These two new components were combined with succinic acid and 1,4-butanediol, the existing components of PBS, to synthesize poly(butylene adipate-co-butylene succinate-co-ethylene adipate-co-ethylene succinate) (PBEAS) resin via esterification and polycondensation reactions of a quaternary aliphatic copolyester. Although the molecular weight and molecular weight distribution of PBEAS are similar to those of PBS, it has excellent tensile strength, stiffness, elastic recovery, and biodegradability, with a low melting point for good production efficiency. These improvements are expected to allow PBEAS resin to be applied to gill nets for fish that require high stiffness, thereby expanding the use of biodegradable fishing gear.

Enhanced Insecticidal Effect and Interface Behavior of Nicotine Hydrochloride Solution by a Vesicle Surfactant

Nicotine hydrochloride (NCT) has a good control effect on hemiptera pests, but its poor interfacial behavior on the hydrophobic leaf leads to few practical applications. In this study, a vesicle solution by the eco-friendly surfactant, sodium diisooctyl succinate sulfonate (AOT), was prepared as the pesticide carrier for NCT. The physical chemical properties of NCT-loaded AOT vesicles (NCT/AOT) were investigated by techniques such as dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and cryogenic transmission electron microscopy (cryo-TEM). The results showed that the pesticide loading and encapsulation efficiency of NCT/AOT were 10.6% and 94.8%, respectively. The size of NCT/AOT vesicle was about 177 nm. SAXS and surface tension results indicated that the structure of the NCT/AOT vesicle still existed with low surface tension even after being diluted 200 times. The contact angle of NCT/AOT was always below 30°, which means it could wet the surface of the cabbage leaf well. Consequently, NCT/AOT vesicles could effectively reduce the bounce of pesticide droplets. In vitro release experiments showed that NCT/AOT vesicles had sustained release properties; 60% of NCT in NCT/AOT released after 24 h, and 80% after 48 h. Insecticidal activity assays against aphids revealed that AOT vesicles exhibited insecticidal activity and could have a synergistic insecticidal effect with NCT after the loading of NCT. Thus, the NCT/AOT vesicles significantly improved the insecticidal efficiency of NCT, which has potential application in agricultural production activities.

Biodegradable chelant-metal complexes enhance cadmium phytoextraction efficiency of Solanum americanum

Toxic contaminants (metals and metal-containing compounds) are accumulating in the environment at an astonishing rate and jeopardize human health. Remarkable industrial revolution and the spectacular economic growth are the prime causes for the release of such toxic contaminants in the environment. Cadmium (Cd) is ranked the 7th most toxic compound by the Agency for Toxic Substances and Disease Registry (USA), owing to its high carcinogenicity and non-biodegradability even at miniscule concentration. The present study assessed the efficiency of four biodegradable chelants [nitrilotriacetic acid (NTA), ethylenediamine disuccinate (EDDS), ethylene glycol tetraacetic acid (EGTA), and citric acid (CA)] and their dose (5 mM and 10 mM) in enhancing metal accumulation in Solanum americanum Mill. (grown under 24 mg Cd kg^-1 soil) through morpho-physiological and metal extraction parameters. Significant variations were observed for most of the studied parameters in response to chelants and their doses. However, ratio of root and shoot length, and plant height stress tolerance index differed non-significantly. The potential of chelants to enhance Cd removal efficiency was in the order - EGTA (7.44%) > EDDS (6.05%) > NTA (4.12%) > CA (2.75%). EGTA and EDDS exhibited dose-dependent behavior for Cd extraction with 10 mM dose being more efficient than 5 mM dose. Structural equation model (SEM) depicted strong positive interaction of metal extraction parameters with chelants (Z-value = 11.61, p = 0.001). This study provides insights into the importance of selecting appropriate dose of biodegradable chelants for Cd extraction, as high chelant concentration might also result in phytotoxicity. In the future, phytoextraction potential of these chelants needs to be examined through field studies under natural environmental conditions.

Dasatinib self-assembled nanoparticles decorated with hyaluronic acid for targeted treatment of tumors to overcome multidrug resistance

Multidrug resistance (MDR) and lack of targeting specificity are the main reasons why traditional drug therapies fail and produce toxic side effects in cancer chemotherapy. In order to increase targeting specificity and maximize therapeutic efficacy, new intelligent drug delivery systems are needed. In this study, we prepared the hyaluronic acid (HA) conjugated dasatinib (DAS) and D-α-tocopherol acid polyethylene glycolsuccinate (TPGS) copolymer nanoparticles (THD-NPs). The water solubility of the hydrophobic drug DAS was improved by chemically linking with HA. HA can bind to the over-expressed CD44 protein of tumor cells to increase targeting specificity, TPGS can inhibit the activity of P-glycoprotein (P-gp), and increase the intracellular accumulation of drugs. The prepared drug-loaded nanoparticle has a particle size of 82.23 ± 1.07 nm with good in vitro stability. Our in vitro studies showed that THD-NPs can be released more rapidly in a weakly acidic environment (pH = 5.5) than in a normal physiological environment (pH = 7.4), which can realize the selective release of nanoparticles in tumor cells. Compared to free drugs, THD-NPs showed more efficient cellular uptake, effectively increased the cytotoxic effect of DAS on nasopharyngeal carcinoma HNE1 cells drug resistance HNE1/DDP cells and increased the accumulation of drugs in HNE1/DDP cells, which may be due to the inhibitory effect of TPGS on the efflux function of P-gp. In vivo experiments showed that THD-NPs can effectively inhibit tumor growth without obvious side effects. In conclusion, the targeted and pH-sensitive nanosystem, we designed has great potential to overcome drug resistance and increase therapeutic effects in cancer treatment.

Mechanism-Based Inactivation of Mycobacterium tuberculosis Isocitrate Lyase 1 by (2R,3S)-2-Hydroxy-3-(nitromethyl)succinic acid

The isocitrate lyase paralogs of Mycobacterium tuberculosis (ICL1 and 2) are essential for mycobacterial persistence and constitute targets for the development of antituberculosis agents. We report that (2R,3S)-2-hydroxy-3-(nitromethyl)succinic acid (5-NIC) undergoes apparent retro-aldol cleavage as catalyzed by ICL1 to produce glyoxylate and 3-nitropropionic acid (3-NP), the latter of which is a covalent-inactivating agent of ICL1. Kinetic analysis of this reaction identified that 5-NIC serves as a robust and efficient mechanism-based inactivator of ICL1 (kinact/KI = (1.3 ± 0.1) × 103 M-1 s-1) with a partition ratio <1. Using enzyme kinetics, mass spectrometry, and X-ray crystallography, we identified that the reaction of the 5-NIC-derived 3-NP with the Cys191 thiolate of ICL1 results in formation of an ICL1-thiohydroxamate adduct as predicted. One aspect of the design of 5-NIC was to lower its overall charge compared to isocitrate to assist with cell permeability. Accordingly, the absence of the third carboxylate group will simplify the synthesis of pro-drug forms of 5-NIC for characterization in cell-infection models of M. tuberculosis.

Psammaceratin A: A Cytotoxic Psammaplysin Dimer Featuring an Unprecedented (2Z,3Z)-2,3-Bis(aminomethylene)succinamide Backbone from the Red Sea Sponge Pseudoceratina arabica

Bioassay-guided partition of the extract of the Red Sea sponge Pseudoceratina arabica and HPLC purification of the active fraction gave a psammaplysin dimer, psammaceratin A (1), along with psammaplysin A (2). The dimer comprises two units of psammaplysin A (2) connected via the terminal amines with an unprecedented (2Z,3Z)-2,3-bis(aminomethylene)succinamide moiety, and it represents the first dimer to be identified among the psammaplysin family. Data from 1D- and 2D-NMR and HRMS supported the chemical structures of the compounds. Psammaceratin A (1) and psammaplysin A (2) exhibited significant growth inhibition of HCT 116, HeLa, and MBA-MB-231 cells down to 3.1 μM.

