Effects of surfactant micelles on solubilization and DPPH radical scavenging activity of Rutin

Design, Synthesis and Biological Activity of Novel Methoxy- and Hydroxy-Substituted N-Benzimidazole-Derived Carboxamides

This work presents the design, synthesis and biological activity of novel N-substituted benzimidazole carboxamides bearing either a variable number of methoxy and/or hydroxy groups. The targeted carboxamides were designed to investigate the influence of the number of methoxy and/or hydroxy groups, the type of substituent placed on the N atom of the benzimidazole core and the type of substituent placed on the benzimidazole core on biological activity. The most promising derivatives with pronounced antiproliferative activity proved to be N-methyl-substituted derivatives with hydroxyl and methoxy groups at the phenyl ring and cyano groups on the benzimidazole nuclei with selective activity against the MCF-7 cell line (IC50 = 3.1 μM). In addition, the cyano-substituted derivatives 10 and 11 showed strong antiproliferative activity against the tested cells (IC50 = 1.2-5.3 μM). Several tested compounds showed significantly improved antioxidative activity in all three methods compared to standard BHT. In addition, the antioxidative activity of 9, 10, 32 and 36 in the cells generally confirmed their antioxidant ability demonstrated in vitro. However, their antiproliferative activity was not related to their ability to inhibit oxidative stress nor to their ability to induce it. Compound 8 with two hydroxy and one methoxy group on the phenyl ring showed the strongest antibacterial activity against the Gram-positive strain E. faecalis (MIC = 8 μM).

Unveiling the flavone-solubilizing effects of α-glucosyl rutin and hesperidin: probing structural differences through NMR and SAXS analyses

Flavonoids often exhibit broad bioactivity but low solubility and bioavailability, limiting their practical applications. The transglycosylated materials α-glucosyl rutin (Rutin-G) and α-glucosyl hesperidin (Hsp-G) are known to enhance the dissolution of hydrophobic compounds, such as flavonoids and other polyphenols. In this study, the effects of these materials on flavone solubilization were investigated by probing their interactions with flavone in aqueous solutions. Rutin-G and Hsp-G prepared via solvent evaporation and spray-drying methods were evaluated for their ability to dissolve flavones. Rutin-G had a stronger flavone-solubilizing effect than Hsp-G in both types of composite particles. The origin of this difference in behavior was elucidated by small-angle X-ray scattering (SAXS) and nuclear magnetic resonance analyses. The different self-association structures of Rutin-G and Hsp-G were supported by SAXS analysis, which proved that Rutin-G formed polydisperse aggregates, whereas Hsp-G formed core-shell micelles. The observation of nuclear Overhauser effects (NOEs) between flavone and α-glucosyl materials suggested the existence of intermolecular hydrophobic interactions. However, flavone interacted with different regions of Rutin-G and Hsp-G. In particular, NOE correlations were observed between the protons of flavone and the α-glucosyl protons of Rutin-G. The different molecular association states of Rutin-G or Hsp-G could be responsible for their different effects on the solubility of flavone. A better understanding of the mechanism of flavone solubility enhancement via association with α-glucosyl materials would permit the application of α-glucosyl materials to the solubilization of other hydrophobic compounds including polyphenols such as flavonoids.

Phytoferritin functions in two interface-loading of natural pigment betanin and caffeic acid with enhanced color stability and the sustained release of betanin

Betanin, a natural red pigment, is sensitive and prone to fading and discoloration, affecting its stability and bioavailability. Phytoferritin is a nano-diameter protein with unique interior-/exterior-interfaces. By the unique interfaces and pH-induced self-assembly of ferritin, a ferritin-betanin complex (FB) with an encapsulation efficiency of 17.66 ± 1.24% was prepared. The caffeic acid-FB (CFB) was further fabricated by attaching ferritin with caffeic acid, and the binding number n of caffeic acid was 88.47 ± 9.49, with a binding constant K of (1.63 ± 0.33) × 104 M-1. Fluorescence and Fourier transform infrared analysis indicated that the encapsulation of betanin and the binding of caffeic acid influenced the ferritin structure. The interaction between caffeic acid and ferritin was mainly through van der Waals forces and hydrogen bonds. TEM and DLS showed that the globular structure and diameter (12 nm) remained in CFB. Furthermore, the ferritin and caffeic acid exhibited a synergistic effect in enhancing thermal, light, and ferric ion stabilities, and controlled the betanin release in a more sustained manner in the simulated gastrointestinal tract. In addition, the antioxidant capacity of CFB was enhanced compared with free betanin. This study promotes the bioavailability of betanin by two interface-loading of ferritin, and guides the use of ferritin nanoparticles as a nanocarrier for pigment stabilization.

