Chemical Compositions of Propolis from China and the United States and their Antimicrobial Activities Against Penicillium notatum

A First Metabolite Analysis of Norfolk Island Pine Resin and Its Hepatoprotective Potential to Alleviate Methotrexate (MTX)-Induced Hepatic Injury

Drug-induced liver injury (DILI) represents a significant clinical challenge characterized by hepatic dysfunction following exposure to diverse medications. Methotrexate (MTX) is a cornerstone in treating various cancers and autoimmune disorders. However, the clinical utility of MTX is overshadowed by its ability to induce hepatotoxicity. The current study aims to elucidate the hepatoprotective effect of the alcoholic extract of Egyptian Araucaria heterophylla resin (AHR) on MTX-induced liver injury in rats. AHR (100 and 200 mg/kg) significantly decreased hepatic markers (AST, ALT, and ALP), accompanied by an elevation in the antioxidant's markers (SOD, HO-1, and NQO1). AHR extract also significantly inhibited the TGF-β/NF-κB signaling pathway as well as the downstream cascade (IL-6, JAK, STAT-3, and cyclin D). The extract significantly reduced the expression of VEGF and p38 with an elevation in the BCL2 levels, in addition to a significant decrease in the IL-1β and TNF-α levels, with a prominent effect at a high dose (200 mg/kg). Using LC-HRMS/MS analysis, a total of 43 metabolites were tentatively identified, and diterpenes were the major class. This study presents AHR as a promising hepatoprotective agent through inhibition of the TGF-β/NF-κB and JAK/STAT3 pathways, besides its antioxidant and anti-inflammatory effects.

Propolis-loaded nanostructured lipid carriers halt breast cancer progression through miRNA-223 related pathways: an in-vitro/in-vivo experiment

The most frequent malignant tumor in women is breast cancer, and its incidence has been rising every year. Propolis has been used for its antibacterial, antifungal, and anti-inflammatory properties. The present study aimed to examine the effect of the Egyptian Propolis Extract (ProE) and its improved targeting using nanostructured lipid carriers (ProE-NLC) in Ehrlich Ascites Carcinoma (EAC) bearing mice, the common animal model for mammary tumors. EAC mice were treated either with 5-fluorouracil (5-FU), ProE, ProE-NLC, or a combination of ProE-NLC and 5-FU. Their effect on different inflammatory, angiogenic, proliferation and apoptotic markers, as well as miR-223, was examined. ProE and ProE-NLC have shown potential anti-breast cancer activity through multiple interrelated mechanisms including, the elevation of antioxidant levels, suppression of angiogenesis, inflammatory and mTOR pathways, and induction of the apoptotic pathway. All of which is a function of increased miRNA-223 expression. The efficiency of propolis was enhanced when loaded in nanostructured lipid carriers, increasing the effectiveness of the chemotherapeutic agent 5-FU. In conclusion, this study is the first to develop propolis-loaded NLC for breast cancer targeting and to recommend propolis as an antitumor agent against breast cancer or as an adjuvant treatment with chemotherapeutic agents to enhance their antitumor activity and decrease their side effects. Tumor targeting by ProE-NLC should be considered as a future therapeutic perspective in breast cancer.

Antioxidant and antibacterial activity of Apis laboriosa honey against Salmonella enterica serovar Typhimurium

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a common food-borne pathogen that commonly causes gastroenteritis in humans and animals. Apis laboriosa honey (ALH) harvested in China has significant antibacterial activity against Staphylococcus aureus, Escherichia coli, and Bacillus subtilis. We hypothesize that ALH has antibacterial activity against S. Typhimurium. The physicochemical parameters, minimum inhibitory and bactericidal concentrations (MIC and MBC) and the possible mechanism were determined. The results showed that there were significantly different physicochemical parameters, including 73 phenolic compounds, among ALH samples harvested at different times and from different regions. Their antioxidant activity was affected by their components, especially total phenol and flavonoid contents (TPC, TFC), which had a high correlation with antioxidant activities except for the O₂- assay. The MIC and MBC of ALH against S. Typhimurium were 20-30% and 25-40%, respectively, which were close to those of UMF5+ manuka honey. The proteomic experiment revealed the possible antibacterial mechanism of ALH1 at IC₅₀ (2.97%, w/v), whose antioxidant activity reduced the bacterial reduction reaction and energy supply, mainly by inhibiting the citrate cycle (TCA cycle), amino acid metabolism pathways and enhancing the glycolysis pathway. The results provide a theoretical basis for the development of bacteriostatic agents and application of ALH.