Stereoselective Access to Antimelanoma Agents by Hybridization and Dimerization of Dihydroartemisinin and Artesunic acid

A library of five hybrids and six dimers of dihydroartemisinin and artesunic acid has been synthetized in a stereo-controlled manner and evaluated for the anticancer activity against metastatic melanoma cell line (RPMI7951). Among novel derivatives, three artesunic acid dimers showed antimelanoma activity and cancer selectivity, being not toxic on normal human fibroblast (C3PV) cell line. Among the three dimers, the one bearing 4-hydroxybenzyl alcohol as a spacer showed no cytotoxic effect (CC50 >300 μM) and high antimelanoma activity (IC50 =0.05 μM), which was two orders of magnitude higher than that of parent artesunic acid, and of the same order of commercial drug paclitaxel. In addition, this dimer showed cancer-type selectivity towards melanoma compared to prostate (PC3) and breast (MDA-MB-231) tumors. The occurrence of a radical mechanism was hypothesized by DFO and EPR analyses. Qualitative structure activity relationships highlighted the role of artesunic acid scaffold in the control of toxicity and antimelanoma activity.

Optimization, in vitro release and toxicity evaluation of novel pH sensitive itaconic acid-g-poly(acrylamide)/sterculia gum semi-interpenetrating networks

BACKGROUND

In recent era, pH sensitive polymeric carriers that combines the materials engineering and medicine is gaining researcher's attention as they maximizes drug concentration at site of absorption and reduces side effects for e.g. orally administered cetirizine HCl (CTZ HCl) upsets the stomach and furthermore shows high intestinal absorption. Thus, development of pH sensitive hydrogels with sufficient mechanical strength will be good candidate to address this issue.

METHODS

Here, we developed pH sensitive itaconic acid-g-poly(acrylamide)/sterculia gum (IA-g-poly(AM)/sterculia gum) semi-interpenetrating network (semi-IPN) by free radical polymerization technique for intestinal delivery of CTZ HCL.

RESULTS

Optimized formulation (I5) with 6% w/w IA showed negligible swelling at pH 1.2, and maximum swelling at pH 7.4. Solid state characterization of optimized formulation showed successful development of semi-IPN structure and incorporation of drug without any noticeable drug-carrier interaction. In vitro release study showed biphasic pH dependent release of CTZ HCl, where initial burst release was observed at acidic pH followed by sustained release at basic pH. Acute oral toxicity and histopathological studies confirmed the non-toxic nature of IA-g-poly(AM)/sterculia gum.

CONCLUSION

Conclusively, developed biocompatible semi-IPN hydrogels with sufficient pH sensitivity and mechanical strength could serve as a potential carrier for intestinal delivery of CTZ HCL to maximize its absorption and reduce side effects.

Heterogeneous multimeric structure of isocitrate lyase in complex with succinate and itaconate provides novel insights into its inhibitory mechanism

During the glyoxylate cycle, isocitrate lyases (ICLs) catalyze the lysis of isocitrate to glyoxylate and succinate. Itaconate has been reported to inhibit an ICL from Mycobacterium tuberculosis (tbICL). To elucidate the molecular mechanism of ICL inhibition, we determined the crystal structure of tbICL in complex with itaconate. Unexpectedly, succinate and itaconate were found to bind to the respective active sites in the dimeric form of tbICL. Our structure revealed the active site architecture as an open form, although the substrate and inhibitor were bound to the active sites. Our findings provide novel insights into the conformation of tbICL upon its binding to a substrate or inhibitor, along with molecular details of the inhibitory mechanism of itaconate.

Covalent Inactivation of Mycobacterium tuberculosis Isocitrate Lyase by cis-2,3-Epoxy-Succinic Acid

The isocitrate lyases (ICL1/2) are essential enzymes of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis. At present, no ICL1/2 inhibitors have progressed to clinical evaluation, despite extensive drug discovery efforts. Herein, we surveyed succinate analogs against ICL1 and found that dicarboxylic acids constrained in their synperiplanar conformations, such as maleic acid, comprise uncompetitive inhibitors of ICL1 and inhibit more potently than their trans-isomers. From this, we identified cis-2,3 epoxysuccinic acid (cis-EpS) as a selective, irreversible covalent inactivator of Mtb ICL1 (kinact/Kinact= (5.0 ± 1.4) × 104 M-1 s-1; Kinact = 200 ± 50 nM), the most potent inactivator of ICL1 yet characterized. Crystallographic and mass spectrometric analysis demonstrated that Cys191 of ICL1 was S-malylated by cis-EpS, and a crystallographic "snapshot" of inactivation lent insight into the chemical mechanism of this inactivation. Proteomic analysis of E. coli lysates showed that cis-EpS selectively labeled plasmid-expressed Mtb ICL1. Consistently, cis-EpS, but not its trans-isomer, inhibited the growth of Mtb under conditions in which ICL function is essential. These findings encourage the development of analogs of cis-2,3-epoxysuccinate as antituberculosis agents.

Rp-HPLC Determination of Quercetin in a Novel D-α-Tocopherol Polyethylene Glycol 1000 Succinate Based SNEDDS Formulation: Pharmacokinetics in Rat Plasma

Despite its proven efficacy in diverse metabolic disorders, quercetin (QU) for clinical use is still limited because of its low bioavailability. D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) is approved as a safe pharmaceutical adjuvant with marked antioxidant and anti-inflammatory activities. In the current study, several QU-loaded self-nanoemulsifying drug delivery systems (SNEDDS) were investigated to improve QU bioavailability. A reversed phase high performance liquid chromatography (RP-HPLC) method was developed, for the first time, as a simple and sensitive technique for pharmacokinetic studies of QU in the presence of TPGS SNEDDS formula in rat plasma. The analyses were performed on a Xterra C₁₈ column (4.6 × 100 mm, 5 µm) and UV detection at 280 nm. The analytes were separated by a gradient system of methanol and phosphate buffer of pH 3. The developed RP-HPLC method showed low limit of detection (LODs) of 7.65 and 22.09 ng/mL and LOQs of 23.19 and 66.96 ng/mL for QU and TPGS, respectively, which allowed their determination in real rat plasma samples. The method was linear over a wide range, (30-10,000) and (100-10,000) ng/mL for QU and TPGS, respectively. The selected SNEDDS formula, containing 50% w/w TPGS, 30% polyethylene glycol 200 (PEG 200), and 20% w/w pumpkin seed oil (PSO), showed a globule size of 320 nm and -28.6 mV zeta potential. Results of the pharmacokinetic studies showed 149.8% improvement in bioavailability of QU in SNEDDS relative to its suspension. The developed HPLC method proved to be simple and sensitive for QU and TPGS simultaneous determination in rat plasma after oral administration of the new SNEDDS formula.

Phase I evaluation of the safety, tolerability, and pharmacokinetics of GSK3640254, a next-generation HIV-1 maturation inhibitor

Despite advances in HIV-1 management with antiretroviral therapy, drug resistance and toxicities with multidrug regimens can result in treatment failure. Hence, there is a continuing demand for antiretroviral agents (ARVs) with novel mechanisms of action. Maturation inhibitors inhibit HIV-1 replication via a unique mechanism of action and can be combined with other ARVs. Two phase I randomized clinical trials were conducted for a maturation inhibitor, GSK3640254, to determine safety, pharmacokinetics (NCT03231943), and relative bioavailability (NCT03575962) in healthy adults. The first trial was conducted in two parts. Part 1 was conducted in a two-cohort, interlocking, eight-period fashion in 20 participants with single ascending doses of GSK3640254 (1-700 mg) or placebo. In Part 2, 58 participants were randomized to receive GSK3640254 (n = 44) or placebo (n = 14). Four participants reported adverse events (AEs) leading to study discontinuation, with one adverse drug reaction (maculopapular rash). There was no relationship between frequency or severity of AEs and dose. Pharmacokinetic assessments showed that GSK3640254 was slowly absorbed, with time to maximum concentration (tmax) occurring between 3.5 and 4 hours and half-life of ~24 hours. In the relative bioavailability study of GSK3640254 mesylate salt vs bis-hydrochloride salt capsules in 14 healthy adults, the mesylate salt performed slightly better than the bis-hydrochloride formulation (12%-16% increase in area under the concentration-time curve and maximum concentration); tmax (5 hours) was similar between the formulations. Initial pharmacokinetic and safety data from these healthy-participant studies informed further development of GSK3640254 for once-daily dosing for the treatment of HIV-1 infection.

