Propolis: a review of properties, applications, chemical composition, contact allergy, and other adverse effects. Dermatitis. 2013;24:263-282. [PMID: 24201459 DOI: 10.1097/der.0000000000000011]

Results of patch testing propolis in the European baseline series: A 4-year retrospective study

BACKGROUND

Propolis was added to the European baseline series (EBS) in 2019.

OBJECTIVES

To investigate the frequency and relevance of positive patch tests to propolis in the EBS and to study co-reactivities.

PATIENTS AND METHODS

Retrospective study in patients patch tested between June 2019 and November 2023 in a university hospital in Amsterdam, The Netherlands.

RESULTS

Of 3134 consecutive patients, 299 (9.5%) had a positive reaction to propolis 10% pet. Only nine reactions (3%) were judged to be clinically relevant. There were significant co-reactivities to Myroxylon pereirae resin (balsam of Peru), colophonium, fragrance mixes 1 and 2, and to limonene and linalool hydroperoxides. A steep increase in rates of positive reactions to propolis was observed from 2020 to 2023. This was highly likely the result of the replacement of Chinese propolis with Brazilian propolis by the manufacturer.

CONCLUSIONS

Positive patch tests for propolis are very frequent in Amsterdam, but only a few of these reactions are relevant. Most are probably (pseudo-)cross-reactions in patients with fragrance allergies. Propolis in the EBS has very limited value for dermatologists and patients in The Netherlands. Changes in patch test materials should be provided to all users to avoid misinterpretation of patch test results.

Effects of short- and long-term use of propolis extracts on liver and kidney in rats

Propolis is widely used as a supplementary food product for its health benefits. The aim of this study was to determine the effects of commercial propolis extracts on the liver and kidney. Propolis extracts (250 mg/kgbw/day) were administered orally to adult male Wistar albino rats in solvents of ethanol, propylene glycol, water, and olive oil. Liver enzyme levels were determined biochemically in blood samples, and histopathological examinations were performed on the liver. Damage rate in both kidney tissue in the propolis-ethanol extract group increased significantly compared with the other groups after 30 and 90 days of application (p < .05). According to the results, ethanol, used as a common solvent in propolis products, may adversely affect the liver in long-term use. The data indicate that propolis-olive oil extract may be an essential alternative due to its effective and reliable properties.

Adverse Effects of Natural Products in the Oral Mucosa and Face: A Scoping Review

Objective: This scoping review aimed to map the adverse reactions in the oral mucosa and face caused by the use of natural products. Methodology: This review was performed according to the Joanna Briggs Institute Manual for Evidence Synthesis and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, with a protocol registered in the Open Science Framework (DOI 10.17605/OSF.IO/R57D8). The search was carried out systematically using PubMed, Scopus, Web of Science, Embase, LILACS, and LIVIVO databases, as well as gray literature through Google Scholar and OpenGrey. Reports of clinical cases on the adverse effects of natural products on the oral mucosa or perioral region of the face resulted from inappropriate use or self-medication were included. Data from the included studies were described in a narrative form. Results: Seven hundred and six studies were identified, and after removing duplicates and applying the eligibility criteria, 28 studies were included. The year of publication ranged from 1976 to 2022. The studies were conducted in 19 countries. Fifty patients were mentioned in the included studies and 34 were female (68%). The natural products most related to adverse reactions were propolis (n = 17), with manifestations such as perioral eczema, edema, erosions, erythema, allergic contact dermatitis, and garlic (n = 9), with manifestations such as chemical burn, burning sensation, vesicles and blisters, crusts, and ulcerations. Conclusion: Propolis and garlic were the natural products with the most reported adverse effects on the oral mucosa and perioral region.

Contact allergies to dental materials in patients

BACKGROUND

Concerns regarding contact allergies and intolerance reactions to dental materials are widespread among patients. Development of novel dental materials and less frequent amalgam use may alter sensitization profiles in patients with possible contact allergy.

OBJECTIVES

To analyse current sensitization patterns to dental materials in patients with suspected contact allergy.

METHODS

This retrospective, multicentre analysis from the Information Network of Departments of Dermatology (IVDK) selected participants from 169 834 people tested in 2005-2019 and registered with (i) an affected area of 'mouth' (and 'lips'/'perioral'), (ii) with the dental material in question belonging to one of three groups (dental filling materials, oral implants or dentures or equivalents) and (iii) with patch-testing done in parallel with the German baseline series, (dental) metal series and dental technician series.

RESULTS

A total of 2730 of 169 834 tested patients met the inclusion criteria. The patients were predominantly women (81.2%) aged ≥ 40 years (92.8%). The sensitization rates with confirmed allergic contact stomatitis in women (n = 444) were highest for metals (nickel 28.6%, palladium 21.4%, amalgam 10.9%), (meth)acrylates [2-hydroxyethyl methacrylate (HEMA) 4.8%] and the substances propolis (6.8%) and 'balsam of Peru' (11.4%). The most relevant acrylates were HEMA, 2-hydroxypropyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate and pentaerythritol triacrylate. Few men were diagnosed with allergic contact stomatitis (n = 68); sensitization rates in men were highest for propolis (14.9%) and amalgam (13.6%).

CONCLUSIONS

Allergic contact stomatitis to dental materials is rare. Patch testing should not only focus on metals such as nickel, palladium, amalgam and gold, but also (meth)acrylates and the natural substances propolis and 'balsam of Peru'.

Physicochemical Characterization, Antioxidant, and Proliferative Activity of Colombian Propolis Extracts: A Comparative Study