Antitumor Effects of Poplar Propolis on DLBCL SU-DHL-2 Cells

Propolis is resinous natural product produced by Western honeybees using beeswax and plant and bud exudates, which has a wide range of biological activities, including antioxidation, antibacterial, anti-inflammation, immune regulation, antitumor, and so on. Diffuse large B-cell lymphoma (DLBCL) is an aggressive cancer, and accounts for about 30% of all lymphomas. The effect of poplar propolis on DLBCL has not been reported. The IC₅₀ of propolis on the proliferation of DLBCL SU-DHL-2 cell line and its proteins and gene expressions were detected by CCK-8 kit, label-free proteomic, and RT-PCR. The results showed that the IC₅₀ of propolis at the 5 × l05/mL cell for 24 h was 5.729 μg/mL. Label-free-based proteomics analysis showed that there were 115 differentially expressed proteins (61 up-regulated and 54 down-regulated proteins) between IC₅₀ dose-treated and solvent control groups. There were 32.47% differential proteins located in the nucleus, 20.78% in the cytoplasm, and 14.29% in mitochondria. The most significant different pathway (p = 0.0016) of protein enrichment was ferroptosis (including glutamate-cysteine ligase regulatory subunit, ferritin, and heme oxygenase). The relative expression trend of 17 of the total 22 genes selected according to proteomics results was in line with their encoded protein. The highest protein-protein interaction was serine/threonine-protein kinase PLK, which interacted with 16 differential proteins. In conclusion, poplar propolis inhibited SU-DHL-2 cells via ferroptosis pathway, accelerating cell death and down-regulated serine/threonine-protein kinase PLK1, affecting apoptosis of cell. This result provides a theoretical basis for the treatment of DLBCL using propolis.

High efficiency of in-situ cross-linking and acid triggered drug delivery by introducing tobramycin into injectable and biodegradable hydrogels

High efficiency of in-situ cross-linking and acid triggered drug delivery is realized by introducing tobramycin into the hydrogels. Injectable and biodegradable hydrogels are prepared through two steps: First generation of reactive aldehyde groups in the sodium alginate (A-Alg) and then introduction of antibiotic tobramycin as cross-linker. Due to the formation of dynamic Schiff base bonds between the amino groups in tobramycin and aldehyde groups in A-Alg, the gelation of hydrogels can be realized immediately. Thus, tobramycin acts well as the first role cross-linker and the hydrogels containing tobramycin can be injected into the wound during the treatment. In addition, the acid from the decomposition of organic compounds by the bacteria can break the cross-linking points previously formed by tobramycin in the hydrogels. Therefore, tobramycin can be released and act as the second role model drug to kill the bacteria. Because the hydrogels network is broken, the release of tobramycin is more efficient than the traditional drug delivery from hydrogels by diffusion. Based on these unique properties, the present hydrogels containing tobramycin exhibit a good injectable and biodegradable capability. In addition, due to the existence of the reversible acid-labile linkages in the hydrogels, the hydrogels containing tobramycin are also self-healing, which additionally is favorable for the application of wound dressing. More importantly, the antibacterial hydrogels also demonstrate good biocompatibility in vitro and significantly therapeutic effects on an infected mice model in vivo. Based on the above special properties, the hydrogels cross-linked by tobramycin indicate a new approach to prepare hydrogel dressings with low-cost, non-toxicity and good anti-bacterial performance in the treatment of infectious wounds.

