Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles

Thymol Induces Fenton-Reaction-Dependent Ferroptosis in Vibrio parahemolyticus

Thymol has efficient bactericidal activity against a variety of pathogenic bacteria, but the bactericidal mechanism against Vibrio parahemolyticus (V. parahemolyticus) has rarely been reported. In the current study, we investigated the bactericidal mechanism of thymol against V. parahemolyticus. The Results revealed that 150 μg/mL of thymol had 99.9% bactericidal activity on V. parahemolyticus. Intracellular bursts of reactive oxygen species (ROS), Fe2+accumulation, lipid peroxidation, and DNA breakage were checked by cell staining. The exogenous addition of H2O2 and catalase promoted and alleviated thymol-induced cell death to a certain extent, respectively, and the addition of the ferroptosis inhibitor Liproxstatin-1 also alleviated thymol-induced cell death, confirming that thymol induced Fenton-reaction-dependent ferroptosis in V. parahemolyticus. Proteomic analysis revealed that relevant proteins involved in ROS production, lipid peroxidation accumulation, and DNA repair were significantly upregulated after thymol treatment. Molecular docking revealed two potential binding sites (amino acids 46H and 42F) between thymol and ferritin, and thymol could promote the release of Fe2+ from ferritin proteins through in vitro interactions analyzed. Therefore, we hypothesized that ferritin as a potential target may mediate thymol-induced ferroptosis in V. parahemolyticus. This study provides new ideas for the development of natural inhibitors for controlling V. parahemolyticus in aquatic products.

Encapsulation of W/O/W Acerola Emulsion by Spray Drying: Optimization, Release Kinetics, and Storage Stability

Acerola (Malpighia emarginata DC.) is a sub-tropical and tropical fruit renowned for its high levels of vitamin C and phenolic compounds, which offer health benefits. This study aimed to optimize the spray drying process by determining the inlet and outlet temperatures using response surface methodology (RSM) with the central composite design. Additionally, it aimed to evaluate the release kinetics in the hydrophilic food simulation environment and the stability of the resulting powder under various storage temperatures. The RSM method determined the optimal inlet and outlet temperatures as 157 °C and 91 °C, respectively. High-accuracy prediction equations (R2 ≥ 0.88) were developed for moisture content (3.02%), process yield (91.15%), and the encapsulation yield of total polyphenol content (61.44%), total flavonoid content (37.42%), and vitamin C (27.19%), with a predicted monolayer moisture content below 4.01%, according to the BET equation. The powder exhibited good dissolution characteristics in the acidic hydrophilic food simulation environment and showed greater stability when stored at 10 °C for 30 days, compared to storage at 35 °C and 45 °C.

Comparative analysis of chemical profiles, antioxidant, antibacterial, and anticancer effects of essential oils of two Thymus species from Montenegro

The essential oils of Thymus vulgaris (TVEO) and Thymus serpyllum (TSEO) show different biological activities. The aim of the study was to evaluate the biological activities of TVEO and TSEO from Montenegro. The main components of TVEO were p-cymene (29.52%), thymol (22.8%) and linalool (4.73%) while the main components of TSEO were p-cymene (19.04%), geraniol (11,09%), linalool (9.16%), geranyl acetate (6.49%) and borneol (5.24%). Antioxidant activity determined via DPPH for TVEO was 4.49 and FRAP 1130.27, while for TSEO it was estimated that DPPH was 4.88 μL/mL and FRAP was 701.25 μmol FRAP/L. Both essential oils were active against all tested bacteria, with the highest level of sensitivity of E. coli with MIC of 1.5625 μL/mL. Essential oils showed strong cytotoxic effects on human cancer cell lines, with IC50 values ranging from 0.20 to 0.24 μL/mL for TVEO and from 0.32 to 0.49 μL/mL for TSEO. TVEO caused apoptosis in cervical adenocarcinoma HeLa cells through activation of caspase-3 and caspase-8, while TSEO caused apoptosis through caspase-3. EOs decreased levels of oxidative stress in normal MRC-5 cells. HeLa cells treated with TVEO had reduced MMP2 expression levels, while cells treated with TSEO had lowered MMP2 and MMP9 levels. The treatment of HeLa cells with TVEO increased the levels of miR-16 and miR-34a, indicating potential tumor-suppressive properties. Our findings suggest that Thymus essential oils may be considered as good candidates for further investigation as cancer-chemopreventive and cancer-therapeutic agents.