Propolis extracts have been widely studied due to their popularity in traditional medicine, presenting incredible biodiversity. This study aimed to analyze propolis extracts' phytochemical, physicochemical, and biological activities from four different biogeographic zones of the Huila region (Colombia). The raw material samples were collected by the scraping method and the ethanolic extracts (EEPs) were obtained by cold maceration with ethanol (96%). The physicochemical and sensory characterization was carried out according to the protocols recommended by the Brazilian Ministry of Agriculture and the main components of the EEPs were identified by LC-HRMS analysis. The determination of total phenols and flavonoids was carried out using colorimetric techniques. The antioxidant activity, cytotoxicity, and cell cycle regulation analyses in L929 and HGnF cells were evaluated using DPPH, Alamar Blue, and 7-amino actinomycin D (7-AAD) assays. The propolis samples presented an average yield of 33.1%, humidity between 1.6 and 2.8%, melting point between 54 and 62 °C, ashes between 1.40 and 2.19%, and waxes of 6.6-17.9%, respectively. The sensory characteristics of all samples were heterogeneous, complying with the quality specifications established by international standards. The polyphenolic and total flavonoid content was representative in the samples from Quebradon (255.9 ± 9.2 mg GAE/g, 543.1 ± 8.4 mg QE/g) and Arcadia (543.1 ± 8.4 mg GAE/g, 32.5 ± 1.18 g QE/g) (p < 0.05) that correlated with high antioxidant activity (Quebradon: 37.2 ± 1.2 µmol/g, Arcadia: 38.19 ± 0.7 µmol/g). In the chemical composition analysis, 19 compounds were characterized as phenolic acids and flavonoids, the most representative being chrysoeriol-O-methyl-ether, ellagic acid, and 3,4-O-dimethylcaffeic acid. Regarding biological activity, Quebradon and Arcadia propolis presented low toxicity with IC50 of 2.83 ± 2.3 mg/mL and 4.28 ± 1.4 mg/mL in HGnF cells, respectively, and an arrest of the cell cycle in the G2/M phase of 71.6% and 50.8% compared to the control (11.9%) (p < 0.05). In general, the results of this study contribute to the identification of valid quality criteria to evaluate Colombian propolis, contributing to its study and chemical and biological characterization as a source of raw material for industrial and pharmaceutical use. In addition, Quebradon and Arcadia propolis can be important sources of bioactive molecules for the development of new drugs.

Algerian Propolis from Distinct Geographical Locations: Chemical Profiles, Antioxidant Capacity, Cytotoxicity and Inhibition of 5-Lipoxygenase Product Biosynthesis

Propolis was collected from honeybee hives in three geographically distinct Algerian climates and extracts were characterized for composition and bioactivity. Bees were identified as native subspecies using an in-silico DraI mtDNA COI-COII test. Over 20 compounds were identified in extracts by LC-MS. Extracts from the Medea region were more enriched in phenolic content (302±28 mg GAE/g of dry extract) than those from Annaba and Ghardaia regions. Annaba extracts had the highest flavonoid content (1870±385 mg QCE/g of dry extract). Medea extracts presented the highest free-radical scavenging activity (IC50=13.5 μg/mL) using the DPPH radical assay while Ghardaia extracts from the desert region were weak (IC50>100 μg/mL). Antioxidant activities measured using AAPH oxidation of linoleic acid were similar in all extracts with IC50 values ranging from 2.9 to 4.9 μg/mL. All extracts were cytotoxic (MTT assay) and proapoptotic (Annexin-V) against human leukemia cell lines in the low μg/mL range, although the Annaba extract was less active against the Reh cell line. Extracts inhibited cellular 5-lipoxygenase product biosynthesis with IC50 values ranging from 0.6 to 3.2 μg/mL. Overall, examined propolis extracts exhibited significant biological activity that warrant further characterization in cellular and in vivo models.

Influence of the Encapsulating Agent on the Bioaccessibility of Phenolic Compounds from Microencapsulated Propolis Extract during In Vitro Gastrointestinal Digestion

The aim of this work is to develop different encapsulated propolis ingredients by spray-drying and to evaluate their bioaccessibility using simulated in vitro digestion. To achieve these goals, first, microparticles of a propolis extract with inulin as the coating polymer were prepared under the optimal conditions previously determined. Then, a fraction of inulin was replaced with other encapsulating agents, namely sodium alginate, pectin, and chitosan, to obtain different ingredients with controlled release properties in the gastrointestinal tract. The analysis of the phenolic profile in the propolis extract and microparticles showed 58 compounds tentatively identified, belonging mainly to phenolic acid derivatives and flavonoids. Then, the behavior of the free extract and the formulated microparticles under gastrointestinal conditions was studied through an in vitro gastrointestinal digestion process using the INFOGEST protocol. Digestion of the free extract resulted in the degradation of most compounds, which was minimized in the encapsulated formulations. Thus, all developed microparticles could be promising strategies for improving the stability of this bioactive extract under gastrointestinal conditions, thereby enhancing its beneficial effect.

Effects of ginger extract and/or propolis extract on immune system parameters of vaccinated broilers

Newcastle disease (ND), avian influenza (AI, H5N8), and infectious bronchitis (IB) are important diseases in the poultry industry and cause significant losses. Vaccination is the most practical method for controlling infectious diseases. To reduce vaccination costs and several disorders in poultry farms, using herbal water supplements for immunomodulation with vaccination is critical to improving or preventing some conditions in the poultry industry. However, drinking water supplementation of ginger extract (GE)/propolis extract (PE) alone/in combination may increase broilers' humoral and cellular immunity due to the immunomodulatory effects of ginger and propolis. This protocol aimed to see how GE/PE alone or in combination improved the immunity, immune organ gene expression, and histology of the immune organs of broilers for 35 d after vaccination against NDV, H5N8, IBV, and IBDV. The chicks were dispensed into 5 groups according to GE and/or PE with vaccination. The control group was offered normal drinking water without any supplements or vaccinations. The GE group was supplemented with ginger extract (1 mL/L drinking water) in the drinking water before and after vaccination for 2 and 3 d, respectively. The GE+PE group was supplemented with GE (0.5 mL/L drinking water) and PE (0.5 mL/L drinking water) in the drinking water before and after vaccination for 2 and 3 d, respectively. The PE group was supplemented with propolis extract (1 mL/L drinking water) in the drinking water before and after vaccination for 2 and 3 d, respectively. The fifth group was the vaccinated untreated group. This experiment showed the immunomodulatory properties of GE and/or PE against 3 common diseases, NDV, AI, and IB, in broiler chicken farms for 35 d applied to a vaccination program. Thus, ginger extract and propolis extract supplementation in drinking water increased antibody titer, INF, IL10, and IL2 and TLR3 gene expression in the bursa of Fabricius, thymus, and spleen, respectively, as well as cellular immunity as indicated by increased CD3, CD4, and CD8 in the bursa of Fabricius, thymus, and spleen, respectively, with normal lymphocytes in the medulla of the bursa, thymus, and spleen. In conclusion, propolis extracts alone or with GE improved all of the metrics mentioned above without harming the histology of the immune organs.

Advances in propolis and propolis functionalized coatings and films for fruits and vegetables preservation

Propolis, as a natural active substance, is rich in polyphenols, with low toxicity, antioxidant, antifungal and antibacterial properties, which can be applied to the post-harvest preservation of fruits and vegetables. Propolis extracts and propolis functionalized coatings and films have exhibited good freshness in various types of fruits and vegetables as well as fresh-cut vegetables. They are mainly used to prevent water loss after harvesting, to inhibit the infestation of bacteria and fungi after harvesting and to enhance the firmness and apparent quality of fruits and vegetables. Moreover, propolis and propolis functionalized composites have a small or even insignificant effect on the physicochemical parameters of fruits and vegetables. Furthermore, how to cover the special smell of propolis itself so that it does not affect the flavor of fruits and vegetables, and the application of propolis extract in wrapping paper and packaging bag of fruits and vegetables, are worthwhile to further investigate.

