Antihypertensive effect of a nanoemulsion of baccharis dracunculifolia leaves extract in sodium-dependent hypertensive rats.

Baccharis dracunculifolia (DC) is an important botanical source of Brazilian green propolis and have many compounds with potential antihypertensive activity. However, little is known about the specific antihypertensive properties of DC, or the mechanisms involved. Here we aimed to chemically characterise an ethanolic DC extract (eDC), test its antihypertensive properties and the involvement of neurogenic mechanisms using an animal model of salt-dependent hypertension. The chemical analysis of the eDC revealed the presence of many antihypertensive compounds. Administering the eDC in a nanoemulsion formulation (25 to 50 mg/kg) effectively normalised blood pressure in hypertensive rats. The result also suggested that neurogenic mechanisms are involved in the antihypertensive action of eDC. The treatment with p-coumaric acid (0.32 to 3 mg/kg), a polyphenol abundant in the eDC, produced no significant antihypertensive effect. The findings indicate that the eDC has antihypertensive properties, and that these effects may be mediated through neurogenic pressor mechanisms.

Enhanced absorption of prenylated cinnamic acid derivatives from Brazilian green propolis by turmeric in humans and rats.

Prenylated cinnamic acid derivatives are the bioactive components of Brazilian green propolis (BGP). The effect of other botanical components on the pharmacokinetic profiles of these derivatives remains relatively unexplored. In the present study, we investigated the influence of several herbal extracts (turmeric, ginkgo leaf, coffee fruit, soybean, and gotu kola) on the plasma concentrations of cinnamic acid derivatives after BGP consumption. When the herbal extracts were co-administered with BGP in the clinical study, the area under the curve (AUC) values of artepillin C and drupanin, the major BGP components in plasma, were significantly increased by 1.7- and 1.5-fold, respectively, compared to those after BGP administration alone. Among the herbal extracts administered to rats, turmeric extract increased the AUC. Furthermore, a bidirectional transport assay suggested that artepillin C and drupanin are substrates of breast cancer resistance protein (BCRP), a drug elimination transporter. These results suggest that curcumin-containing turmeric extract may increase the plasma concentrations of artepillin C and drupanin via BCRP. Our findings enabled us to estimate the food-herb and herb-herb interactions in vivo in foods and herbal medicines containing cinnamic acid derivatives and prenylated compounds.

Antimicrobial photodynamic therapy with Brazilian green propolis controls intradermal infection induced by methicillin-resistant Staphylococcus aureus and modulates the inflammatory response in a murine model.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of skin and soft tissue infections worldwide. This microorganism has a wide range of antibiotics resistance, a fact that has made the treatment of infections caused by MRSA difficult. In this sense, antimicrobial photodynamic therapy (aPDT) with natural products has emerged as a good alternative in combating infections caused by antibiotic-resistant microorganisms. The objective of the present study was to evaluate the effects of aPDT with Brazilian green propolis against intradermal MRSA infection in a murine model. Initially, 24 Balb/c mice were infected intradermally in the ears with 1.5 × 108 colony-forming units of MRSA 43300. After infection, they were separated into 4 groups (6 animals per group) and treated with the vehicle, only Brazilian green propolis, only blue LED light or with the aPDT protocol (Brazilian green propolis + blue LED light). It was observed in this study that aPDT with Brazilian green propolis reduced the bacterial load at the site of infection. Furthermore, it was able to inhibit weight loss resulting from the infection, as well as modulate the inflammatory response through greater recruitment of polymorphonuclear cells/neutrophils to the infected tissue. Finally, aPDT induced an increase in the cytokines IL-17A and IL-12p70 in the draining retromaxillary lymph node. Thus, aPDT with Brazilian green propolis proved to be effective against intradermal MRSA infection in mice, reducing bacterial load and modulating the immune response in the animals. However, more studies are needed to assess whether such effects are repeated in humans.

Brazilian Green Propolis' Artepillin C and Its Acetylated Derivative Activate the NGF-Signaling Pathways and Induce Neurite Outgrowth in NGF-Deprived PC12 Cells.

Artepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12 cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP-43 and Synapsin I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug-likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF-signaling pathways but through different neuronal proteins. Furthermore, in silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.

pH-Dependence Cytotoxicity Evaluation of Artepillin C against Tumor Cells.