Development, characterization, and evaluation of the antioxidant activity of nanocarriers based on surfactant swollen micelles that encapsulate essential oils

This work aimed to compare the performance of two relatively underexplored methods for the swollen micelles (SMs) production as nanocarriers for essential oils (EOs). Origanum vulgare and Thymus vulgaris EOs were examined. The first method (SMs-1), involved a self-assembly process, while the second one (SMs-2), employed titration operation of an emulsion into a surfactant solution for SMs formation. Tween 80 and ethanol were used as surfactant and co-surfactant, respectively. The solubilization kinetics and the saturation concentration of EOs were determined. Particle size (measured by DLS) and encapsulation efficiency (EE) were the control parameters assessed, along with the EOs-loaded SMs' stability during 30 days of storage. Additionally, the EOs-loaded SMs' morphology was analyzed using atomic force microscopy (AFM). Finally, the antioxidant activity through the ABTS+ radical scavenging and the reducing power of EOs encapsulated in SMs was determined. The results showed that the solubilization of EOs in SMs was a rapid process with high EE. EOs-loaded SMs-2 systems exhibited greater colloidal stability and higher EE compared to EOs-loaded SMs-1 systems, showing smaller and more homogeneous particle sizes. Moreover, EOs-loaded SMs-2 systems maintained constant EE throughout the storage period. AFM imaging confirmed the rounded and heterogeneous morphology of EOs-loaded SMs-1 and the smaller, more homogeneous, and spherical morphology of EOs-loaded SMs-2. EOs-loaded SMs-2 showed high ABTS+ radical scavenging and reducing power when encapsulated in SMs. In conclusion, the SMs-2 method emerged as an effective approach for producing efficient nanocarriers for EOs, signifying a promising path for future developments in antioxidant delivery systems.

Preparation of nanoformulation of 5-fluorouracil to improve anticancer efficacy: integrated spectroscopic, docking, and MD simulation approaches

Nanoformulations (NFs) can be used as a novel drug delivery system to treat all cancer types. One of the major drawbacks of conventional anticancer drugs is that they have poor specificity and higher toxicity towards normal cells. 5-fluorouracil (5-FU) is a well-studied anticancer drug that has a significant role in various cancers, specifically colorectal cancer therapy. This study was performed to determine the functional groups, particle size, surface charge, heterogeneity, and stability of the NF. The NFs of 5-FU were prepared through the ultrasonication technique by increasing the surfactant (Tween-80) concentrations. Among all three NFs, nanoformulated 5-FU (n5-FU) showed the most effective particle size (10.72 nm) with a zeta potential of (-4.57 mV). The cytotoxicity and apoptosis profiles confirmed that n5-FU enhanced the anticancer effect of the pure drug in HCT-116 cells, as evident from MTT assay, fluorescence microscopy, and FACS analysis. In HCT-116 cells, the IC50 values of pure and n5-FU were obtained as 41.3 μM and 18.8 μM, respectively, indicating that n5-FU was more effective against the cancer cell line. The cellular uptake study was performed to check the intake of NF in cancer cells. However, the microtubule-affinity regulating kinase-4 (MARK-4), a cancer-target protein, was purified to study the inhibition and interaction studies. The inhibition assay confirmed the inhibitory potential of 5-FU against MARK-4 protein. the multi-spectroscopic, molecular docking and MD simulation studies were performed to analyse the conformational changes, binding studies, intermolecular interactions, and stability of MARK-4 protein upon binding 5-FU. This demonstrates that NF can enhance the effectiveness of anticancer drugs.Communicated by Ramaswamy H. Sarma.

HRMAS-NMR and simulation study of the self-assembly of surfactants on carbon nanotubes

Polyethoxylated surfactants, such as those of the Tween and Pluronic series, are commonly used to disperse carbon nanotubes (CNTs) and other nanoparticles. However, the current understanding of the nature of interactions between these surfactants and CNTs is limited. The nature of the interactions between surfactants (Tween-80 [T80] and Pluronic F68 [PF68]) and CNTs was investigated using high-resolution magic angle spinning nuclear magnetic resonance (HRMAS-NMR) and coarse-grained molecular dynamics (MD) simulations. HRMAS-NMR revealed that T80 molecules interact with single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs) via the oleyl chain, whereas PF68 molecules interact with the surface of SWCNTs and MWCNTs via the polypropylene oxide residues. The polyethylene oxide chains were oriented towards the external aqueous environment. The HRMAS-NMR results were supported by MD simulations, and the latter provided further insights into the nature of the interactions.