Comparison of Maceration and Ultrasonication for Green Extraction of Phenolic Acids from Echinacea purpurea Aerial Parts

Echinacea purpurea is used in herbal medicinal products for the prevention and treatment of the common cold, as well as for skin disorders and minor wounds. In this study, the efficiency of traditional maceration using water and ethanol was compared with the maceration using mixtures of water and glycerol, a non-toxic, biodegradable solvent from renewable sources. It was found that the glycerol-water mixtures were as effective as ethanol/water mixtures for the extraction of caffeic acid derivatives. All the prepared extracts demonstrated notable antiradical properties. Furthermore, an efficient ultrasound-assisted extraction using glycerol-water mixtures was developed using six independent variables. Their levels needed for the maximum extraction of caffeic acid derivatives were as follows: glycerol 90% (m/m), temperature 70 °C, ultrasound power 72 W, time 40 min, and ascorbic acid 0 mg/mL. Under the optimized conditions, ultrasound-assisted extraction was superior to maceration. It achieved significantly higher yields of phenolic acids in shorter extraction time. The presence of zinc in plant material may contribute to the beneficial effects of E. purpurea preparations. Since glycerol is a non-toxic solvent with humectant properties, the prepared extracts can be directly used for the preparation of cosmetics or oral pharmaceutical formulations without the need for solvent removal.

Coupled Electrochemical and Microbial Catalysis for the Production of Polymer Bricks

Power-to-X technologies have the potential to pave the way towards a future resource-secure bioeconomy as they enable the exploitation of renewable resources and CO2 . Herein, the coupled electrocatalytic and microbial catalysis of the C5 -polymer precursors mesaconate and 2S-methylsuccinate from CO2 and electric energy by in situ coupling electrochemical and microbial catalysis at 1 L-scale was developed. In the first phase, 6.1±2.5 mm formate was produced by electrochemical CO2 reduction. In the second phase, formate served as the substrate for microbial catalysis by an engineered strain of Methylobacterium extorquens AM-1 producing 7±2 μm and 10±5 μm of mesaconate and 2S-methylsuccinate, respectively. The proof of concept showed an overall conversion efficiency of 0.2 % being 0.4 % of the theoretical maximum.

Anticancer activity of functional polysuccinates with N-acetyl-cysteine in side chains

The synthesis and characteristics of functional polyesters with a potential anticancer activity have been described, followed by a post-modification process of biologically active polymers. First, biodegradable functional polysuccinates possessing pendant allyl groups, that are susceptible to thiol-ene reaction, were obtained by polyaddition of succinic anhydride and allyl glycidyl ether. The functionality of such polyesters was regulated by replacing a part of unsaturated glycidyl ether with saturated ones. Polymers containing 20-100% mers with allyl groups were reacted with N-acetyl-cysteine (NAC). The use of simple click reaction allowed obtaining polyesters containing different amounts of N-acetyl-cysteine in side chains. The thus obtained polymers with a molecular weight of several thousand are characterized by solubility in methanol as opposed to their initial precursors. Modified polyesters show no toxicity to normal human keratinocytes (HaCaT) cells, similar to the NAC in normal human fibroblasts (NHDF), whereas the anticancer activities were observed against squamous carcinoma (SCC-25), and melanoma (Me45) cells. A standard colorimetric assay (MTS), to assessing cells viability and cytotoxicity of tested compounds, was performed against NHDF for NAC, HaCaT, SCC-25, and Me45 cells, within 24-144 h long-term expositions. Neither contact with NAC alone, and tested materials, nor long incubation decreased normal cell viability or induced inflammation. That reassumed the potential of anticancer activities of tested materials, with the tendency to visible selectivity against cancer cell lines in vitro, confirmed with live microscopic imaging against the Me45 cell line.

Phosphate Derivatives of 3-Carboxyacylbetulin: SynThesis, In Vitro Anti-HIV and Molecular Docking Study

Lupane-type pentacyclic triterpenes such as betulin and betulinic acid play an important role in the search for new therapies that would be effective in controlling viral infections. The aim of this study was the synthesis and evaluation of in vitro anti-HIV-1 activity for phosphate derivatives of 3-carboxyacylbetulin 3-5 as well as an in silico study of new compounds as potential ligands of the C-terminal domain of the HIV-1 capsid-spacer peptide 1 (CA-CTD-SP1) as a molecular target of HIV-1 maturation inhibitors. In vitro studies showed that 28-diethoxyphosphoryl-3-O-(3',3'-dimethylsuccinyl)betulin (compound 3), the phosphate analog of bevirimat (betulinic acid derivative, HIV-1 maturation inhibitor), has IC50 (half maximal inhibitory concentration) equal to 0.02 μM. Compound 3 inhibits viral replication at a level comparable to bevirimat and is also more selective (selectivity indices = 1250 and 967, respectively). Molecular docking was used to examine the probable interaction between the phosphate derivatives of 3-carboxyacylbetulin and C-terminal domain (CTD) of the HIV-1 capsid (CA)-spacer peptide 1 (SP1) fragment of Gag protein, designated as CTD-SP1. Compared with interactions between bevirimat (BVM) and the protein, an increased number of strong interactions between ligand 3 and the protein, generated by the phosphate group, were observed. These compounds might have the potential to also inhibit SARS-CoV2 proteins, in as far as the intrinsically imprecise docking scores suggest.

Comparative evaluation of itaconate and its derivatives reveals divergent inflammasome and type I interferon regulation in macrophages

Following activation, macrophages undergo extensive metabolic rewiring^1,2. Production of itaconate through the inducible enzyme IRG1 is a key hallmark of this process³. Itaconate inhibits succinate dehydrogenase^4,5, has electrophilic properties⁶ and is associated with a change in cytokine production⁴. Here, we compare the metabolic, electrophilic and immunologic profiles of macrophages treated with unmodified itaconate and a panel of commonly used itaconate derivatives to examine its role. Using wild-type and Irg1^-/- macrophages, we show that neither dimethyl itaconate, 4-octyl itaconate nor 4-monoethyl itaconate are converted to intracellular itaconate, while exogenous itaconic acid readily enters macrophages. We find that only dimethyl itaconate and 4-octyl itaconate induce a strong electrophilic stress response, in contrast to itaconate and 4-monoethyl itaconate. This correlates with their immunosuppressive phenotype: dimethyl itaconate and 4-octyl itaconate inhibited IκBζ and pro-interleukin (IL)-1β induction, as well as IL-6, IL-10 and interferon-β secretion, in an NRF2-independent manner. In contrast, itaconate treatment suppressed IL-1β secretion but not pro-IL-1β levels and, surprisingly, strongly enhanced lipopolysaccharide-induced interferon-β secretion. Consistently, Irg1^-/- macrophages produced lower levels of interferon and reduced transcriptional activation of this pathway. Our work establishes itaconate as an immunoregulatory, rather than strictly immunosuppressive, metabolite and highlights the importance of using unmodified itaconate in future studies.

Chemical Diversity of Bastard Balm (Melittis melisophyllum L.) as Affected by Plant Development

The phytochemical diversity of Melittis melissophyllum was investigated in terms of seasonal changes and age of plants including plant organs diversity. The content of phenolics, namely: coumarin; 3,4-dihydroxycoumarin; o-coumaric acid 2-O-glucoside; verbascoside; apiin; luteolin-7-O-glucoside; and o-coumaric; p-coumaric; chlorogenic; caffeic; ferulic; cichoric acids, was determined using HPLC-DAD. Among these, luteolin-7-O-glucoside, verbascoside, chlorogenic acid, and coumarin were the dominants. The highest content of flavonoids and phenolic acids was observed in 2-year-old plants, while coumarin in 4-year-old plants (272.06 mg 100 g-1 DW). When considering seasonal changes, the highest content of luteolin-7-O-glucoside was observed at the full flowering, whereas verbascoside and chlorogenic acid were observed at the seed-setting stage. Among plant organs, the content of coumarin and phenolic acids was the highest in leaves, whereas verbascoside and luteolin-7-O-glucoside were observed in flowers. The composition of essential oil was determined using GC-MS/GC-FID. In the essential oil from leaves, the dominant was 1-octen-3-ol, whilst from flowers, the dominant was α-pinene.

