Anti-acetylcholinesterase and toxicity against Artemia salina of chitosan microparticles loaded with essential oils of Cymbopogon flexuosus, Pelargonium x ssp and Copaifera officinalis

Study of the synergistic properties of copaiba oil co-electrospun with poly(L-co-D,L lactic acid) and natural rubber latex for application in bioactive wound dressings

Wound healing is a complex process involving a sequence of factors that can be disrupted, negatively impacting the quality of life for patients and overburdening healthcare systems. Advanced dressings obtained by electrospinning are highlighted by the optimization of this process, allowing air exchange and protection against microorganisms. Aiming to develop bioactive dressings, this study investigated the physicochemical, mechanical, microbiological, and in vitro biological properties of membranes containing 25 %, 50 %, 75 %, and 90 % copaiba oil (CO) co-electrospun with poly(L-co-D,L-lactic acid) (PLDLA) and natural rubber latex (NR). CO, with antimicrobial and anti-inflammatory properties, was co-electrospun with the system, which integrates the bioactivity and elasticity of NR with the mechanical strength of PLDLA. FTIR analysis indicated a physical interaction between CO and PLDLA/NR, promoting its efficient and sustained release. Scanning electron microscopy (SEM) revealed a fibrous and porous morphological structure. The mechanical tensile test revealed the plasticizing effect of CO. The low Young's modulus (26.6 MPa) for 25 % CO indicated its elastic capacity under low stress. In vitro tests have demonstrated efficacy in preventing bacterial infections against Staphylococcus aureus, due to its bacteriostatic effect and air-filtering capacity, allowing gas exchange while preventing the entry of microorganisms. The system composed of PLDLA/NR/25 % CO also exhibited cell viability of 93 % and 80 % after 24 and 72 h, respectively. The scratch assay using PLDLA/NR/25 % CO demonstrated efficacy in promoting cell migration. These results suggest that co-electrospun membranes hold promise as advanced wound dressings, with the potential to accelerate the wound healing process.

Essential Oil Composition and Anti-Cholinesterase Properties of Cryptomeria japonica Foliage Harvested in São Miguel Island (Azores) in Two Different Seasons

The Azorean Cryptomeria japonica forest operations and wood industry generate considerable foliage biomass residues that are used for local essential oil (EO) production. However, research on seasonal variation of C. japonica EO remains scarce. In this study, the EOs from fresh Azorean C. japonica foliage (Az-CJF) collected in autumn (Aut) and spring (Spr) were obtained via hydrodistillation and investigated for their physical properties, yield, chemical composition, and bioactivities. Both EOs presented a strong odor, a yellowish color, a density around 0.9 g·mL-1, and similar yields (approximately 1% v/w, dry matter). Nevertheless, the GC-MS analyses showed a decrease in monoterpene hydrocarbons (MH) and an increase in oxygenated sesquiterpenes (OS) contents in Spr-EO compared with Aut-EO (16% vs. 35% for MH and 45% vs. 31% for OS, respectively). In addition, the predominant components were kaur-16-ene (23%) for Spr-EO and phyllocladene (19%) for Aut-EO, revealing that both EOs were rich in diterpene hydrocarbons (29% vs. 26%). Concerning its toxicity against brine shrimp, a low mortality (0-38%) was observed at a concentration range of 100-180 μg·mL-1. Regarding the anti-cholinesterase properties, both EOs were inactive against acetylcholinesterase but showed anti-butyrylcholinesterase activity superior to (-)-α-pinene, a major compound of Az-CJF EO (IC50 values: 84, 148, and 648 μg·mL-1 for Spr-EO, Aut-EO, and α-pinene, respectively). Overall, the results indicate the potential benefit of both seasonal EOs in Alzheimer's disease treatment. In conclusion, this study demonstrated that season strongly influences the Az-CJF EO quantitative composition and thus its bioactivity, aiding in the selection of the most high-quality raw materials for use in Azorean C. japonica EO aromatherapy industry.