Investigation into Propolis Components Responsible for Inducing Skin Allergy: Air Oxidation of Caffeic Acid and Its Esters Contribute to Hapten Formation

Propolis is a resin-like material produced by bees from the buds of poplar and cone-bearing trees and is used in beehive construction. Propolis is a common additive in various biocosmetics and health-related products, despite the fact that it is a well-known cause of contact allergy. Caffeic acid and its esters have been the primary suspects behind the sensitization potency of propolis-induced contact allergy. However, the chemical structures of the protein adducts formed between these haptens and skin proteins during the process of skin sensitization remain unknown. In this study, the reactivity of three main contact allergens found in propolis, namely, caffeic acid (CA), caffeic acid 1,1-dimethylallyl ester (CAAE), and caffeic acid phenethyl ester (CAPE), was investigated. These compounds were initially subjected to the kinetic direct peptide reactivity assay to categorize the sensitization potency of CA, CAAE, and CAPE, but the data obtained was deemed too unreliable to confidently classify their skin sensitization potential based on this assay alone. To further investigate the chemistry involved in generating possible skin allergy-inducing protein adducts, model peptide reactions with CA, CAAE, and CAPE were conducted and analyzed via liquid chromatography-high-resolution mass spectrometry. Reactions between CA, CAAE, and CAPE and a cysteine-containing peptide in the presence of oxygen, both in closed and open systems, were monitored at specific time points. These studies revealed the formation of two different adducts, one corresponding to thiol addition to the α,β-unsaturated carbonyl region of the caffeic structure and the second corresponding to thiol addition to the catechol, after air oxidation to o-quinone. Observation of these peptide adducts classifies these compounds as prehaptens. Interestingly, no adduct formation was observed when the same reactions were performed under oxygen-free conditions, highlighting the importance of air oxidation processes in CA, CAAE, and CAPE adduct formation. Additionally, through NMR analysis, we found that thiol addition occurs at the C-2 position in the aromatic ring of the CA derivatives. Our results emphasize the importance of air oxidation in the sensitization potency of propolis and shed light on the chemical structures of the resultant haptens which could trigger allergic reactions in vivo.

Development of a peptide reactivity assay for screening botanicals and natural substances: Proof of concept studies

Consumer products containing botanicals or natural substances (BNS) are often preferred because there is a perception that 'natural' is safe. As with any product ingredient, a thorough safety assessment must be conducted, including a determination of skin sensitization potential. A modification of the Peroxidase Peptide Reactivity Assay (PPRA) was explored for screening BNS (B-PPRA) for their reactivity to a model cysteine peptide. The PPRA incorporates a horseradish peroxidase‑hydrogen peroxide (+HRP/P) oxidation system for the activation of potential pre- and pro-haptens. BNS test materials contained <2% botanical constituent in either glycerin/water or propylene glycol/water. Stock solutions prepared in acetonitrile were diluted to 8 working concentrations. Direct reactivity was determined in reaction mixtures containing peptide and deferoxamine in potassium phosphate buffer. Enzyme-mediated reactivity determinations were performed with addition of +HRP/P. Initial studies demonstrated that results were reproducible and impact of carrier low. To determine the sensitivity of the assay, experiments were conducted with chamomile extract spiked with three sensitizers. Peptide depletion was observed in the +HRP/P reaction mixtures with isoeugenol spikes as low as 0.05%. The B-PPRA shows promise as a screening method for skin sensitization potential and could become part of a framework for the skin sensitization safety assessment of BNS.

Bee Products and Colorectal Cancer—Active Components and Mechanism of Action

Colorectal cancer is one of the most common malignancies in the world. Lifestyle and eating patterns may have a significant impact on the prevention of this type of cancer. Bioactive food ingredients influence the gut microbiome and can have a protective effect. Bee products (honey, propolis, royal jelly, and bee venom) or pharmacologically active fractions obtained from them are widely used in many fields of medicine, pharmacy, and cosmetics. Some evidence suggests that bee products may have anti-cancer potential. The main bioactive components with anti-colon cancer potential from propolis and bee honey are polyphenols such as pinocembrin, galangin, luteolin, CAPE, Artepilin C, chrysin, caffeic, and p-coumaric acids. This review is focused on the new data on epidemiology, risk factors for colon cancer, and current reports on the potential role of bee products in the chemoprevention of this type of cancer.

Extraction of Antioxidant Compounds from Brazilian Green Propolis Using Ultrasound-Assisted Associated with Low- and High-Pressure Extraction Methods

The demand for bee products has been growing, especially regarding their application in complementary medicine. Apis mellifera bees using Baccharis dracunculifolia D.C. (Asteraceae) as substrate produce green propolis. Among the examples of bioactivity of this matrix are antioxidant, antimicrobial, and antiviral actions. This work aimed to verify the impact of the experimental conditions applied in low- and high-pressure extractions of green propolis, using sonication (60 kHz) as pretreatment to determine the antioxidant profile in the extracts. Total flavonoid content (18.82 ± 1.15-50.47 ± 0.77 mgQE·g^-1), total phenolic compounds (194.12 ± 3.40-439.05 ± 0.90 mgGAE·g^-1) and antioxidant capacity by DPPH (33.86 ± 1.99-201.29 ± 0.31 µg·mL^-1) of the twelve green propolis extracts were determined. By means of HPLC-DAD, it was possible to quantify nine of the fifteen compounds analyzed. The results highlighted formononetin (4.76 ± 0.16-14.80 ± 0.02 mg·g^-1) and p-coumaric acid (<LQ-14.33 ± 0.01 mg·g^-1) as majority compounds in the extracts. Based on the principal component analysis, it was possible to conclude that higher temperatures favored the release of antioxidant compounds; in contrast, they decreased the flavonoid content. Thus, the obtained results showed that samples pretreated with 50 °C associated with ultrasound displayed a better performance, which may support the elucidation of the use of these conditions.