Plant genetic diversity by DNA barcoding to investigate propolis origin

Identify the botanical origins of a certain type of propolis may be challenging and time demanding, since it involves bee's behavior observation, plant resins collection and chemical analysis. Thus, this study aimed to determine the plant genetic materials in propolis from southern Brazil using the DNA barcoding to investigate their botanical origins, as well as to compare it with the phytochemical composition determined by ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) and with the pollinic profile. As principal results, non-native Populus carolinensis Moench (Salicaceae) was almost the only DNA source in some propolis samples, which coincided with the presence of flavonoids typical from poplar exudates. Conversely, other propolis samples had DNA material coming mainly from native plant species, most of them characterized to the species level, although no specific chemical markers from those plants could be identified by UHPLC-HRMS. However, pollen from several plants identified by the DNA barcoding were extracted from some propolis samples. Despite the identification of typical diterpenes, DNA material from Araucaria angustifolia (Bertol.) Kuntze (Araucariaceae), which have been indicated as a major resin source for propolis from preservation areas in southern Brazil, was found in very small abundancies, likely because bees do not drag tissue material containing DNA when collecting resin from this native species. In conclusion, DNA barcoding analysis successfully provided information about the provenance of propolis, although, depending on the plant resin sources, this information is likely to come from pollen.

Computational Study of Asian Propolis Compounds as Potential Anti-Type 2 Diabetes Mellitus Agents by Using Inverse Virtual Screening with the DIA-DB Web Server, Tanimoto Similarity Analysis, and Molecular Dynamic Simulation

Propolis contains a wide range of pharmacological activities because of their various bioactive compounds. The beneficial effect of propolis is interesting for treating type-2 diabetes mellitus (T2DM) owing to dysregulation of multiple metabolic processes. In this study, 275 of 658 Asian propolis compounds were evaluated as potential anti-T2DM agents using the DIA-DB web server towards 18 known anti-diabetes protein targets. More than 20% of all compounds could bind to more than five diabetes targets with high binding affinity (<−9.0 kcal/mol). Filtering with physicochemical and pharmacokinetic properties, including ADMET parameters, 12 compounds were identified as potential anti-T2DM with favorable ADMET properties. Six of those compounds, (2R)-7,4′-dihydroxy-5-methoxy-8-methylflavone; (RR)-(+)-3′-senecioylkhellactone; 2′,4′,6′-trihydroxy chalcone; alpinetin; pinobanksin-3-O-butyrate; and pinocembrin-5-methyl ether were first reported as anti-T2DM agents. We identified the significant T2DM targets of Asian propolis, namely retinol-binding protein-4 (RBP4) and aldose reductase (AKR1B1) that have important roles in insulin sensitivity and diabetes complication, respectively. Molecular dynamic simulations showed stable interaction of selected propolis compounds in the active site of RBP4 and AKR1B1. These findings suggest that Asian propolis compound may be effective for treatment of T2DM by targeting RBP4 and AKR1B1.

Alterations in Mycelial Morphology and Flow Cytometry Assessment of Membrane Integrity of Ganoderma boninense Stressed by Phenolic Compounds

Global increase in demand for palm oil has caused an intensification in oil palm plantation; however, production is greatly hindered by Basal Stem Rot (BSR) disease caused by Ganoderma boninense. There are many approaches to controlling BSR, although, there is no accurate, sustainable and effective method to suppress G. boninense completely. Hence, four phenolic compounds [Gallic acid (GA), Thymol (THY), Propolis (PRO) and Carvacrol (CARV)] were selected to evaluate their antifungal effect, ability to alter the mycelium morphology, and fungal cell integrity against G. boninense. Significant differences (p < 0.05) were observed and 94% of inhibition was exerted by GA on G. boninense growth. Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy observations revealed that GA and THY treatment caused severe damage to the mycelium and recorded the highest amount of sugar and electrolyte leakage. The study of cell integrity and morphological disruption has elucidated the reduction of G. boninense cell viability. Generally, our findings confirm the fungistatic effects of GA and THY. The evolution of phenolic compounds during the phytopathology studies indicated their coherence in eradicating the G. boninense. It is proposed that GA and THY had the potential to be developed further as a natural antifungal treatment to suppress G. boninense.