Reduction-sensitive poly(ethylene glycol)-polypeptide conjugate micelles for highly efficient intracellular delivery and enhanced antitumor efficacy of hydroxycamptothecin

The non-specific biodistribution of traditional chemotherapeutic drugs against tumors is the key factor that causes systemic toxicity and hinders their clinical application. In this study, a reduction-sensitive polymer conjugate micelle was manufactured to achieve tumor-specific targeting, reduce toxic side-effects and improve anti-tumor activity of a natural anti-cancer drug, hydroxycamptothecin (HCPT). Therefore, HCPT was conjugated with methoxy-poly(ethylene glycol)-poly(β-benzyl-L-aspartate) (mPEG-PBLA) by a disulfide bond or succinate bond for the first time to obtain the mPEG-PBLA-SS-HCPT (PPSH) and mPEG-PBLA-CC-HCPT (PPCH) that would form micelles after high-speed agitation and dialysis. The PPSH micelles showed an average particle size of 126.3 nm, a low polydispersity index of 0.209, and a negative surface charge of -21.1 mV zeta potential. Transmission electron microscopy showed the PPSH micelles to have spherical morphology. PPSH had a low critical micelle concentration of 1.29 μg ml^-1 with high dilution stability, storage stability and reproducibility. Moreover, the particle size of the PPSH micelles had no significant change after incubation with rat plasma for 72 h, probably resulting in high long circulation in the blood. The PPSH micelles showed significant reduction sensitivity to glutathione. Their sizes increased by 403.2 nm after 24 h post-incubation, and 87.6% drug release was achieved 48 h post-incubation with 40 mM glutathione solutions. The PPSH micelles showed stronger inhibition of HepG2 cells in vitro and growth of H-22 tumor in vivo than the PPCH and HCPT solutions after intravenous injection. The accumulation of PPSH micelles in the tumor tissue contributed to the high anti-tumor effect with little side-effect on the normal tissues. The reduction-sensitive PPSH micelles were a promising carrier of HCPT and other poorly soluble anti-cancer drugs.

Hypromellose acetate succinate based amorphous solid dispersions via hot melt extrusion: Effect of drug physicochemical properties

In this study, the impact of drug and hydroxypropyl methylcellulose acetate succinate (HPMCAS) grades physicochemical properties on extrusion process, dissolution and stability of the hot melt extruded amorphous solid dispersions (ASDs) of nifedipine and efavirenz was investigated. Incorporation of drugs affected the extrusion temperature required for solid dispersion preparation. Differential scanning calorimetry and powder X-ray diffraction studies confirmed the amorphous conversion of the drugs in the prepared formulations. The amorphous nature of ASDs was unchanged after 3 months of stability testing at 40 °C and 75% relative humidity. The dissolution efficiency of the ASDs was dependent on the log P of the drug. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and dose of the drug. The dissolution efficiency and dissolution rate of the ASDs were dependent on the log P of the drug and solubility and hydrophilicity of the polymer grade respectively. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and the dissolution dose of the drug.

Cichoric acid from witloof inhibit misfolding aggregation and fibrillation of hIAPP

The misfolding, aggregation and fibrillation of human islet amyloid polypeptide (hIAPP) has been acknowledged as a hallmark event in type-II diabetes. Hence, inhibiting the misfolding, aggregation and fibrillation of hIAPP have been accepted as a vital factor to treat the disease. Here cichoric acid was extracted from witloof to explore its inhibition effects on misfolding, aggregation and fibrillation of hIAPP. Thioflavin-T (ThT) fluorescence assay, dynamic light scattering (DLS) and atomic force microscopy (AFM) images showed that cichoric acid inhibited the aggregation and fibrillation of hIAPP in a dosage-dependent manner. Circular dichroism (CD) spectra showed that cichoric acid inhibited the misfolding of hIAPP from unfolded to β-sheet. Molecular docking and further experiments revealed interactions between hIAPP and cichoric acid. Cichoric acid could bind to K1 and R11 of hIAPP via electrostatic interaction. In addition, cichoric acid could form π-π stacking with hIAPP residues F15 and F23. These interactions inhibited the misfolding, aggregation and fibrillation of hIAPP. These results, together with cichoric acid's good cytocompatibility and significant protective effects in hIAPP lesioned cell models, not only showed that cichoric acid could be used to fight against amyloidosis, but also brought a new perspective for Chinese herbal medicine as natural compound's medical potential.

Molecular mechanism underlying the effects of temperature and pH on the size and surface charge of octenylsuccinated oat β-glucan aggregates

Environmental temperature and pH induced significant changes in the size and surface charge (ζ) of octenylsuccinated oat β-glucan aggregates. The underlying mechanisms were explored by using ¹H-NMR, fluorescence spectra, thermodynamic analysis, and SAXS. At pH 6.5, the size decreased with temperature while ζ continuously increased. With increasing pH at 293 K, parabolic and U-shaped trends were observed in the size and ζ, peaking at pH 8.5 and 6.5, respectively. At any tested pH, the size decreased with temperature. Overall, ζ significantly increased with temperature at each pH. As temperature increased, the compactness of hydrophobic-domains increased while the compactness of hydrophilic-domains decreased. In an acidic environment, both the compactness increased with decreasing pH, but in an alkaline environment, they decreased with pH. The compactness changes were co-driven by enthalpy and entropy and corresponded to changes in the hydrophobic interactions in hydrophobic-domains, hydrogen bonds in hydrophilic-domains and electrostatic repulsions among octenylsuccinate molecules.

Metabolite Profiling and Distribution of Militarine in Rats Using UPLC-Q-TOF-MS/MS

Militarine, a natural glucosyloxybenzyl 2-isobutylmalate, isolated from Bletilla striata, was reported with a prominent neuroprotective effect recently. The limited information on the metabolism of militarine impedes comprehension of its biological actions and pharmacology. This study aimed to investigate the metabolite profile and the distribution of militarine in vivo, which help to clarify the action mechanism further. A total of 71 metabolites (57 new metabolites) in rats were identified with a systematic method by ultra-high-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). The proposed metabolic pathways of militarine include hydrolyzation, oxidation, glycosylation, esterification, sulfation, glucuronidation and glycine conjugation. Militarine and its metabolites were distributed extensively in the treated rats. Notably, six metabolites of militarine were identified in cerebrospinal fluid (CSF), which were highly consistent with the metabolites after oral administration of gastrodin in rats. Among the metabolites in CSF, five of them were not reported before. It is the first systematic metabolic study of militarine in vivo, which is very helpful for better comprehension of the functions and the central nervous system (CNS) bioactivities of militarine. The findings will also provide an essential reference for the metabolism of other glucosylated benzyl esters of succinic, malic, tartaric and citric acids.

Preparation and Characterization of Octenyl Succinate β-Cyclodextrin and Vitamin E Inclusion Complex and Its Application in Emulsion

Vitamin E (VE) and β-cyclodextrin (β-CD) can form an inclusion complex; however, the inclusion rate is low because of the weak interaction between VE and β-CD. The results of a molecular docking study showed that the oxygen atom in the five-membered ring of octenyl succinic anhydride (OSA) formed a strong hydrogen bond interaction (1.89 Å) with the hydrogen atom in the hydroxyl group of C-6. Therefore, β-CD was modified using OSA to produce octenyl succinic-β-cyclodextrin (OCD). The inclusion complexes were then prepared using OCD with VE. The properties of the inclusion complex were investigated by Fourier-transform infrared spectroscopy (FT-IR), ¹³C CP/MAS NMR, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results demonstrated that VE had been embedded into the cavity of OCD. Furthermore, the emulsifying properties (particle size distribution, ζ-potential, and creaming index) of the OCD/VE inclusion-complex-stabilized emulsion were compared with that stabilized by β-CD, OCD, and an OCD/VE physical mixture. The results showed that the introduction of the OS group and VE could improve the physical stability of the emulsion. In addition, the OCD/VE inclusion complex showed the strongest ability to protect the oil in the emulsion from oxidation. OCD/VE inclusion complex was able to improve the physical and oxidative stability of the emulsion, which is of great significance to the food industry.

Comparative Activation Process of Pb, Cd and Tl Using Chelating Agents from Contaminated Red Soils

Adding chelating agents is a critical technique of heavy metal activation for enhancing phytoextraction through the formation of soluble metal complexes which will be more readily available for extraction. The preliminary, dynamic, equilibrium activation experiments and speciation analysis of Pb, Cd and Tl in contaminated red soils were used to select six chelates with relatively good activation performance from nine chelates, and the effects of dosage and pH on the heavy metals activation were studied systematically. Results showed that the activation of Pb, Cd and Tl by chelates reached equilibrium within 2 h, and the activation process showed three stages. Under neutral conditions, chelates had better activation performance on Pb- and Cd-contaminated soils. Except for S,S-ethylenediamine disuccinic acid (S,S-EDDS) and citric acid (CA), the maximum equilibrium activation effect (MEAE) of ethylenediaminetetraacetic acid (EDTA), N,N-bis (carboxymethyl) glutamic acid (GLDA), diethylenetriaminepentaacetic acid (DTPA) and aminotriacetic acid (NTA) was over 81%. The MEAE of Tl-contaminated soil was less than 15%. The decreasing order of the dosage of chelating agents corresponding to MEAE for three types of contaminated soils was Pb-, Cd- and Tl-contaminated soil, relating to the forms of heavy metals, the stability constants of metal–chelates and the activation of non-target elements Fe in red soil. Under acidic conditions, the activation efficiencies of chelates decreased to differing degrees in Pb- and Cd-contaminated soils, whereas the activation efficiencies of chelating agents in Tl-contaminated soils were slightly enhanced.