Thymol encapsulated chitosan-Aloe vera films for antimicrobial infection

Wound healing is an extremely intricate process involving various potential factors that can contribute towards delayed healing, one of them being bacterial colonization. The current research addresses this issue through the development of herbal antimicrobial films that can be stripped off easily, formed using an essential oil component thymol, biopolymer chitosan, and herbal plant Aloe vera. In comparison to the conventionally used nanoemulsions, thymol encapsulated in chitosan-Aloe vera (CA) film exhibited high encapsulation efficiency (95.3 %) with alleviated physical stability, as established using a high zeta potential value. The pronounced loss of crystallinity, validated using X-ray diffractometry, combined with the results obtained from Infrared and Fluorescence spectroscopic analysis, confirmed the encapsulation of thymol in CA matrix through hydrophobic interactions. This encapsulation increases the spaces between biopolymer chains facilitating greater intrusion of water, conducive for preventing the possibility of bacterial infection. Antimicrobial activity was tested against various pathogenic microbes such as Bacillus, Staphylococcus, Escherichia, Pseudomonas, Klebsiella and Candida. Results showed potential antimicrobial activity in the prepared films. Release test was also run at 25 °C suggesting a two-step biphasic release mechanism. The encapsulated thymol had higher biological activity, as assessed by antioxidant DPPH assay, likely due to improved dispersibility.

Adsorption of Phenanthrene on Multi-Walled Carbon Nanotubes in the Presence of Nonionic Surfactants

The bioavailability and mobility of phenanthrene (Phe) adsorbed by multi-walled carbon nanotubes (MWCNTs) may be substantially influenced by nonionic surfactants used both in the synthesis and dispersion of MWCNTs. The adsorption mechanisms of Phe adsorbed onto MWCNTs under the different nonionic surfactants Tween 80 (TW-80) and Triton X-100 (TX-100) in the aqueous phase were investigated in terms of changes in the MWCNTs' compositions and structures. The results showed that TW-80 and TX-100 were easily adsorbed onto MWCNTs. Phe adsorption data onto MWCNTs were better suited to the Langmuir equation than the Freundlich equation. Both TW-80 and TX-100 reduced the adsorption capacity of Phe onto MWCNTs. When TW-80 and TX-100 were added in the adsorption system, the saturated adsorption mass of Phe decreased from 35.97 mg/g to 27.10 and 29.79 mg/g, respectively, which can be attributed to the following three reasons. Firstly, the hydrophobic interactions between MWCNTs and Phe became weakened in the presence of nonionic surfactants. Secondly, the nonionic surfactants covered the adsorption sites of MWCNTs, which caused Phe adsorption to be reduced. Finally, nonionic surfactants can also promote the desorption of Phe from MWCNTs.

Self-assembled surfactant-based nanoparticles as a platform for solubilization and enhancement of the photothermal activity of sepia melanin

Background

Sepia melanin (SM) is a natural photothermal biopolymer. Its biomedical applications are limited due to its poor solubility and bioavailability. This study aims to prepare a soluble formulation of sepia melanin to enhance its solubility, in turn, its bioavailability, and its use in photothermal therapy of cancer. SM was extracted from a sepia ink sac and prepared as insoluble powdered (SM) which is identified by FTIR, 1H-NMR, thermogravimetric analysis (TGA), and scanning electron microscope. SM was self-assembled using tween 80 into dispersed nanoparticles (SM-NP-Tw). The prepared SM-NP-Tw were fully characterized. The photothermal performance of SM-NP-Tw was assessed. Dark and photocytotoxicity of SM-NP-Tw was studied on HepG2 cells using two wavelengths (660 nm and 820 nm).

Results

The insoluble powdered (SM) exhibited a spherical nanoparticle-like shape as revealed by scanning electron microscope and was soluble only in an alkaline aqueous solution. TGA of SM showed high resistance to thermal degradation indicating good thermal stability. The prepared SM-NP-Tw exhibited a spherical shape with mean sizes of 308 ± 86 nm and a zeta potential of − 25 mv. The cell viability decreased significantly upon increasing the concentration and upon radiation at 820 nm. The results of UV–Vis spectroscopy and the photothermal performance revealed that melanin can absorb light in a wide range of wavelengths including near the IR region; thus, it can emit sufficient heat to kill cells through the photoheat conversion effects.

Conclusion

Sepia melanin nanoparticles self-assembled into tween-based nanostructures could be a promising natural platform for photothermal cancer therapy.