North American Contact Dermatitis Group Patch Test Results: 2019-2020

Background: Patch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD). Objective: This study documents the North American Contact Dermatitis Group (NACDG) patch testing results from January 1, 2019, to December 31, 2020. Methods: At 13 centers in North America, patients were tested in a standardized manner with a screening series of 80 allergens, and, as indicated, supplemental allergens. Results: Overall, 4121 patients were tested; 2871 (69.7%) had at least 1 positive/allergic patch test reaction and 2095 patients (51.2%) had a primary diagnosis of ACD. The most commonly positive allergens were nickel (18.2%), methylisothiazolinone (MI) (13.8%), fragrance mix (FM) I (12.8%), hydroperoxides of linalool (HPL) (11.1%), and benzisothiazolinone (BIT) (10.4%). Compared with that of 2017-2018, prevalence of top 20 allergens statistically increased for FM I, HPL, BIT, propolis, and hydroperoxides of limonene (3.5%). For the first time, MI positivity did not increase between reporting periods. Approximately one-fifth of patients (20.3%) had ≥1 clinically relevant reaction(s) to allergens/substances not on the NACDG series. Conclusions: The epidemic of MI contact allergy in North America may have reached a plateau. Patch testing using a robust screening series, and supplemental allergens as indicated, is necessary for comprehensive evaluation of ACD.

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.

Structural, Optical, and Electrical Characterization of Biological and Bioactive Propolis Films

Natural substances are potential compounds for green electronic devices. So, scientists have to explore and optimize their properties to insert them as active layers in electronic heterostructures. In this study, microstructural, optical, and electrical properties of thin layers of the propolis are investigated. Propolis is a biological organic bioactive material produced by honeybees. A stable, bioactive, green, and low-cost thin layer of this biocompatible material was deposited on different substrates using a propolis alcohol solution. The morphological studies show that the propolis thin film is dense and well covers the substrate surfaces. Transmittance spectra show that propolis film cuts off blue and ultraviolet (UV) radiation, which are responsible for food oxidation, nutrient losses, flavor degradation, and discoloration. Therefore, to prevent food deterioration, a propolis film can be used in food packaging. For red and near-infrared radiation (∼600-2700 nm), a propolis film is transparent. Between near-infrared and mid-infrared radiation (∼2700-3200 nm), a propolis film reveals significant photosensitivity and so can be used as a photosensor. The propolis film reveals an energy gap of 2.88 eV at room temperature, which enables potential optoelectronic applications in the UV and blue ranges. The electrical study shows that the propolis layer has semiconductor behavior and can be a potential active layer in biocompatible temperature sensors. In addition to its medical, pharmaceutical, and food industry applications, in light of this study, propolis presents amazing optical and electrical properties and is a promising candidate for food packaging, optoelectronics, transparent electronics, and bioelectronics.

Cytotoxicity of Propolis Extracts obtained using Dichloromethane and Hexane Solvent on Human Salivary Gland Tumor Cell Line

AIM

This in vitro study aimed to investigate the effect of propolis extracts from two different solvents on human submandibular salivary gland (HSG) tumor cell line.

MATERIALS AND METHODS

Propolis was extracted by dichloromethane (DCM) and hexane (HEX). Crude extracts were prepared from 6.25 to 200 µg/mL in Dulbecco's modified eagle medium without serum. Flavonoid and total phenolic contents of crude extracts were measured using a modified colorimetric method. The cytotoxicity was evaluated by 3-[4, 5-dimethylthiazol-2-yl]-2,5 diphenyl-tetrazolium (MTT) assay and lactate dehydrogenase (LDH) release assay. The statistics were analyzed by independent sample t-test.

RESULTS

Propolis extracts obtained using DCM and HEX exhibited comparable % yield (38.58 and 38.25) and physical characteristics and different amounts of flavonoid (0.439 ± 0.02 and 0.250 ± 0.01 mg catechin/g sample) and total phenolic compounds (3.759 ± 0.03 and 1.618 ± 0.03 mg gallic acid equivalents/g sample). The DCM group at 25, 50, 100, and 200 µg/mL as well as the HEX group at 50, 100, and 200 µg/mL significantly displayed a decrease in % cell viability and an increase in % cytotoxicity, compared with the untreated control group (P < 0.05). The DCM group showed the half-maximal inhibitory concentration (IC50) of MTT (42.93 ± 2.70) and LDH (34.94 ± 0.22). The HEX group showed the IC50 of MTT (61.30 ± 5.39) and LDH (42.32 ± 1.00). Propolis extracts obtained using both DCM and HEX are effective to inhibit HSG viability.

CONCLUSION

Regarding to the cell morphological observation, MTT and LDH assays, propolis extracts obtained using DCM and HEX exhibited the cytotoxic effect on HSG tumor cell line. Based on our knowledge, this research demonstrates the first preliminary result suggesting propolis as a natural product of choice for salivary gland cancer prevention and therapy.

Allergic Inflammation: Effect of Propolis and Its Flavonoids

The incidence of allergic diseases and their complications are increasing worldwide. Today, people increasingly use natural products, which has been termed a "return to nature". Natural products with healing properties, especially those obtained from plants and bees, have been used in the prevention and treatment of numerous chronic diseases, including allergy and/or inflammation. Propolis is a multi-component resin rich in flavonoids, collected and transformed by honeybees from buds and plant wounds for the construction and adaptation of their nests. This article describes the current views regarding the possible mechanisms and multiple benefits of flavonoids in combating allergy and allergy-related complications. These benefits arise from flavonoid anti-allergic, anti-inflammatory, antioxidative, and wound healing activities and their effects on microbe-immune system interactions in developing host responses to different allergens. Finally, this article presents various aspects of allergy pathobiology and possible molecular approaches in their treatment. Possible mechanisms regarding the antiallergic action of propolis on the microbiota of the digestive and respiratory tracts and skin diseases as a method to selectively remove allergenic molecules by the process of bacterial biotransformation are also reported.

Propolis: An update on its chemistry and pharmacological applications

Propolis, a resinous substance produced by honeybees from various plant sources, has been used for thousands of years in traditional medicine for several purposes all over the world. The precise composition of propolis varies according to plant source, seasons harvesting, geography, type of bee flora, climate changes, and honeybee species at the site of collection. This apiary product has broad clinical applications such as antioxidant, anti-inflammatory, antimicrobial, anticancer, analgesic, antidepressant, and anxiolytic as well asimmunomodulatory effects. It is also well known from traditional uses in treating purulent disorders, improving the wound healing, and alleviating many of the related discomforts. Even if its use was already widespread since ancient times, after the First and Second World War, it has grown even more as well as the studies to identify its chemical and pharmacological features, allowing to discriminate the qualities of propolis in terms of the chemical profile and relative biological activity based on the geographic place of origin. Recently, several in vitro and in vivo studies have been carried out and new insights into the pharmaceutical prospects of this bee product in the management of different disorders, have been highlighted. Specifically, the available literature confirms the efficacy of propolis and its bioactive compounds in the reduction of cancer progression, inhibition of bacterial and viral infections as well as mitigation of parasitic-related symptoms, paving the way to the use of propolis as an alternative approach to improve the human health. However, a more conscious use of propolis in terms of standardized extracts as well as new clinical studies are needed to substantiate these health claims.

