Compounds In Propolis Research Articles

Polyphenolic compounds from propolis modulate immune responses and increase host resistance to tumour cells

Propolis contains a variety of polyphenolic compounds. We investigated the effect of a water-soluble derivatives of propolis (WSDP) and polyphenolic compounds, components of propolis, on growth of Ehrlich ascites tumour (EAT) in mice. Tumour in peritoneal cavity was produced by 2×106 EAT cells. WSDP and polyphenolic compounds (caffeic acid-CA, caffeic acid phenethyl ester-CAPE and quercetin-QU) were given to mice perorally (po). It was found that the volume of ascitic fluid induced by EAT cells and total number of cells present in the peritoneal cavity was markedly reduced in EAT-bearing mice treated with test components and the survival time of treated mice was prolonged. Inhibition of EAT growth was due to their effect on the immune system of mice. When innate and acquired immune responses were evaluated, a dose-related increase of cytotoxic T-cell, NK and B cells activity was observed in test components-treated mice. Furthermore, exposure of animals to test components increased functional activity of macrophages to produce factors regulating the function of B-, T-, and NK- cells respectively. In conclusion, these findings imply that the antitumour activity of WSDP and polyphenolic compounds of propolis enhanced host resistance in the EAT tumour model, increasing the activities of macrophages, cytotoxic T cells, B cells and NK cells.

Properties of BKCa Channels in Oral Keratinocytes

Keratinocytes are important for epithelial antimicrobial barrier function. The activity of ion channels can affect the proliferation of keratinocytes. Little is known about Ca2+-activated K+ currents in these cells. Ion currents in normal human oral keratinocytes were characterized with a patch-clamp technique. In whole-cell configuration, depolarizing pulses evoked K+ outward currents (I(K)) in oral keratinocytes. Iberiotoxin (200 nM) and paxilline (1 microM) suppressed I(K); however, neither apamin (200 nM) nor 5-hydroxydecanoate (30 microM) had any effects on it. Caffeic acid phenethyl ester, a compound of honeybee propolis, increased I(K) with an EC50 value of 12.8 +/- 1.2 microM. In inside-out patches, a BK(Ca) channel was observed in keratinocytes, but not in oral squamous carcinoma (OCE-M1) cells. Caffeic acid phenethyl ester or cinnamyl-3,4-dihydroxy-alpha-cyanocinnamate applied to the intracellular surface of a detached patch increased BK(Ca)-channel activity. The results demonstrate that the properties of BK(Ca) channels in normal human oral keratinocytes are similar to those described in other types of cells. Caffeic acid derivatives can also stimulate BK(Ca)-channel activity directly.

The Xanthine Oxidase Inhibitory Activity and Hypouricemia Effect of the Propolis in Rats

The xanthine oxidase (XOD) inhibitory activity of propolis from China and Brazil was measured. The propolis from both place were seen to have XOD inhibitory activity. However, a stronger tendency was shown in the propolis from China. The compounds in each the propolis were measured quantitatively. A great deal of chrysin, galangin, and caffeic acid phenetyl ester were found in the propolis from China, an abundance of p-coumaric acid and artepillin C in the propolis from Brazil. Therefore it was revealed that the propolis compounds are very different depending on their place of origin. The XOD inhibitory activity of these five compounds was measured. Caffeic acid phenetyl ester had the strongest activity, with chrysin and galangin next; p-coumaric acid and artepillin C showed weak XOD inhibitory activity. We evaluated the hypouricemic effect of propolis from China on hyperuricemia induced by the uricase inhibitor, oxonic acid (500 mg/kg p.o., 1 h before the test drugs), and measured plasma uric acid values in rats. Oral propolis had a hypouricemic effect 2 h after its administration to oxonate-pretreated rats. These results suggested that a continuous intake of propolis may be effective for the prevention and the treatment of gout and hyperuricemia.