Brazilian green propolis is a well-known product that is consumed globally. Its major component, Artepillin C, showed potential as an antitumor product. This study explored the impact of Artepillin C on fibroblast and glioblastoma cell lines, used as healthy and very aggressive tumor cell lines, respectively. The focus of the study was to evaluate the pH-dependence of Artepillin C cytotoxicity, since tumor cells are known to have a more acidic extracellular microenvironment compared to healthy cells, and Artepillin C was shown to become more lipophilic at lower pH values. Investigations into the pH-dependency of Artepillin C (6.0-7.4), through viability assays and live cell imaging, revealed compelling insights. At pH 6.0, MTT assays showed the pronounced cytotoxic effects of Artepillin C, yielding a notable reduction in cell viability to less than 12% among glioblastoma cells following a 24 h exposure to 100 µM of Artepillin C. Concurrently, LDH assays indicated significant membrane damage, affecting approximately 50% of the total cells under the same conditions. Our Laurdan GP analysis suggests that Artepillin C induces autophagy, and notably, provokes a lipid membrane packing effect, contributing to cell death. These combined results affirm the selective cytotoxicity of Artepillin C within the acidic tumor microenvironment, emphasizing its potential as an effective antitumor agent. Furthermore, our findings suggest that Artepillin C holds promise for potential applications in the realm of anticancer therapies given its pH-dependence cytotoxicity.

Characterization of Brazilian green propolis as a photosensitizer for LED light-induced antimicrobial photodynamic therapy (aPDT) against methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-intermediate Staphylococcus aureus (VISA).

Staphylococcus aureus is the primary cause of skin and soft tissue infections. Its significant adaptability and the development of resistance are the main factors linked to its spread and the challenges in its treatment. Antimicrobial photodynamic therapy emerges as a promising alternative. This work aimed to characterize the antimicrobial photodynamic activity of Brazilian green propolis, along with the key bioactive compounds associated with this activity. Initially, a scanning spectrometry was conducted to assess the wavelengths with the potential to activate green propolis. Subsequently, reference strains of methicillin-resistant Staphylococcus aureus (MRSA ATCC 43300) and vancomycin-intermediate Staphylococcus aureus (VISA ATCC 700699) were exposed to varying concentrations of green propolis: 1 µg/mL, 5 µg/mL, 10 µg/mL, 50 µg /mL and 100 µg/mL and were stimulated by blue, green or red LED light. Finally, high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques, along with classic molecular networking analysis, was performed to identify potential bioactive molecules with photodynamic activity. Brazilian green propolis exhibits a pronounced absorption peak and heightened photo-responsiveness when exposed to blue light within the range of 400 nm and 450 nm. This characteristic reveals noteworthy significant photodynamic activity against MRSA and VISA at concentrations from 5 µg/mL. Furthermore, the propolis comprises compounds like curcumin and other flavonoids sourced from flavone, which possess the potential for photodynamic activity and other antimicrobial functions. Consequently, Brazilian green propolis holds promise as an excellent bactericidal agent, displaying a synergistic antibacterial property enhanced by light-induced photodynamic effects.

Brazilian green propolis prevent Alzheimer's disease-like cognitive impairment induced by amyloid beta in mice.

BACKGROUND: The increasing incidence of cognitive impairment has become a health problem in the aging society. Owing to its antioxidant and anti-inflammatory properties, Brazilian green propolis-derived from Baccharis dracunculifolia-is anticipated to possess anticognitive properties. However, the preventive effect of Brazilian green propolis on cognitive impairment remains unexplained. This study aimed to investigate the effect of Brazilian green propolis on cognitive impairment using a mouse model of Alzheimer's disease (AD) induced by intracerebroventricular injection of amyloid beta (Aß)25‒35. METHODS: Five-week-old male Slc:ddY mice were randomly divided into five groups (n = 8). The groups were pretreated with vehicle and propolis at a dose of 100, 300 and 900 mg/kg body weight for 8 days, then AD-like phenotypes were induced by intracerebroventricular (ICV) injection of Aß25‒35. A sham operation group was set as the control. Memory and learning ability were measured at 7 to 8 days after ICV injection. Gene expression and histological studies were performed at the endpoint of the study. RESULTS: In a passive avoidance test, the administration of Brazilian green propolis prevented the impairment of learning and memory function. Furthermore, comprehensive gene expression analysis in the hippocampus and forebrain cortex revealed that Brazilian green propolis suppressed Aß25-35-induced inflammatory and immune responses. In particular, Brazilian green propolis prevented alterations in gene expressions of microglial and astrocytic markers such as Trem2 and Lcn2 induced by Aß25‒35 injection, suggesting the suppression of excessive activation of glial cells in the brain. In addition, Brazilian green propolis suppressed the elevation of plasma interleukin (IL)-6 levels induced by Aß25‒35 injection. CONCLUSIONS: The results suggest that the prophylactic administration of Brazilian green propolis has a preventive effect against AD by suppressing excessive inflammation and immune response in glial cells. To our knowledge, this study is the first to demonstrate that Brazilian green propolis may inhibit the hyperactivation of microglia and astrocytes as a mechanism of action to prevent AD. Thus, it is a promising ingredient for preventing AD-type dementia.