Effect of biodegradable chelators on induced phytoextraction of uranium- and cadmium- contaminated soil by Zebrina pendula Schnizl

This study investigated the effect of ethylenediamine-N,N'-disuccinic acid (EDDS), oxalic acid (OA), and citric acid (CA) on phytoextraction of U- and Cd-contaminated soil by Z. pendula. In this study, the biomass of tested plant inhibited significantly following treatment with the high concentration (7.5 mmol·kg-1) EDDS treatment. Maximum U and Cd concentration in the single plant was observed with the 5 mmol·kg-1 CA and 7.5 mmol·kg-1 EDDS treatment, respectively, whereas OA treatments had the lowest U and Cd uptake. The translocation factors of U and Cd reached the maximum in the 5 mmol·kg-1 EDDS. The maximum bioaccumulation of U and Cd in the single plants was 1032.14 µg and 816.87 µg following treatment with 5 mmol·kg-1 CA treatment, which was 6.60- and 1.72-fold of the control groups, respectively. Furthermore, the resultant rank order for available U and Cd content in the soil was CA > EDDS > OA (U) and EDDS > CA > OA (Cd). These results suggested that CA could greater improve the capacity of phytoextraction using Z. pendula in U- and Cd- contaminated soils.

Injectable hydrogel based on dialdehyde galactomannan and N-succinyl chitosan: a suitable platform for cell culture

Regenerative medicine proposes to regenerate or even replace human damaged tissues to return to normal functions. Hence, biomaterials have been used to provide appropriate environment for cell development. Among the groups of biodegradable biomaterials, hydrogels, which are characterized by three-dimensional and cross-linked networks of water-soluble polymers, have been highlighted as suitable matrices for such applications. An injectable hydrogel based on oxidized galactomannan (OxGM) from Delonix regia and N-succinyl chitosan (NSC) was developed and characterized according to its physicochemical and biocompatible properties. The hydrogel was formed by Schiff base (-CH = N-) cross-linking between aldehyde groups from OxGM and NH₂ groups from NSC, in few minutes (9.7 min) without any external stimulus. A hydrogel with macroporous structure, interconnected pores, and porosity of 69% was obtained. The biomaterial exhibited excellent injectability. No change in volume or integrity was observed in the hydrogel after its swelling in phosphate buffered saline (PBS) medium. This is an important property because when the hydrogel is injected into the site of interest and it fills the environment, it will not have additional space to occupy. Biocompatibility studies were conducted in vitro, which revealed the non-cytotoxic nature of the material and demonstrated the potential of the hydrogel based on dialdehyde galactomannan and N-succinyl chitosan for cell culture and soft tissue engineering.

Bio-based thermoplastic poly(butylene succinate-co-propylene succinate) copolyesters: effect of glycerol on thermal and mechanical properties

Poly(butylene succinate-co-propylene succinate) (PBSPS) was polymerized using succinic acid, 1,4-butanediol, 1,3-propanediol, and glycerol (GC). The PBSPS copolyester with a BS/PS ratio of 7/3 has a low melting point (Tm, 80 °C) and crystallization temperature (Tc, 20 °C) in addition to excellent thermal stability with a thermal degradation temperature (Td) above 300 °C. Isodimorphism was observed for 30-50 mol% PS, lowering Tm and Tc. The featured crystalline lattices (021) and (110) of PBS at 2θ = 21.5° and 22.5° gradually disappeared with PS content greater than 50 mol% and transformed into a PPS crystalline lattice at 2θ = 22.3°. Young's modulus decreased with increasing PS content due to crystallinity loss. Wide-angle X-ray diffraction demonstrated that the chain movement regularity was affected by the GC content, reducing the crystallinity. The PBSPS copolyesters were elastic with 0.001 mol% GC but became rigid with GC content greater than 0.01 mol%. The chain conformation was flexible for 0.001-0.01 mol% GC and exhibited an irregular steric architecture for 0.02-0.03 mol% GC due to more GC acting as nodes. Thus, the thermal and mechanical properties of the synthesized bio-based PBSPS copolyesters can be controlled by adjusting the GC content; therefore, such copolyesters are suitable for medical support, coating, and phase-change material applications.

New Phosphorus Analogs of Bevirimat: Synthesis, Evaluation of Anti-HIV-1 Activity and Molecular Docking Study

Since the beginning of the human immunodeficiency virus (HIV) epidemic, many groups of drugs characterized by diverse mechanisms of action have been developed, which can suppress HIV viremia. 3-O-(3′,3′-Dimethylsuccinyl) betulinic acid, known as bevirimat (BVM), was the first compound in the class of HIV maturation inhibitors. In the present work, phosphate and phosphonate derivatives of 3-carboxyacylbetulinic acid were synthesized and evaluated for anti-HIV-1 activity. In vitro studies showed that 30-diethylphosphonate analog of BVM (compound 14a) has comparable effects to BVM (half maximal inhibitory concentrations (IC₅₀) equal to 0.02 μM and 0.03 μM, respectively) and is also more selective (selectivity indices: 3450 and 967, respectively). To investigate the possible mechanism of antiviral effect of 14a, molecular docking was carried out on the C-terminal domain (CTD) of HIV-1 capsid (CA)–spacer peptide 1 (SP1) fragment of Gag protein, designated as CTD-SP1, which was described as a molecular target for maturation inhibitors. Compared with interactions between BVM and the protein, an increased number of strong interactions between ligand 14a and protein, generated by the phosphonate group, was observed.

Insights into Micellization of Octenylsuccinated Oat β-Glucan and Uptake and Controlled Release of β-Carotene by the Resultant Micelles

The core-shell structured micelles from octenylsuccinated oat β-glucan (OSβG) are able to solubilize β-carotene (βC). This study reveals molecular interactions governing the formation, stabilization, and βC uptake of OSβG micelles (OSβG-Ms) by means such as water contact angle, ¹H nuclear magnetic resonance, dynamic light scattering, and confocal laser scanning microscopy. The results indicated that the micellization of OSβG molecules is triggered by hydrophobic interactions between octenylsuccinate (OSA) moieties, while OSβG-Ms are stabilized via both hydrophobic interactions and hydrogen bonds. For their uptake of βC, βC molecules are first adsorbed onto OSβG-Ms by interacting with OSA moieties scattered on micelle surface. By further interacting with OSA moieties located in micelle shell, βC molecules travel across the shell and finally are trapped in the hydrophobic core. In simulated gastrointestinal fluids, βC is controlled released from OSβG-Ms as an integrated consequence of its diffusion as well as the swelling and erosion of OSβG-Ms. As a result, this study first uncovered the mechanism underlying the uptake of βC by OSβG-Ms, which will certainly facilitate the effective loading of hydrophobic ingredients by OSβG-Ms.

Photo-Fenton treatment of saccharin in a solar pilot compound parabolic collector: Use of olive mill wastewater as iron chelating agent, preliminary results

The aim of this work was to investigate the treatment of the artificial sweetener saccharin (SAC) in a solar compound parabolic collector pilot plant by means of the photo-Fenton process at pH 2.8. Olive mill wastewater (OMW) was used as iron chelating agent to avoid acidification of water at pH 2.8. For comparative purposes, Ethylenediamine-N, N-disuccinic acid (EDDS), a well-studied iron chelator, was also employed at circumneutral pH. Degradation products formed along treatment were identified by LC-QTOF-MS analysis. Their degradation was associated with toxicity removal, evaluated by monitoring changes in the bioluminescence of Vibrio fischeri bacteria. Results showed that conventional photo-Fenton at pH 2.8 could easily degrade SAC and its intermediates yielding k, apparent reaction rate constant, in the range of 0.64-0.82 L kJ^-1, as well as, eliminate effluent's chronic toxicity. Both OMW and EDDS formed iron-complexes able to catalyse H₂O₂ decomposition and generate HO. OMW yielded lower SAC oxidation rates (k = 0.05-0.1 L kJ^-1) than EDDS (k = 2.21-7.88 L kJ^-1) possibly due to its higher TOC contribution. However, the degradation rates were improved (k = 0.13 L kJ^-1) by increasing OMW dilution in the reactant mixture. All in all, encouraging results were obtained by using OMW as iron chelating agent, thus rendering this approach promising towards the increase of process sustainability.

