Flavonoids In Propolis Research Articles

Pinocembrin prevents glutamate-induced apoptosis in SH-SY5Y neuronal cells via decrease of bax/ bcl-2 ratio

Pinocembrin is the most abundant flavonoids in propolis, and has been proven to have antioxidant, antibacterial and anti-inflammatory property. To assess the protective effects of pinocembrin on neurons, SH-SY5Y neuronal cells were pretreated with pinocembrin for 2 h followed by co-treatment with glutamate (2 mM) for 12 h. Cell viability was determined by(3,4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide assay, and apoptosis was confirmed by cell morphology, capillary zone electrophoresis and flow cytometry assay. Cell morphology was evaluated with Hoechst33258/PI dye. Treatment with pinocembrin (10 − 5 , 10 − 6 , 10 − 7 mol/l) increased cell viability dose-dependently, inhibited LDH release and attenuated apoptosis. Intracellular free [Ca 2+] was increased after glutamate exposure, and this increase was attenuated in cells treated with pinocembrin. bax mRNA expression increased remarkably following glutamate exposure and pinocembrin treatment manifested a reduction effect. bcl-2 mRNA expression changes were not detected in groups with or without pinocembrin. Western blotting results indicated that pinocembrin treatment reduced the expression of Bax and had no effect on Bcl-2, thus decreased the Bax–Bcl-2 ratio, which is in consistent with the gene expression result. Pinocembrin could also down-regulate the expression of p53 protein, and inhibit the release of cytochrome c from mitochondria to cytosol. Thus we conclude that pinocembrin exerts its neuroprotective effects in glutamate injury model partly by inhibiting p53 expression, thus Bax–Bcl-2 ratio, and the release of cytochrome c.

The formation of organic (propolis films)/inorganic (layered crystals) interfaces for optoelectronic applications

Propolis (honeybee glue) organic films were prepared from an alcoholic solution on the surfaces of inorganic layered semiconductors (indium, gallium and bismuth selenides). Atomic force microscopy (AFM) and X-ray diffraction (XRD) are used to characterize structural properties of an organic/inorganic interfaces. It is shown that nanodimensional linear defects and nanodimensional cavities of various shapes are formed on the van der Waals (VDW) surfaces of layered crystals as a result of chemical interaction between the components of propolis (flavonoids, aminoacids and phenolic acids) and the VDW surfaces as well as deformation interaction between the VDW surfaces and propolis films during their polymerization. The nanocavities are formed as a result of the rupture of strong covalent bonds in the upper layers of layered crystals and have the shape of hexagons or triangles in the (0001) plane. The shape, lateral size and distribution of nanodimensional defects on the VDW surfaces depends on the type of crystals, the magnitude and distribution of surface stresses. We have obtained self-organized nanofold structures of propolis/InSe interface. It is established that such heterostructures have photosensitivity in the infrared range h ν < 1.2 eV (the values of energy gap are 1.2 eV for InSe and 3.07 eV for propolis films at room temperature).

Evaluation of the Radioprotective Effects of Propolis and Flavonoids in Gamma-Irradiated Mice: The Alkaline Comet Assay Study

The radioprotective effects of water-soluble derivate of propolis (WSDP) collected in Croatia, and single flavonoids, caffeic acid, chrysin and naringin in the whole-body irradiated CBA mice were investigated. Irradiation was performed using a gamma-ray source ((60)Co), and absorbed doses were 4 and 9 Gy. The efficiency of test components was evaluated when given intraperitoneally (i.p.) at dose of 100 mg kg(-1) for 3 consecutive days before and/or after irradiation. Moreover, possible genotoxic effects of all test components were assessed on non-irradiated animals. The higher efficiency of test components was observed when given preventively. The results suggest that propolis and related flavonoids given to mice before irradiation protected mice from lethal effects of whole-body irradiation and diminish primary DNA damage in their white blood cells as detected by the alkaline comet assay.