Development and Characterization of New Green Propolis Extract Formulations as Promising Candidates to Substitute for Green Propolis Hydroalcoholic Extract.

The technologies used to produce the different dosage forms of propolis can selectively affect the original propolis compounds and their biological activities. The most common type of propolis extract is hydroethanolic. However, there is considerable demand for ethanol-free propolis presentations, including stable powder forms. Three propolis extract formulations were developed and investigated for chemical composition and antioxidant and antimicrobial activity: polar propolis fraction (PPF), soluble propolis dry extract (PSDE), and microencapsulated propolis extract (MPE). The different technologies used to produce the extracts affected their physical appearance, chemical profile, and biological activity. PPF was found to contain mainly caffeic and p-Coumaric acid, while PSDE and MPE showed a chemical fingerprint closer to the original green propolis hydroalcoholic extract used. MPE, a fine powder (40% propolis in gum Arabic), was readily dispersible in water, and had less intense flavor, taste, and color than PSDE. PSDE, a fine powder (80% propolis) in maltodextrin as a carrier, was perfectly water-soluble and could be used in liquid formulations; it is transparent and has a strong bitter taste. PPF, a purified solid with large amounts of caffeic and p-Coumaric acids, had the highest antioxidant and antimicrobial activity, and therefore merits further study. PSDE and MPE had antioxidant and antimicrobial properties and could be used in products tailored to specific needs.

Potential Use of Brazilian Green Propolis Extracts as New Photosensitizers for Antimicrobial Photodynamic Therapy against Cariogenic Microorganisms.

The synergic effect of Streptococcus mutans and Candida albicans increases dental caries severity. Antimicrobial photodynamic therapy (aPDT) is a non-invasive treatment for antimicrobial aspects. However, the current photosensitizers (PS) have many downsides for dental applications. This study aimed to evaluate the efficiency of two different Brazilian green propolis (BGP-AF and BGP-AG) as PS for aPDT against these microorganisms. A single-species biofilm was irradiated with crude extracts and their fractions and controls. Such extracts showed the best results and were evaluated in dual-species biofilms. Photodegradation, reactive oxygen species (ROS), cytotoxicity, and color stability assays were also investigated. Reductions higher than 3 log10 CFU/mL (p < 0.0001) occurred for crude BGP in single- and dual-species biofilms. Singlet oxygen was produced in BGP (p < 0.0001). BGP-mediated aPDT delayed S. mutans and C. albicans regrowth after 24 h of treatment (p < 0.0001). Both BGP did not change the color of dental materials (p > 0.05). BGP-AF-mediated aPDT showed 72.41% of oral keratinocyte viability (p < 0.0001). BGP extracts may be used in aPDT against S. mutans and C. albicans. Specifically, BGP-AF may represent a promising PS for dental applications.

Brazilian green propolis improves gut microbiota dysbiosis and protects against sarcopenic obesity.