A Nano-Liposomal Formulation of Caffeic Acid Phenethyl Ester Modulates Nrf2 and NF-κβ Signaling and Alleviates Experimentally Induced Acute Pancreatitis in a Rat Model

The currently available management strategies for acute pancreatitis are inadequately effective which calls for exploration of new approaches to treat this condition. Caffeic acid phenethyl ester (CAPE) is a major bioactive constituent of honeybee propolis with promising therapeutic and preventive applications. However, its pharmaceutical potential and clinical use are hindered by its poor water solubility and limited plasma stability. In this study, we aimed to prepare, characterize and evaluate a CAPE-loaded nanoliposomal formulation to improve the efficacy of CAPE for the management of acute pancreatitis. The CAPE-loaded nanoliposomes (CAPE-loaded-NL) were prepared by a thin layer evaporation technique and were optimized using three edge activators. CAPE-loaded-NL were characterized for their vesicle size (VS), zeta potential (ZP), encapsulation efficiency (EE), polydispersity index (PDI), crystalline state and morphology. The protective effect of the optimal CAPE-loaded-NL was evaluated in a rat model of acute pancreatitis induced by administering a single intraperitoneal injection of L-ornithine. Oral pretreatment with CAPE-loaded-NL significantly counteracted ornithine-induced elevation in serum activities of pancreatic digestive enzymes and pancreatic levels of malondialdehyde, nuclear factor kappa B (NF-κB) p65, tumor necrosis factor-alpha, nitrite/nitrate, cleaved caspase-3 and myeloperoxidase activity. Moreover, pretreatment with CAPE-loaded-NL significantly reinstated the ornithine-lowered glutathione reductase activity, glutathione, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 levels and ATP/ADP ratio, and potentiated the Bcl-2/Bax ratio in pancreatic tissue. CAPE-loaded-NL displayed superior antioxidant, anti-inflammatory and anti-apoptotic effects compared to free CAPE oral suspension and achieved a more potent correction of the derangements in serum amylase and pancreatic myeloperoxidase activities. The histological observations were in line with the biochemical findings. Our results suggest that CAPE-loaded-NL provide a promising interventional approach for acute pancreatitis mainly through the enhancement of the exerted antioxidant, anti-inflammatory and anti-apoptotic effects which may be mediated, at least in part, through modulation of Nrf2 and NF-κβ signaling.

The effect of propolis on 5-fluorouracil-induced cardiac toxicity in rats

5-Fluorouracil (5-FU) is one of the most common chemotherapeutic agents used in treating solid tumors, and the 5-FU-induced cardiotoxicity is the second cause of cardiotoxicity induced by chemotherapeutic drugs. Propolis (Pro) has vigorous anti-inflammatory activity. Its cardio-protective characteristic against doxorubicin-induced cardiotoxicity was previously proven. The current study aimed to appraise the effect of Pro on 5-FU-induced cardiotoxicity in rats. Twenty-four male Wistar rats were divided into four groups: Control, 5-FU, 5-FU + Pro 250 mg/kg, and 5-FU + Colchicine (CLC) 5 mg/kg. Different hematological, serological, biochemical, histopathological, and molecular assays were performed to assess the study’s aim. Moreover, a rat myocardium (H9C2(2–1)) cell line was also used to assess this protective effect in-vitro. 5-FU resulted in significant cardiotoxicity represented by an increase in malondialdehyde (MDA) levels, cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) expression, cardiac enzyme levels, and histopathological degenerations. 5-FU treatment also decreased bodyweight, total anti-oxidant capacity (TAC), catalase (CAT) levels, blood cell counts, and hemoglobin (Hb) levels. In addition, 5-FU disrupted ECG parameters, including increased elevation in the ST-segment and increased QRS complex and QTc duration. Treating with Pro reduced oxidative stress, cardiac enzymes, histopathological degenerations, and COX-2 expression in cardiac tissue alleviated ECG disturbances and increased the number of blood cells and TAC levels. Moreover, 5-FU-induced bodyweight loss was ameliorated after treatment with Pro. Our results demonstrated that treatment with Pro significantly improved cardiotoxicity induced by 5-FU in rats.

Potential of propolis antifungal activity for clinical applications

The high incidence of skin diseases of microbial origin along with the widespread increase of microbial resistance demand for therapeutic alternatives. Research on natural compounds has been opening new perspectives for the development of new therapies with health positive impacts. Propolis, a resinous mixture produced by honeybees from plant exudates, is widely used as a natural medicine since ancient times, mainly due to its antimicrobial properties. More recently, antioxidant, anti-tumor, anti-inflammatory, hepatoprotective and immunomodulatory activities were also reported for this natural product, highlighting its high potential pharmacological interest. In the present work, an extensive review of the main fungi causing skin diseases as well as the effects of natural compounds, particularly propolis, against such disease-causing microorganisms was organized and compiled in concise handy tables. This information allows to conclude that propolis is a highly effective antimicrobial agent suggesting that it could be used as an alternative skin treatment against pathogenic microorganisms and also as a cosmeceutic component or as a source of bioactive ingredients.

Impact of Portuguese propolis on keratinocyte proliferation, migration and ROS protection: Significance for applications in skin products

OBJECTIVE

Propolis has been used since antiquity, but recent reports of its biological properties hint that it could be employed as a topical pharmaceutical and cosmetic ingredient. This work aims to probe the action of Portuguese propolis extracts on skin cells, providing mechanistic insights into its mode of action and preliminarily assessing its applicability as a skin repair ingredient.

METHODS

The total phenolic content of propolis extracts was measured by the Folin Ciocalteu method. The cytotoxic effect of propolis extracts in human keratinocytes was determined and non-cytotoxic concentrations of the extracts were used to study the impact on collective cell migration, cell cycle and intracellular ROS levels.

RESULTS

o significant impact was observed in collective cell migration, but one of the extracts mildly increased G2 phase while reducing the % of sub-G1 at a non-cytotoxic concentration. The two extracts with higher phenolic content strongly prevented intracellular cellular ROS accumulation upon exposure to TBHP. Collectively, these results indicate that the putative beneficial effects of propolis extracts in skin repair may not be attributable to induction of collective cell migration but could be partially ascribed to the protection from oxidative stress, which could act in synergy with its well-known antimicrobial activity.

CONCLUSION

These data support the applicability of this material in topical and cosmetic formulations and further in vivo assays should be conducted to fully characterize its efficacy and safety.

The Honey Bee Apis mellifera: An Insect at the Interface between Human and Ecosystem Health

Simple Summary

Apis mellifera Linnaeus (1758), a honey bee, is a eusocial insect widely known for its role in pollination, an essential ecosystem service for plant biodiversity, and quality of vegetables and fruit products. In addition, honey bees and bee products are valuable bioindicators of pollutants, such as airborne particulate matter, heavy metals, and pesticides. In this review, we explore the provisioning, regulating, and cultural services provided by the honey bee, an insect at the interface between human and ecosystem health.