Development and validation of a liquid chromatographic–tandem mass spectrometric method for the determination of caffeic acid phenethyl ester in rat plasma and urine

Caffeic acid phenethyl ester (CAPE) is one of the most bioactive compounds of propolis, a resinous substance collected and elaborated by honeybees. A new liquid chromatography–electrospray ionisation tandem mass spectrometric method was developed and validated for its determination in rat plasma and urine, using taxifolin as internal standard. After sample preparation by liquid/liquid extraction with ethyl acetate, chromatographic separations were carried out with an ODS-RP column using a binary mobile phase gradient of acetonitrile in water. Detection was performed using a turboionspray source operated in negative ion mode and by multiple reaction monitoring. The method was validated, showing good selectivity, sensitivity (LOD = 1 ng/ml), linearity (5–1000 ng/ml; r ≥ 0.9968), intra- and inter-batch precision and accuracy (≤14.5%), and recoveries (94–106%) in both plasma and urine. Stability assays have shown that CAPE is rapidly hydrolysed by plasmatic esterases, which are however inhibited by sodium fluoride. The method was applied to the determination of CAPE levels in rat plasma and urine after oral administration, showing that CAPE is rapidly absorbed and excreted in urine both as unmodified molecule and as glucuronide conjugate.

Galangin expresses bactericidal activity against multiple-resistant bacteria: MRSA, Enterococcus spp. and Pseudomonas aeruginosa

The antimicrobial activity of three propolis ethanol extracts (EEP) was examined for various Gram-negative and Gram-positive bacterial species, including multiple-resistant Staphylococcus aureus, Enterococcus spp. and Pseudomonas aeruginosa strains. EEP had a good bactericidal activity against Gram-positive species, and all multiple-resistant bacterial strains tested were sensitive to EEP. Minimal inhibitory concentrations (MICs) were lower in samples of higher flavonoid content (from 0.65 to 7.81 mg mL −1), indicating the influence of the concentration of some potent bactericidal compound(s) in propolis or synergism among some bactericidal compounds. Antimicrobial-guided separation of flavonoid aglycones (bioassay in situ on thin-layer chromatogram) showed that galangin (3,5,7-trihydroxyflavone) is one compound in EEP with bactericidal activity. Galangin was isolated by preparative chromatography. After determining the quantity present, the MIC against multiple-resistant bacteria was determined. The MIC of galangin against multiple-resistant bacterial strains was significantly lower (from 0.16 to 0.44 mg mL −1, p < 0.05) than that of EEP. The bactericidal activity of galangin against P. aeruginosa strains was present at 0.17 ± 0.05 mg mL −1.

Development and validation of a liquid chromatographic–tandem mass spectrometric method for the determination of caffeic acid phenethyl ester in rat plasma and urine

Caffeic acid phenethyl ester (CAPE) is one of the most bioactive compounds of propolis, a resinous substance collected and elaborated by honeybees. A new liquid chromatography–electrospray ionisation tandem mass spectrometric method was developed and validated for its determination in rat plasma and urine, using taxifolin as internal standard. After sample preparation by liquid/liquid extraction with ethyl acetate, chromatographic separations were carried out with an ODS-RP column using a binary mobile phase gradient of acetonitrile in water. Detection was performed using a turboionspray source operated in negative ion mode and by multiple reaction monitoring. The method was validated, showing good selectivity, sensitivity (LOD = 1 ng/ml), linearity (5–1000 ng/ml; r ≥ 0.9968), intra- and inter-batch precision and accuracy (≤14.5%), and recoveries (94–106%) in both plasma and urine. Stability assays have shown that CAPE is rapidly hydrolysed by plasmatic esterases, which are however inhibited by sodium fluoride. The method was applied to the determination of CAPE levels in rat plasma and urine after oral administration, showing that CAPE is rapidly absorbed and excreted in urine both as unmodified molecule and as glucuronide conjugate.

Immunomodulatory and antimetastatic action of propolis and related polyphenolic compounds

The effect of polyphenolic compounds isolated from propolis and propolis itself was investigated on the growth and metastatic potential of a transplantable mammary carcinoma (MCa) of CBA mouse. Metastases in the lung were generated by intravenous injection of tumor cells (2 × 10 5). A water-soluble derivative of proplis (WSDP), caffeic acid (CA), caffeic acid phenethyl ester (CAPE) and quercetin (QU) were given to mice per os before tumor cells inoculation. Tested compounds significantly decreased the number of tumor nodules in the lung. According to the results obtained the antitumor activity of tested compounds can be related to the immunomodulatory properties of the compounds, their cytotoxicity to tumor cells, and their capacity to induce apoptosis and necrosis. The experimental data support that WSDP, CA, CAPE and QU could be potentially useful in the control of tumor growth in experimental models.