Analysis of Chemical Composition, Antioxidant Activity, and Toxicity of Essential Oil from Virola sebifera Aubl (Myristicaceae)

Volatile oils or essential oils (EOs) were extracted from three V. sebifera samples (labeled as A, B, and C) in September 2018 and February 2019; the extraction process involved hydrodistillation of the leaves. The chemical compositions of the EOs were analyzed using gas chromatography-mass spectrometry (GC/MS). The volatile components were identified by comparing their retention indices and mass spectra with standard substances documented in the literature (ADAMS). The antioxidant activity of the EOs was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), while their toxicity was assessed using Artemia salina Leach. Molecular docking was utilized to examine the interaction between the major constituents of V. sebifera EO and acetylcholinesterase (AChE), a molecular target linked to toxicity in A. salina models. The EO obtained from specimen A, collected in September 2018, was characterized by being primarily composed of (E,E)-α-farnesene (47.57%), (E)-caryophyllene (12.26%), and α-pinene (6.93%). Conversely, the EO from specimen A, collected in February 2019, was predominantly composed of (E,E)-α-farnesene (42.82%), (E)-caryophyllene (16.02%), and bicyclogermacrene (8.85%), the EO from specimen B, collected in September 2018, primarily contained (E,E)-α-farnesene (47.65%), (E)-caryophyllene (19.67%), and α-pinene (11.95%), and the EO from the leaves collected in February 2019 was characterized by (E,E)-α-farnesene (23.57%), (E)-caryophyllene (19.34%), and germacrene D (7.33%). The EO from the leaves collected in September 2018 contained (E,E)-α-farnesene (26.65%), (E)-caryophyllene (15.7%), and germacrene D (7.72%), while the EO from the leaves collected in February 2019 was primarily characterized by (E,E)-α-farnesene (37.43%), (E)-caryophyllene (21.4%), and α-pinene (16.91%). Among these EOs, sample B collected in February 2019 demonstrated the highest potential for inhibiting free radicals, with an inhibition rate of 34.74%. Conversely, the EOs from specimen A exhibited the highest toxic potentials, with an lethal concentration 50 (LC50) value of 57.62 ± 1.53 µg/mL, while specimen B had an LC50 value of 74.72 ± 2.86 µg/mL. Molecular docking results suggested that hydrophobic interactions significantly contributed to the binding of the major compounds in the EO from sample B to the binding pocket of AChE.

Synergistic and antibiofilm activity of DNase I and glucose oxidase loaded chitosan nanoparticles against dual-species biofilms of Listeria monocytogenes and Salmonella

Salmonella and Listeria monocytogenes are two of the most common foodborne pathogens in the food industry. They form dual-species biofilms, which have a higher sensitivity to antimicrobial treatment and a greater microbial adhesion. In this experiment, we loaded DNase I and glucose oxidase (GOX) on chitosan nanoparticles (CSNPs) to explore their inhibitory effects on and disruption of dual-species biofilms of Salmonella enterica and L. monocytogenes. Transmission electron microscopy (TEM) showed that CSNP-DNase-GOX and CSNPs were spherical in shape. CSNP-DNase-GOX was shifted and altered compared to the infrared peaks of CSNPs. CSNPs loaded with DNase I and GOX showed an increase in the particle size and an alteration in the polydispersity index (PDI) and the zeta potential. Compared to free DNase I or GOX, DNase I and GOX loaded on CSNPs had higher stability at different temperatures. CSNP-DNase-GOX was more effective in inhibiting dual-species biofilms than CSNP-GOX. Scanning electron microscopy (SEM) and fluorescence microscopy were used to observe the structure of the biofilm, which further illustrated that CSNP-DNase-GOX disrupted the dual-species biofilms of S. enterica and L. monocytogenes.

Lemongrass essential oil micro- and nanoencapsulation for industrial application: Production techniques and potential applications

Due to its characteristic aroma and diverse therapeutic properties, lemongrass essential oil (LEO) has garnered increased attention in the pharmaceutical, food, and cosmetic industries. However, LEO's volatile nature, low chemical stability, and limited solubility in water limits its applications in the industry. Micro- and nanoencapsulation technologies emerge as a promising solution to overcome these challenges. A systematic methodology involving keyword searches in databases was employed to gather relevant literature on LEO micro- and nanoencapsulation, providing an extensive overview of techniques, processes, encapsulating materials, and possible applications. Beyond established methods, emerging techniques were explored. This review highlights the critical role of encapsulation in enhancing the thermal and chemical stability, applicability, bioavailability, and controlled release of LEO.

