Red Propolis Extract Research Articles

Toxicity Assessment of Biogenic Gold Nanoparticles on Crop Seeds and Zebrafish Embryos: Implications for Agricultural and Aquatic Ecosystems.

The demand for food production has been growing exponentially due to the increase in the global population. Innovative approaches to enhance agricultural productivity have been explored, including the new applications of nanoparticles in agriculture. The nanoparticle application in agriculture can generate environmental and human health risks since nanoparticles can contaminate the soil and inevitably reach groundwater, potentially causing toxicity in aquatic organisms. In this study, we evaluated the benefits and toxicity of gold nanoparticles (GNPs), synthesized via green chemistry, on the growth of cultivated plants and in the zebrafish embryo model. GNPs were synthesized through an economical and environmentally friendly method using Brazilian red propolis (BRP) extract (BRP-GNPs). BRP-GNPs exhibited negative and positive effects on plant germination, depending on the concentration tested and the plant species involved. Moreover, BRP-GNPs induced developmental toxicity in fish embryos in a dose-dependent manner. Our results provide valuable insights for assessing the environmental risks of biogenic GNPs.

Antimicrobial, Antioxidant, and Anticancer Effects of Nanoencapsulated Brazilian Red Propolis Extract: Applications in Cancer Therapy

This study evaluates the antimicrobial, antioxidant, and anticancer effects of Brazilian red propolis extract (BRPE) and its nanoencapsulated form (NCBRPE) to address bacteria and conditions associated with the ovarian cancer microenvironment. The NCBRPE showed an average size of 178.3 ± 3.3 nm, a polydispersity index (PdI) of 0.06, and an encapsulation efficiency exceeding 97% for the main bioactive compounds of propolis. Antimicrobial assays revealed that BRPE exhibited minimum inhibitory concentrations (MICs) ranging from 4 to 256 mg/L against seven bacterial strains, while NCBRPE demonstrated sustained efficacy, with a biofilm inhibitory concentration (BIC) of 128 mg/L against Burkholderia cepacia. In clonogenic assays, NCBRPE reduced long-term cancer cell proliferation, achieving a 10-fold decrease in colony formation compared to untreated controls, significantly outperforming BRPE. Flow cytometry indicated that NCBRPE induced apoptosis in 29% ± 0.4 of ovarian cancer cells (OVCAR-3). Additionally, the DPPH assay confirmed the antioxidant activity of NCBRPE, demonstrating that it retained most of the extract’s original antioxidant capacity. This was further supported by oxidative burst assays, which showed a significant reduction in reactive oxygen species (ROS) production in neutrophils. These findings position NCBRPE as a multi-functional therapeutic candidate for managing infections, oxidative stress, and tumor progression in the ovarian cancer microenvironment.

Bioactive metabolites of Brazilian Red Propolis: Cytotoxic, antimalarial, and antimicrobial properties.

Brazilian Red Propolis (BRP) is a natural product known for its rich chemical composition and therapeutic potential. This study investigates the phytochemical profile and evaluates the cytotoxic, antiplasmodial, and antimicrobial properties of red propolis extract and its isolated compounds vestitol (1), neovestitol (2), medicarpin (3), 7-O-methylvestitol (4), and oblongifolin B (5). The extract showed selective cytotoxicity against cancer cell lines (IC50: 16-39 μg/mL). Compound 3 exhibited a promising cytotoxicity against SK-OV-3 with and IC50 of 6.65 μM. BRP had moderate antimicrobial effects; however, 3 was effective against Cryptococcus neoformans (IC50: 19.29 μM), while 5 was active against Pseudomonas aeruginosa (IC50: 15.77 μM). BRP exhibited antiplasmodial activity against Plasmodium falciparum strains D6 and W2 (IC50: 13.8 μg/mL and 5.7 μg/mL); also, 4 and 5 had IC50 concentrations ranging from: 2.99-6.96 μM). Molecular docking for P. falciparum lactate dehydrogenase (PfLDH), suggest that compound 4 has significant interactions with critical residues in the PfLDH active site, such as TYR85, THR97, and ASP53, and falls within optimal ranges for oral bioavailability. These findings highlight the significant bioactive potential of BRP and its compounds, suggesting their potential as therapeutic agents in vitro and in-silico. Further studies are recommended to explore their mechanisms of action and therapeutic applications.