Ácido canárico (3,4-seco derivado do lupano) em própolis do Ceará

Phytochemical investigation of a propolis sample from Alto Santo - Ceara, Brazil, allowed identification of triterpenes (lupeol, lupenone, germanicone, canaric acid) and flavonoids (quercetin, kaempferol and acacetin), which were identified by spectroscopic data (IR, MS, and NMR, including 2D techniques). This is the first report of canaric acid in propolis. Propolis extract and flavonoids showed antioxidant activity using a DPPH radical scavenging assay.

Selective analysis of phenolic compounds in propolis by HPLC‐MS/MS

Phenolic compounds (flavonoids and phenolic acid derivatives) are major active constituents of the resinous fraction of propolis, and also represent its allergenic principles. We have developed a chromatography electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS/MS) method to characterise the polyphenolic fraction of propolis rapidly and quali-quantitatively. With precursor ion scanning, selective detection of caffeic esters was easily achieved, confirming the identification of prenyl caffeate, benzyl caffeate and phenylethyl caffeate by comparison with synthetic standards. The ionisation and fragmentation behaviour of the major propolis flavonoids was rationalised and applied to selected real samples. Taken together, the results of this study show that the introduction of precursor ion analysis leads to a significant improvement in the characterisation of the phenolic fraction of propolis, paving the way to the establishment of a better quality control for this important natural remedy.

Brazilian red propolis--chemical composition and botanical origin.

Propolis contains resinous substances collected by honey bees from various plant sources and has been used as a traditional folk medicine since ca 300 BC. Nowadays, the use of evidence-based complementary and alternative medicine (CAM) is increasing rapidly and so is the use of propolis in order to treat or support the treatment of various diseases. Much attention has been focused on propolis from Populus sp. (Salicaceae) and Baccharis dracunculifolia (Asteracea), but scientific information about the numerous other types of propolis is still sparse. We gathered six samples of red propolis in five states of Northeastern Brazil. The beehives were located near woody perennial shrubs along the sea and river shores. The bees were observed to collect red resinous exudates on Dalbergia ecastophyllum (L) Taub. (Leguminosae) to make propolis. The flavonoids of propolis and red resinous exudates were investigated using reversed-phase high-performance liquid chromatography and reversed-phase high-performance thin-layer chromatography. We conclude that the botanical origin of the reddish propolis is D. ecastophyllum. In areas where this source (D. ecastophyllum) was scarce or missing, bees were collecting resinous material from other plants. Propolis, which contained the chemical constituents from the main botanical origin, showed higher antimicrobial activity.

Food preservative based on propolis: Bacteriostatic activity of propolis polyphenols and flavonoids upon Escherichia coli

Propolis was tested as food preserver, due its recognized bactericidal and bacteriostatic properties. Furthermore, most propolis components are natural constituents of food and recognized as safe substances. Fifteen propolis from Santa Fe, Argentine in 20% w/w ethanolic extracts, were tested upon Escherichia coli ATCC 25922 by agar diffusion and plate culture methods. Considering propolis physicochemical characteristics and inhibitory effects, tested samples were classified in three groups. A minimum inhibitory concentration mean value of 14.3 ± 6 mg soluble compounds/ml of the most active propolis was capable of inhibiting 10 5 cfu/ml cellular concentration. Such extract had 32.31% total soluble compounds (2.1% coumaric + siringic acids, 5.16% quercetin, 0.47 apigenine, 8.15 galangine, 7.2 caffeic acid + crisine and 9.23% no-identified phenolics compounds). By relating the zone of growth inhibition with extracts concentration, a linear response was obtained. On the propolis samples tested, a single value of the minimum inhibitory concentration could not be established. Those values were strongly dependent on propolis composition and botanical origin. The propolis extracts tested, may successfully inhibit the E. coli development in vitro, and consequently may be useful as natural food preserver.