The Impact of Flavonoid-Loaded Nanoparticles in the UV Protection and Safety Profile of Topical Sunscreens

Excessive UV radiation exposure is harmful to skin cells since sunburn is accompanied by oxidative burst, leading to a rapid increase in skin cancer. However, the insufficient UV photoprotection of approved sunscreens and the negative impact of their compositions on ecosystems and human health makes the utility of sunscreen a questionable recommendation. Therefore, discovering UV filters with significant antioxidant activity and improved topical performance and photostability is an urgent need. Recently, the use of nanosized natural molecules incorporated in sunscreens has been a scientific hot topic, as it has been suggested that they provide a synergistic effect with synthetic UV filters, improving overall SPF and antioxidant activity, higher retention on the epidermis, and less toxicity. The aim of this review was to verify the usefulness of sunscreens incorporating flavonoid-loaded nanoparticles. A literature review was performed, where original and review articles published in the last 6 years were analyzed. Formulations containing nanosized flavonoids with improved UVA photoprotection and safer toxicological profiles, associated or not with synthetic filters, are promising sunscreens and more clinical investigation must be performed to validate these findings.

Chitosan binding to a novel alfalfa phytoferritin nanocage loaded with baicalein: Simulated digestion and absorption evaluation

Phytoferritin was explored as an attractive nanocarrier to encapsulate bioactive compounds due to its excellent stability and biocompatibility. In the present study, a novel phytoferritin derived from alfalfa (Medicago sativa) was successfully expressed, purified and characterized. Results confirmed that alfalfa ferritin, self-assembled by 24 subunits, formed a spherical hollow structure. Baicalein exhibits superior antioxidant properties and nutritious values, but low bioavailability and solubility limit its application. Herein, we fabricated water-soluble chitosan-ferritin-baicalein nanoparticles to overcome its drawbacks. It was calculated that one apoferritin cage could encapsulate 52 molecules of baicalein. Moreover, chitosan-ferritin-baicalein nanoparticles prolonged the release of baicalein in simulated gastrointestinal tract digestion. Caco-2 cell monolayer absorption analysis demonstrated that baicalein encapsulated within ferritin-chitosan double layers was more efficient in cellular transportation. These results indicated that alfalfa ferritin, as a novel cage-like protein, has potential application in improving the bioavailability of insoluble bioactive molecules.

Supramolecular Vector/Drug Coassemblies of Polyglycerol Dendrons and Rutin Enhance the pH Response

A coassembly strategy for a supramolecular vector/drug was proposed with a biocompatible ternary dodecyl-bi(third-generation polyglycerol (PG) dendrons) (C₁₂-(G3)₂) amphiphile, dodecyl sulfobetaine (SB3-12) surfactant, and poorly water-soluble drug rutin. C₁₂-(G3)₂ and rutin will mutually enhance their pH response by protonation and deprotonation of dendritic PG and rutin's ionization as the pH changes from the acidic gastric lumen to the weakly alkaline intestine. SB3-12 may increase the payload and bring about sustained release for rutin by intermolecular interactions. Self-assembling behaviors of C₁₂-(G3)₂, SB3-12, sodium dodecyl sulfate (SDS), and dodecyl trimethylammonium bromide (DTAB) and their hybrids with rutin were characterized by UV-vis spectroscopy, a fluorescence probe, and ¹H NMR. UV-vis and ¹H NMR were used to identify the position and orientation of rutin in the vectors. The functions of the vector/drug were confirmed by measuring the solubility and in vitro release of rutin. The ternary coassembling vector/drug easily imparted functions of pH-responsive and sustained release without complex synthetic processes. The nanocaves framed by PG dendrons in the micelles provide pH-responsive compartments for rutin and SB3-12 in the supramolecular vector/drug anchors that accommodate rutin by weak interactions. The finely matched supramolecular vector/drug coassemblies exhibit the pH-responsive function for a potential application in the treatment of inflammatory bowel disease.

l-Arginine Improves Solubility and ANTI SARS-CoV-2 Mpro Activity of Rutin but Not the Antiviral Activity in Cells

The COVID-19 pandemic outbreak prompts an urgent need for efficient therapeutics, and repurposing of known drugs has been extensively used in an attempt to get to anti-SARS-CoV-2 agents in the shortest possible time. The glycoside rutin shows manifold pharmacological activities and, despite its use being limited by its poor solubility in water, it is the active principle of many pharmaceutical preparations. We herein report our in silico and experimental investigations of rutin as a SARS-CoV-2 Mpro inhibitor and of its water solubility improvement obtained by mixing it with l-arginine. Tests of the rutin/l-arginine mixture in a cellular model of SARS-CoV-2 infection highlighted that the mixture still suffers from unfavorable pharmacokinetic properties, but nonetheless, the results of this study suggest that rutin might be a good starting point for hit optimization.