Adding red propolis to the diet of Lacaune lambs: Effects on animal health, ruminal environment, performance, and meat quality

This study determined the influence of red propolis ethanolic extract in lambs' diets on the ruminal environment, animal health, and growth. Two experiments were carried out to achieve these objectives. Pilot study: Twenty-four female Lacaune lambs were divided into four groups, with three replicates and two animals per replicate (pen): T0 (Control), TP1.3, TP2.7, and TP5.3, representing 0, 1.3, 2.7, and 5.3 mL of propolis extract per animal/day, respectively. The highest daily weight gain was observed in lambs that consumed 2.7 mL of propolis extract per day, and they also had the lowest feed conversion rate compared to the control. Lower total leukocyte counts were observed in lambs that consumed propolis extract compared to control due to lower granulocyte and lymphocyte counts. Ceruloplasmin and C-reactive protein levels were lower in the serum of lambs that consumed propolis compared to the control. Lambs that consumed 1.3 and 2.7 mL of propolis extract had lower TBARS levels than the control. The effect of treatment was observed for ruminal pH, which was higher in lambs that consumed propolis extract than in control. A lower concentration of short-chain fatty acids was observed in lambs that consumed propolis than the control due to lower concentrations of acetic and butyric acid. In experiment II, 36 male Lacaune lambs were selected and divided into two groups: MONENSIN (23.45 ppm of monensin per kg/dry matter (DM)) and PROPOLIS (3.8 mL of propolis per animal/day). The animals that consumed propolis extract had greater body weight, weight gain, and average daily gain. These also had a shorter time to reduce methylene blue, thus demonstrating more significant bacterial activity in the rumen. Furthermore, they had lower counts of Escherichia coli, total coliforms, and Enterobacteria. The meat's fatty acid profile in animals fed the red propolis extract showed higher concentrations of monounsaturated fatty acids. In conclusion, adding red propolis extract to the concentrate increased weight gain, average daily gain, and oxidative balance with an antimicrobial and anti-inflammatory effect.

Development of a Benzophenone-Free Red Propolis Extract and Evaluation of Its Efficacy against Colon Carcinogenesis.

Brazilian red propolis has attracted attention for its pharmacological properties. However, signs of toxicity were recently observed in long-term studies using the hydroalcoholic extract of red propolis (RPHE), likely due to polyprenylated benzophenones. This study aimed to develop a benzophenone-free red propolis extract (BFRP) and validate an HPLC-PDA method to quantify its main constituents: isoliquiritigenin, vestitol, neovestitol, medicarpine, and 7-O-methylvestitol. BFRP's toxicity was assessed in zebrafish larvae through a vibrational startle response assay (VSRA) and morphological analysis. Genotoxicity was evaluated using the micronucleus test in rodents, and the extract's effects on chemically induced preneoplastic lesions in rat colon were studied. An HPLC-PDA method was used to quantify BFRP's main compounds. BFRP primarily contained vestitol (128.24 ± 1.01 μg/mL) along with isoliquiritigenin, medicarpin, neovestitol, and 7-O-methylvestitol. Zebrafish larvae exposed to 40 µg/mL of BFRP exhibited toxicity, higher than the 10 µg/mL for RPHE, though no morphological differences were found. Fluorescent staining in the notochord, branchial arches, and mouth was observed in larvae treated with both BFRP and RPHE. No genotoxic or cytotoxic effects were observed up to 2000 mg/kg in rodents, with no impact on hepatotoxicity or nephrotoxicity markers. Chemoprevention studies showed a 41.6% reduction in preneoplastic lesions in rats treated with 6 mg/kg of BFRP. These findings indicate that BFRP is a safe, effective propolis-based extract with potential applications for human health, demonstrating reduced toxicity and chemopreventive properties.