Development of silanized bacterial cellulose aerogels for the incorporation of natural oils with healing properties: Copaiba (Copaifera officinalis), bourbon geranium (Pelargonium X ssp.) essential oils and buriti (Mauritia flexuosa) vegetable oil

Bacterial cellulose (BC) represents a promising biomaterial, due to its unique and versatile properties. We report, herein, on purposely-designed structural modifications of BC that enhance its application as a wound dressing material. Chemical modification of the functional groups of BC was performed initially to introduce a hydrophobic/oleophilic character to its surface. Specifically, silanization was carried out in an aqueous medium using methyltrimethoxisilane (MTMS) as the silanizing agent, and aerogels were subsequently prepared by freeze-drying. The BC-MTMS aerogel obtained displayed a highly porous (99 %) and lightweight structure with an oil absorption capacity of up to 52 times its dry weight. The XRD pattern indicated that the characteristic crystallographic planes of the native BC were maintained after the silanization process. Thermal analysis showed that the thermal stability of the BC-MTMS aerogel increased, as compared to the pure BC aerogel (pBC). Moreover, the BC-MTMS aerogel was not cytotoxic to fibroblasts and keratinocytes. In the second step of the study, the incorporation of natural oils into the aerogel's matrix was found to endow antimicrobial and/or healing properties to BC-MTMS. Bourbon geranium (Pelargonium X ssp.) essential oil (GEO) was the only oil that exhibited antimicrobial activity against the tested microorganisms, whereas buriti (Mauritia flexuosa) vegetable oil (BVO) was non-cytotoxic to the cells. This study demonstrates that the characteristics of the BC structure can be modified, while preserving its intrinsic features, offering new possibilities for the development of BC-derived materials for specific applications in the biomedical field.

UHPLC-ESI-QTOF-MS metabolite profiles of different extracts from Pelargonium endlicherianum parts and their biological properties based on network pharmacological approaches

In the present study, we aimed to investigate the chemical profiles and biological activities of different extracts (ethyl acetate, dichloromethane, ethanol, and water) of Pelargonium endlicherianum parts (aerial parts and roots). Free radical scavenging, reducing power, phosphomolybdenum, and metal chelating were assayed for antioxidant properties. To detect enzyme inhibitory properties, cholinesterase, amylase, glucosidase, and tyrosinase were chosen as target enzymes. The ethanol extract of the aerial parts contained higher amounts of total bioactive compounds (120.53 mg GAE/g-24.46 mg RE/g). The ethanol and water extracts of these parts were tentatively characterized by UHPLC-ESI-QTOF-MS and 95 compounds were annotated. In addition, the highest acetylcholiesterase (3.74 mg GALAE/g) and butyrylcholinesterase (3.92 mg GALAE/g) abilities were observed by the ethanol extract of roots. The water extract from aerial parts exhibited the most pronounced inhibitory effects on multiple cancer cell lines, especially A549 (IC50: 23.2 µg/mL) and HT-29 (IC50: 27.43 µg/mL) cells. Using network pharmacology, P. endlicherianum compounds were studied against cancer, revealing well-connected targets such as epidermal growth factor receptor (EGFR), phosphoinositide-3-kinase (PI3K), AKT, receptor tyrosine-protein kinase erbB-2, and growth factor receptor bound protein 2 (GRB2) with significant impact on cancer-related pathways. The results could open a new path from natural treasure to functional applications with P. endlicherianum and highlight a new study on other uninvestigated Pelargonium species.

Chemical Composition, Preliminary Toxicity, and Antioxidant Potential of Piper marginatum Sensu Lato Essential Oils and Molecular Modeling Study

The essential oils (OEs) of the leaves, stems, and spikes of P. marginatum were obtained by hydrodistillation, steam distillation, and simultaneous extraction. The chemical constituents were identified and quantified by GC/MS and GC-FID. The preliminary biological activity was determined by assessing the toxicity of the samples to Artemia salina Leach larvae and calculating the mortality rate and lethal concentration (LC50). The antioxidant activity of the EOs was determined by the DPPH radical scavenging method. Molecular modeling was performed using molecular docking and molecular dynamics, with acetylcholinesterase being the molecular target. The OES yields ranged from 1.49% to 1.83%. The EOs and aromatic constituents of P. marginatum are characterized by the high contents of (E)-isoosmorhizole (19.4-32.9%), 2-methoxy-4,5-methylenedioxypropiophenone (9.0-19.9%), isoosmorhizole (1.6-24.5%), and 2-methoxy-4,5-methylenedioxypropiophenone isomer (1.6-14.3%). The antioxidant potential was significant in the OE of the leaves and stems of P. marginatum extracted by SD in November (84.9 ± 4.0 mg TE·mL-1) and the OEs of the leaves extracted by HD in March (126.8 ± 12.3 mg TE·mL-1). Regarding the preliminary toxicity, the OEs of Pm-SD-L-St-Nov and Pm-HD-L-St-Nov had mortality higher than 80% in concentrations of 25 µg·mL-1. This in silico study on essential oils elucidated the potential mechanism of interaction of the main compounds, which may serve as a basis for advances in this line of research.