Inactivation of E. coli and E. faecalis by solar photo-Fenton with EDDS complex at neutral pH in municipal wastewater effluents

Photo-Fenton is a solar disinfection technology widely demonstrated to be effective to inactivate microorganisms in water by the combined effect of photoactivated iron species and the direct action of solar photons. Nevertheless, the precipitation of iron as ferric hydroxide at basic pH is the main disadvantage of this process. Thus, challenge in photo-Fenton is looking for alternatives to iron salts. Polycarboxylic acids, such as Ethylendiamine-N',N'-disuccinic acid (EDDS), can form strong complex with Fe³⁺ and enhance the dissolution of iron in natural water through photochemical process. The aim of this study was to evaluate the disinfection effectiveness of solar photo-Fenton with and without EDDS in water. Several reagent concentrations were assessed, best bacterial (Escherichia coli and Enterococcus faecalis) inactivation was obtained with 0.1:0.2:0.3 mM (Fe³⁺:EDDS:H₂O₂) in isotonic water. The benefit of using EDDS complexes to increase the efficiency of kept dissolved iron in water at basic pH was proven. Solar disinfection and H₂O₂/solar with and without EDDS, and Fe³⁺:EDDS complexes were also investigated. Bacterial inactivation results in municipal wastewater effluents (MWWE) demonstrated that the competitive role of organic matter and inorganic compounds strongly affect the efficacy of Fe³⁺:EDDS at all concentrations tested, obtaining the fastest inactivation kinetics with H₂O₂/solar (0.3 mM).

Foaming Properties and Linear and Nonlinear Surface Dilatational Rheology of Sodium Caseinate, Tannin Acid, and Octenyl Succinate Starch Ternary Complex

In this paper, the foaming and surface properties of sodium caseinate (SC), sodium caseinate/tannin acid (SC/TA), sodium caseinate/octenyl succinate starch (SC/OSA-starch), and sodium caseinate/tannin acid/octenyl succinate starch (SC/TA/OSA-starch) complex systems are described. First, foaming properties of different samples were compared at pH 6.0. The interface adsorption and linear surface dilatational rheological of different samples were characterized in the linear viscoelastic region to explore the relationship between macroscopic foaming properties and surface properties. At equal protein concentrations, the foamability and foam stability of the SC/TA/OSA-starch complex was markedly higher than that of the SC/TA complex. Meanwhile, the surface properties of the SC/TA/OSA-starch complex were also superior to those of the SC/TA complex. Finally, to investigate the nonlinear surface dilatational rheological behavior of the air/water interface stabilized by complex systems, the large-amplitude oscillatory dilatational rheology and Lissajous plots were studied. For the SC/TA/OSA-starch complex, the OSA-starch increases the degree of strain softening in extension, suggesting that the surface structure may change from a surface gel to a mixed phase of SC/TA patches and OSA-starch domains. These findings indicate that the complex formed between polyphenols, proteins, and polysaccharides could be used as a good alternative to understand and, consequently, improve the surface and foaming properties in food matrices.

DL-Amino Acid Analysis Based on Labeling with Light and Heavy Isotopic Reagents Followed by UPLC-ESI-MS/MS

L-Pyroglutamic acid succinimidyl ester (L-PGA-OSu) and its isotopic variant (L-PGA[d₅]-OSu) were synthesized and used as the chiral labeling reagents for the enantioseparation of amino acids by reversed-phase UPLC-ESI-MS/MS. The enantiomers of amino acids were labeled with the reagents at 60 °C for 10 min in an alkaline medium. The resulting diastereomers were well separated by the reversed-phase chromatography using an ODS column, packed with small particles (1.7 μm) (Rs = 1.95-8.05). A highly sensitive detection at a low-fmol level (0.5-3.2 fmol) was obtained from the selected reaction monitoring (SRM) chromatograms. An isotope labeling strategy using light and heavy variants for the differential analysis of the DL-amino acids in different sample groups is also presented in this paper. The ratios of D/L-alanine in different yogurt products were successfully determined by the proposed method. The D/L ratios were almost comparable to those obtained from only using light reagent (i.e., L-PGA-OSu). Therefore, the proposed strategy seems to be useful for the differential analysis of DL-amino acids, not only in food products but also in biological samples.

Methods for Absolute Quantification of Human Plasma Free Amino Acids by High-Performance Liquid Chromatography/Electrospray Ionization Mass Spectrometry Using Precolumn Derivatization

Plasma free amino acid (PFAA) concentrations in humans are affected by various diseases. However, the variations caused are not dramatic, so a high accurate and precise method for analyzing PFAAs is required. The PFAA analysis protocol described in this chapter covers blood sampling, sample pretreatment, amino acid derivatization, and LC-MS analysis. Each procedure is important for accurate and precise quantification.In the protocol, a human blood sample is collected using an EDTA-2Na or 2K vacuum collection tube and then immediately cooled in water mixed with crushed ice. The sample is then centrifuged on cooling to allow a plasma sample to be removed. A stable-isotope-labeled internal standard solution is added to the plasma, and then the plasma is deproteinized with acetonitrile. The amino acids in the plasma are then derivatized using 3-aminopyridyl-N-hydroxysuccinimidyl carbamate (APDS) reagent which is designed for LC-MS analysis. The derivatized amino acids are separated by reverse-phase HPLC and detected by electrospray ionization mass spectrometry. Using this method, 21 amino acids in human plasma can be analyzed with a 12 min cycle. The accuracy and precision are both better than the required criteria given by the US Food and Drug Administration in guidance of Bioanalytical Method Validation.

The role of chelating agents and amino acids in preventing free radical formation in bleaching systems

The control of bleaching reaction is important in hair bleaching and laundry detergents to ensure quality of the final product. A better understanding of the reaction mechanisms is needed to minimize product failures. ³¹P NMR-spectroscopy-based spin trap technique was employed to detect and quantify the free radical species that were generated in different bleaching solutions. These solutions contained the key actives in an alkaline hair colorant/bleaching product, an ammonium salt and hydrogen peroxide at pH = 10. Generally, the main radical species detected in hair oxidative coloring or bleaching processes, were hydroperoxyl/superoxide radicals HO₂·/O₂^.-, amino radicals ·NH₂ and hydroxyl radicals ·OH. Their amounts showed a variation based on the chemical composition of the bleaching systems and the metal ion content. The generation of free radicals from reactions between transition metal ions, such as copper, and hydrogen peroxide at pH = 10 was evaluated. In the absence of chelating agents, the copper ions generated a significant level of hydroxyl radicals in a Fenton-like reaction with hydrogen peroxide at pH = 10. Besides that, an increase in copper ion content led to an increase of amino radical ·NH₂, whereas the concentration of superoxide radical O₂^·- decreased which was not yet well reported in the previous literature. The effect of chelating agents like ethylenediaminetetraacetic acid (EDTA), tetrasodium-iminodisuccinate (IDS), a mixture of basic amino acids and dicarboxylic acid on free radical formation was investigated in the presence of binary Cu²⁺-Ca²⁺ bleaching systems. As expected, in the binary Cu²⁺-Ca²⁺ ion system EDTA did not suppress hydroxyl radical formation effectively, but the mixture containing sodium succinate, lysine and arginine reduced hydroxyl radical formation, whereas IDS (nearly) completely inhibited hydroxyl radical formation. The results indicated that each bleaching solution has its characteristic performance and damage profile. Whereas the reactivity can be controlled by the usage of chelating agents.

Konjac glucomannan octenyl succinate (KGOS) as an emulsifier for lipophilic bioactive nutrient encapsulation

BACKGROUND

Konjac glucomannan octenyl succinate (KGOS) has excellent emulsification properties and can potentially be used in the food industry as an emulsifier, stabilizer and microcapsule wall material. In the present study, the in vitro digestion properties and emulsification capability and stability of KGOS were studied to evaluate the transport and encapsulation characteristics of KGOS with insoluble bioactive nutrients.