Preparative Fractionation of Brazilian Red Propolis Extract Using Step-Gradient Counter-Current Chromatography.

Propolis is a resinous bee product with a very complex composition, which is dependent upon the plant sources that bees visit. Due to the promising antimicrobial activities of red Brazilian propolis, it is paramount to identify the compounds responsible for it, which, in most of the cases, are not commercially available. The aim of this study was to develop a quick and clean preparative-scale methodology for preparing fractions of red propolis directly from a complex crude ethanol extract by combining the extractive capacity of counter-current chromatography (CCC) with preparative HPLC. The CCC method development included step gradient elution for the removal of waxes (which can bind to and block HPLC columns), sample injection in a single solvent to improve stationary phase stability, and a change in the mobile phase flow pattern, resulting in the loading of 2.5 g of the Brazilian red propolis crude extract on a 912.5 mL Midi CCC column. Three compounds were subsequently isolated from the concentrated fractions by preparative HPLC and identified by NMR and high-resolution MS: red pigment, retusapurpurin A; the isoflavan 3(R)-7-O-methylvestitol; and the prenylated benzophenone isomers xanthochymol/isoxanthochymol. These compounds are markers of red propolis that contribute to its therapeutic properties, and the amount isolated allows for further biological activities testing and for their use as chromatographic standards.

Red propolis extract reduces the lipid oxidation of lamb meat

Context Brazilian red propolis stands out for its diverse composition, which includes phenolic compounds whose effects may be similar to those of synthetic feed additives. Aims The objective of this study was to evaluate the effects of red propolis extract on the carcass and meat characteristics of lambs finished under confinement conditions. Methods The meat quality characteristics of the longissimus lumborum muscle were evaluated in 35 Santa Inês lambs, with an average age of 5 months and an initial average body weight of 17.08 ± 2.36 kg (mean ± s.d.), submitted to five distinct treatments (0, 7, 14, 21, 28 mL of red propolis extract/animal.day) over 68 days. Key results The use of propolis did not affect (P > 0.05) the characteristics of the carcass, as well as the chemical composition and cholesterol content. Among the physico-chemical parameters of meat, only the shear force had a quadratic effect (P < 0.05). There was also an exponential effect for lipid oxidation (P < 0.05), where the treatment with propolis had greater antioxidant effect. Meat with a lower content (P < 0.05) of saturated fatty acids was observed in sheep that received extract. There was also an increase (P < 0.05) in the content of monounsaturated acids and consequently an improvement in nutritional quality, atherogenicity and thrombogenicity indexes of desirable fatty acids. Conclusions The red propolis extract improved the lipid profile of the lamb meat. We recommend the inclusion of 7 mL red propolis extract/animal.day (or 59.50 mg total flavoloids/animal.day) in the diet of lambs finished under confinement conditions. Implications The red propolis extract proved to be a viable alternative as a natural feed additive.

Effect of Adding Red Propolis to Edible Biodegradable Protein Films for Coating Grapes: Shelf Life and Sensory Analysis.

Red propolis is an active ingredient of great nutritional interest which offers numerous benefits as an antioxidant and antimicrobial agent. Thus, the objective of this research was to evaluate the application of an edible and antimicrobial gelatine coating containing red propolis to increase the shelf life of grapes. Gelatine films with an addition of 5, 10, 15, 20 and 25% of red propolis extract were produced to evaluate their antimicrobial activity using the disk diffusion test in solid media. The films with 25% red propolis extract showed antimicrobial activity against the bacteria Staphylococcus aureus and Pseudomonas aeruginosa. The grapes were coated with pure gelatine, without a plasticizer and with gelatine with 25% red propolis and then stored for 1, 4, 10, 19 and 25 days at temperatures of 25 °C and 5 °C. The results showed that the gelatine coating with propolis reduced the mass loss of grapes stored at 25 °C for 19 days by 7.82% and by 21.20% for those kept at 5 °C for 25 days. The pH, total titratable acidity, soluble solids and color of the grapes increased due to the ripening process. Furthermore, the sensory acceptability indexes of the refrigerated grapes with coatings were superior (>78%) to those of the control samples (38%), proving the effectiveness of the coatings in maintaining the quality of grapes during storage.