Impact of Drying Processes on the Nutritional Composition, Volatile Profile, Phytochemical Content and Bioactivity of Salicornia ramosissima J. Woods

Salicornia ramosissima J. Woods is a halophyte plant recognized as a promising natural ingredient and will eventually be recognized a salt substitute (NaCl). However, its shelf-life and applicability in several food matrices requires the use of drying processes, which may have an impact on its nutritional and functional value. The objective of this study was to evaluate the effect of oven and freeze-drying processes on the nutritional composition, volatile profile, phytochemical content, and bioactivity of S. ramosissima using several analytical tools (LC-DAD-ESI-MS/MS and SPME-GC-MS) and bioactivity assays (ORAC, HOSC, and ACE inhibition and antiproliferative effect on HT29 cells). Overall, results show that the drying process changes the chemical composition of the plant. When compared to freeze-drying, the oven-drying process had a lower impact on the nutritional composition but the phytochemical content and antioxidant capacity were significantly reduced. Despite this, oven-dried and freeze-dried samples demonstrated similar antiproliferative (17.56 mg/mL and 17.24 mg/mL, respectively) and antihypertensive (24.56 mg/mL and 18.96 mg/mL, respectively) activities. The volatile composition was also affected when comparing fresh and dried plants and between both drying processes: while for the freeze-dried sample, terpenes corresponded to 57% of the total peak area, a decrease to 17% was observed for the oven-dried sample. The oven-dried S. ramosissima was selected to formulate a ketchup and the product formulated with 2.2% (w/w) of the oven-dried plant showed a good consumer acceptance score. These findings support the use of dried S. ramosissima as a promising functional ingredient that can eventually replace the use of salt.

Chrysin: Perspectives on Contemporary Status and Future Possibilities as Pro-Health Agent

Chrysin belongs to the group of natural polyphenols. It can be found, among others, in honey, propolis and fruits and has a wide range of biological activities, including the prevention of oxidative stress, inflammation, neurodegeneration and carcinogenesis. Being a part of the human diet, chrysin is considered to be a promising compound to be used in the prevention of many diseases, including cancers, diabetes and neurodegenerative diseases such as Alzheimer's or Parkinson's. Nevertheless, due to the low solubility of chrysin in water and under physiological conditions, its bioavailability is low. For this reason, attempts at its functionalization have been undertaken, aiming to increase its absorption and thus augment its in vivo therapeutic efficacy. The aim of this review is to summarize the most recent research on chrysin, including its sources, metabolism, pro-health effects and the effects of its functionalization on biological activity and pharmacological efficacy, evaluated both in vitro and in vivo.

Effects of Propolis on Infectious Diseases of Medical Relevance

Infectious diseases are a significant problem affecting the public health and economic stability of societies all over the world. Treatment is available for most of these diseases; however, many pathogens have developed resistance to drugs, necessitating the development of new therapies with chemical agents, which can have serious side effects and high toxicity. In addition, the severity and aggressiveness of emerging and re-emerging diseases, such as pandemics caused by viral agents, have led to the priority of investigating new therapies to complement the treatment of different infectious diseases. Alternative and complementary medicine is widely used throughout the world due to its low cost and easy access and has been shown to provide a wide repertoire of options for the treatment of various conditions. In this work, we address the relevance of the effects of propolis on the causal pathogens of the main infectious diseases with medical relevance; the existing compiled information shows that propolis has effects on Gram-positive and Gram-negative bacteria, fungi, protozoan parasites and helminths, and viruses; however, challenges remain, such as the assessment of their effects in clinical studies for adequate and safe use.