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...

Creating molecular diversity from antioxidants in Brazilian propolis. Combination of TOPS-MODE QSAR and virtual structure generation.

A QSAR model for antioxidative activity based on the Sub-Structural Molecular Design (TOPS-MODE) approach is developed for a series of compounds present in Brazilian propolis. This approach permitted the structural interpretation of the antioxidative activity of these compounds in terms of bond contributions. By these means we have identified the structural groups and regions that contribute to the antioxidative activity of the cinnamic acid and flavonoid derivatives present in the propolis. These results were then used to identify the positions and substituents to be used in a virtual compound generation experiment. Using this approach a total of 327 compounds were generated from which more than 70 are predicted to be more active than the most powerful antioxidants in the Brazilian propolis. From these 70 compounds less than 20 have been reported in the literature. Consequently, a high proportion of novel compounds with potential antioxidative activity has been identified by the current approach. This contributes to enhance the molecular diversity of the analogues of Brazilian propolis compounds with antioxidative properties.

Influence of honey bee products on transplantable murine tumours

The effect of propolis [it is a water-soluble derivative (WSDP)] and related polyphenolic compounds of propolis (caffeic acid, caffeic acid phenethyl ester and quercetin), honey, royal jelly and bee venom on tumour growth, metastasizing ability and induction of apoptosis and necrosis in murine tumour models (mammary carcinoma and colon carcinoma) was investigated. WSDP and related polyphenolic compounds showed significant anti-metastatic effect (P < 0.01 and P < 0.001) given either before or after tumour-cell inoculation. Oral or systemic application of WSDP or caffeic acid significantly reduced subcutaneous tumour growth and prolonged the survival of mice. Honey also exerted pronounced anti-metastatic effect (P < 0.05) when applied before tumour-cell inoculation (peroral 2 g kg(-1) for mice or 1 g kg(-1) for rats, once a day for 10 consecutive days). Royal jelly did not affect metastasis formation when given intraperitoneally or subcutaneously. However, intravenous administration of royal jelly before tumour-cell inoculation significantly (P < 0.05) inhibited metastasis formation. When mice were given 10(5) tumour cells intravenously immediately after bee venom injection, the number of tumour nodules in the lung was significantly lower (P < 0.001) than in untreated mice or mice treated with bee venom subcutaneously. Local presence of bee venom in the tissue caused significant delay in subcutaneous tumour formation. These findings clearly demonstrate that anti-tumour and anti-metastatic effects of bee venom are highly dependent on the route of injection and on close contact between components of the bee venom and tumour cells. These data show that honey bee products given orally or systemically may have an important role in the control of tumour growth and tumour metastasizing ability.

Inhibitory Effect of Water-Soluble Derivative of Propolis and Its Polyphenolic Compounds on Tumor Growth and Metastasizing Ability: A Possible Mode of Antitumor Action

Polyphenolic compounds are widely distributed in the plant kingdom and display a variety of biological activities, including chemoprevention and tumor growth inhibition. Propolis is made up of a variety of polyphenolic compounds. We compared how the routes of administration of polyphenolic compounds deriving from propolis and of propolis itself affect the growth and metastatic potential of a transplantable mammary carcinoma (MCa) of the CBA mouse. The influence of tested compounds on local tumor growth was also studied. Metastases in the lung were generated by 2 × 105 tumor cells injected intravenously (IV). A water-soluble derivative of propolis (WSDP) and polyphenolic compounds (caffeic acid, CA, and CA phenethyl ester, CAPE) were given to mice per os (PO) or intraperitoneally (IP) before or after tumor cell inoculation. Tested compounds significantly decreased the number of lung colonies. When mice were inoculated with 105 MCa cells in the exact site of subcutaneous injection of different doses of WSDP, CA, or CAPE, tumor growth was inhibited, and survival of treated mice was prolonged. Antitumor activity, according to the results obtained, is mostly related to the immunomodulatory properties of the compounds and their capacity to induce apoptosis and necrosis. In conclusion, results presented here indicate that WSDP, CA, and CAPE could be potential useful tools in the control of tumor growth in experimental tumor models when administrated PO; because PO administration is the easiest way of introducing a compound used for prevention and/or cure of any disease, it is likely that this article has reached the goal of the investigation.