Red Propolis Prevents Lipid Oxidation and Reduces Microbial Growth in Fish Nuggets with Green Banana Flour

ABSTRACT Green banana flour (GBF) and hydroalcoholic extract of red propolis (HERP) imporve the nutricional quality and preservation of fish nuggets. The nuggets were formulated using 13% of GBF and different concentrations (0%, 0.4%, 0.6%, and 0.8%) of the HERP, while the control was without the addition of GBF and HERP. The addition of the HERP influenced (p < .05) the acceptance of the sensory attributes, with an acceptability index > 70%. The nuggets containing 0.4% of HERP presented ash, lipid, resistant starch, and polyphenol contents superior (p < .05) to the commercial brand fish nugget sample. After 15 days stored at 4°C, the nuggets treated with the HERP presented lower lipid oxidation and psychrotrophic counts, when compared to samples added with sodium erythorbate. The use of GBF improved the nutritional quality of the fish nuggets and EHPV reduced the lipid oxidation of the samples.

Red propolis extract associated to platelet-rich plasma and stromal cells with focus in cell therapy and functional tissue regeneration.

The use of platelet-rich plasma (PRP) and adipose-derived stromal cells (ADSC) have been investigated as a form of wound healing enhancement. The objective of this work was to evaluate the association of red propolis (RP) and PRP as inducers of ADSC for application in tissue regeneration. Adipose tissue post-collection and post-cryopreservation was isolated with type II collagenase, characterized by flow cytometry, and differentiated into osteogenic, chondrogenic and adipose cell. The viability of ADSC was evaluated when exposed to different concentrations of RP using the MTT and trypan blue assay. Acridine orange and ethidium bromide (AO/EB) was performed to evaluate cell death events. Horizontal migration methods were investigated in ADSC using autologous and homologous PRP associated with RP (PRP/RP). All assays were processed in triplicate. Flow cytometry and cellular differentiation showed that type II collagenase was effective for isolating ADSC post-collection and post-cryopreservation. RP extracts at concentrations of up to 50 μg.mL-1 presented no cytotoxic effects. Association of PRP and RP at 25 and 50 μg.ml-1 influenced ADSC migration, with total closure on the seventh day after exposition. The results here presented could stimulate proliferation of ADSC cells that may contribute directly or indirectly to the reconstructive process of tissue regeneration.

Non-carcass components of confined lambs in feedlot using red propolis extract

The objective of this work was to evaluate the non-carcass components of crossbred Santa Inês lambs finished in feedlot with the inclusion of different levels of red propolis extract (RPE). Thirty-five crossbred lambs were used with an average weight of 17.08 ± 2.36 kg and mean age of five months, distributed in a completely randomized design with five treatments and seven replications. The treatments evaluated were: 0; 7; 14 and 21 mL of extract/animal/day Before slaughter, each animal was individually weighed to obtain the body weight at slaughter (BWS). The weights and yields of non-carcass components were evaluated, weights and yields of regional dishes (Buchada and Panelada). The addition of different levels of red propolis extract (RPE) did not influence (p &gt; 0.05) the weights and yields of non-carcass components, by-products and adipose deposits, to the weight and yield of regional dishes. The use of red propolis extract in diets up to the level studied (28 mL day-1) did not change the characteristics evaluated.

Study of the Oxidative and Microbiological Stability of Nitrite-Reduced, Vacuum-Packed, Refrigerated Lamb Sausages Supplemented with Red Propolis Extract.