Management of Brain Cancer and Neurodegenerative Disorders with Polymer-Based Nanoparticles as a Biocompatible Platform

The blood-brain barrier (BBB) serves as a protective barrier for the central nervous system (CNS) against drugs that enter the bloodstream. The BBB is a key clinical barrier in the treatment of CNS illnesses because it restricts drug entry into the brain. To bypass this barrier and release relevant drugs into the brain matrix, nanotechnology-based delivery systems have been developed. Given the unstable nature of NPs, an appropriate amount of a biocompatible polymer coating on NPs is thought to have a key role in reducing cellular cytotoxicity while also boosting stability. Human serum albumin (HSA), poly (lactic-co-glycolic acid) (PLGA), Polylactide (PLA), poly (alkyl cyanoacrylate) (PACA), gelatin, and chitosan are only a few of the significant polymers mentioned. In this review article, we categorized polymer-coated nanoparticles from basic to complex drug delivery systems and discussed their application as novel drug carriers to the brain.

Nanohybrid of Thymol and 2D Simonkolleite Enhances Inhibition of Bacterial Growth, Biofilm Formation, and Free Radicals

Due to the current concerns against opportunistic pathogens and the challenge of antimicrobial resistance worldwide, alternatives to control pathogen growth are required. In this sense, this work offers a new nanohybrid composed of zinc-layered hydroxide salt (Simonkolleite) and thymol for preventing bacterial growth. Materials were characterized with XRD diffraction, FTIR and UV–Vis spectra, SEM microscopy, and dynamic light scattering. It was confirmed that the Simonkolleite structure was obtained, and thymol was adsorbed on the hydroxide in a web-like manner, with a concentration of 0.863 mg thymol/mg of ZnLHS. Absorption kinetics was described with non-linear models, and a pseudo-second-order equation was the best fit. The antibacterial test was conducted against Escherichia coli O157:H7 and Staphylococcus aureus strains, producing inhibition halos of 21 and 24 mm, respectively, with a 10 mg/mL solution of thymol–ZnLHS. Moreover, biofilm formation of Pseudomonas aeruginosa inhibition was tested, with over 90% inhibition. Nanohybrids exhibited antioxidant activity with ABTS and DPPH evaluations, confirming the presence of the biomolecule in the inorganic matrix. These results can be used to develop a thymol protection vehicle for applications in food, pharmaceutics, odontology, or biomedical industries.

Stabilization of Carbon Nanotubes and Graphene by Tween-80: Mechanistic Insights from Spectroscopic and Simulation Studies

Polyoxyethylene sorbitan monooleate is commonly used to obtain stable dispersions of nanoparticles (NPs) such as carbon nanotubes (CNTs) and graphene. However, the mechanism underlying dispersion is poorly understood. The present study aimed at investigating the mechanism of stabilization of carbon NPs (CNPs), namely, single-walled CNTs (SWCNTs), multi-walled CNTs (MWCNTs), and graphene, by Tween-80 using attenuated total internal reflection-Fourier transform infrared and nuclear magnetic resonance (NMR) spectroscopy. Molecular dynamics (MD) simulations were performed to identify, at the atomic scale, the significant interactions that underlie the adsorption and the stabilizing effect of Tween-80 on CNPs, in this way corroborating the spectroscopy results. Spectroscopic analysis revealed that the alkyl chain tether to SWCNT, MWCNT, and graphene surface, presumably through π-π interactions between the carbon-carbon double bond in the alkyl chain and the aromatic rings of CNPs. The hydrophilic polyethoxylate chains extend into the aqueous environment and stabilize the suspension by steric hindrance. MD simulations also showed that Tween-80 molecules interact with the CNP surface via the alkyl chain, thus corroborating spectroscopy results. MD simulations additionally revealed that Tween-80 aggregates on the CNP surface shifted from planar to micelle-like with increasing Tween-80 ratios, underscoring concentration-dependent changes in the nature of these interactions.

Polysorbate 80 and histidine quantitative analysis by NMR in the presence of virus‐like particles

Polysorbate‐80 (PS80) and histidine are common excipients in vaccine and therapeutic protein formulation. A simple quantitative NMR method to measure both PS80 and histidine in human papillomavirus (HPV) virus‐like particle (VLP) vaccine for aqueous and alum‐containing samples is described. The new NMR method is compared to current colorimetric methods for PS80 and RP HPLC for histidine. The new NMR method is comparable to current assays with an advantage of a simpler sample treatment for PS80. The efficiency is also increased because one method can now provide two assay results instead of two separate methods. Furthermore, the NMR method can detect PS80 stability due to hydrolysis and oxidation when PS80 is stored in a stainless steel container by observing a change of its NMR line shape profile.