Chitosan (CS)/Hydroxyapatite (HA)/Tricalcium Phosphate (β-TCP)-Based Composites as a Potential Material for Pulp Tissue Regeneration

This research focused on developing new materials for endodontic treatments to restore tissues affected by infectious or inflammatory processes. Three materials were studied, namely tricalcium phosphate β-hydroxyapatite (β-TCP), commercial and natural hydroxyapatite (HA), and chitosan (CS), in different proportions. The chemical characterization using infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the composition of the composite. Scanning electron microscopy (SEM) demonstrated that the design and origin of the HA, whether natural or commercial, did not affect the morphology of the composites. In vitro studies using Artemia salina (A. salina) indicated that all three experimental materials were biocompatible after 24 h, with no significant differences in mortality rate observed among the groups. The subdermal implantation of the materials in block form exhibited biocompatibility and biodegradability after 30 and 60 days, with the larger particles undergoing fragmentation and connective tissue formation consisting of collagen type III fibers, blood vessels, and inflammatory cells. The implanted material continued to undergo resorption during this process. The results obtained in this research contribute to developing endodontic technologies for tissue recovery and regeneration.

Copaiba Oil-Loaded Polymeric Nanocapsules: Production and In Vitro Biosafety Evaluation on Lung Cells as a Pre-Formulation Step to Produce Phytotherapeutic Medicine

Copaiba oil has been largely used due to its therapeutic properties. Nanocapsules were revealed to be a great nanosystem to carry natural oils due to their ability to improve the bioaccessibility and the bioavailability of lipophilic compounds. The aim of this study was to produce and characterize copaiba oil nanocapsules (CopNc) and to evaluate their hemocompatibility, cytotoxicity, and genotoxicity. Copaiba oil was chemically characterized by GC-MS and FTIR. CopNc was produced using the nanoprecipitation method. The physicochemical stability, toxicity, and biocompatibility of the systems, in vitro, were then evaluated. Β-bisabolene, cis-α-bergamotene, caryophyllene, and caryophyllene oxide were identified as the major copaiba oil components. CopNc showed a particle size of 215 ± 10 nm, a polydispersity index of 0.15 ± 0.01, and a zeta potential of -18 ± 1. These parameters remained unchanged over 30 days at 25 ± 2 °C. The encapsulation efficiency of CopNc was 54 ± 2%. CopNc neither induced hemolysis in erythrocytes, nor cytotoxic and genotoxic in lung cells at the range of concentrations from 50 to 200 μg·mL^-1. In conclusion, CopNc showed suitable stability and physicochemical properties. Moreover, this formulation presented a remarkable safety profile on lung cells. These results may pave the way to further use CopNc for the development of phytotherapeutic medicine intended for pulmonary delivery of copaiba oil.

Determination of Anti-Alzheimer's Disease Activity of Selected Plant Ingredients

Neurodegenerative diseases, among which one of the more common is Alzheimer’s disease, are the one of the biggest global public health challenges facing our generation because of the increasing elderly population in most countries. With the growing burden of these diseases, it is essential to discover and develop new treatment options capable of preventing and treating them. Neurodegenerative diseases, among which one of the most common is Alzheimer’s disease, are a multifactorial disease and therefore demand multiple therapeutic approaches. One of the most important therapeutic strategies is controlling the level of acetylcholine—a neurotransmitter in cholinergic synapses—by blocking the degradation of acetylcholine using acetylcholinesterase inhibitors such as tacrine, galantamine, donepezil and rivastigmine. However, these drugs can cause some adverse side effects, such as hepatotoxicity and gastrointestinal disorder. Thus, the search for new, more effective drugs is very important. In the last few years, different active constituents from plants have been tested as potential drugs in neurodegenerative disease therapy. The availability, lower price and less toxic effects of herbal medicines compared with synthetic agents make them a simple and excellent choice in the treatment of neurodegenerative diseases. The empirical approach to discovering new drugs from the systematic screening of plant extracts or plant-derived compounds is still an important strategy when it comes to finding new biologically active substances. The aim of this review is to identify new, safe and effective compounds that are potential candidates for further in vivo and clinical tests from which more effective drugs for the treatment of Alzheimer’s disease could be selected. We reviewed the methods used to determine anti-Alzheimer’s disease activity. Here, we have discussed the relevance of plant-derived compounds with in vitro activity. Various plants and phytochemical compounds have shown different activity that could be beneficial in the treatment of Alzheimer’s disorders. Most often, medicinal plants and their active components have been investigated as acetylcholinesterase and/or butyrylcholinesterase activity inhibitors, modifiers of β-amyloid processing and antioxidant agents. This study also aims to highlight species with assessed efficacy, usable plant parts and the most active plant components in order to identify species and compounds of interest for further study. Future research directions are suggested and recommendations made to expand the use of medicinal plants, their formulations and plant-derived active compounds to prevent, mitigate and treat Alzheimer’s disease.