Vacuum-packed lamb sausages with or without red propolis extract and a reduced sodium nitrite content were evaluated for oxidative and microbiological stability during storage for 21 days at 2 °C. The following treatments were evaluated: EN150 (control, base formulation (BF) + 500 mg/kg sodium erythorbate and 150 mg/kg sodium nitrite); EN75 (BF + 500 mg/kg sodium erythorbate and 75 mg/kg sodium nitrite); P1N75 (without the addition of erythorbate, BF + 1800 mg/kg propolis extract and 75 mg/kg sodium nitrite); and P2N75 (without the addition of erythorbate, BF + 3600 mg/kg propolis extract and 75 mg/kg sodium nitrite). Analyses were conducted to characterize the samples on day 0 with respect to the proximate composition (moisture, protein, fat, and ash) and sensory acceptance. Stability during refrigerated storage was evaluated on days 0, 7, 14 and 21 for the parameters pH, color profile (L*, a*, and b*), TBARs index (oxidative stability) and microbiological count of aerobic psychrotrophic microorganisms. Texture profile, cooking weight loss (WLC), peroxide index and free fatty acids were evaluated on days 0 and 21. The treatments with propolis and reduced nitrite (EN150 and P1N75) showed a red color intensity (a*) similar to the treatment with erythorbate and the same nitrite content (EN75) at the end of storage, maintaining the characteristic reddish color of the sausages. The extract slowed down lipid oxidation during storage, especially P2N75, which showed the lowest level of TBARS (0.39 mg MDA/kg) and the peroxide index (2.13 mEq g O2) on day 21. The residual nitrite value in EN75 was the lowest (p < 0.05) on day 21, showing that synthetic antioxidants are more efficient than the extract in nitrite reduction reactions. The results for the counts of psychrotrophic microorganisms showed that the extract did not have the expected antimicrobial effect on the growth of this microorganisms, and leveling the results revealed no differences (p < 0.05) between the treatments. Despite the red propolis extract not showing a significant antimicrobial improvement in lamb sausages, it can be considered a healthy option with good prospects for replacing synthetic antioxidants with a natural product.

Red propolis extract as a natural ionophore for confined sheep: performance and morphological and histopathological changes

Red propolis extract as a natural ionophore for confined sheep: performance and morphological and histopathological changes

Effects of simulated gastrointestinal digestion/epithelial transport on phenolics and bioactivities of particles of brewer’s spent yeasts loaded with Brazilian red propolis

Red propolis from northeast Brazil contains mainly isoflavonoids as bioactive compounds, and its consumption may counteract unregulated and exacerbated formation of reactive oxygen species and inflammatory cytokines/chemokines. Moreover, the production of particles using sustainable carriers have been studied to increase the use of propolis as a functional food ingredient. Hence, the objective of this work was to investigate the effects of simulated gastrointestinal digestion followed by a cell-based epithelial transport on phenolic profile, anti-inflammatory and antioxidant activities of particles of brewer’s spent yeasts (BSY) loaded with ethanolic extract of Brazilian red propolis (EEP). As a result, the EEP phenolic diversity decreased throughout the simulated gastrointestinal system, and was modulated by the particle production, as detected by high-performance liquid chromatography – electrospray ionization – quadrupole-time-of-flight-mass spectrometry (HPLC-ESI-QTOF-MS). Concomitantly, the antioxidant activity, as assessed by the ability to scavenge peroxyl and superoxide radicals, hydrogen peroxide, and hypochlorous acid, generally decreased at a higher extent for the particles of EEP with BSY (EEP-BSY) throughout the experiments. Nonetheless, after epithelial transport through the Caco-2 cell monolayer, the basolateral fraction of both EEP-BSY and EEP decreased the activation of pro-inflammatory transcription factor NF-κB by 83% and 65%, respectively, as well as the release of TNF-α (up to 51% and 38%, respectively), and CXCL2/MIP-2 (up to 33% and 25%, respectively). Therefore, BSY may be an interesting carrier for EEP bioencapsulation, since it preserves its anti-inflammatory activity. Further studies should be encouraged to investigate the feasibility of adding it in formulations of functional foods, considering its effect on sensory attributes.

Brazilian red propolis extract free and encapsulated into polymeric nanoparticles against ovarian cancer: formulation, characterisation and biological assays in 2D and 3D models.