Advances in micro interfacial phenomena of adsorptive micellar flocculation: Principles and application for water treatment

Among various aqua remediation technologies, separation aims at cleaning pollutants by isolating them despite their destruction; solutes can also be recovered after the process. Adsorptive micellar flocculation (AMF) has been known as an important surfactant-based technique to separate poorly water-soluble hazardous pollutants from aqua media as an efficient and energy-intensive replacement for other surfactant-based techniques, as such AMF should be known. AMF is based on the partitioning of solutes gradient from bulk solution into the nanosized smart anionic surfactant micelle followed by flocculation. However, unlike coagulation/flocculation or adsorption, AMF is not viable for the production of drinking water in water utilities due to the loss of surfactant monomers. Unfortunately, it can be used as a reservoir or for the recycling/recovery of organic pollutants (intermediates) (ions, organics/bioactive, dyes, etc.), even at high concentrations. The performance of AMF depends on various parameters, and this review briefly summarizes the existing researches on different pollutants removal by AMF and material recovery/recycling. This includes operating condition factors (surfactants, flocculants, surfactant-flocculant or surfactant-pollutant concentration ratio, and water conditions chemistry). Because varieties of micro interfacial phenomena other than physical interactions occur in a versatile micellar environment in the AMF process, emphases are given to adsorptive oxidation, micellar catalysis, selectivity. Furthermore, for the first time, this review gives an overview of understanding the state-of-the-art multifunctional nano amphiphile-based AMF that behaves mimetic to aquatic organisms in the process of pollutant removal. The efficiency of AMF, including recycling concentrated solution without noticeable deterioration, as an auxiliary resource/income for the next cycle, signifies economic viability, versatility, and manifold applications in aqua remediation. Significance, ways to achieve enhanced process efficiency, as well as challenges and future opportunities in wastewater treatment, are also highlighted.

Antimicrobial and Antioxidative Activity of Newly Synthesized Peptides Absorbed into Bacterial Cellulose Carrier against Acne vulgaris

The ongoing search for effective treatment of Acne vulgaris is concentrated, i.a., on natural peptides with antimicrobial properties. The aim of this work was the development of new amino acid derivatives with potential activity on dermal infections against selected microorganisms, including the facultative anaerobe C. acne. The peptides P1–P6 were synthesized via Fmoc solid phase peptide synthesis using Rink amide AM resin, analyzed by RP-HPLC-MS, FTIR, DPPH radical scavenging activity, and evaluated against C. acne and S. aureus, both deposited and non-deposited in BC. Peptides P1–P6 presented a lack of cytotoxicity, antimicrobial activity, or antioxidative properties correlated with selected structural properties. P2 and P4–P6 sorption in BC resulted in variable data, i.a., confirming the prospective topical application of these peptides in a BC carrier.

Encapsulation of phenolic compounds within nano/microemulsion systems: A review

Phenolic compounds (phenolics) have received great attention in the food, pharmaceutical and nutraceutical industries due to their health-promoting attributes. However, their extensive use is limited mainly due to their poor water dispersibility and instability under both processing conditions and/or gastrointestinal interactions, affecting their bioavailability/bioaccessibility. Therefore, different nanocarriers have been widely used to encapsulate phenolics and overcome the aforementioned challenges. To the best of our knowledge, besides many research studies, no comprehensive review on encapsulation of phenolics by microemulsions (MEs) and nanoemulsions (NEs) has been published so far. The present study was therefore attempted to review the loading of phenolics into MEs and NEs. In addition, the fundamental characteristics of the developed systems such as stability, encapsulation efficiency, cytotoxicity, bioavailability and releasing rate are also discussed. Both MEs and NEs are proved as appropriate vehicles to encapsulate and protect phenolics which may expand their applications in foods, supplements and pharmaceuticals.