Interactions with Microbial Proteins Driving the Antibacterial Activity of Flavonoids

Flavonoids are among the most abundant natural bioactive compounds produced by plants. Many different activities have been reported for these secondary metabolites against numerous cells and systems. One of the most interesting is certainly the antimicrobial, which is stimulated through various molecular mechanisms. In fact, flavonoids are effective both in directly damaging the envelope of Gram-negative and Gram-positive bacteria but also by acting toward specific molecular targets essential for the survival of these microorganisms. The purpose of this paper is to present an overview of the most interesting results obtained in the research focused on the study of the interactions between flavonoids and bacterial proteins. Despite the great structural heterogeneity of these plant metabolites, it is interesting to observe that many flavonoids affect the same cellular pathways. Furthermore, it is evident that some of these compounds interact with more than one target, producing multiple effects. Taken together, the reported data demonstrate the great potential of flavonoids in developing innovative systems, which can help address the increasingly serious problem of antibiotic resistance.

Research progress on radioprotective effects of bee products

Radiation exposure is an on going and serious threat in military and public health concern. There is an unmet need for effective preventative or mitigative treatments against radiation-induced injuries. The handful of Food and Drug Administration in the US approved radiation protection agents cannot be widely used due to their side effects. Some natural nontoxic compounds such as bee products have been reported to prevent and treat radiation-induced injuries (e.g. scavenging free radicals, inhibiting cell apoptosis and reducing DNA damage), indicating that they may be a potential option as a safe radioprotective agent. Bee products are nontoxic and have no known side effects on the human body, and are effective in the field of radiation protection. They are expected to be interesting drug candidates for preventing and treating radiation-induced injuries. This article reviews the prevention and treatment of bee products on radiation-induced injuries.

iTRAQ-based quantitative proteomic analysis of the antimicrobial mechanism of lactobionic acid against Staphylococcus aureus

Staphylococcus aureus is a common pathogenic microorganism that causes foodborne diseases. Lactobionic acid (LBA) is a natural polyhydroxy acid widely used in the food industry. To understand the antibacterial action of LBA against S. aureus better and identify 274 differentially expressed proteins upon LBA treatment, an isobaric tag was used for relative and absolute quantification-based quantitative proteomics. Combined with ultrastructural observations, results suggested that LBA inhibited S. aureus by disrupting cell wall and membrane integrity, regulating adenosine triphosphate binding cassette transporter expression, affecting cellular energy metabolism, attenuating S. aureus virulence and reducing infection, and decreasing the levels of proteins involved in stress and starvation responses. Quantitative real-time polymerase chain reaction analysis was used to validate the proteomic data. The results provide new insights into the inhibitory effects of LBA on S. aureus and suggest that LBA application may be a promising method to ensure food and pharmaceutical product safety.

Biosynthesis and characterization of gold nanoparticles using Brazilian red propolis and evaluation of its antimicrobial and anticancer activities

Gold nanoparticles (AuNPs) are highlighted due to their low toxicity, compatibility with the human body, high surface area to volume ratio, and surfaces that can be easily modified with ligands. Biosynthesis of AuNPs using plant extract is considered a simple, low-cost, and eco-friendly approach. Brazilian Red Propolis (BRP), a product of bees, exhibits anti-inflammatory, anti-tumor, antioxidant, and antimicrobial activities. Here, we described the biosynthesis of AuNPs using BRP extract (AuNPextract) and its fractions (AuNPhexane, AuNPdichloromethane, AuNPethyl acetate) and evaluated their structural properties and their potential against microorganisms and cancer cells. AuNPs showed a surface plasmon resonance (SPR) band at 535 nm. The sizes and morphologies were influenced by the BRP sample used in the reaction. FTIR and TGA revealed the involvement of bioactive compounds from BRP extract or its fractions in the synthesis and stabilization of AuNPs. AuNPdichloromethane and AuNPhexane exhibited antimicrobial activities against all strains tested, showing their efficacy as antimicrobial agents to treat infectious diseases. AuNPs showed dose-dependent cytotoxic activity both in T24 and PC-3 cells. AuNPdichloromethane and AuNPextract exhibited the highest in vitro cytotoxic effect. Also, the cytotoxicity of biogenic nanoparticles was induced by mechanisms associated with apoptosis. The results highlight a potential low-cost green method using Brazilian red propolis to synthesize AuNPs, which demonstrated significant biological properties.