INTRODUCTION: Brazilian green propolis is an important honeybee product that is considered beneficial for health. Here, we examined the therapeutic potential of dietary supplementation with propolis against sarcopenic obesity using Db/Db mice. METHODS: Db/m mice fed a normal diet alone and Db/Db mice fed normal diet alone, or supplemented with different amounts of propolis (0.08, 0.4 and 2%), were examined for effects on sarcopenic obesity. RESULTS: Propolis improved the glucose tolerance (P < 0.001), increased the grip strength (P < 0.001) and the weight of soleus (P = 0.006) and plantaris muscles (P = 0.008). Moreover, propolis improved the non-alcoholic fatty liver disease activity score (P < 0.001) and decreased the expression of genes related to inflammation, liver fibrosis and fatty acid metabolism. Propolis decreased the accumulation of saturated fatty acids in the liver and increased their excretion in faeces. With regard to the innate immunity, propolis decreased the ratio of M1 macrophages (P = 0.008) and Type 1 and 3 innate lymphoid cells to CD45-positive cells (P < 0.001) and increased the ratio of M2 macrophages (P = 0.002) and ILC2s (P = 0.007) in the liver. Additionally, propolis decreased the expression of genes related to muscle atrophy and inflammation and the concentration of saturated fatty acids in the soleus muscle. 16S rRNA phylogenetic sequencing revealed that propolis increased the Bacteroidetes/Firmicutes ratio, and the abundance of Butyricicoccus and Acetivibrio genera. Gut microbiota related to the pentose phosphatase pathway and glycerolipid metabolism was more prevalent after the administration of propolis. CONCLUSIONS: This is the first study to demonstrate that propolis can improve sarcopenic obesity by improving dysbiosis due to overeating and provides new insights into diet-microbiota interactions during sarcopenic obesity.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by artepillin C, a major component of Brazilian green propolis.

OBJECTIVES: In this report, we attempt to clarify the immune modulatory effects of Brazilian green propolis (BGP) and its major component, artepillin C, on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells. We also estimate the physiological mechanism affecting artepillin C's upon the cells. METHODS: Male C3H/HeN mouse spleen cells stimulated by antiCD3 monoclonal antibody were co-cultured with BGP, artepillin C, and HC030031, a transient receptor potential ankyrin 1 (TRPA1) Ca2+ channel antagonist. The synthesis of interferon (IFN)-γ, interleukin (IL)-6, IL-17, IL-4, IL-10, and IL-2 was assayed by enzyme-linked immunoassay. The expression of IL-2 mRNA and the protein product were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively. RESULTS: The production of IL-2 was markedly enhanced, while that of IL-4 and IL-10 was not significantly affected; by contrast, the production of IFN-γ, IL-6, and IL-17 was significantly reduced in the antibody-stimulated spleen cells treated with BGP at a non-cytostatic concentration. These effects were reproduced in the cells treated with artepillin C. The expression of IL-2 mRNA was unaffected; however, that of the protein was significantly enhanced in the artepillin C-treated cells compared to untreated control cells. The enhancement of protein expression and the production of IL-2 by artepillin C was significantly alleviated by adding HC030031. CONCLUSIONS: Artepillin C is an important regulator of cytokine synthesis from activated spleen cells. The agent specifically augmented the expression of IL-2 via the Ca2+-permeable cation channel, TRPA1, at least in part, at the translational or secretion levels.

Metabolic pathways of cinnamic acid derivatives in Brazilian green propolis in rats.

Cinnamic acid derivatives, which are dietary phenolic compounds, are attracting attention for their health benefits. Artepillin C, drupanin, baccharin, and p-coumaric acid are major cinnamic acid derivatives in Brazilian green propolis (BGP) used as functional food materials. To investigate the metabolism of these cinnamic acid derivatives, each compound was administered to rats, and their metabolic profiles were compared with those administered with BGP. Artepillin C is metabolized to hydroxylated metabolites (capillartemisin A), as well as glucuronide. Drupanin sulfate, glucuronide, and hydroxylated form were detected in plasma both after ingestion of drupanin and its 3-phenylpropionic acid ester (baccharin). p-Coumaric acid underwent sulfation, but not glucuronidation. These results reveal that the metabolic pathways of cinnamic acid derivatives in rats comprise ester hydrolysis and hydroxylation, as well as phase-II conjugation. Our findings may provide significant information for estimating the potential activity of various cinnamic acid derivatives derived from functional food materials.

Baccharin from Brazilian green propolis induces neurotrophic signaling pathways in PC12 cells: potential for axonal and synaptic regeneration.