Phenolic Compound Profile by UPLC-MS/MS and Encapsulation with Chitosan of Spondias mombin L. Fruit Peel Extract from Cerrado Hotspot-Brazil

Taperebá (Spondias mombin L.) is a native species of the Brazilian Cerrado that has shown important characteristics such as a significant phenolic compound content and biological activities. The present study aimed to characterize the phenolic compound profile and antioxidant activity in taperebá peel extract, as well as microencapsulating the extract with chitosan and evaluating the stability of the microparticles. The evaluation of the profile of phenolic compounds was carried out by UPLC-MS/MS. The in vitro antioxidant activity was evaluated by DPPH and ABTS methods. The microparticles were obtained by spray drying and were submitted to a stability study under different temperatures. In general, the results showed a significant content of polyphenols and antioxidant activity. The results of UPLC-MS/MS demonstrated a significant content of polyphenols in taperebá peel, highlighting the high content of ellagic acid and quercetin compounds. There was significant retention of phenolic compounds when microencapsulated, demonstrating high retention at all evaluated temperatures. This study is the first to microencapsulate the extract of taperebá peel, in addition to identifying and quantifying some compounds in this fruit.

Antibacterial and antibiofilm activities of chitosan nanoparticles loaded with Ocimum basilicum L. essential oil

Nanoencapsulation has been verified to be an effective technique to improve the physical stability of essential oils. In this study, Ocimum basilicum L. essential oil (BEO) was encapsulated into chitosan nanoparticles by emulsion and ionic gelation. The success of BEO loading was revealed by Fourier transform infrared (FTIR) spectroscopy, ultraviolet visible spectrophotometry and X-ray diffraction (XRD) analyses. Scanning electron microscopy (SEM) images and dynamic light scattering (DLS) illustrated regular distribution and spherical morphology with a particle size range of 198.7 - 373.4 nm. The prepared samples had an encapsulation efficiency (EE) range of 50.39 - 5.13% and a loading capacity (LC) range of 7.22-19.78%. Encapsulation of BEO into chitosan nanocarriers demonstrated strong antibacterial and antibiofilm capacity against E. coli and S. aureus with inhibition diameter of 15.3 mm and 21.0 mm, respectively, and the obtained nanoparticles were found to damage cell membranes and cause the leakage of biological macromolecules.

Chemical Composition and Preliminary Toxicity Evaluation of the Essential Oil from Peperomia circinnata Link var. circinnata. (Piperaceae) in Artemia salina Leach

Peperomia Ruiz and Pav, the second largest genus of the Piperaceae, has over the years shown potential biological activities. In this sense, the present work aimed to carry out a seasonal and circadian study on the chemical composition of Peperomia circinata essential oils and aromas, as well as to evaluate the preliminary toxicity in Artemia salina Leach and carry out an in silico study on the interaction mechanism. The chemical composition was characterized by gas chromatography (GC/MS and GC-FID). In the seasonal study the essential oil yields had a variation of 1.2-7.9%, and in the circadian study the variation was 1.5-5.6%. The major compounds in the seasonal study were β-phellandrene and elemicin, in the circadian they were β-phellandrene and myrcene, and the aroma was characterized by the presence of β-phellandrene. The multivariate analysis showed that the period and time of collection influenced the essential oil and aroma chemical composition. The highest toxicity value was observed for the essential oil obtained from the dry material, collected in July with a value of 14.45 ± 0.25 μg·mL-1, the in silico study showed that the major compounds may be related to potential biological activity demonstrated by the present study.