RESULTS

Confocal scanning laser microscopy (CSLM) suggested that oil droplets could be encapsulated by KGOS into regular spheres. In vitro digestion properties showed that KGOS is effective for colon-targeted transport. β-Carotene was selected as a representative lipophilic bioactive compound to evaluate the emulsification characteristics of KGOS. The loading capacity of the 0.4 mg mL^-1 KGOS solution for β-carotene was 3.26%, and transmission electron microscopy suggested that the self-aggregate particles of KGOS/β-carotene (KGOSC) were more uniform than KGOS. With a composition of 0.03% β-carotene, 0.3% KGOS and 10% medium-chain triglycerides, the emulsification yield of the KGOSC nanoemulsion was more than 95%. After 30 days of storage, the particle size and polydispersity index of the KGOSC nanoemulsion were less than 5 nm and 0.5, respectively, and the sensitivity of KGOSC nanoemulsions to storage conditions decreased in the order temperature, oxygen and light.

CONCLUSION

The results of this study suggested that KGOS is a good potential emulsifier and stabilizer for lipophilic bioactive nutrient encapsulation. © 2018 Society of Chemical Industry.

NIPAM-based Microgel Microenvironment Regulates the Therapeutic Function of Cardiac Stromal Cells

To tune the chemical, physical, and mechanical microenvironment for cardiac stromal cells to treat acute myocardial infarction (MI), we prepared a series of thermally responsive microgels with different surface charges (positive, negative, and neutral) and different degrees of hydrophilicity, as well as functional groups (carboxyl, hydroxyl, amino, and methyl). These microgels were used as injectable hydrogels to create an optimized microenvironment for cardiac stromal cells (CSCs). Our results indicated that a hydrophilic and negatively charged microenvironment created from poly( N-isopropylacrylamide- co-itaconic acid) was favorable for maintaining high viability of CSCs, promoting CSC proliferation and facilitating the formation of CSC spheroids. A large number of growth factors, such as vascular endothelial growth factor (VEGF), insulin-like growth factor I (IGF-1), and stromal-derived factor-1 (SDF-1) were released from the spheroids, promoting neonatal rat cardiomyocyte activation and survival. After injecting the poly( N-isopropylacrylamide- co-itaconic acid) microgel into mice, we examined their acute inflammation and T-cell immune reactions. The microgel itself did not elicit obvious immune response. We then injected the same microgel-encapsulated with CSCs into MI mice. The result revealed the treatment-promoted MI heart repair through angiogenesis and inhibition of apoptosis with an improved cell retention rate. This study will open a door for tailoring poly( N-isopropylacrylamide)-based microgel as a delivery vehicle for CSC therapy.

Preservation of Cichoric Acid Antioxidant Properties Loaded in Heat Treated Lactoferrin Nanoparticles

In the current research, a new cichoric acid (CA) encapsulation system was investigated. The optimal condition for the formation of lactoferrin-cichoric acid nanoparticles (LF-CA NPs) was determined by controlling the solution pH, the thermal treatment conditions, and the concentration of CA. Fluorescence indicated that the electrostatic force and the hydrophobic force were the main forces in the formation of LF-CA NPs. LF-CA NPs prepared under different conditions were spherical in shape with smaller particle sizes and good zeta potential demonstrating good colloidal stability. Especially, the prepared particle size of the LF-CA NPs at pH 7 and 95 °C was about 67.20 ± 1.86 nm. The circular dichroism (CD) and the Fourier transform infrared spectroscopy (FTIR) results showed that the combination of LF (lactoferrin) and CA affected the secondary structure of the LF. The differential scanning calorimetry (DSC) results indicated that the addition of CA increased the thermal stability of LF. In vitro antioxidant experiments confirmed the antioxidant capacity of LF-CA NPs was better than CA. CA was successfully encapsulated into LF NPs with high encapsulated efficiency (97.87⁻99.87%) by high performance liquid chromatography (HPLC). These results showed that LF could be used as the wall material of CA with excellent nature.

Ethylenediamine disuccinic acid enhanced phytoextraction of nickel from contaminated soils using Coronopus didymus (L.) Sm

In a screenhouse, the applicability of biodegradable chelant ethylenediamine disuccinic acid (EDDS) to enhance Ni-phytoextraction by Coronopus didymus was tested for the first time. This study assayed the hypothesis based upon the role of EDDS on physiological and biochemical alterations and ameliorating phytoextraction capacity of C. didymus under nickel (Ni) stress. Pot experiments were conducted for 6 weeks and C. didymus plants were cultivated in soil artificially contaminated with 30, 50, and 70 mg kg^-1 Ni treatments. Soil was amended with EDDS (2 mmol kg^-1). Plants were harvested, 1 week after EDDS application. At 70 mg kg^-1 Ni level, EDDS application dramatically enhanced the root and shoot Ni concentration from 665 and 644 to 1339 and 1338 mg kg^-1, respectively. Combination of Ni + EDDS induced alterations in biochemical parameters of plants. EDDS addition posed pessimistic effects on growth, biomass, photosynthetic activity and protein content of the plants. Besides, application of EDDS stimulated the generation of superoxide anion, H₂O₂ content and MDA level. However, EDDS assisted mount in antioxidant activities (superoxide dismutase, catalase and glutathione peroxidase) considerably neutralised the toxicity induced by reactive oxygen species in plant tissues. The results revealed EDDS efficacy to ameliorate the performance of antioxidant enzymes and improved Ni translocation in plant tissues, thus strongly marked its affinity to be used together with C. didymus for Ni-phytoextraction.

Fabrication of an Effective Avermectin Nanoemulsion Using a Cleavable Succinic Ester Emulsifier

In this study, a new emulsifier precursor was prepared via esterification of avermectin with succinic anhydride. The chemical structure of the product was confirmed to be monosubstituted avermectin. After neutralization with triethanolamine, it exhibited adequate emulsification ability for avermectin. Avermectin was then encapsulated in nanoparticles in the nanoemulsion with a high drug loading up to 60 wt % and high stability. The nanoemulsion of nanoparticles that serves as a carrier of avermectin shows highly efficient pesticide characteristics, including low surface tension, high affinity to leaves, and improved photostability. In the presence of esterase or under strongly basic conditions, the ester bonds of the emulsifier can be hydrolyzed, and the encapsulated avermectin molecules can be released in an accelerated manner. The nanoemulsion exhibited improved insecticidal effect compared with commercial emulsifiable concentrate, which was attributed to the cleavage of ester bonds of the emulsifier by esterase in vivo.

The chemical biology and coordination chemistry of putrebactin, avaroferrin, bisucaberin, and alcaligin

Dihydroxamic acid macrocyclic siderophores comprise four members: putrebactin (putH₂), avaroferrin (avaH₂), bisucaberin (bisH₂), and alcaligin (alcH₂). This mini-review collates studies of the chemical biology and coordination chemistry of these macrocycles, with an emphasis on putH₂. These Fe(III)-binding macrocycles are produced by selected bacteria to acquire insoluble Fe(III) from the local environment. The macrocycles are optimally pre-configured for Fe(III) binding, as established from the X-ray crystal structure of dinuclear [Fe₂(alc)₃] at neutral pH. The dimeric macrocycles are biosynthetic products of two endo-hydroxamic acid ligands flanked by one amine group and one carboxylic acid group, which are assembled from 1,4-diaminobutane and/or 1,5-diaminopentane as initial substrates. The biosynthesis of alcH₂ includes an additional diamine C-hydroxylation step. Knowledge of putH₂ biosynthesis supported the use of precursor-directed biosynthesis to generate unsaturated putH₂ analogues by culturing Shewanella putrefaciens in medium supplemented with unsaturated diamine substrates. The X-ray crystal structures of putH₂, avaH₂ and alcH₂ show differences in the relative orientations of the amide and hydroxamic acid functional groups that could prescribe differences in solvation and other biological properties. Functional differences have been borne out in biological studies. Although evolved for Fe(III) acquisition, solution coordination complexes have been characterised between putH₂ and oxido-V(IV/V), Mo(VI), or Cr(V). Retrosynthetic analysis of 1:1 complexes of [Fe(put)]⁺, [Fe(ava)]⁺, and [Fe(bis)]⁺ that dominate at pH < 5 led to a forward metal-templated synthesis approach to generate the Fe(III)-loaded macrocycles, with apo-macrocycles furnished upon incubation with EDTA. This mini-review aims to capture the rich chemistry and chemical biology of these seemingly simple compounds.

