Search Results (19)

The bioaccumulation of pesticides in honeybee products (HBPs) should be studied for a number of reasons. The presence of pesticides in HBPs can provide new data on the risk related to the use of pesticides and their role in bee colony losses. Moreover, the degree of contamination of HBPs can lower their quality, weaken their beneficial properties, and, in consequence, may endanger human health. The aim of this study was to quantify a broad range of pesticide residues in three different HBPs—bee pollen, propolis, and royal jelly. Samples were collected in the years 2017–2019 from the apiary in west-central Poland. Bee products were analyzed for the presence of over 550 pesticides using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method. Twenty-nine of the contaminants were quantified at least in one of the samples. Nine of them exceeded the maximum residue levels for honey. It should be noted that any dose of pesticides can cause a health hazard due to toxicity, since these substances may act synergistically. This current study revealed the high need for the pesticide monitoring of HBPs and proved that there is a need to expand the European Union Pesticides Database to include more HBPs. Full article

Honeybees are some of the smallest farmed animals, and apiculture by-products, e.g., honey, beeswax, propolis, royal jelly, and pollen contribute to animal nutrition. For the effective production of these by-products, the optimal development and nutrient supply of the honeybee is required. Beginning with the development of the mouth and anal pores on the second day of embryonic development, the digestive tract differentiates into the mouth and fore-, mid-, and hindgut during the pupal stage. The various glands within the oral cavity are particularly important, secreting enzymes and substances that are crucial for digestion and hive nutrition, e.g., invertase and royal jelly. Honeybees rely on a specialized caste system, with worker bees collecting nectar, pollen, water, and resin for the nutrition of the entire hive. Macronutrients, including proteins, carbohydrates, and lipids, obtained primarily from pollen and nectar, are essential for the growth and development of larvae and the overall health of the colony. Inadequate nutrient intake can lead to detrimental effects on larval development, prompting cannibalism within the hive. Apiculture by-products possess unique nutritional and therapeutic properties, leading to a growing interest in the use of honey, beeswax, propolis, and pollen as a feed additive. In recent years, the use of apicultural by-products in animal nutrition has been primarily limited to in vivo studies, which have demonstrated various positive impacts on the performance of farm animals. Honey, beeswax, propolis, royal jelly, and pollen are listed feed stuffs according to Regulation (EC) No. 68/2013. However, for animal nutrition there is not any specific legal definition for these products and no legal requirements regarding their ingredients as given for honey or beeswax in European food law. Full article

Ethanol extracts obtained from 13 poplar propolis samples originating from various European countries by traditional maceration were tested for total polyphenols, flavonoid content, and antioxidant activity. Moreover, the content of 18 polyphenolic compounds (from the group of phenolic acids and flavonoids) was determined using the HPLC method. The inhibitory effect of six selected extracts with the highest activity was assessed by well-diffusion method against five strains (Bifidobacterium spp., L. rhamnosus, L. acidophilus, E. coli, and Bacteroides spp.) of intestinal bacteria self-isolated from the faeces of obese probands with the use of selective media. It was found that the antioxidant activity of propolis varied depending on geographical origin and even among samples from the same region, which indicates that some other factors also influence propolis quality. The samples of different geographical origin varied mainly in the share of individual phenolic compounds, and it was not possible to find a characteristic marker of origin, excluding the galangin present in the Polish samples only. Assessing the inhibitory activity of propolis (in the range of 70 mg to 10 µg per mL) indicated that the concentration of 100 µg/mL was found as being safe for tested fecal bacteria (Bifidobacterium spp., L. rhamnosus, L. acidophilus, E. coli, and Bacteroides spp.). As no negative effect of low doses of propolis on the intestinal microflora was found, it can be suggested that its use in recommended doses brings only beneficial effects to the body. Full article