Abstract

The concept of ecosystem services is widely understood as the services and benefits thatecosystems provide to humans, and they have been categorised into provisioning, regulating, supporting, and cultural services. This article aims to provide an updated overview of the benefits that the honey bee Apis mellifera provides to humans as well as ecosystems. We revised the role of honey bees as pollinators in natural ecosystems to preserve and restore the local biodiversity of wild plants; in agro-ecosystems, this species is widely used to enhance crop yield and quality, meeting the increasing food demand. Beekeeping activity provides humans not only with high-quality food but also with substances used as raw materials and in pharmaceuticals, and in polluted areas, bees convey valuable information on the environmental presence of pollutants and their impact on human and ecosystem health. Finally, the role of the honey bee in symbolic tradition, mysticism, and the cultural values of the bee habitats are also presented. Overall, we suggest that the symbolic value of the honey bee is the most important role played by this insect species, as it may help revitalise and strengthen the intimate and reciprocal relationship between humans and the natural world, avoiding the inaccuracy of considering the ecosystems as mere providers of services to humans.

The Study of Chemical Profile and Antioxidant Properties of Poplar-Type Polish Propolis Considering Local Flora Diversity in Relation to Antibacterial and Anticancer Activities in Human Breast Cancer Cells

Nine samples of ethanolic extracts of poplar-type propolis (EEP) originated from South-Eastern Poland were analyzed in terms of the diversity of the flora around the apiary. The mineral composition, antioxidant properties, polyphenolic profile (HPTLC), and main polyphenolic constituents (HPLC-DAD) were determined. Only minor differences in chemical composition and antioxidant capacity between tested EEPs were found regardless of their botanical origin. However, the biological activity of the EEPs was more diversified. The tested EEPs showed stronger antibacterial activity against Gram-negative bacteria (Escherichia coli) compared to Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis). Staphylococci biofilm inhibition occurred as a result of exposure to the action of four out of nine EEPs (P1–P4). Due to the various compositions of individual EEPs, a different MCF-7 cellular response was observed according to inhibition of cells migration and proliferation. Almost every sample inhibited the migration of breast cancer cells at a low concentration (0.04 µg/mL) of propolis. Even at the lowest concentration (0.02 µg/mL), each EEP inhibited the proliferation of MCF-7 cells, however, the level of inhibition varied between samples.

Radioimaging in the Evaluation of the Therapeutic Effect of the Vegetable Extract Obtained from Epilobium Parviflorum Schreb

For years, apical microleakage has been considered the main factor in endodontic failure therapy. Sealing abilities and antibacterial properties of root canal sealers and intracanal medicaments between appointments have been recognized as important factors for the success of endodontic treatment. Background: Apical periodontitis (AP) is an inflammatory disease around the apex of a tooth root. The microorganisms reach the pulp by dentinal tubules especially when there is an open cavity after a coronal fracture and the pulp is in contact with the septic oral environment. The aim of the study was to evaluate the dynamics of healing by recording periapical index (PAI), after two appointment endodontic procedure with commercial or experimental intracanal medicament. Methods: A total of 40 patients with primary chronic apical periodontitis requiring root canal treatment were assigned randomly into four groups according to the teeth medicated with dehydrated plant extract, calcium hydroxide, calcium hydroxide mixed with chlorhexidine (CHX) gel 2%, Walkhoff paste and obturated on a second visit, 7 days later. Patients were recalled at intervals of 3, 6, and 12 months to evaluate the treated teeth both clinically and radiographically for periapical healing. A 5-score scale PAI was used to evaluate stages of the periapical healing on a periapical radiography using a Kodak Dental imaging software provided by the radio-imagistic center. Results: Radiological evaluation revealed that the experimental intracanal medicament had a cumulative positive healing capacity by reducing the PAI as well as all resorbable pastes used in endodontic conventional therapy. Conclusions: The results suggest that the vegetable dry extract obtained from Epilobium parviflorum Schreb can be used as an inter-appointment medication among with the root canal filling for the positive effect on apical healing quantified by reducing the PAI.

Evaluation of the Skin-Sensitizing Potential of Brazilian Green Propolis

Propolis is a resinous mixture produced by bees from their secretions and plant material, so its composition varies depending on its botanical origin. Propolis has several beneficial bioactivities, but its skin sensitization properties have long been suspected. Nevertheless, the skin sensitization potency of Brazilian green propolis (BGP) has not been scientifically evaluated. Here, we used scientifically reliable tests to evaluate it. In vitro antigenicity test based on the human cell line activation test (OECD TG 442E) was performed by measuring the expression of CD54 and CD86, which are indicators of the antigenicity of test substances, on THP-1 and DC2.4 cells. BGP did not affect the expression of either marker on THP-1 cells, but upregulated the expression of CD86 on DC2.4 cells, suggesting that BGP may be a skin sensitizer. Then, we performed local lymph node assay (LLNA, OECD TG 429) as a definitive in vivo test. LLNA showed that 1.70% BGP primed skin sensitization and is a "moderate sensitizer". Our results indicate scientific proof of the validity of arbitrary concentrations (1-2%), which have been used empirically, and provide the first scientific information on the safe use of BGP.

Unusual presentation of oral hemangioma in tongue and the potential use of propolis as an adjunctive treatment

Tongue hemangioma is a rare case of vascular tumors that causes symptoms such as pain, bleeding, difficulty in chewing, speaking, and breathing. We report a case of an oral lobular capillary hemangioma on the dorsal surface of the tongue treated with surgical excision and postoperative application of propolis extract.

Patch Testing with Propolis of Different Geographical Origins in a Baseline Series

The chemical composition of propolis varies with geographical origin; however, it is not known whether this affects the frequency of contact allergy to propolis. In order to study the frequency of contact allergy to propolis of different geographical origins and concomitant reactions, 1,470 consecutive patients with dermatitis from Denmark, Lithuania and Spain were patch tested with propolis from China, Lithuania, North America and Sweden, and with a baseline series. Patch test reactions to any type of propolis ranged from 1.3% to 5.8%. There were no statistically significant differences in the frequency of positive reactions between the 4 types of propolis in the respective countries. Testing with a single commercially available type of propolis detects only approximately half of propolis-allergic patients. In patients allergic to propolis, concomitant reactions to Myroxylon pereirae resin, colophonium and Fragrance mix I were common, ranging from 12.5% to 50.0%.