Neurodegenerative diseases are characterized by progressive loss of the structure and function of specific neuronal populations, and have been associated with reduced neurotrophic support. Neurotrophins, like NGF (nerve growth factor), are endogenous proteins that induce neuritogenesis and modulate axonal growth, branching, and synapsis; however, their therapeutic application is limited mainly by low stability, short half-life, and inability to cross the blood-brain barrier (BBB). Small neurotrophic molecules that have suitable pharmacokinetics and are able to cross the BBB are potential candidates for neuroprotection. Baccharin is a bioactive small molecule isolated from Brazilian green propolis. In the present study, we investigated the neurotrophic and neuroprotective potential of baccharin in the PC12 cell neuronal model. We used pharmacological inhibitors (K252a, LY294002, and U0126), and ELISA (phospho-trkA, phospho-Akt, and phospho-MEK) to investigate the involvement of trkA receptor, PI3k/Akt pathway, and MAPK/Erk pathway, respectively. Additionally, we evaluated the expression of axonal (GAP-43) and synaptic (synapsin I) proteins by western blot. The results showed that baccharin induces neuritogenesis in NGF-deprived PC12 cells, through activation of trkA receptor and the downstream signaling cascades (PI3K/Akt and MAPK/ERK), which is the same neurotrophic pathway activated by NGF in PC12 cells and neurons. Baccharin also induced the expression of GAP-43 and synapsin I, which mediate axonal and synaptic plasticity, respectively. Additionally, in silico predictions of baccharin showed favorable physicochemical properties, pharmacokinetics, drug-likeness, and medicinal chemistry friendliness. Altogether, these findings suggest that baccharin is a promising neurotrophic agent whose therapeutic application in neurodegeneration should be further investigated.

Brazilian green propolis reduces worm burden and hepatic granuloma formation in a Schistosoma mansoni experimental murine model.

Characterized as an acute and chronic parasitic disease, schistosomiasis mansoni has as its central pathology the formation of hepatic granulomas in response to the parasite's eggs trapped in the host's liver. In recent years, research on propolis has grown; however, there is little anthelmintic work on this bee product. In the propolis scenario, Brazilian ones receive attention, with green and red propolis standing out. This study aims to evaluate in vivo the standardized extract of Brazilian green propolis (Pex) against Schistosoma mansoni. The in vivo antiparasitic activity of Pex was conducted in female BALB/c mice infected with S. mansoni and of the three groups treated with Pex (300 mg/kg); G2 (35th to 42nd dpi) reduced the total worm burden by 55.32%, followed by G3 (42nd to 49th dpi) and G4 (49th to 56th dpi), with about 46%. Furthermore, G2 significantly reduced the total egg load in the ileum (59.33%) and showed an increase in the dead eggs. Similarly, histological analysis of the livers showed a significant reduction in the number and diameter of the granulomas. Based on these results, there is an interesting schistosomicidal activity of Pex and its potential against the formation of hepatic granulomas, paving the way for more detailed studies of propolis in the animal model of schistosomiasis mansoni.

Brazilian green propolis promotes TNFR2 expression on regulatory T cells.

FoxP3+ regulatory T cells (Tregs) are needed to suppress inflammatory diseases and maintain immune homeostasis. The suppressive function of Tregs can be used to control autoimmune or inflammatory diseases; therefore, it is well studied how Tregs can be artificially up- or downregulated in vitro and in vivo, by using antibodies, chemical compounds, foods, and natural resources. Propolis is a famous functional food that has an anti-inflammatory effect. However, the influences of propolis on Treg function have not been fully evaluated so far. Here, we demonstrated that Brazilian green propolis increases TNFR2 expression in Tregs via the IRF4/cMyc axis, and artepillin C was a major effective component of propolis on Tregs. These results indicate that propolis and artepillin C have the potential as Treg activators via TNFR2 expression and may be useful for the prevention and/or therapy of autoimmune or inflammatory diseases.

Development and validation of a UHPLC-ESI-MS/MS method for the quantification of artepillin C in Brazilian green propolis

Objectives: The aim of this study was the development and validation of a fast method to quantify artepillin C in green propolis using ultra high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS). Methods: High purity (97.8%) artepillin C was isolated from green propolis using chromatography techniques. Quantification was performed using a C18 (2.1 x 100 mm; 1.7 µm) column, gradient of water and methanol (with 0.01% formic acid) as mobile phase, at a flow rate of 0.4 mL/min and 45 ºC in temperature. A mass spectrometer operated in selected reaction monitoring mode to monitor the deprotonated molecular ion of artepillin C (m/z 299) > fragment ion (m/z 200.12). Several parameters such as specificity, linearity, limit of detection (LOD), limit of quantitation (LOQ), precision, accuracy, and robustness were determined. Results: The method was linear in the 50 ­ 400 µg/mL range (r2 = 0.9906), showing LOD = 10.79 µg/mL and LOQ = 32.70 µg/mL with satisfactory intra-day and inter-day precision with relative standard deviation (RSD %) of 1.9% and 3.4%, respectively. The accuracy showed recovery of 93-104%, the method was robust and artepillin C was quantified in green propolis at 6.51%. Conclusions: The proposed method showed advantages in comparison with other methods, such as short analysis time and high selectivity for artepillin C.