Energy transduction through FRET in self-assembled soft nanostructures based on surfactants/polymers: current scenario and prospects

The self-assembled systems of surfactants/polymers, which are capable of supporting energy funneling between fluorophores, have recently gained significant attraction. Surfactant and polymeric micelles form nanoscale structures spanning a radius of 2-10 nm are generally suitable for the transduction of energy among fluorophores. These systems have shown great potential in Förster resonance energy transfer (FRET) due to their unique characteristics of being aqueous based, tendency to remain self-assembled, spontaneous formation, tunable nature, and responsiveness to different external stimuli. This review presents current developments in the field of energy transfer, particularly the multi-step FRET processes in the self-assembled nanostructures of surfactants/polymers. The part one of this review presents a background and brief overview of soft systems and discusses certain aspects of the self-assemblies of surfactants/polymers and their co-solubilization property to bring fluorophores to close proximity to transduce energy. The second part of this review deals with single-step and multi-step FRET in the self-assemblies of surfactants/polymers and links FRET systems with advanced smart technologies including multicolor formation, data encryption, and artificial antenna systems. This review also discusses the diverse examples in the literature to present the emerging applications of FRET. Finally, the prospects regarding further improvement of FRET in self-assembled soft systems are outlined.

Physico-Chemical and Pharmaco-Technical Characterization of Inclusion Complexes Formed by Rutoside with β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin Used to Develop Solid Dosage Forms

The aim of our study was to obtain rutoside (RUT) inclusion complexes in β-cyclodextrin (β-CD) and in hydroxypropyl-β-cyclodextrin (HP-β-CD), in a 1:1 molar ratio, using the lyophilization method of complexation in solution. The complexes were confirmed and characterized, in comparison with the raw materials and their simple physical mixtures, by SEM, DSC, and FT-IR analyses. The antioxidant activity of the compounds was assessed by using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2’-azino-bis(3-ethylbenzothiazolin-6-sulfonic) acid (ABTS) radicals, determining the radical scavenging activity, and by ferric reducing antioxidant power (FRAP) assay. The results revealed superior antioxidant ability for the inclusion complexes towards rutoside alone. The inclusion complexes were used as active ingredients in formulations of immediate-release tablets. The preformulation studies were performed on the powders for direct compression obtained after mixing the active ingredients with the excipients (Avicel PH 102, Polyplasdone XL-10, magnesium stearate, and talc). The materials were assessed for particle size, flowability, compressibility, and moisture content, establishing they are suitable for a direct compression process. The tablets were characterized regarding their pharmaco-technical properties and the results proved that the formulations lead to high-quality delivery systems, showing a good mechanical resistance with a low friability, excellent disintegration times, and satisfying dissolution rate. The performances were very similar for both formulations and the physico-mechanical properties of the tablets are not influenced by type of the used cyclodextrin, but the RUT- HP-β-CD tablets presented a higher dissolution rate.

Using coarse-grained molecular dynamics to rationalize biomolecule solubilization mechanisms in ionic liquid-based colloidal systems

Solubilizing agents are widely used to extract poorly soluble compounds from biological matrices. Aqueous solutions of surfactants and hydrotropes are commonly used as solubilizers, however, the underlying mechanism that determines their action is still roughly understood. Among these, ionic liquids (IL) are often used not only for solubilization of a target compound but in liquid-liquid extraction processes. Molecular dynamics simulations can shed light into this issue by providing a microscopic insight of the interactions between solute and solubilising agents. In this work, a new coarse-grained (CG) model was developed under the MARTINI framework for gallic acid (GA) while the CG models of three quaternary ammonium ionic liquids and salts (QAILS) were obtained from literature. Three QAILS were selected bearing in mind their potential solubilising mechanisms: trimethyl-tetradecylammonium chloride ([N1,1,1,14]Cl) as a surfactant, tetrabutylammonium chloride ([N4,4,4,4]Cl) as a hydrotrope, and tributyl-tetradecylammonium chloride ([N4,4,4,14]Cl) as a system combining the characteristics of the other compounds. Throughout this hydrotrope-to-surfactant spectrum and considering the most prevalent GA species across the pH range, the solvation of GA at two concentration levels in aqueous QAILS solutions were studied and discussed. The results of this study indicate that dispersive interactions between the QAILS and GA are generally the driving force in the GA solubilization. However, electrostatic interactions play an increasingly significant role as the GA becomes deprotonated, affecting their placement within the micelle and ultimately the solvation mechanism. The hydrotropic mechanism seen in [N4,4,4,4]Cl corroborates recent models based on the formation of a hydrotrope-solute aggregates driven by dispersive forces. This work contributes to the application of a transferable approach to partition and solubilization studies using molecular dynamics, which could complement experimental assays and quickly screen molecular candidates for these processes.