Untargeted Ultrahigh-Performance Liquid Chromatography-Hybrid Quadrupole-Orbitrap Mass Spectrometry (UHPLC-HRMS) Metabolomics Reveals Propolis Markers of Greek and Chinese Origin

Chemical composition of propolis depends on the plant source and thus on the geographic and climatic characteristics of the site of collection. The aim of this study was to investigate the chemical profile of Greek and Chinese propolis extracts from different regions and suggest similarities and differences between them. Untargeted ultrahigh-performance liquid chromatography coupled to hybrid quadrupole-Orbitrap mass spectrometry (UHPLC-HRMS) method was developed and 22 and 23 propolis samples from Greece and China, respectively, were analyzed. The experimental data led to the observation that there is considerable variability in terms of quality of the distinctive propolis samples. Partial least squares - discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) models were constructed and allowed the identification of significant features for sample discrimination, adding relevant information for the identification of class-determining metabolites. Chinese samples overexpressed compounds that are characteristic of the poplar type propolis, whereas Greek samples overexpress the latter and the diterpenes characteristic of the Mediterranean propolis type.

Biomedical Properties of Propolis on Diverse Chronic Diseases and Its Potential Applications and Health Benefits

The use of alternative medicine products has increased tremendously in recent decades and it is estimated that approximately 80% of patients globally depend on them for some part of their primary health care. Propolis is a beekeeping product widely used in alternative medicine. It is a natural resinous product that bees collect from various plants and mix with beeswax and salivary enzymes and comprises a complex mixture of compounds. Various biomedical properties of propolis have been studied and reported in infectious and non-infectious diseases. However, the pharmacological activity and chemical composition of propolis is highly variable depending on its geographical origin, so it is important to describe and study the biomedical properties of propolis from different geographic regions. A number of chronic diseases, such as diabetes, obesity, and cancer, are the leading causes of global mortality, generating significant economic losses in many countries. In this review, we focus on compiling relevant information about propolis research related to diabetes, obesity, and cancer. The study of propolis could generate both new and accessible alternatives for the treatment of various diseases and will help to effectively evaluate the safety of its use.

Physiological and Proteomic Analysis of Penicillium digitatum in Response to X33 Antifungal Extract Treatment

Penicillium digitatum is a widespread pathogen among Rutaceae species that causes severe fruit decay symptoms on infected citrus fruit (known as citrus green mold). The employment of fungicides can effectively control the citrus green mold, significantly reducing agricultural economic loss. In this study, we found that the X33 antifungal extract produced by Streptomyces lavendulae strain X33 inhibited the hyphae polarization of P. digitatum. Additionally, physiological and proteomic analysis strategies were applied to explore the inhibitory mechanism of the X33 antifungal extract of the S. lavendulae strain X33 on the mycelial growth of P. digitatum. A total of 277 differentially expressed proteins, consisting of 207 upregulated and 70 downregulated, were identified from the comparative proteomics analysis. The results indicated that the X33 antifungal extract induced mitochondrial membrane dysfunction and cellular integrity impairment, which can affect energy metabolism, oxidative stress, and transmembrane transport. The improved alkaline phosphatase activity and extracellular conductivity, increased H₂O₂ and malondialdehyde contents, and inhibition of energy, amino acid, and sugar metabolism indicated that the oxidative stress of P. digitatum is induced by the X33 antifungal extract. These findings provided insight into the antifungal mechanism of the X33 antifungal extract against P. digitatum by suggesting that it may be an effective fungicide for controlling citrus postharvest green mold.

The Chemical Composition of Brazilian Green Propolis and Its Protective Effects on Mouse Aortic Endothelial Cells against Inflammatory Injury