Prevalence and trend of allergen sensitization in patients with a diagnosis of stasis dermatitis referred for patch testing, North American contact dermatitis group data, 2001-2016

BACKGROUND

Few studies explored the relationship between stasis dermatitis (SD) and allergic contact dermatitis (ACD).

OBJECTIVE

To examine trends, associations, and clinical relevance of ACD in patients referred for patch testing who had a final SD diagnosis.

METHODS

Retrospective analysis from 2001 to 2016 of 38,723 patients from the North American Contact Dermatitis Group.

RESULTS

After patch testing, 303 (0.7%) patients were diagnosed with SD; 46.7% had a concomitant diagnosis of ACD. Patients with vs. without a final SD diagnosis had similar proportions of ≥ 1 positive allergic reaction (59.7% vs. 64.7%; Chi-square, P = 0.0724) but higher odds of allergic reactions to fragrance mix I, bacitracin, quaternium-15, Myroxylon pereirae, benzalkonium chloride, ethyleneurea melamine formaldehyde, diazolidinyl urea, and propylene glycol. The most commonly relevant allergens in patients with final SD diagnosis were fragrance mix I, Myroxylon pereirae, bacitracin, quaternium-15, and formaldehyde. The most common allergen sources were personal care products, topical medications and other health aid products.

CONCLUSION

Nearly half of patients with a final SD diagnosis were also diagnosed with ACD, supporting the role of patch testing in select SD patients.

How diverse is the chemistry and plant origin of Brazilian propolis?

Propolis is a honey bee product containing chiefly beeswax and resins originated from plant buds or exudates. Propolis resin exerts a diversity of biological activities, such as antitumoral, anti-inflammatory, antimicrobial, and defense of the hive against pathogens. Chemical standardization and identification of botanical sources is crucial for characterization of propolis. Types of Brazilian propolis are characteristic of geographical regions and respective biomes, such as savannas (Cerrado), mangroves, dry forest (Caatinga), rain forests (Amazon, Atlantic, and Interior forests), altitudinal fields ("Campos Rupestres"), Pantanal, and Araucaria forests. Despite the wide diversity of Brazilian biomes and flora, relatively few types of Brazilian propolis and corresponding resin plant sources have been reported. Factors accounting for the restricted number of known types of Brazilian propolis and plant sources are tentatively pointed out. Among them, the paper discusses constraints that honey bees must overcome to collect plant exudates, including the characteristics of the lapping-chewing mouthpart of honey bee, which limit their possibilities to cut and chew plant tissues, as well as chemical requirements that plant resins must fulfil, involving antimicrobial activity of its constituents and innocuity to the insects. Although much still needs to be done toward a more comprehensive picture of Brazilian propolis types and corresponding plant origins, the prospects indicate that the actual diversity of plant sources of honey bee propolis will remain relatively low.

The effectiveness of propolis extract in reducing dentin hypersensitivity: A systematic review

OBJECTIVE

This systematic review was performed to evaluate the effectiveness of propolis on dentin hypersensitivity reduction.

DESIGN

The search was conducted in Pubmed, Scopus, Web of science, Latin American and Caribbean Health Sciences Literature data base (Lilacs), Brazilian Library in Dentistry (BBO), Embase, and Cochrane Library aiming to identify relevant randomized clinical trials that evaluated the effect of propolis on dentin hypersensitivity. The Cochrane Collaboration tool was used for assessing the risk of bias.

RESULTS

From the total of 63 articles found in the search, six clinical trials were selected. All studies reported that propolis was more effective in reducing hypersensitivity than the placebo. No side effects were observed.

CONCLUSIONS

Overall, propolis extract can be considered an effective, safe and low-cost alternative to reduce the dentin hypersensitivity.

A New Approach to Atopic Dermatitis Control with Low-Concentration Propolis-Loaded Cold Cream

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is difficult to treat. Traditional cold cream, a water-in-oil emulsion made from beeswax, is used to alleviate AD symptoms in clinical practice, although its effectiveness has not been scientifically proven. The addition of propolis has the potential to impart anti-inflammatory properties to cold cream. However, in high concentrations, propolis can trigger allergic reactions. Thus, the objective of this work was to develop a cold cream formulation based on purified beeswax containing the same amount of green propolis present in raw beeswax. The impact of adding this low propolis concentration to cold cream on AD control was evaluated in patients compared to cold cream without added propolis (CBlank). Raw beeswax was chemically characterized to define the propolis concentration added to the propolis-loaded cold cream (CPropolis). The creams were characterized as to their physicochemical, mechanical, and rheological characteristics. The effect of CPropolis and CBlank on the quality of life, disease severity, and skin hydration of patients with AD was evaluated in a triple-blind randomized preclinical study. Concentrations of 34 to 120 ng/mL of green propolis extract reduced TNF-α levels in LPS-stimulated macrophage culture. The addition of propolis to cold cream did not change the cream’s rheological, mechanical, or bioadhesive properties. The preclinical study suggested that both creams improved the patient’s quality of life. Furthermore, the use of CPropolis decreased the disease severity compared to CBlank.

Effect of Different Host-Related Factors on Postoperative Endodontic Pain in Necrotic Teeth Dressed with Interappointment Intracanal Medicaments: A Multicomparison Study

Objectives  The current study aimed to assess the impact of factors such as age, gender, and the tooth type on postoperative endodontic pain in necrotic teeth with symptomatic periapical periodontitis and radiolucency dressed randomly with either calcium hydroxide or propolis paste.

Materials and Methods  The standard chemomechanical root canal preparation of 80 teeth was performed by the primary investigator. The intracanal medicaments were inserted by the secondary operator. Patients self-recorded their postoperative endodontic pain intensity with the help of visual analog scale at 4, 12, 24 (day 2), 48 (day 3), and 72 (day 4) hours. During analysis, patients (68/80) were grouped according to gender, age, and the tooth type.

Statistical Analysis  Mann–Whitney’s U test was applied for mean pain score comparison between genders and between tooth type. Kruskal–Wallis’ test was applied for mean pain score comparison between the age groups.

Results  No significant difference ( p > 0.05) in pain scores was found between the age groups and between the tooth types. Males had significantly higher pain scores as compared with females at days 2 ( p = 0.035), 3 ( p = 0.023), and 4 ( p = 0.020).

Conclusion  The results suggested that there was no impact of age and tooth types on postoperative endodontic pain.

The use of propolis in dentistry, oral health, and medicine: A review

BACKGROUND

Propolis is a resinous product that is collected from plants by bees to cover holes and crevices in their hives. Propolis has potent antibacterial, antiviral, anti-inflammatory, wound healing, and anticancer properties. Propolis has been used therapeutically by humans for centuries, including the treatment of dental caries and mouth infections.