Propolis, owing to its antibacterial and anti-inflammatory properties, acts as a cariostatic agent, capable of preventing the accumulation of dental plaque and inhibiting inflammation. The anti-inflammatory properties of propolis are attributed to caffeic acid phenethyl ester (CAPE), which is present in European propolis. The objective of the conducted study was to assess the anti-inflammatory effects of the Polish ethanolic extract of propolis (EEP) and isolated CAPE on stimulated with LPS and IFN-α, as well as the combination of LPS and IFN-α. The cytotoxicity of the tested compounds was determined using the MTT assay. The concentrations of specific cytokines released by the HGF-1 cell line following treatment with EEP (25–50 µg/mL) or CAPE (25–50 µg/mL) were assessed in the culture supernatant. In the tested concentrations, both CAPE and EEP did not exert cytotoxic effects. Our results demonstrate that CAPE reduces TNF-α and IL-6 in contrast to EEP. Propolis seems effective in stimulating HGF-1 to release IL-6 and IL-8. A statistically significant difference was observed for IL-8 in HGF-1 stimulated by LPS+IFN-α and treated EEP at a concentration of 50 µg/mL (p = 0.021201). Moreover, we observed that CAPE demonstrates a stronger interaction with IL-8 compared to EEP, especially when CAPE was administered at a concentration of 50 µg/mL after LPS + IFN-α stimulation (p = 0.0005). Analysis of the phenolic profile performed by high-performance liquid chromatography allowed identification and quantification in the EEP sample of six phenolic acids, five flavonoids, and one aromatic ester—CAPE. Propolis and its compound—CAPE—exhibit immunomodulatory properties that influence the inflammatory process. Further studies may contribute to explaining the immunomodulatory action of EEP and CAPE and bring comprehensive conclusions. Full article

Propolis is a natural bee-produced substance with antimicrobial, anti-inflammatory, and wound-healing properties, containing some components from the leaves, buds and resins of plants. It has been used for centuries for various health benefits. In this manuscript, our group reviewed the radioprotective effect of propolis using PubMed and Embase, and our review was conducted according to the PRISMA statement. Finally, 27 articles were included in this review, which includes the radioprotective effect of propolis from cell-based studies (n = 8), animal models (n = 14), and human trials (n = 5). Results reflected that the dosage forms of propolis extracted in the scientific literature were ethanolic extracts of propolis, a water-soluble derivate of propolis, or capsules. The efficacy of the radioprotective properties from propolis is extracted from the bibliography, as several compounds of this resinous mixture individually or synergistically are possible candidates that have the radioprotective effect. In fact, studies prior to 2011 lacked a comprehensive characterization of propolis due to the variability in active compounds among different batches of propolis and were limited to analytical techniques. Furthermore, in this manuscript, we have selected studies to include primarily propolis types from Brazil, Croatia, Egypt, European countries, and those commercialized in Spain. They all contained ethanolic extract of propolis (EEP) and were influenced by different dosage forms. EEP showed a significant presence of lipophilic bioactive compounds like flavones, flavonols, and flavanones. Full article

Tyrosinase is a key enzyme in the melanogenesis pathway. Melanin, the product of this process, is the main pigment of the human skin and a major protection factor against harmful ultraviolet radiation (UVR). Increased melanin synthesis due to tyrosinase hyperactivity can cause hyperpigmentation disorders, which in consequence causes freckles, age spots, melasma, or postinflammatory hyperpigmentation. Tyrosinase overproduction and hyperactivity are triggered by the ageing processes and skin inflammation as a result of oxidative stress. Therefore, the control of tyrosinase activity is the main goal of the prevention and treatment of pigmentation disorders. Natural products, especially propolis, according to their phytochemical profile abundant in polyphenols, is a very rich resource of new potential tyrosinase inhibitors. Therefore, this study focused on the assessment of the tyrosinase inhibitory potential of six extracts obtained from the European propolis samples of various origins. The results showed the potent inhibitory activity of all tested propolis extracts towards commercially available mushroom tyrosinase. The four most active propolis extracts showed inhibitory activity in the range of 86.66–93.25%. Apart from the evaluation of the tyrosinase inhibition, the performed research included UHPLC–DAD–MS/MS (ultra high performance liquid chromatography coupled with diode array detection and tandem mass spectrometry) phytochemical profiling as well as antioxidant activity assessment using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the 2,2”-azino-bis(3-ethylbenzothiazoline-6-sulfuric acid (ABTS) radical scavenging tests. Moreover, statistical analysis was used to correlate the tyrosinase inhibitory and antioxidant activities of propolis extracts with their phytochemical composition. To summarise, the results of our research showed that tested propolis extracts could be used for skin cosmeceutical and medical applications. Full article