Aktivitas antibakteri flavonoid propolis Trigona sp terhadap bakteri Streptococcus mutans (in vitro) (In vitro antibacterial activity of flavonoids Trigona sp propolis against Streptococcus mutans)

A number of investigations have shown a positive correlation between the number of Streptococcus mutans (S. mutans) in dental plaque and the prevalence of dental caries. Consequently, this microorganism has been the prime target for the prevention of dental caries. Propolis being a substance made by the honeybee, is a potent antibacterial agent. The main chemical class present in propolis is flavonoids. Flavonoids are well-known plant compounds that have antibacterial property. Because S. mutans is accepted to be one of the microorganisms responsible for dental caries and flavonoids in propolis are antibacterial, the purpose of this study was to evaluate in vitro the antibacterial activity of flavonoids Trigona sp propolis against S. mutans as a first step in its possible use as an alternative anticaries agent. Extract flavonoids was purified from ethanol extract of propolis which was obtained from Bulukumba Regency South Sulawesi using thin layer chromatography. The purification of flavonoids was carried-out by UVradiation at λ max 254 nm and λ max 366 nm and treatment with ammonia. Extract flavonoids was diluted in aquadest to 0.05%; 0.075%; 0.1%; 0.25%; 0.5%; 0.75% concentrations. Aquadest and 10% Povidone iodine were also used as control solution. S mutans were grown in medium glucose nutrient agar and incubated with flavonoids for 24 and 48 hours, at 37° C. Antibacterial activity was reflected by the diameter of the inhibition zones around the stainless steel cylinder. The data were analyzed by using ANOVA followed by LSD test with significance level of 5%. The results of this study showed that after being incubated for 24 and 48 hours, all flavonoid concentrations significantly (p < 0.05) inhibited the growth of S mutans. 0.1% flavonoid was the most effective concentration to inhibit the growth of S mutans after 24 hours of incubation and 0.5% flavonoid after 48 hours of incubator.

Note: Effect of High Hydrostatic Pressure on Extraction of Flavonoids in Propolis

The effect of high hydrostatic pressure (HHP) on the extraction of flavonoids components (chrysin and galangin) of propolis was studied. The experimental results showed that HHP did not modify their molecular structure. The extraction yields of flavonoids compounds by HHP for 1min were even higher than those obtained with extraction at room temperature (ERT) for 7 days. These excellent results showed a bright prospect for extraction of flavonoids components from propolis.

Histological analysis of rat dental pulp tissue capped with propolis

The aim of the present study was to assess the response of rat dental pulp to direct pulp capping with propolis. Flavonoid and non-flavonoid materials were purified from an ethanol extract of propolis obtained from South Sulawesi, Indonesia. A Class I cavity was prepared on the occlusal surface of the right maxillary first molar in Sprague Dawley rats. The dental pulp was exposed and then capped with a zinc oxide-based filler as a control (group I), or with propolis flavonoids (group II) or non-flavonoids (group III). The animals were sacrificed at week 1, 2 or 4, biopsy samples were obtained, and these were stained and viewed by light microscopy. The results showed that pulp inflammation occurred in groups I and III as early as week 1. No dentin bridge formation was seen in these groups. In contrast, there was no evident inflammatory response in group II at week 1. Mild and moderate pulp inflammation in this group occurred at 2 and 4 weeks after treatment, respectively. Partial dentinal bridge formation was seen in group II at week 4. Therefore, the present results suggest that direct pulp capping with propolis flavonoids in rats may delay dental pulp inflammation and stimulate reparative dentin.

Identification of metabolites in plasma and urine of Uruguayan propolis-treated rats.

Propolis is a resinous substance collected by honeybees from various plant sources. It is extensively used in food and beverages to improve health and prevent diseases such as heart disease, diabetes, and cancer. To investigate the absorption and metabolism of the components in propolis, in the present study, we administered ethanol extracts of Uruguayan propolis (poplar type propolis) orally to rats and analyzed their plasma and urine by high-performance liquid chromatography with photodiode array and mass spectrometric detection. After deconjugation of the components by beta-glucuronidase/sulfatase treatment of the specimen, pinobanksin 5-methyl ether, pinobanksin, kaempferol, chrysin, pinocembrin, and galangin were detected in plasma of rats orally administered propolis. These compounds were detected also in urine after beta-glucuronidase/sulfatase treatment. Furthermore, pinobanksin 5-methyl ether, pinobanksin, chrysin, pinocembrin, and galangin were present in the urine also in free form. These results suggest that flavonoids in propolis are metabolized and circulate in the body after oral administration of propolis.