Approach to Optimization of FRAP Methodology for Studies Based on Selected Monoterpenes

Terpenes, wide-spread secondary plant metabolites, constitute important parts of many natural compounds that hold various biological activities, including antioxidant, calming, antiviral, and analgesic activities. Due to their high volatility and low solubility in water, studies of compounds based on terpenes are difficult, and methodologies must be adjusted to their specific characteristics. Considering the significant influence of iron ions on dementia development, the activity of terpenes in reducing Fe³⁺ represents an important area to be determined. Previously obtained results were unreliable because ferric-reducing antioxidant power (FRAP) methodology was not adjusted regarding studying terpenes. Taking this fact into account, the aim of this study was to optimize the method for monoterpene assessment. The study included three modifications, namely, (1) slightly adjusting the entire FRAP procedure, (2) replacing methanol with other solvents (heptane, butanone, or ethyl acetate), and (3) adding Tween 20. Additionally, a thin layer chromatography (TLC) -FRAP assay was performed. The obtained results revealed significant improvement in the reduction activity of selected terpenes (linalool, α-phellandrene, and α-terpinene) in studies with Tween 20, whereas replacing methanol with other solvents did not show the expected effects.

Exploiting self-assembled soft systems based on surfactants, biopolymers and their mixtures for inhibition of Citral degradation under harsh acidic Conditions

The chemical instability of Citral in acidic conditions is viewed as hurdle to commercialize it in food/beverage industries. We attempted to stabilize citral in various single and mixed surfactant systems at pH 1.0 and temperature 25 °C. The study highlights the importance of amount and density of positive charge of cationic surfactants and oxyethylene content of nonionic surfactants at the interface of self-assembly in inhibiting citral degradation. The hybrid of Chitosan and P123 showed a significant increase in the half-life of citral compared to that in its individual components. The results of the study suggest that it is possible to stabilize citral in strong acidic environs having a pH as low as 1.0 using mixed surfactant or polymer-amphiphile systems with significant positive charge/number of oxyethylene in their single components. Such polymer-surfactant systems formulations if biocompatible/food grade may act as promising media to enhance shelf life of citral.

Extrapulmonary Surfactant Therapy: Review of Available Data and Research/Development Issues

Since the discovery of surfactant, a large amount of knowledge has been accumulated about its biology and pharmacology. Surfactant is the cornerstone of neonatal respiratory critical care, but its proteins and phospholipids are produced in various tissues and organs, with possible roles only partially similar to that played in the alveoli. As surfactant research is focused mainly on its respiratory applications, knowledge about the possible role of surfactant in extrapulmonary disorders has never been summarized. Here we aim to comprehensively review the data about surfactant biology and pharmacology in organs other than the lung, especially focusing in the more promising surfactant extrapulmonary roles. We also review any preclinical or clinical data available about the therapeutic use of surfactant in these contexts. We offer a summary of knowledge and research/development milestones, as possible useful guidance for researchers of multidisciplinary background.

Electrostatic Interactions Enable Nanoparticle Delivery of the Flavonoid Myricetin

Flavonoids are natural polyphenolic compounds with myriad biological activities and potential as prophylactic and therapeutic agents. However, poor aqueous solubility and low bioavailability have limited the clinical utility of flavonoids, suggesting that drug delivery systems (DDSs) may improve their clinical relevance. Therefore, loading of a representative flavonoid (i.e., myricetin) into a diblock, polymeric nanoparticle carrier (NPC) DDS with a cationic corona and hydrophobic core was investigated. Absorbance and fluorescence spectroscopy results revealed association constants and standard Gibbs free energy values that align with previously reported values (K _a = ∼1-3 × 10⁴ M^-1; ΔG° = -5.4 to -6.0 kcal mol^-1), suggesting that NPCs load myricetin via electrostatic interactions. The zeta potential and gel electrophoresis analysis confirmed this loading mechanism and indicated that NPCs improve myricetin solubility >25-fold compared to myricetin alone. Finally, the dual-drug loading of NPCs was tested using a combination of myricetin and a hydrophobic drug (i.e., farnesol). Electrostatic loading of NPCs with myricetin at concentrations ≤1.2 mM did not affect NPC core loading and release of farnesol, thus demonstrating a novel formulation strategy for the dual-drug-loaded NPC. These findings offer key insights into the NPC DDS design that may enhance the clinical relevance of flavonoid-based therapeutic approaches.

Rutin-Loaded Poloxamer 407-Based Hydrogels for In Situ Administration: Stability Profiles and Rheological Properties

Rutin is a flavone glycoside contained in many plants, and exhibits antioxidant, anti-inflammatory, anticancer, and wound-healing properties. The main disadvantage related to the use of this molecule for pharmaceutical application is its poor bioavailability, due to its low solubility in aqueous media. Poloxamer 407-hydrogels show interesting thermo-sensitive properties that make them attractive candidates as pharmaceutical formulations. The hydrophobic domains in the chemical structure of the copolymer, a polymer made up of two or more monomer species, are useful for retaining poorly water-soluble compounds. In this investigation various poloxamer 407-based hydrogels containing rutin were developed and characterized as a function of the drug concentration. In detail, the Turbiscan stability index, the micro- and dynamic rheological profiles and in vitro drug release were investigated and discussed. Rutin (either as a free powder or solubilized in ethanol) did not modify the stability or the rheological properties of these poloxamer 407-based hydrogels. The drug leakage was constant and prolonged for up to 72 h. The formulations described are expected to represent suitable systems for the in situ application of the bioactive as a consequence of their peculiar versatility.