Molecular Insights into the Antistress Potentials of Brazilian Green Propolis Extract and Its Constituent Artepillin C.

Propolis, also known as bee-glue, is a resinous substance produced by honeybees from materials collected from plants they visit. It contains mixtures of wax and bee enzymes and is used by bees as a building material in their hives and by humans for different purposes in traditional healthcare practices. Although the composition of propolis has been shown to depend on its geographic location, climatic zone, and local flora; two largely studied types of propolis: (i) New Zealand and (ii) Brazilian green propolis have been shown to possess Caffeic Acid Phenethyl Ester (CAPE) and Artepillin C (ARC) as the main bioactive constituents, respectively. We have earlier reported that CAPE and ARC possess anticancer activities, mediated by abrogation of mortalin-p53 complex and reactivation of p53 tumor suppressor function. Like CAPE, Artepillin C (ARC) and the supercritical extract of green propolis (GPSE) showed potent anticancer activity. In this study, we recruited low doses of GPSE and ARC (that did not affect either cancer cell proliferation or migration) to investigate their antistress potential using in vitro cell based assays. We report that both GPSE and ARC have the capability to disaggregate metal- and heat-induced aggregated proteins. Metal-induced aggregation of GFP was reduced by fourfold in GPSE- as well as ARC-treated cells. Similarly, whereas heat-induced misfolding of luciferase protein showed 80% loss of activity, the cells treated with either GPSE or ARC showed 60-80% recovery. Furthermore, we demonstrate their pro-hypoxia (marked by the upregulation of HIF-1α) and neuro-differentiation (marked by differentiation morphology and upregulation of expression of GFAP, ß-tubulin III, and MAP2). Both GPSE and ARC also offered significant protection against oxidative stress and, hence, may be useful in the treatment of old age-related brain pathologies.

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.

Effects of Brazilian green propolis extract on planktonic cells and biofilms of multidrug-resistant strains of Klebsiella pneumoniae and Pseudomonas aeruginosa.

Propolis could represent an alternative therapeutic agent for targeting multidrug-resistant bacteria due to its antimicrobial potential. The effect of Brazilian green propolis (BGP) aqueous extract (AqExt) was evaluated on eight multidrug-resistant clinical strains of Klebsiella pneumoniae and Pseudomonas aeruginosa, as well as on one reference strain for each bacterial species. The minimum bactericidal concentration (MBC) was determined and optimal concentrations were further evaluated in comparison with 0.12% chlorhexidine. The natural extract was chemically characterized by HPLC-DAD analysis. The MBC values ranged between 3.12 and 27.5 mg ml-1. Analysis of bacterial metabolic activity after treatment for 5 min with BGP-AqExt revealed a strong antimicrobial potential, similar to chlorhexidine. The extract comprised several active compounds including quercetin, gallic acid, caffeic and p-coumaric acid, drupani, galangin, and artepillin C. Altogether, the findings suggest that BGP-AqExt is fast and effective against multidrug-resistant strains of K. pneumoniae and P. aeruginosa in planktonic cultures and biofilms.

Isolation, Identification, and Synthesis of a New Prenylated Cinnamic Acid Derivative from Brazilian Green Propolis and Simultaneous Quantification of Bioactive Components by LC-MS/MS.

A new cinnamic acid derivative, (E)-3-[4-hydroxy-3-((E)-3-formyl-2-butenyl)phenyl]-2- propenoic acid (20) has been isolated from the ethanol extract of Brazilian green propolis along with three known cinnamic acid derivatives, 3,4-dihydroxy-5-prenyl-(E)-cinnamic acid (4), capillartemisin A (6), and 2,2-dimethylchromene-6-(E)-propenoic acid (8), and a flavonoid, dihydrokaempferide (16) by liquid-liquid participation, a series of column chromatography and preparative HPLC. Their structures have been determined by spectroscopic analyses and chemical synthesis of compound 20. The simultaneous quantification of 20 constituents, including 10 cinnamic acid derivatives, 7 flavonoids, and 3 caffeoylquinic acid derivatives, has also been developed and validated using LC-MS/MS. The new compound 20 was shown to activate PPAR α but not PPAR ß or γ.