Propolis samples from a geographical part of northwest Greece (Prespa National Park, PNP), which is characterized as a plant endemism center and biodiversity hotspot, were characterized through pollen analysis, chemically analyzed, and biologically evaluated. The majority of the studied propolis showed typical chemical constituents (phenolic acids, flavonoids, and chalcones) of European type, while a sample of Mediterranean-type propolis (rich in diterpenes) was also identified. The palynological characterization was implemented to determine the botanical origin and to explain the chemical composition. The total phenolic content and the DPPH assay showed that the European-type propolis samples possessed strong antioxidant activity (86–91% inhibition at 200 μg/mL). Moreover, promising antibacterial activity of the extracts (MIC values 0.56–1.95 mg/mL) and moderate antifungal activity (MIC values 1.13–2.40 mg/mL) were noticed, while the sample with the highest activity had a significant content in terpenes (Mediterranean type). Propolis samples from the PNP area represent a rich source of antibacterial and antioxidant compounds and confirm the fact that propolis is a significant natural product with potential use for improving human health and stimulating the body’s defense. Finally, it is noteworthy that a significant chemical diversity was demonstrated, even in samples from a limited geographical area as this of PNP. Full article

Propolis or “bee glue” is a resinous waxy substance that is produced by honeybees (Apis mellifera) by mixing the exudates collected from plants, namely tree buds, sap flows, leaves, branches and barks with their saliva and beeswax. Propolis composition is very complex. Its main constituents are resins and volatiles originating from plants and wax added by the bee. The biological activity of propolis is assigned to these plant-derived substances. The main three types of propolis are European propolis, called poplar type propolis; Green Brazilian propolis (derived mainly from the leaf resin of Baccharis dracunculifolia) and Red Cuban propolis (from the floral resin of Clusia rosea). The plant’s source gives it a specific composition and properties for the propolis types that are coming from different regions of the world. For this reason, studies on the chemical composition of propolis as well as its botanical sources resulting in its geographically conditioned diversity, were a very good theme for the present Special Issue (SI) of Plants journal. The present SI contains nine original contributions addressing propolis plant sources, their chemical composition and different bioactive properties derived from this origin. The chemical composition of propolis that is made by the bees was also discussed, as well as the different medical activities of propolis extract. The papers cover a wide range of subjects, including (i) the plant species used by the bees as raw material for propolis production, (ii) the biological activities of plant extracts related to propolis, (iii) the chemical composition of different types of propolis, (iv) the biological activity of propolis, (v) propolis and human health, and (vi) synergism between plants and propolis in human health. The studies have been carried out in both in vitro and in vivo surveys and a wide range of geographic regions are covered in the sample collection. Full article

This review aims to analyze propolis as a potential raw material for the development and manufacture of new health-promoting products. Many scientific publications were retrieved from the Scopus, PubMed, and Google Scholar databases via searching the word "propolis". The different extraction procedures, key biologically active compounds, biological properties, and therapeutic potential of propolis were analyzed. It was concluded that propolis possesses a variety of biological properties because of a very complex chemical composition that mainly depends on the plant species visited by bees and species of bees. Numerous studies found versatile pharmacological activities of propolis: antimicrobial, antifungal, antiviral, antioxidant, anticancer, anti-inflammatory, immunomodulatory, etc. In this review, the composition and biological activities of propolis are presented from a point of view of the origin and standardization of propolis for the purpose of the development of new pharmaceutical products on its base. It was revealed that some types of propolis, especially European propolis, contain flavonoids and phenolic acids, which could be markers for the standardization and quality evaluation of propolis and its preparations. One more focus of this paper was the overview of microorganisms’ sensitivity to propolis for further development of antimicrobial and antioxidant products for the treatment of various infectious diseases with an emphasis on the illnesses of the oral cavity. It was established that the antimicrobial activity of different types of propolis is quite significant, especially to Gram-negative bacteria and lipophilic viruses. The present study could be also of interest to the pharmaceutical industry as a review for the appropriate design of standardized propolis preparations such as mouthwashes, toothpastes, oral drops, sprays, creams, ointments, suppositories, tablets, and capsules, etc. Moreover, propolis could be regarded as a source for the isolation of biologically active substances. Furthermore, this review can facilitate partially overcoming the problem of the standardization of propolis preparations, which is a principal obstacle to the broader use of propolis in the pharmaceutical industry. Finally, this study could be of interest in the area of the food industry for the development of nutritionally well-balanced products. The results of this review indicate that propolis deserves to be better studied for its promising therapeutic effects from the point of view of the connection of its chemical composition with the locality of its collection, vegetation, appropriate extraction methods, and standardization. Full article