Propolis has a very complex composition, with antibacterial, anti-inflammatory and other properties. To determine the composition of ethanol extracts of Brazilian green propolis (EEP-B) and their protective effect on mouse aortic endothelial cells (MAECs), the chemical composition of EEP-B was analysed by UPLC/Q-TOF-MS/MS, and the protective effect of EEP-B on the proliferation of lipopolysaccharide (LPS)-induced MAECs was determined by Cell Counting Kit-8 (CCK-8) assays. The protein levels of inflammatory cytokines tumour necrosis factor-α (TNF-α) and interleukin- 6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA), and ICAM-1, VCAM-1 and MCP-1 expressions were analysed by western blotting. The results showed that a total of 24 compounds belonging to cinnamic acids and flavonoids, including 3,5-diisopentenyl-4-hydroxycinnamic acid (artepillin C), kaempferide, 3-isoprenyl p-coumaric acid, pinocembrin and 4′-methoxy pinobanksin, were identified in EEP-B. Among them, a new component, suggested to be 5-isoprenyl caffeic acid p-coumaric acid ester, was reported for the first time. The LPS-induced levels of TNF-α, IL-6, ICAM-1, VCAM-1 and MCP-1 were downregulated in response to 5, 10 and 20 μg/mL EEP-B. This study revealed that EEP-B could reduce LPS-induced inflammatory reactions, improve cell survival, and protect MAECs by regulating ICAM-1, VCAM-1 and MCP-1 expression. These findings could provide a theoretical basis for MAEC treatment using EEP-B.

Effect of the Solvent on Propolis Phenolic Profile and its Antifungal, Antioxidant, and In Vitro Cytoprotective Activity in Human Erythrocytes Under Oxidative Stress

Propolis is a natural bee product with various beneficial biological effects. The health-promoting properties of propolis depend on its chemical composition, particularly the presence of phenolic compounds. The aim of this study was to evaluate the relationship between extraction solvent (acetone 100%, ethanol 70% and 96%) and the antifungal, antioxidant, and cytoprotective activity of the extracts obtained from propolis. Concentrations of flavonoids and phenolic acids in the propolis extracts were determined using ultrahigh-performance liquid chromatography. The antioxidant potential of different extracts was assessed on the basis of 2,2-diphenyl-1-picrylhydrazyl (DPPH·) free-radical-scavenging activity, Fe³⁺-reducing power, and ferrous ion (Fe²⁺)-chelating activity assays. The ability of the extracts to protect human red blood cell membranes against free-radical-induced damage and their antifungal activity was also determined. The results showed that the concentration of flavonoids in the propolis extracts was dependent on the solvent used in the extraction process and pinocembrin, chrysin, galangin, and coumaric acid were the most abundant phenols. All extracts exhibited high antioxidant potential and significantly protected human erythrocytes against oxidative damage. On the other hand, the antifungal activity of the propolis extracts depended on the solvent used in extraction and the fungal strains tested. It needs to be stressed that, to the best of our knowledge, there is no study relating the effect of solvent used for extraction of Polish propolis to its phenolic profile, and its antifungal, antioxidant, and cytoprotective activity.

Chemical, Biological and Mechanical Characterization of Wood Treated with Propolis Extract and Silicon Compounds

The development of new bio-friendly alternatives for wood conservation is of great interest and necessary for environmental protection. In this paper, the preparations based on the propolis extract and silicon compounds were used as green wood preservatives. The wood was treated with 15% propolis extract (EEP) and two propolis-silane preparations, namely, EEP-VTMOS/TEOS (EEP with vinyltrimethoxysilane and tetraethyl orthosilicate) and EEP-MPTMOS/TEOS (EEP with 3-(trimethoxysilyl) propyl methacrylate and tetraethyl orthosilicate). The aim of the research was to determine the properties of treated wood, which was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), atomic absorption spectroscopy (AAS), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). Moreover, the resistance against brown-rot fungus Coniophora puteana and the mechanical properties of treated wood were also determined. The analysis of phenolic compounds concentration in treated wood indicated that phenols were in greater extent leached from wood treated with the propolis extract than from wood impregnated with the propolis-silane preparations. The presence of silicon in treated wood both before and after leaching was confirmed by CP MAS NMR measurements. In turn, AAS and XRF analyses indicated that the degree of Si leaching from wood impregnated with EEP-VTMOS/TEOS was approximately two times lower than from EEP-MPTMOS/TEOS treated wood. The results of chemical analyses confirmed that the constituents of the propolis-silane preparations formed permanent bonds with wood. In turn, the results of the antifungal efficacy against C. puteana showed that the propolis extract and the propolis-silane preparations limited the fungus activity, even the wood was subjected to leaching procedure. The treated wood showed an increase in bending strength and a decrease in the modulus of elasticity compared to untreated wood. The obtained results indicate that the propolis-silane preparations can be promising green wood preservatives, harmless for the natural environment.