The Effect of Okra (Abelmoschus esculentus (L.) Moench) Seed Extract on Human Cancer Cell Lines Delivered in Its Native Form and Loaded in Polymeric Micelles

Cancer is a noncommunicable disease with a high worldwide incidence and mortality rate. The National Cancer Institute of Thailand reports increasing cumulative incidence of breast, colorectal, liver, lung, and cervical cancers, accounting for more than 60% of all cancers in the kingdom. In this current work, we attempt to elucidate the phytochemical composition of the okra (Abelmoschus esculentus (L.) Moench) seed extract (OSE) and study its anticancer activity, delivered in its native form as well as in the form of polymeric micelles with enhanced solubility, in three carcinoma cell lines (MCF-7, HeLa, and HepG2). The presence of flavonoid compounds in the OSE was successfully confirmed, and direct delivery had the highest cytotoxic effect on the breast cancer cell line (MCF-7), followed by the hepatocellular carcinoma (HepG2) and cervical carcinoma (HeLa) cell lines in that order, while its delivery in polymeric micelles further increased this effect only in the HepG2 cell line. The OSE’s observed cytotoxic effects on cancer cell lines demonstrated a dose and time-dependent cell proliferation and migration inhibition plausibly due to VEGF production inhibition, leading to apoptosis and cell death, conceivably due to the four flavonoid compounds noted in the current study, one of which was isoquercitrin. However, in view of the latter compound’s isolated effects being inferior to those observed by the OSE, we hypothesize that either isoquercitrin requires the biological synergy of any one or all of the observed flavonoids or any of the three in isolation or all in concert are responsible. Further studies are required to elucidate the nature of the three unknown compounds. Furthermore, as we encountered significant problems in dissolving the okra seed extract and creating the polymeric micelles, further studies are needed to devise a clinically beneficial delivery and targeting system.

The Effect of Okra (Abelmoschus esculentus (L.) Moench) Seed Extract on Human Cancer Cell Lines Delivered in Its Native Form and Loaded in Polymeric Micelles

Cancer is a noncommunicable disease with a high worldwide incidence and mortality rate. The National Cancer Institute of Thailand reports increasing cumulative incidence of breast, colorectal, liver, lung, and cervical cancers, accounting for more than 60% of all cancers in the kingdom. In this current work, we attempt to elucidate the phytochemical composition of the okra (Abelmoschus esculentus (L.) Moench) seed extract (OSE) and study its anticancer activity, delivered in its native form as well as in the form of polymeric micelles with enhanced solubility, in three carcinoma cell lines (MCF-7, HeLa, and HepG2). The presence of flavonoid compounds in the OSE was successfully confirmed, and direct delivery had the highest cytotoxic effect on the breast cancer cell line (MCF-7), followed by the hepatocellular carcinoma (HepG2) and cervical carcinoma (HeLa) cell lines in that order, while its delivery in polymeric micelles further increased this effect only in the HepG2 cell line. The OSE's observed cytotoxic effects on cancer cell lines demonstrated a dose and time-dependent cell proliferation and migration inhibition plausibly due to VEGF production inhibition, leading to apoptosis and cell death, conceivably due to the four flavonoid compounds noted in the current study, one of which was isoquercitrin. However, in view of the latter compound's isolated effects being inferior to those observed by the OSE, we hypothesize that either isoquercitrin requires the biological synergy of any one or all of the observed flavonoids or any of the three in isolation or all in concert are responsible. Further studies are required to elucidate the nature of the three unknown compounds. Furthermore, as we encountered significant problems in dissolving the okra seed extract and creating the polymeric micelles, further studies are needed to devise a clinically beneficial delivery and targeting system.