The aims of this work were to develop polymeric nanoparticles with Brazilian red propolis extract and compare their action with the free extract against ovarian cancer cells. Box Behnken design was used and nanoparticles were characterised using the techniques dynamic light scattering, nanoparticle tracking analysis, transmission electron microscopy, differential scanning calorimetry and encapsulation efficiency. Activity against OVCAR-3 was also tested on 2D and 3D models. Nanoparticles' sizes were ~200 nm with monomodal size distribution, negative zeta potential, spherical shape and with extract molecularly dispersed. Encapsulation efficiency was above 97% for the biomarkers chosen. Nanoparticles had greater efficacy in comparison with free propolis in OVCAR-3. So far, the nanoparticles here described have the potential to be a chemotherapy treatment in the future.

Anti-Inflammatory, Antimicrobial, Antioxidant and Photoprotective Investigation of Red Propolis Extract as Sunscreen Formulation in Polawax Cream

Many activities have been described for propolis, including, antiviral, antibacterial, antifungal, anti-inflammatory, immunoregulatory, antioxidant and wound healing properties. Recently, propolis has been highlighted due to its potential application in the pharmaceutical and cosmetic industries, motivating a better understanding of its antioxidant and anti-inflammatory activities. Propolis and its main polyphenolic compounds presented high antioxidant activity, and effectiveness as broad spectrum UVB and UVA photoprotection sunscreens. Through a qualitative phytochemical screening, the ethanolic red propolis extracts (EEPV) (70% at room temperature and 70% at a hot temperature) presented a positive result for flavonoids and terpenoids. It presented an antioxidant activity for reducing 50% of DPPH of 17 and 12 μg/mL for extraction at room temperature and at a hot temperature, respectively. The UPLC-QTOF-MS/MS analysis allowed the annotation of 40 substances for EEPV-Heated and 42 substances for EEPV-Room Temperature. The IC50 results of the ABTS scavenging activity was 4.7 μg/mL for both extractions, at room temperature and at a hot temperature. Additionally, we also evaluated the cytotoxic profile of propolis extracts against macrophage (RAW 264.7 cells) and keratinocytes (HaCaT cells), which showed non-cytotoxic doses in cell viability assays even after a long period of exposure. In addition, propolis extracts showed antibacterial activity for Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis), demonstrating potential biological activity for the creation of formulations aimed at disease control and prevention.

Dynamic gastrointestinal digestion/intestinal permeability of encapsulated and nonencapsulated Brazilian red propolis: Active compounds stability and bioactivity

The objectives were to investigate the effect of dynamic gastrointestinal digestion/Caco-2 cell transport on active compounds stability and antioxidant/anti-inflammatory activities of the ethanolic extract of Brazilian red propolis (EEBRP), whether encapsulated or not; and the in vivo acute toxicity of the EEBRP after digestion. Eight isoflavonoids, one flavanone, and one chalcone were identified by HPLC-ESI-QTOF-MS, and quantified by HPLC-PDA. Bioaccessibility was higher for the encapsulated EEBRP (21.4%-57.6%) than for the nonencapsulated (19.3%-30.2%). Conversely, the Caco-2 cell transport was higher for the nonencapsulated EEBRP. Similarly, the nonencapsulated EEBRP showed higher ability to scavenge reactive oxygen species, which was especially attributed to calycosin, and to decrease NF-κB activation, and the levels of TNF-α and CXCL2/MIP-2 after Caco-2 cell transport. Hence, there is an indication that EEBRP is a promising alternative dietary source of bioavailable isoflavonoids. Further studies on encapsulation should be encouraged to improve bioactivity, and expand its food applications.