Synthesis of Bioactive Materials by In Situ One-Step Direct Loading of Syzygium aromaticum Essential Oil into Chitosan-Based Hydrogels

Hydrogel conjugates based on chitosan and an essential oil were synthetized by an ultrasound-assisted emulsification approach. Rheology studies revealed a gel-type structure with pronounced compactness and flexibility while SEM showed the formation of a two-level ordered network with highly interconnected pores. The swelling studies indicated a pH-dependent behavior with a significant overshooting effect. The synergistic effects of the components in clove essential oil led to a strong antioxidant character and an enhanced antimicrobial activity of the conjugate hydrogels. The bioactivity was maintained for 6 months, despite a slight decrease in the antimicrobial effect. Hydrogel conjugates were found to be very stable even after two months immersed in acidic solutions that would otherwise dissolve the chitosan matrix. Ultrasound emulsification was proved as an efficient one-step loading method of hydrophobic clove essential oil into hydrophilic chitosan matrix. It was found that clove oil and its components have a double role. Besides providing bioactivity, they also behave as gelation-inducing agents, acting as an alternative to the classical chemical cross-linkers to ensure the good physical and chemical stabilization of chitosan.

Encapsulation of volatile compounds in liquid media: Fragrances, flavors, and essential oils in commercial formulations

The first marketed example of the application of microcapsules dates back to 1957. Since then, microencapsulation techniques and knowledge have progressed in a plethora of technological fields, and efforts have been directed toward the design of progressively more efficient carriers. The protection of payloads from the exposure to unfavorable environments indeed grants enhanced efficacy, safety, and stability of encapsulated species while allowing for a fine tuning of their release profile and longer lasting beneficial effects. Perfumes or, more generally, active-loaded microcapsules are nowadays present in a very large number of consumer products. Commercial products currently make use of rigid, stable polymer-based microcapsules with excellent release properties. However, this type of microcapsules does not meet certain sustainability requirements such as biocompatibility and biodegradability: the leaking via wastewater contributes to the alarming phenomenon of microplastic pollution with about 4% of total microplastic in the environment. Therefore, there is a need to address new issues which have been emerging in relation to the poor environmental profile of such materials. The progresses in some of the main application fields of microencapsulation, such as household care, toiletries, cosmetics, food, and pesticides are reviewed herein. The main technologies employed in microcapsules production and the mechanisms underlying the release of actives are also discussed. Both the advantages and disadvantages of every technique have been considered to allow a careful choice of the most suitable technique for a specific target application and prepare the ground for novel ideas and approaches for encapsulation strategies that we expect to be proposed within the next years.

Polysorbate-Based Drug Formulations for Brain-Targeted Drug Delivery and Anticancer Therapy

Polysorbates (PSs) are synthetic nonionic surfactants consisting of polyethoxy sorbitan fatty acid esters. PSs have been widely employed as emulsifiers and stabilizers in various drug formulations and food additives. Recently, various PS-based formulations have been developed for safe and efficient drug delivery. This review introduces the general features of PSs and PS-based drug carriers, summarizes recent progress in the development of PS-based drug formulations, and discusses the physicochemical properties, biological safety, P-glycoprotein inhibitory properties, and therapeutic applications of PS-based drug formulations. Additionally, recent advances in brain-targeted drug delivery using PS-based drug formulations have been highlighted. This review will help researchers understand the potential of PSs as effective drug formulation agents.

Structural investigation and application of Tween 80-choline chloride self-assemblies as osmotic agent for water desalination

Forward osmosis (FO) process has been extensively considered as a potential technology that could minimize the problems of traditional water desalination processes. Finding an appropriate osmotic agent is an important concern in the FO process. For the first time, a nonionic surfactant-based draw solution was introduced using self-assemblies of Tween 80 and choline chloride. The addition of choline chloride to Tween 80 led to micelles formation with an average diameter of 11.03 nm. The ¹H NMR spectra exhibited that all groups of Tween 80 were interacted with choline chloride by hydrogen bond and Van der Waals’ force. The influence of adding choline chloride to Tween 80 and the micellization on its osmotic activity was investigated. Despite the less activity of single components, the average water flux of 14.29 L m^‒2 h^‒1 was obtained using 0.15 M of Tween 80-choline chloride self-assembly as draw solution in the FO process with DI water feed solution. Moreover, various concentrations of NaCl aqueous solutions were examined as feed solution. This report proposed a possible preparation of nonionic surfactant-based draw solutions using choline chloride additive with enhanced osmotic activities that can establish an innovative field of study in water desalination by the FO process.