Investigation of the flavonoids in Croatian propolis by thin-layer chromatography

Flavonoids and phenolic acids with a variety of biological activity are considered to be the main compounds in propolis — a natural product produced by the honey bee. TLC can be used for rapid screening of pharmacologically active components and to establish the difference between different propolis samples. Our goal was to optimize chromatographic conditions for separation of flavonoids and phenolic acids and to apply the optimized method for analysis of propolis samples from different geographic regions of Croatia. For chromatographic analysis we used 20 cm × 20 cm glass-backed TLC plates coated with 0.25 mm layers of silica gel 60 F 254 . Ethanolic standard solutions (80%) of the flavonoids and phenolic acids (10 μL) were applied to the plates. Chromatograms were developed at room temperature by ascending development in previously saturated vertical, flat-bottomed glass chambers with glass lids. Visualization was performed in short-and long-wavelength UV light and in long-wavelength UV light after spra...

Application of an HPLC Method for Analysis of Propolis Extract

Propolis obtained from honeybee hives has been widely used in medicine, cosmetics, and industry due to its versatile biological activities (antioxidant, antimicrobial, fungicidal, antiviral, antiulcer, immunostimulating, and cytostatic). These activities are mainly attributed to the presence of flavonoids in propolis, which points out the interest in quantifying these constituents in propolis preparations, as well as validation of analytical methodologies. High‐performance liquid chromatography (HPLC) methods have been reported to quantify isolated flavonoids or these compounds in complex biological matrices, such as herbal raw materials and extractive preparations. An efficient, precise, and reliable method was developed for quantification of propolis extractive solution using HPLC with UV detection. The chromatograms were obtained from various gradient elution systems (GES) tested in order to establish the ideal conditions for the analysis of propolis extractive solution, using methanol and water:acetonitrile (97.5:2.5, v/v) as mobile phase. Gradient reversed phase chromatography was performed using a stainless steel column (250 × 4.6 mm i.d., 5 µm) filled with Chromsep RP 18 (Varian), column temperature at 30.0 ± 0.1°C and detection at 310 nm. The main validation parameters of the method were also determined. The method showed linearity for chrysin in the range 0.24–2.4 µg mL−1 with good correlation coefficients (0.9975). Precision and accuracy were determined. The obtained results demonstrate the efficiency of the proposed method. The analytical procedure is reliable and offers advantages in terms of speed and cost of reagents.

Supercritical carbon dioxide extraction enhances flavonoids in water-soluble propolis

Two propolis, obtained from Brazil and China, were ground and individually treated using supercritical carbon dioxide to enhance the extraction and water solubility of nine flavonoids. Co-solvent effects of ethanol and water were examined. Extractions were carried out semi-batchly at 5 mL/min CO2, at pressures ranging from 2000 to 5000 psig, at temperatures ranging from 35 to 65℃, and with propolis to co-solvent ratios of 1:2 and 1:5 (w/v). After supercritical extraction of 500 liters of CO2, the residual propolis in the extractor was further extracted by means of normal solvent extraction using 95% ethanol (ReE extract was obtained) and de-ionized water (ReW extract was obtained). Nine active propolis flavonoids in the extracts were analyzed to verify their inhibitory effects on leukemia cancer cells. Experimental results indicated that the dry SC-CO2 extract mainly contained low-polar wax-like materials. The crude yield of Brazilian propolis in the dry SC-CO2 extract reached around 10% at 45℃ and 4000 psig extraction. The amounts of the nine flavonoids in the Brazilian ReE and ReW extracts were 5% and 120%, higher than those obtained by means of conventional ethanol and water extraction, respectively. The Brazilian ReW extracts clearly contained a few water-soluble compounds and, especially, enhanced amounts of the nine flavonoids. All the extracts were tested for viability and cell proliferation of leukemia HL-60 and U937 cancer cells, and most exhibited a postivie inhibitory effect. The results also suggested that something other than the nine flavonoids in dry SC-CO2 extract was importantly involved in the inhibitory effect.