Design, Fabrication, Characterization, and In Vitro Digestion of Alkaloid-, Catechin-, and Cocoa Extract-Loaded Liposomes

Liposomes containing theobromine, caffeine, catechin, epicatechin, and a cocoa extract were fabricated using microfluidization and sonication. A high encapsulation efficiency and good physicochemical stability were obtained by sonication (75% amplitude, 7 min). Liposomes produced at pH 5.0 had mean particle diameter ranging from 73.9 to 84.3 nm. The structural and physicochemical properties of the liposomes were characterized by transmission electron microscopy, confocal fluorescence microscopy, and antioxidant activity assays. The release profile was measured by ultra-high performance liquid chromatography coupled to diode array detection. The bioaccessibility of the bioactive compounds encapsulated in liposomes was determined after exposure to a simulated in vitro digestion model. Higher bioaccessibilities were measured for all catechins-loaded liposome formulations as compared to nonencapsulated counterparts. These results demonstrated that liposomes are capable of increasing the bioaccessibility of flavan-3-ols, which may be important for the development of nutraceutical-enriched functional foods.

Application of stabilizer improves stability of nanosuspended branched-chain amino acids and anti-inflammatory effect in LPS-induced RAW 264.7 cells

This study investigated the use of polyglyceryl esters (PGE) as stabilizer in improving stability and anti-inflammatory activity of nanosuspended branched-chain amino acids (BCAAs). BCAAs nanosuspended with stabilizer (BS) exhibited improved stability at concentration of 5% saturation level during storage as compared to BCAAs nanosuspended with aqueous solution (BA). Additionally, anti-inflammatory activity of BS was found to be greater than that of BA. Nitric oxide scavenging activity was found to be dose-dependent, with activity of BS in sodium nitroprusside system being significantly higher than that of BA (p < 0.05) at 2.5-20 mg/mL. BS also possesses greater inhibitory activity on production of pro-inflammatory factors including inducible nitric oxide synthase, cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells through suppressed phosphorylation of p65 subunit of NF-κB at 0.5, 2, 8 mg/mL. These results suggest that PGE used as stabilizer improves solubility and biological activity of nanosuspended BCAAs.

Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles

Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. ¹H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals’ force. Ferric reducing antioxidant potential (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) assays showed that the reducing antioxidant activity of free thymol did not change after solubilized in Tween 80 micelles. Compared to free thymol, the solubilized thymol showed higher activities to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. The present study suggested a possible preparation of thymol-carrying micelles with enhanced antioxidant activities that could be applied in food beverages.

A Green Antioxidant Activity-Integrated Dual-Standard Method for Rapid Evaluation of the Quality of Traditional Chinese Medicine Xuebijing Injection by On-Line DPPH-CE-DAD

Much attention has been focused on treatment of sepsis which leads to high mortality all over the world in every year. Antioxidant activity seems to play a prominent role in the treatment of sepsis exhibited by Xuebijing injection. The aim of the present research was to develop an on-line 1, 1-diphenyl-2-picrylhydrazyl- (DPPH-) capillary electrophoresis-diode array detector (on-line DPPH-CE-DAD) method for rapidly assessing antioxidant properties and efficacious material basis of antioxidant activity as a way of quality control of Xuebijing injection. Several parameters affecting the separation were investigated, including the pH and concentrations of buffer, SDS, β-CD, and organic modifier as well as voltage and cassette temperature. Compared to previous traditional method, this improved method shortened the experimental cycle and became more efficient because it was successfully applied to analyze total antioxidant activity and contents of twelve antioxidants of Xuebijing injection under the same condition. The results revealed that the on-line DPPH-CE-DAD method was a reagent-saving, rapid, feasible, and green technique for quality control of Xuebijing injection in terms of pharmacological activity and contents of active ingredients. It also offered new opportunities for the analysis of antioxidant activity of complex matrix.

Sarcandra glabra (Caoshanhu) protects mesenchymal stem cells from oxidative stress: a bioevaluation and mechanistic chemistry

BACKGROUND

Sarcandra glabra (Caoshanhu) is a traditional Chinese herbal medicine used for treating various oxidative-stressed diseases. The present work evaluated its protective effect on mesenchymal stem cells (MSCs) from oxidative stress and then discussed possible mechanisms underlying this observation.

METHODS

Ethanolic extract of S. glabra (ESG) was investigated by chemical methods for its content of total phenolics, rosmarinic acid, and astilbin. ESG, along with rosmarinic acid and astilbin, was investigated for the effect on the viability of Fenton-treated MSCs using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. The observed cell protective effect was further explored by mechanistic chemistry using various antioxidant assays, including DNA protection, •OH-scavenging, •O2--scavenging, FRAP (ferric ion reducing antioxidant power), ABTS+•-scavenging, DPPH•-scavenging, and Fe2+-chelating assays.

RESULTS

Analysis of ESG revealed a content of 46.31 ± 0.56 mg quercetin/g total phenolics, 0.78 ± 0.01 % rosmarinic acid, and 3.37 ± 0.01 % astilbin. Results from the MTT assay revealed that three compounds (rosmarinic acid>astilbin>ESG) could effectively increase the survival of Fenton-treated MSCs. Similarly, in •O2--scavenging, DPPH•-scavenging, and Fe2+-chelating assays, rosmarinic acid exhibited more activity than astilbin; while in FRAP, ABTS+•-scavenging assays, astilbin was stronger than rosmarinic acid.