Probiotics-fermented blueberry juices as potential antidiabetic product: antioxidant, antimicrobial and antidiabetic potentials

BACKGROUND

Fermentation is a traditional food-preserving technique. It is an effective process, widely used to enrich the nutrients diversity and bioactivity of the fermented foods since ancient times. This study aimed at investigating the effects of various fermentation starters on the physicochemical, antioxidant, antimicrobial, and antidiabetic properties of blueberry juices. The blueberry juices were fermented by natural fermentation (NFBJ), self-made starters fermentation (SFBJ), and commercial starters fermentation (CFBJ); fresh blueberry juice (BBJ) was processed without fermentation for comparison.

RESULTS

Probiotics-fermented blueberry juices (SFBJ and CFBJ) showed less total and reducing sugars, higher titratable acidity, and a wider variety and higher amounts of organic acids than non-fermented blueberry juice (BBJ) did. All the fermented blueberry juices (NFBJ, SFBJ, and CFBJ) showed significantly (P < 0.05) higher antioxidant potentials than that of BBJ measured by 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid, cupric-reducing antioxidant capacity, and ferric-reducing ability power assays. The SFBJ exhibited the highest antibacterial activities against Escherichia coli, Staphylococcus aureus, and Salmonella Typhimurium, with inhibition zone diameters of 38.84 ± 1.74 mm, 34.91 ± 1.53 mm, and 36.18 ± 3.16 mm respectively. Compared with BBJ, the α-glucosidase inhibitory activity of the SFBJ and CFBJ increased by two-to threefold. The α-amylase inhibitory activity of the SFBJ and CFBJ increased by 600%, whereas the spontaneous fermentation showed no improvement. The SFBJ and CFBJ promoted glucose consumption of HepG2 cell lines, indicating the promising potential for a higher glucose bio-utilization.

CONCLUSIONS

The SFBJ and CFBJ showed remarkable improvements in the antioxidant, antimicrobial, and antidiabetic activities compared with non-fermented and spontaneous fermented juices, indicating their promising potentials as an antihyperglycemic agent. © 2021 Society of Chemical Industry.

Drying Effects on Chemical Composition and Antioxidant Activity of Lippia thymoides Essential Oil, a Natural Source of Thymol

Leaves of Lippia thymoides (Verbenaceae) were dried in an oven at 40, 50 and 60 °C and the kinetic of drying and the influence of the drying process on the chemical composition, yield, and DPPH radical scavenging activity of the obtained essential oils were evaluated. The composition of the essential oils was determined with gas chromatography-mass spectrometry and gas chromatography-flame ionization detection analyses. The influence of drying on the chemical composition of the essential oils of L. thymoides was evaluated by multivariate analysis, and their antioxidant activity was investigated via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The Midilli model was the most appropriate to describe the behavior of drying kinetic data of L. thymoides leaves. Thymol was the major compound for all analyzed conditions; the maximum content was obtained from fresh leaves (62.78 ± 0.63%). The essential oils showed DPPH radical scavenging activity with an average of 73.10 ± 12.08%, and the fresh leaves showed higher inhibition (89.97 ± 0.31%). This is the first study to evaluate the influence of drying on the chemical composition and antioxidant activity of L. thymoides essential oils rich in thymol.

Exploring the potential of novel xanthine oxidase inhibitory peptide (ACECD) derived from Skipjack tuna hydrolysates using affinity-ultrafiltration coupled with HPLC-MALDI-TOF/TOF-MS

This study aimed to isolate and investigate the potential of the peptide alanine-cysteine-glutamic acid-cysteine-aspartic acid (ACECD), a novel xanthine oxidase inhibitory (XODI) peptide derived from Skipjack tuna hydrolysate (HS). Ultrafiltration membranes were used to obtain HS-based peptides as successive ultrafiltration fractions (of decreasing molecular weight) of UF-1, UF-2, UF-3, and UF-4. Their antioxidant and xanthine oxidase (XOD) inhibitory activities were determined and further characterized by affinity-ultrafiltration coupled with HPLC-MALDI-TOF/TOF-MS and in silico techniques. The results showed that peptides with a molecular weight (MW) cutoff of 600-1000 Da (UF-2) exhibited the highest antioxidant and XODI activities. A novel XODI peptide (ACECD) was identified with an IC₅₀ value of 13.40 mmol/L, which decreased by 21.24% and 51.40% compared to those of UF-2 and HS, respectively. Molecular docking indicated that ACECD inserted into the active center of Mo atoms in XOD, which led to competitive attachment with XOD and caused inhibition. The study findings indicated that the ACECD peptide could be useful as a safe XODI substance to alleviate hyperuricemia.