Evaluation of the release, stability and antioxidant activity of Brazilian red propolis extract encapsulated by spray-drying, spray-chilling and using the combination of both techniques

Red propolis, originary from Northeast Brazil, has a unique composition and a great commercial interest. However, due to the presence of ethanol and its remarkable sensory characteristic, its application in food products is challenging. Thus, the aim of this work was to microencapsulate the red propolis extract by spray-drying, spray-chilling, and combining both techniques. The particles loaded with propolis extracts were characterised and evaluated according to the stability of phenolic compounds, flavonoids and formononetin, during 60 days of storage. In addition, the formononetin release was also monitored during the oral, gastric, and intestinal phases in the in vitro digestion process. All produced particles presented matrix-type with size, distribution, shape, hygroscopicity, and dispersibility parameters that varied according to the carrier and encapsulation process applied. The techniques used to fabricate the particles efficiently obtained powdered propolis extract and protected the extract's bioactive compounds, total flavonoids and formononetin throughout the analysed period. The gastrointestinal release study presented distinctive releases in all phases (oral, gastric, and intestinal). The spray-dried particles, for example, released formononetin mainly in the oral stage. While the spray-chilled particles were primarily released in the intestinal phase, and coated particles were released gradually throughout the assay, reaching maximum relief in the intestinal phase. In conclusion, using microencapsulation techniques by spray-drying, spray-chilling, and their combination developed particles with different levels of protection during storage, releases and characteristics, which resulted in a range of possible applications in the food, feed, cosmetic, and pharmaceutical industries.

Brazilian red propolis in combination with β-lactams exerts an efficient antibacterial action over methicillin-resistantStaphylococcus aureus(MRSA) strains

The antibacterial activity of red propolis extract (RPE) and brown propolis extracts (BPE) and the synergistic effect of RPE with cefoxitin (CEFO), imipenem (IMI), and ertapenem (ERTA) was evaluated in vitro against methicillin-resistant Staphylococcus aureus (MRSA) strains. MRSA ATCC 33591, community-associated (CA-MRSA) USA300, and four clinical isolates were used. A broth microdilution assay was performed to obtain inhibitory and bactericidal concentrations of BPE, RPE, CEFO, IMI, and ERTA. RPE in combination with CEFO, IMI, and ERTA was evaluated on the formation or eradication of biofilm. The bacterial relative membrane conductivity of the strains was assessed after RPE and combinations exposition. Surface/binding computational analyzes between RPE compounds and penicillin binding protein 2a (PBP2a) were performed. BPE samples had no activity against MRSA (MICs 3.2-5 g l-1; MBCs 10-15 g l-1), so the subsequent assays were carried out only with RPE and antimicrobials. RPE exerted a bacteriostatic action (MICs 0.0156-0.125 g l-1; MBCs 0.5-2 g l-1) but the combinations with IMI and ERTA showed the highest inhibition, as observed in the time-kill curve. However, the FICI index showed synergism (≥0.5) only to RPE+IMI. This combination was the most effective in inhibiting the biofilm and showed the highest values of membrane conductivity. Computational predictions indicated that RPE constituents may interact with PBP2a. RPE and RPE+IMI exerted an antibacterial and antibiofilm activity on MRSA strains probably due to membrane/wall damage and interactions with PBP2a.

Brazilian Red Propolis Accelerates Gastric Healing and Reduces Gastric Submucosal Layer Inflammation in Ultrasound-Monitored Rats.

Propolis has been used for the treatment of gastric disturbances in folk medicine, nevertheless, the gastric healing effects of Brazilian red propolis have not been unveiled. This study aimed to assess the gastric healing effect of the hydroalcoholic extract of red propolis (HERP) in the acetic acid-induced ulcer model. Rats under acetic acid-induced-ulcer were treated with HERP (100 mg/kg, p.o.) twice a day for seven days. Histological changes, oxidative stress, and inflammatory parameters were analyzed in the gastric tissue. Moreover, the gastric wall thickness was measured by ultrasound. The in vitro cytotoxicity of HERP and cellular migration of fibroblasts were evaluated. The treatment with HERP promoted gastric healing, reducing gastric wall thickness, macroscopic lesion area, and histopathological damages compared to the vehicle. Moreover, HERP reduced oxidative stress and inflammation in the gastric tissue but did not change mucin or collagen levels. HERP did not show signs of toxicity either in vivo or in vitro. HERP displayed a healing effect in vivo by reducing oxidative stress and inflammation. These data contribute to validating the popular use of this product in the treatment of gastric disorders and advance scientific knowledge in the search for new drugs for the management of gastric ulcers.