Natural products are being discussed as alternatives to commonly used chemicals in antimicrobial therapy. The study aimed to investigate the antimicrobial activity of propolis against microbial species associated with caries, periodontal disease, and Candida infections. Two commercially available ethanolic extracts of Brazilian and one of European propolis (EEP) were used. The minimal inhibitory concentrations (MIC) of propolis and controls against eight microbial strains were determined. Scanning and transmission electron microscopy (SEM and TEM) images visualized the effect of propolis on microorganisms. Subsequently, the activity on three different multi-species biofilms (both formation and existing biofilms) was assessed. All MIC values of the Brazilian EEPs were low against the tested oral species (≤0.1 mg/mL–3.13 mg/mL propolis (Candida albicans)). The European EEP had slightly higher MICs than the Brazilian EEPs. The SEM and TEM images suggest an interaction of propolis with the microbial cell wall. The European EEP exhibited the strongest effect on retarding biofilm formation, whereas the Brazilian EEPs were highly active against preformed biofilms (100 mg/mL propolis of both EEPs reduced colony forming unit counts always by more than 6 log10). The antimicrobial and anti-biofilm activities point to the potential of propolis as an adjunct in oral health care products. Full article

Recently, the honey and propolis of stingless bees have been attracting growing attention because of their health-promoting properties. However, studies on these products of African Meliponini are still very scarce. In this preliminary study, we analyzed the chemical composition of honey, two cerumen, and two resin deposits (propolis) samples of Meliponula ferruginea from Tanzania. The honey of M. ferruginea was profiled by NMR and indicated different long-term stability from Apis mellifera European (Bulgarian) honey. It differed significantly in sugar and organic acids content and had a very high amount of the disaccharide trehalulose, known for its bioactivities. We suggested trehalulose to be a potential marker for African stingless bee honey analogously to the recent proposal for Meliponini honey from Asia, South America, and Australia and demonstrated its easy discrimination by ¹³C NMR. Propolis and cerumen were studied by GC-MS (gas chromatography-mass spectometry). The samples contained mainly terpenoids (di-and triterpenes) but demonstrated qualitative and quantitative differences. This fact was an indication that possibly M. ferruginea has no strict preferences for resins used to construct and protect their nests. The antimicrobial and anti-quorum sensing properties of the two materials were also tested. These first results demonstrated that the honey, cerumen, and propolis of African stingless bees were rich in biologically active substances and deserved further research. Full article

Nowadays, propolis is used as a highly valuable product in alternative medicine for improving health or treating a large spectrum of pathologies, an ingredient in pharmaceutical products, and also as a food additive. Different vegetal materials are collected by honeybees and mixed with wax and other own substances in order to obtain the final product, called propolis. It is known as the bee product with the widest chemical composition due to the raw material collected by the bees. Different types are known worldwide: green Brazilian propolis (having Baccharis dracunculifolia as the major plant source), red Brazilian propolis (from Dalbergia ecastophyllum), European propolis (Populus nigra L.), Russian propolis (Betula verrucosa Ehrh), Cuban and Venezuelan red propolis (Clusia spp.), etc. An impressive number of scientific papers already demonstrate the pharmacological potential of different types of propolis, the most important activities being the antimicrobial, anti-inflammatory, antitumor, immunomodulatory, and antioxidant activities. However, the bioactive compounds responsible for each activity have not been fully elucidated. This review aims to collect important data about the chemical composition and bioactive properties of the vegetal sources and to compare with the chemical composition of respective propolis types, in order to determine the connection between the floral source and the propolis properties. Full article