Flavonoids of Propolis and Their Antibacterial Activities

Flavonoids of Propolis and Their Antibacterial Activities

Profiling propolis flavonoids by means of micellar electrokinetic capillary chromatography, capillary gas chromatography and bactericidal action

There is no proportional correlation between increasing organic solvent polarity from hexane to methanol and the extractability of propolis solids by the solvents or the bactericidal action of the propolis extracts obtained. Hexane (17.7%) and chloroform (62.1%) were the poorest and the best extractants, respectively, for propolis solids. The antibiotic activity of the extracts againstStaphylococcus strains decreased in the order hexane≥ethanol>methanol. Different capillary GC profiles were obtained for persilyl derivatives of propolis extracted with hexane and methanol and for propolis collected in different Brazilian provinces, suggesting the influence of flora variability on propolis composition. Wavelength-selected DAD detection revealed MEKC to be an innovative and sensitive method for monitoring the occurrence in propolis of the flavonoids and phenolcarboxylic acids thought to be responsible for the antimicrobial activity of propolis.

Flavonoid Composition of Tunisian Honeys and Propolis

Flavonoids and other phenolics of Tunisian honey samples and propolis were analyzed to find correlations between botanical and geographical origin and chemical composition. Flavonoid content of honey was very variable (20−2400 μg/100 g). The richest samples contained the characteristic propolis flavonoids, while those containing fewer flavonoids were devoid of these substances. This is a difference with honeys from temperate areas, in which the poplar-derived flavonoids are present in all honey samples. In Tunisian honeys, and propolis, a new flavonoid, myricetin 3,7,4‘,5‘-tetramethyl ether, was detected. This is characteristic of Cistus spp. leaf exudates. Another minor compound was identified as quercetin 3,7,3‘-trimethyl ether. They were present in high amounts in propolis but were only detected in small amounts in honey. These results show that in border areas, such as Tunisia, where poplars are not always available for propolis collection, other plant sources can be used and their constituents detect...

Investigation of Flavonoid Aglycones in Propolis Collected by Two Different Varieties of Bees in the Same Region

The quality and quantity of flavonoids from two types of propolis collected by two different varieties of Apis mellifera bee in the same region were investigated. There was found a remarkable quantitative and qualitative difference of flavonoids in propolis. These results indicate that the chemical composition of propolis was dependent on the variety of the bee.

Flavonoids of Honey and Propolis: Characterization and Effects on Hepatic Drug-Metabolizing Enzymes and Benzo[a]pyrene−DNA Binding in Rats

The influence of dietary sunflower honey, propolis, and a flavonoid extract of propolis was examined on drug-metabolizing enzyme activities in rat liver and on microsome-mediated binding of benzo[a]pyrene to DNA. Characterization of flavonoids present in sunflower honey and propolis was achieved in order to assess the relative effects of different components of honey and propolis. Honey and propolis contained the same major flavonoids, pinocembrin, chrysin, galangin, and pinobanksin. The concentration of flavonoids was higher in propolis. Sunflower honey produced no significant changes on phase I and phase II enzyme activities and no modification of in vitro binding of benzo[a]pyrene to DNA. Propolis treatment produced an increase of ethoxyresorufin deethylase, pentoxyresorufin depentylase, ethoxycoumarin deethylase, glutathione transferase, and epoxide hydrolase activities. A flavonoid extract from propolis slightly enhanced only few enzyme activities, ethoxycoumarin deethylase and epoxide hydrolase. The...

Flavonoids in honey of different geographical origin

The flavonoids present in honey samples from different geographical areas (Europe, North America, Equatorial regions, South America, China and Australia) have been analysed by HPLC. These flavonoids are incorporated into honey from propolis, nectar or pollen. As a general rule, honey samples from the Northern Hemisphere (where poplars, the source of propolis, are native) show flavonoid profiles characterized by the presence of propolis flavonoids. In contrast, honey samples from most Equatorial regions and Australia are generally devoid of propolis-derived flavonoids, showing only flavonoids from other plant sources. However, several honey samples from Central and South America and from New Zealand do contain the flavonoids characteristic of propolis. This means that importedApis mellifera colonies may locate poplar trees, occasionally finding an imported specimen in gardens or agro-industrial exploitations, and incorporate propolis flavonoids into honey. These preliminary results show that flavonoid analysis could be used as an adjunct to geographical origin studies of honey.