Natural Compounds for Wood Protection against Fungi-A Review

Wood is a renewable, versatile material with multiple applications and the largest terrestrial pool of sequestered carbon. However, it is susceptible to degradation, mainly caused by wood-decaying fungi. Since several traditional wood preservatives have been banned owing to their detrimental effects on humans and the environment, extending the lifespan of wood products using new generation natural preservatives is an imperative from the perspectives of human health and environmental protection. Several natural compounds of plant and animal origin have been tested for their fungicidal properties, including essential oils, tannins, wood extractives, alkaloids, propolis or chitosan; and their enormous potential in wood protection has been shown. Although they are not free of limitations, the potential methods to overcome their drawbacks and enhance their bioactivity already exist, such as co-impregnation with different polymers, cross-linkers, metal chelators or antioxidants. The presence of the discrepancies between laboratory tests and the field performance, as well as legislation-related problems resulting from the lack of standards defining the quality and performance of natural protective formulations, however, create an urgent need for further thorough research and arrangements. The collaboration with other industries interested in the utilisation of natural active compounds will reduce the associated costs, thus, will facilitate the successful implementation of alternative antifungal agents.

The Possibility of Propolis Extract Application in Wood Protection

Nowadays, there is a growing interest in extending the service life of wood and wood products by applying natural substances that are harmless to humans and the environment. In this paper, propolis was used as an eco-friendly wood preservative. The aim of this study was to determine the resistance of Scots pine wood treated with the propolis extract against brown-rot fungus Coniophora puteana. The wood biodegradation was assessed by gravimetric method, as well as by the analysis of ergosterol concentration in decayed wood and by the determination of changes in the wood structure by means of Fourier transform infrared spectroscopy. The results indicated that the impregnation of wood with propolis extract above 12% concentration limited fungal decay. The mass loss of wood treated with 18.9% propolis extract was 2.3% and was over 21 times lower than that for untreated wood. The analysis of ergosterol content and the changes in wood structure also confirmed that the propolis extract above 12% concentration protected wood against decay caused by C. puteana. Moreover, the propolis extract used in wood impregnation was rich in phenolic compounds, mainly chrysin, pinocembrin and galangin, which possess antimicrobial activity. The obtained results indicate that the extract of Polish propolis can be a promising natural wood preservative, safe for humans and the natural environment.

Effect of Chinese Propolis as an Intracanal Medicament on Post-Operative Endodontic Pain: A Double-Blind Randomized Controlled Trial

Propolis is a potent anti-microbial and natural anti-inflammatory by-product obtained from the beehive. Studies have demonstrated the superior biocompatibility and anti-microbial properties of propolis as compared to calcium hydroxide. However, its effect on postoperative endodontic pain is unknown. Therefore, this study aimed to investigate the impact of Chinese propolis paste as an intracanal medicament on postoperative endodontic pain intensities compared with calcium hydroxide (control) at different time intervals in necrotic teeth with periapical radiolucency. Eighty patients with single-rooted necrotic teeth with visible periapical radiolucency were recruited and randomly allocated to either the calcium hydroxide or propolis groups. After chemo-mechanical preparation and intracanal medicament insertion, patients were given the VAS (visual analogue scale) to record pain scores. Inter-group data were compared and analyzed using two-way repeated measure ANOVA (Bonferroni test). A p-value of < 0.025 was considered significant. In total, >78% of the patients experienced no or only mild post-operative pain in both the groups at all time intervals, without any significant difference in pain scores between the two groups (p > 0.025). An overall flare-up rate of 14.8% was found. The results suggest that either of these medicaments can be used as an inter-appointment medication for the prevention of postoperative pain in necrotic cases.