CONCLUSION

S. glabra can prevent MSCs from •OH-induced oxidative stress. Such protective effect can be attributed to its antioxidant ability and the presence of two kinds of phytophenols, i.e. caffeoyl derivatives and flavonoids. As the respective representatives of caffeoyl derivatives and flavonoids, rosmarinic acid and astilbin may exert the antioxidant action via direct ROS-scavenging and indirect ROS-scavenging (i.e. Fe2+-chelating). The direct ROS-scavenging ability involves hydrogen atom transfer (HAT) and/or electron transfer (ET) pathway. Astilbin engages the latter pathway more, which can be attributed to the larger planar conjugation in A/C fused rings. Rosmarinic acid, on the other hand, shows more HAT and Fe2+-chelating potential, which may be due to rosmarinic acid bearing one more catechol moiety whereas astilbin has steric-hindrance from 3-α-L-rhamnose and an H-bonding between 4,5 sites. The antioxidant features of rosmarinic acid can be generalized to other caffeoyl derivatives, while that of astilbin cannot be generalized to other flavonoids because of the difference in chemical structures.

Synthesis of homogeneous protein-stabilized rutin nanodispersions by reversible assembly of soybean (Glycine max) seed ferritin

We have studied the soybean seed ferritin stabilized rutin nanodispersions with improved water-solubility, thermal stability, and UV radiation stability.

Antioxidant activity of leaf extracts from different Hibiscus sabdariffa accessions and simultaneous determination five major antioxidant compounds by LC-Q-TOF-MS

Hibiscus sabdariffa has gained attention for its antioxidant activity. There are many accessions of H. sabdariffa in the world. However, information on the quantification of antioxidant compounds in different accessions is rather limited. In this paper, a liquid chromatography/quadrupole-time-of-flight mass spectrometry (LC-Q-TOF-MS) method for simultaneous determination of five antioxidant compounds (neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, rutin, and isoquercitrin) in H. sabdariffa leaves was developed. The method was validated for linearity, sensitivity, precision, repeatability and accuracy. The validated method has been successfully applied for determination of the five analytes in eight accessions of H. sabdariffa. The eight accessions of H. sabdariffa were evaluated for their antioxidant activities by DPPH free radical scavenging assay. The investigated accessions of H. sabdariffa were rich in rutin and exhibited strong antioxidant activity. The two accessions showing the highest antioxidant activities were from Cuba (No. 2) and Taiwan (No. 5). The results indicated that H. sabdariffa leaves could be considered as a potential antioxidant source for the food industry. The developed LC-Q-TOF-MS method is helpful for quality control of H. sabdariffa.

An inhibitory effect of self-assembled soft systems on Fenton driven degradation of xanthene dye Rhodamine B

Rhodamine B (RhB) is known to be a common organic pollutant despite having various technical applications. Treatment of effluents containing such compounds is important so as to minimize their effect on environment. Advanced Oxidation Processes (Fenton and Fenton like reactions) are such methods that can oxidize the contaminants powerfully and non-selectively. This work investigates the oxidation kinetics of dye RhB by hydroxyl radical (OH) generated via Fenton reaction in presence of surfactant assemblies of varying architectures using spectrophotometric, spectrofluorometic and tensiometric methods. The presence of surfactants viz. cationics, non-ionics and some binary mixtures in the pre-micellar and post micellar concentration ranges were found to inhibit the degradation of RhB to a varying degree. However, the reaction was totally inhibited in anionic surfactant. The experimental data was fitted to a pseudo first order kinetic model and the kinetic parameters obtained thereof were explained on the basis of the nature and type of interaction between the cationic form of RhB and the surfactants of varying architectures. The work has a critical significance in view of the fact that degradation studied in presence of surfactant assemblies is more representative than studied in aqueous solution because such conditions compare well with the conditions prevailing in the environment.

Antitumor and scavenging radicals activities of some polyphenols related to dehydroabietylamine derivatives

A novel series of polyphenols 4-9 were synthesized by the reaction of catechol with dehydroabietylamine derivatives. The antitumor activities of these compounds against L02 and HepG2 cells were investigated. Among them, compounds 4, 5, and 9 can inhibit HepG2 cells viability, but have lower inhibitory effect on L02 cells in the same concentration, indicating their potential for further development. Meanwhile, the novel series of polyphenols exhibited stronger radical-scavenging activities than the control groups.