Synthesis and Bioactivity of Polymer-Based Synthetic Mimics of Antimicrobial Peptides (SMAMPs) Made from Asymmetrically Disubstituted Itaconates

A series of asymmetrically disubstituted diitaconate monomers is presented. Starting from itaconic anhydride, functional groups could be placed selectively at the two nonequivalent carbonyl groups. By using 2D NMR spectroscopy, it was shown that the first functionalization step occurred at the carbonyl group in the β position to the double bond. These monomers were copolymerized with N,N-dimethylacrylamide (DMAA) to yield polymer-based synthetic mimics of antimicrobial peptides (SMAMPs). They were obtained by free radical polymerization, a metal-free process, and still maintained facial amphiphilicity at the repeat unit level. This eliminates the need for laborious metal removal and is advantageous from a regulatory and product safety perspective. The poly(diitaconate-co-DMAA) copolymers obtained were statistical to alternating, and the monomer feed ratio roughly matched that of the repeat unit content of the copolymers. Investigations of varied R group hydrophobicity, repeat unit ratio, and molecular mass on antimicrobial activity against Escherichia coli and on compatibility with human keratinocytes showed that the polymers with the longest R groups and lowest DMAA content were the most antimicrobial and hemolytic. This is in agreement with the biological activity of previously reported SMAMPs. Thus, the design concept of facial amphiphilicity has successfully been transferred, but the selectivity of these polymers for bacteria over mammalian cells still needs to be optimized.

Enhanced effect of EDDS and hydroxylamine on Fe(II)-catalyzed SPC system for trichloroethylene degradation

This study presents a performance comparison of Fe(II)-catalyzed sodium percarbonate (SPC), Fe(II)-EDDS-catalyzed SPC, and of the innovative hydroxylamine hydrochloride (HA)-Fe(II)-EDDS-catalyzed SPC for the degradation of trichloroethylene (TCE) in water. TCE degradation was greater in the Fe(II)-EDDS-catalyzed SPC system compared to the Fe(II)-catalyzed SPC system, indicating the effectiveness of adding EDDS as an enhancement factor for the removal of TCE. Moreover, TCE degradation was faster in the HA-Fe(II)-EDDS-catalyzed SPC system compared to the Fe(II)-EDDS-catalyzed SPC system, illustrating that HA can play a synergistic role in TCE degradation. Analysis of iron distribution in the three systems demonstrated that EDDS addition maintained iron in soluble form, and that the generation of soluble ferrous from ferric iron was expedited with addition of HA. Studies using nitrobenzene and carbon tetrachloride probes provided insights on the generation of hydroxyl radical (HO•) and superoxide anion radical (O2•-) in the three systems. A gradual increasing contribution of O2•- to TCE removal in Fe(II)-catalyzed SPC, Fe(II)-EDDS-catalyzed SPC, and HA-Fe(II)-EDDS-catalyzed SPC systems was verified through free-radical scavenger tests. Finally, monitoring of Cl- concentrations manifested the complete dechlorination of TCE. A possible mechanism of TCE degradation involving two pathways of HO• oxidation and O2•- reaction was proposed.

Joint Effects of Granule Size and Degree of Substitution on Octenylsuccinated Sweet Potato Starch Granules As Pickering Emulsion Stabilizers

The granules of sweet potato starch were size fractionated into three portions with significantly different median diameters ( D₅₀) of 6.67 (small-sized), 11.54 (medium-sized), and 16.96 μm (large-sized), respectively. Each portion was hydrophobized at the mass-based degrees of substitution (DS_m) of approximately 0.0095 (low), 0.0160 (medium), and 0.0230 (high). The Pickering emulsion-stabilizing capacities of modified granules were tested, and the resultant emulsions were characterized. The joint effects of granule size and DS_m on emulsifying capacity (EC) were investigated by response surface methodology. For small-, medium-, and large-sized fractions, their highest emulsifying capacities are comparable but, respectively, encountered at high (0.0225), medium (0.0158), and low (0.0095) DS_m levels. The emulsion droplet size increased with granule size, and the number of freely scattered granules in emulsions decreased with DS_m. In addition, the term of surface density of the octenyl succinic group (SD_-OSG) was first proposed for modified starch granules, and it was proved better than DS_m in interpreting the emulsifying capacities of starch granules with varying sizes. The present results implied that, as the particulate stabilizers, the optimal DS_m of modified starch granules is size specific.

Self-controlled release of Oxaliplatin prodrug from d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) functionalized mesoporous silica nanoparticles for cancer therapy

Oxaliplatin is a promising antitumor drug, but its effectiveness is limited by its side effects in vivo. In this study, we introduced an Oxaliplatin prodrug (Oxa(IV)) self-controlled release strategy, in which Oxa(IV) is encapsulated by TPGS functionalized mesoporous silica nanoparticles (MSNs), and its release is controlled by biological stimuli, such as acidic environments in tumor tissue and high concentrations of reductants in cancer cells. Despite the lack of auxiliary "gatekeepers" to MSNs, this simplified model of Oxa(IV)-MSNs-TPGS could fine-tune the movements of the drug release. Furthermore, we utilized a prodrug approach to avoid the side effects of Oxaliplatin, and we used TPGS groups to reduce multidrug resistance (MDR). Finally, the toxicity of Oxa(IV)-MSNs-TPGS to a human lung adenocarcinoma cell line (A549) in vitro was significantly lower than that of Oxaliplatin. This model demonstrates the considerable potential of a simple self-controlled release system with multiple functions.

Increase in insulin sensitivity by the association of chicoric acid and chlorogenic acid contained in a natural chicoric acid extract (NCRAE) of chicory (Cichorium intybus L.) for an antidiabetic effect

ETHNOPHARMACOLOGICAL RELEVANCE

Chicory (Cichorium intybus L.) is an indigenous vegetable widely cultivated in Europe, America and Asia. In ancient times, the leaves, flowers, seeds, and roots have been used as a wealth of health benefits including its tonic effects, the ability to ease digestive problems and to detoxify liver. In Indian traditional therapy, chicory was known to possess antidiabetic effect. In the traditional medicine of Bulgaria and Italy, chicory was used as hypoglycemic decoctions.

AIMS OF THE STUDIES

We wanted to obtain the complete chemical composition of the natural chicoric acid extract (NCRAE), a chicory root extract rich in chicoric acid, which previously showed its glucose tolerance effect in normal rats. To investigate if the whole NCRAE is required to be effective, we performed a comparative in vivo experiment on STZ diabetic rats treated either with NCRAE or a mixture composed of the two major compounds of NCRAE.

MATERIALS AND METHODS

LC-MS method has been used to analyze the exhaustive composition of NCRAE: we have determined that chicoric acid and chlorogenic acid represented 83.8% of NCRAE. So, we have prepared a solution mixture of chicoric acid and chlorogenic acid named SCCAM, in order to compare in vivo the antidiabetic effects of this last and NCRAE in streptozotocin diabetic rats. In vitro experiments were performed on L6 cell line both for glucose uptake and for the protective effect against H2O2 oxidative stress. Also, we have evaluated DPPH and ORAC (Oxygen Radical Absorbance Capacity) antioxidative capacities of the two compositions.

RESULTS

The LC-MS analysis confirmed the high abundance of chicoric acid (64.2%) in NCRAE and a second part of NCRAE is composed of caffeoylquinic acids (CQAs) at 19.6% with among them the chlorogenic acid. This result has permitted us to prepare a mixture of synthetic L-chicoric acid (70%) and synthetic chlorogenic acid (30%): the solution is designated SCCAM. Our results showed that both NCRAE and SCCAM are able to improve a glucose tolerance in STZ diabetic rats after a subchronic administration of seven days. Alone NCRAE allows to significantly decrease the basal hyperglycemia after six days of treatment. To explain these difference of effects between NCRAE and SCCAM, we have compared their in vitro effects on the L6 muscle cell line both for the insulin sensitizing effect and for their protective action in pretreatment against H2O2. We have also compared their antioxidant capacities. In conclusion, we demonstrated that NCRAE, a natural extract of chicory (Cichorium intybus) rich in CRA and CQAs improves glucose tolerance and reduces the basal hyperglycemia in STZ diabetic rats.