HIGHLIGHT

This review article attempts to analyze the potential use of propolis in general dentistry and oral health management.

CONCLUSION

Propolis is potentially useful in dentistry and oral health management based on available in vitro, in vivo, and ex vivo studies, as well as human clinical trials.

Plant Sources Responsible for the Chemical Composition and Main Bioactive Properties of Poplar-Type Propolis

Propolis is a resinous mixture, made by the honeybees from substances collected from tree or other plant buds, plant exudates, or resins found in the stem, branches, or leaves of different plants. The geographical origin of propolis is given by plant sources from respective areas. Different studies have classified this bee product according to the vegetal material from the same areas. Poplar-type propolis has the widest spread in the world, in the temperate zones from Europe, Asia, or North America. The name is given by the main plant source from where the bees are collecting the resins, although other vegetal sources are present in the mentioned areas. Different Pinus spp., Prunus spp., Acacia spp. and also Betula pendula, Aesculus hippocastanum, and Salix alba are important sources of resins for "poplar-type" propolis. The aim of this review is to identify the vegetal material's chemical composition and activities of plant resins and balms used by the bees to produce poplar-type propolis and to compare it with the final product from similar geographical regions. The relevance of this review is to find the similarities between the chemical composition and properties of plant sources and propolis. The latest determination methods of bioactive compounds from plants and propolis are also reviewed.

New Insights for Red Propolis of Alagoas-Chemical Constituents, Topical Membrane Formulations and Their Physicochemical and Biological Properties

The main objectives of this study were to evaluate the chemical constitution and allergenic potential of red propolis extract (RPE). They were evaluated, using high performance liquid chromatography (HPLC) and the release of β-hexosaminidase, respectively. A plethora of biologically active polyphenols and the absence of allergic responses were evinced. RPE inhibited the release of β-hexosaminidase, suggesting that the extract does not stimulate allergic responses. Additionally, the physicochemical properties and antibacterial activity of hydrogel membranes loaded with RPE were analyzed. Bio-polymeric hydrogel membranes (M) were obtained using 5% carboxymethylcellulose (M1 and M2), 1.0% of citric acid (M3) and 10% RPE (for all). Their characterization was performed using thermal analysis, Fourier transform infrared (FTIR), total phenolic content, phenol release test and, antioxidant activity through 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and Ferric Reducing Antioxidant Power (FRAP). The latter appointed to the similar antioxidant capacity of the M1, M2 and M3. The degradation profiles showed higher thermostability to M3, followed by M2 and M1. The incorporation of RPE into the matrices and the crosslinking of M3 were evinced by FTIR. There were differences in the release of phenolic compounds, with a higher release related to M1 and lower in the strongly crosslinked M3. The degradation profiles showed higher thermostability to M3, followed by M2 and M1. The antibacterial activity of the membranes was determined using the disc diffusion assay, in comparison with controls, obtained in the same way, without RPE. The membranes elicited antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis, with superior performance over M3. The hydrogel membranes loaded with RPE promote a physical barrier against bacterial skin infections and may be applied in the wound healing process.

Seasonal allergic rhinitis and the role of apitherapy

BACKGROUND

Apitherapy represents a certain form of complementary and alternative medicine that uses bee products in combination with other methods from this field. One of the basic concepts of this type of medicine is that all diseases can be treated using apitherapy. This study was performed to assess the recommendations from authors of books on apitherapy regarding the treatment of seasonal allergic rhinitis and compare them to findings from the scientific literature.

METHODS

One hundred and twenty-nine books on apitherapy were analysed regarding recommendations for allergic seasonal rhinitis. Scientific evidence regarding the efficacy of using various bee products was searched via PubMed and JUSTfind.

RESULTS

Only 38.8% of the apitherapy books mentioned seasonal allergic rhinitis. Among these books, we found 29 different recommendations in favour of bee products and one against the use of honey. The most reasonable recommendation according to clinical studies on the subject, namely the use of a mix of honey and pollen, was only found once (0.8%).

CONCLUSIONS

The large discrepancies and number of different recommendations demonstrate that apitherapy is not a consistent type of medicine. The recommendations regarding seasonal allergic rhinitis in the vast majority of apitherapy books cannot be considered adequate when compared to the scientific findings.

The effect of propolis on anthropometric indices and lipid profile: a systematic review and meta-analysis of randomized controlled trials

Background & objectives

The current evidence base regarding the impact of propolis consumption on lipid profile in humans is equivocal. Thus, we sought to investigate the impact of propolis consumption on anthropometric indices and lipid profile in this meta-analysis.

Methods

Cochrane Library, Scopus, PubMed, and Web of Science electronic databases were searched up to December 2019. A random-effects model used to pool effect size. The leave-one-out method used to conduct sensitivity analysis.

Results

Five RCTs were included in this study. Our findings indicated a significant decrease in triglyceride (TG) (WMD: -3.91 mg/dl, 95% CI: -4.22, -3.60), and a significant increase in high-density lipoprotein (HDL) (WMD: 3.41 mg/dl, 95% CI: 0.05, 6.76), however, for body mass index, weight, cholesterol (CL), and low-density lipoprotein (LDL), no significant alterations were evident.

Conclusion

This study revealed that consumption of propolis is associated with a reduction in TG levels, in addition to an increase in HDL levels. Nevertheless, additional research is required to further delineate the relationship between propolis consumption and lipid profile.

Chemical Profile and Antibacterial Activity of a Novel Spanish Propolis with New Polyphenols also Found in Olive Oil and High Amounts of Flavonoids

Propolis is a natural product obtained from hives. Its chemical composition varies depending on the flora of its surroundings, but nevertheless, common for all types of propolis, they all exhibit remarkable biological activities. The aim of this study was to investigate the chemical composition and antimicrobial activity of a novel Spanish Ethanolic Extract of Propolis (SEEP). It was found that this new SEEP contains high amounts of polyphenols (205 ± 34 mg GAE/g), with unusually more than half of this of the flavonoid class (127 ± 19 mg QE/g). Moreover, a detailed analysis of its chemical composition revealed the presence of olive oil compounds (Vanillic acid, 1-Acetoxypinoresinol, p-HPEA-EA and 3,4-DHPEA-EDA) never detected before in propolis samples. Additionally, relatively high amounts of ferulic acid and quercetin were distinguished, both known for their important therapeutic benefits. Regarding the antimicrobial properties of SEEP, the minimal inhibitory and bactericidal concentrations (MIC and MBC) against Staphylococcus epidermidis strains were found at the concentrations of 240 and 480 µg/mL, respectively. Importantly, subinhibitory concentrations were also found to significantly decrease bacterial growth. Therefore, the results presented here uncover a new type of propolis rich in flavonoids with promising potential uses in different areas of human health.