In vitro antagonistic inhibitory effects of palm seed crude oils and their main constituent, lauric acid, with oxacillin in Staphylococcus aureus

Infections caused by Staphylococcus aureus are a serious global threat, and with the emergence of antibiotic resistance, even more difficult to treat. One of the possible complications in antistaphylococcal therapy represents negative interactions of antibiotics with food. In this study, the in vitro interaction between oxacillin and crude palm seed oil from Astrocaryum vulgare, Cocos nucifera, and Elaeis guineensis against nine strains of S. aureus was determined using the checkerboard method. Lauric acid was identified as a major constituent of all tested oils by gas chromatography. The results showed strong concentration dependent antagonistic interactions between palm oils and oxacillin with values of fractional inhibitory concentrations indices ranging from 4.02 to 8.56 at concentrations equal or higher than 1024 µg/mL of the tested oils. Similarly, lauric acid in combination with oxacillin produced antagonistic action with fractional inhibitory concentration indices ranging from 4.01 to 4.28 at 1024 µg/mL. These findings suggest that interference between oxacillin and palm oils and their constituents can negatively affect the treatment of staphylococcal infections in humans and other animals.

Natural Antibiotic Oregano in Hydroxyapatite-Coated Titanium Reduces Osteoclastic Bone Resorption for Orthopedic and Dental Applications

Traditional infection prevention and treatment methods include synthetic antibiotics, which can cause severe adverse side effects. Carvacrol and thymol are biologically active monoterpenoid extractants from oregano leaves with antibiotic capabilities; however, little is known regarding their effects on bone tissue engineering. The objective of this work is to understand their effects on osteogenesis, specifically with osteoblast and osteoclast cells, from surface-modified Ti6Al4V with plasma sprayed hydroxyapatite (HA) coatings. This system is an alternative to cemented implants to aid in bone healing. Results reveal that full carvacrol release from the HA matrix is successful in aqueous environments and modulation of release kinetics can also be made using polycaprolactone (PCL) and polyethylene glycol (PEG) polymers. From HA-pressed disc samples in physiological pH, full carvacrol release is achieved in 10 days using PCL/PEG, about 95% release in 50 days using no polymer, and 60% in 50 days when using a PCL coating. Without polymer, full carvacrol release is achieved after 3 days from HA coatings in both physiological pH and acidic pH, mimicking the post-surgery environment. The release is assessed as a diffusion-based mechanism in phosphate-buffered saline but degradation-based mechanism in acetate buffer solution. Carvacrol and thymol show bacterial inhibition of Staphylococcus epidermidis and no cytotoxic effects on osteoblast proliferation in vitro. Carvacrol and thymol also induce a significant 7% reduction in osteoclast tartrate-resistant acid phosphatase (TRAP) activity, caused by poorly attached cellular morphologies, leading to an approximately 65% reduction in osteoclast resorption pit formation. Our goal is to demonstrate a natural medicinal system that can support bone healing while providing infection prevention and reducing costly revision surgeries for orthopedic and dental applications.

Monoterpenes and Their Derivatives-Recent Development in Biological and Medical Applications

Monoterpenes, comprising hydrocarbons, are the largest class of plant secondary metabolites and are commonly found in essential oils. Monoterpenes and their derivatives are key ingredients in the design and production of new biologically active compounds. This review focuses on selected aliphatic, monocyclic, and bicyclic monoterpenes like geraniol, thymol, myrtenal, pinene, camphor, borneol, and their modified structures. The compounds in question play a pivotal role in biological and medical applications. The review also discusses anti-inflammatory, antimicrobial, anticonvulsant, analgesic, antiviral, anticancer, antituberculosis, and antioxidant biological activities exhibited by monoterpenes and their derivatives. Particular attention is paid to the link between biological activity and the effect of structural modification of monoterpenes and monoterpenoids, as well as the introduction of various functionalized moieties into the molecules in question.