Stemphylium vesicarium (Wallr.) E. G. Simmons is the pathogen responsible of brown spot disease in pear and has become one of the main concerns for European pear producers. In Portugal, S. vesicarium is responsible for significant yield reduction and economic losses in “Rocha” pear (Pyrus communis L. cv Rocha) production. Considering the antimicrobial potential of propolis, the high incidence of brown spot in pears and the emergence of fungicides resistance in S. vesicarium, this study aimed to evaluate the potential of Portuguese propolis as an alternative strategy to control brown spot disease in “Rocha” pear. In vitro assays showed that propolis extracts were able to inhibit up to 90% the S. vesicarium mycelial growth. In vivo assays in artificially wounded and inoculated “Rocha” pears showed that, compared to the control, the disease incidence decreased up to 25% and the lesions diameter up to 57%, in fruits treated with propolis. Moreover, propolis seems to be more efficient in reducing the disease incidence when applied after pathogen inoculation (curative assay) than when applied before pathogen inoculation (prophylactic assay). Thus, the results suggest that propolis extracts have potential to be applied as part of an integrated approach for the control of brown spot of pear. Full article

Nosema ceranae is a widespread obligate intracellular parasite of the ventriculus of many species of honey bee (Apis), including the Western honey bee Apis mellifera, in which it may lead to colony death. It can be controlled in A. mellifera by feeding the antibiotic fumagillin to a colony, though this product is toxic to humans and its use has now been banned in many countries, so in beekeeping, there exists a need for alternative and safe products effective against N. ceranae. Honeybees produce propolis from resinous substances collected from plants and use it to protect their nest from parasites and pathogens; propolis is thought to decrease the microbial load of the hive. We hypothesized that propolis might also reduce N. ceranae infection of individual bees and that they might consume propolis as a form of self-medication. To test these hypotheses, we evaluated the effects of an ethanolic extract of propolis administered orally on the longevity and spore load of experimentally N. ceranae-infected worker bees and also tested whether infected bees were more attracted to, and consumed a greater proportion of, a diet containing propolis in comparison to uninfected bees. Propolis extracts and ethanol (solvent control) increased the lifespan of N. ceranae-infected bees, but only propolis extract significantly reduced spore load. Our propolis extract primarily contained derivatives of caffeic acid, ferulic acid, ellagic acid and quercetin. Choice, scan sampling and food consumption tests did not reveal any preference of N. ceranae-infected bees for commercial candy containing propolis. Our research supports the hypothesis that propolis represents an effective and safe product to control N. ceranae but worker bees seem not to use it to self-medicate when infected with this pathogen. Full article

There is growing interest in the development of non-toxic, natural wood preservation agents to replace conventional chemicals. In this paper, the antifungal activities of silver nanoparticles, chitosan oligomers, and propolis ethanolic extract were evaluated against white-rot fungus Trametes versicolor (L.) Lloyd, with a view to protecting Populus spp. wood. In order to create a more realistic in-service type environment, the biocidal products were assessed according to EN:113 European standard, instead of using routine in vitro antimicrobial susceptibility testing methods. Wood blocks were impregnated with the aforementioned antifungal agents by the vacuum-pressure method in an autoclave, and their biodeterioration was monitored over 16 weeks. The results showed that treatments based on silver nanoparticles, at concentrations ranging from 5 to 20 ppm, presented high antifungal activity, protecting the wood from fungal attack over time, with weight losses in the range of 8.49% to 8.94% after 16 weeks, versus 24.79% weight loss in the control (untreated) samples. This was confirmed by SEM and optical microscopy images, which showed a noticeably higher cell wall degradation in control samples than in samples treated with silver nanoparticles. On the other hand, the efficacy of the treatments based on chitosan oligomers and propolis gradually decreased over time, which would be a limiting factor for their application as wood preservatives. The nanometal-based approach is thus posed as the preferred choice for the industrial treatment of poplar wood aimed at wood-based engineering products (plywood, laminated veneer lumber, cross-laminated timber, etc.). Full article