Antioxidants and Nanotechnology: Promises and Limits of Potentially Disruptive Approaches in the Treatment of Central Nervous System Diseases

Many central nervous system (CNS) diseases are still incurable and only symptomatic treatments are available. Oxidative stress is suggested to be a common hallmark, being able to cause and exacerbate the neuronal cell dysfunctions at the basis of these pathologies, such as mitochondrial impairments, accumulation of misfolded proteins, cell membrane damages, and apoptosis induction. Several antioxidant compounds are tested as potential countermeasures for CNS disorders, but their efficacy is often hindered by the loss of antioxidant properties due to enzymatic degradation, low bioavailability, poor water solubility, and insufficient blood-brain barrier crossing efficiency. To overcome the limitations of antioxidant molecules, exploitation of nanostructures, either for their delivery or with inherent antioxidant properties, is proposed. In this review, after a brief discussion concerning the role of the blood-brain barrier in the CNS and the involvement of oxidative stress in some neurodegenerative diseases, the most interesting research concerning the use of nano-antioxidants is introduced and discussed, focusing on the synthesis procedures, functionalization strategies, in vitro and in vivo tests, and on recent clinical trials.

Essential oil from Lippia microphylla Cham. modulates nitric oxide pathway and calcium influx to exert a tocolytic effect in rat uterus

The essential oil of Lippia microphylla (LM-OE) presents several pharmacological activities. This work evaluates the tocolytic effect of LM-OE on rats. LM-OE inhibited phasic contractions and relaxed tonic contractions on rat uterus. Considering that nitric oxide (NO) pathway regulates uterine contraction, LM-OE potency was attenuated in the presence of NO synthase (NOS) inhibitor and this reduction was reversed in the presence of a NOS substrate. Similarly, the relaxant potency of LM-OE was reduced in the presence of soluble guanylyl cyclase (sGC) and protein kinase G (PKG) inhibitors. LM-OE also demonstrates a positive modulation of large and small conductance calcium-activated, voltage-gated and adenosine triphosphate-sensitive potassium channels and inhibited curves to CaCl₂ as well as relaxed the uterus pre-contracted by S-(-)-Bay K8644, suggesting voltage-gated calcium channels type-1 (Ca_V1) blockade. Thus, the tocolytic effect of LM-OE on rat involves positive modulation of NO/NOS/sGC/PKG/K⁺-channels pathway and Ca²⁺ influx blockade through Ca_V1.[Formula: see text].

Production of thymol nanoemulsions stabilized using Quillaja Saponin as a biosurfactant: Antioxidant activity enhancement

Thymol oil-in-water nanoemulsions as a potential natural alternative for synthetic antioxidant agents were developed. The nanoemulsions were formulated using Quillaja Saponin bio-surfactant and green solvents including high oleic sunflower oil (HOSO), tricaprylin (TC), and cinnamaldehyde (CA). The 4% thymol nanoemulsions containing TC and HOSO remained stable during long-term storage (at least 30 d). The antioxidant activity (AA) of free thymol and thymol nanoemulsions was compared with butylated hydroxytoluene (BHT) and ascorbic acid. The results obtained from DPPH, FRAP, and CUPRAC antioxidant assays showed a substantial improvement (p < 0.05) of the AA of free thymol through emulsification. The outcomes from the AA of the nanoemulsions in raw chicken breast meat measured by the TBARS assay revealed a significant improvement (p < 0.05) of the AA when thymol was encapsulated. These nanoemulsions may be applicable in the food industry as well as in cosmetic and health care products.

Encapsulation of Thymol in cyclodextrin nano-cavities: A multi spectroscopic and theoretical study

Cyclodextrins have a wide range of applications in different areas of drug delivery and pharmaceutical industry due to their complexation ability and other versatile characteristics. Here we have studied the binding interactions of a small biologically important phenolic molecule, Thymol (Th), with both α and β cyclodextrins (CDs), which are well known drug delivery vehicles. Extent of encapsulation has been determined using several spectroscopic techniques. In fluorescence experiments, significant increase in fluorescence intensities have been discerned for both the CDs but there had been a much early saturation for αCD. Anisotropy experiments have been performed too and very surprisingly no appreciable increase in anisotropy value was observed in either case. Isothermal titration calorimetry (ITC) data, however, show signature of binding of Th with the βCD. These intriguing results were explained with the help of molecular docking and dynamics simulation studies. The docking calculations have shown that Th goes inside both α and βCD. In keeping with the final NMR data and molecular dynamics we have ultimately concluded that solvated Th molecules are the main participants in the interaction with CDs which is responsible for these intriguing behaviors. Finally we have also performed an antioxidant assay to reveal the practical application of such encapsulation. It has been found that on encapsulation there is an enhancement of the antioxidant behavior of Th. Then we have also performed an antibacterial assay to show the unchanged antibacterial properties of Th on encapsulation. Hence it can be deduced that Th can be safely delivered through CDs in living system without hampering its beneficial properties.