Antibacterial activity of honey and propolis from Apis mellifera and Tetragonisca angustula against Staphylococcus aureus.

The antibacterial activity against Staphylococcus aureus of honey and propolis produced by Apis mellifera and Tetragonisca angustula was evaluated. Secondary aims included the study of the chemical composition of propolis and honey samples and its relationship with antibacterial activity against S. aureus. The antibacterial activity of honey and propolis was determined by the method of macrodilution. The minimum inhibitory concentration (MICs) of A. mellifera honey ranged from 126.23 to 185.70 mg ml(-1) and of T. angustula from 142.87 to 214.33 mg ml(-1). For propolis, the MIC ranged from 0.36 to 3.65 mg ml(-1) (A. mellifera) and from 0.44 to 2.01 mg ml(-1) (T. angustula). Honey and propolis were evaluated by high-performance liquid chromatography. Some typical compounds of Brazilian propolis were also identified in honey samples. Principal component analysis revealed that the chemical composition of honey and propolis samples was distinct based on the geographical location of the samples. Propolis samples had higher antibacterial activity against S. aureus when compared with honey. However, both propolis and honey samples had antibacterial against S. aureus. These antimicrobial properties would warrant further studies on the clinical applications of propolis and honey against S. aureus.

Distribution of quinic acid derivatives and other phenolic compounds in Brazilian propolis.

The quinic acid derivatives (including 4-feruoyl quinic and 5-ferruoyl quinic acids characterized for first time in propolis samples) and other phenolic compounds were quantified in thirteen Brazilian propolis samples by HPLC analysis. For chemometrical analysis, the distribution of quinic acid derivatives and other phenolic compounds were considered. The results suggest that the Brazilian propolis with floral origin from Citrus sp. have the highest concentration of the quinic acid derivatives (between 11.0 to 58.4 mg/mg of the dried crude hydroalcoholic extract) and therefore would probably show a more effective hepatoprotective activity.

Unusual chemical composition of a sample of Brazilian propolis, as assessed by analysis of a chloroform extract

SUMMARYA chloroform extract from a sample of propolis collected in the state of São Paulo (south-east Brazil) was analysed by column chromatography and the resultant fractions analysed by GC-MS. In comparison with similar analyses carried out with samples of ‘green propolis’ from Minas Gerais (also in south-east Brazil), relatively few shikimate-derived compounds were found, while isoprenoids and acetate-malonate-derived compounds predominated. Among the volatile compounds, sesquiterpenoids prevailed. Dehydrocostus lactone, a sesquiterpenoid known to possess diverse pharmacological properties, was found in relatively high amounts. Free carboxylic acids and pentacyclic triterpenoids, such as α- and β-amyrin, bauer-7–en-3β-yl acetate, D:C-friedoolean-3–one, polyketide-derived phenols (e.g. 3–nonadecylphenol and 3–heptadecylphenol), lactones (e.g. γ-palmitolactone, 6–tridecyl-tetrahydro-2H-piran-2–one), 1–benzylidene-2,2,3,3–tetramethylcyclopropane and 2–t-butyl-naphto-[2,3–b]-furan-4,9–dione, were found among other substances. Several compounds here detected had previously not been reported as propolis constituents. Some characteristic prenylated compounds of green propolis were also detected in the more polar fractions from the chromatographic columns.

In vivo anti-oxidant activities of tectochrysin

The anti-oxidant activities of tectochrysin, a major compound of propolis, were investigated. Tectochrysin exhibited a significant decrease in serum transaminase activities elevated by hepatic damage induced by CCl4-intoxication in rats. Tectochrysin tested exhibited a lipid peroxidation causing a significant decrease in MDA production in TBA-reactant assay. Tectochrysin was strong in the increase in the anti-oxidant enzymes such as hepatic cytosolic superoxide dismutase, catalase and glutathione peroxidase activities in CCl4-intoxicated rats. These results suggest that tectochrysin possess not only the anti-oxidant, but also the activities in CCl4-intoxicated rats. Especially, tectochrysin was found to cause significant increases in the rat liver cytosolic SOD, catalase, GSH-px activities as well as a significant decrease in the MDA production.

Phenolic compounds of propolis from Central Chilean matorral.

Pinocembrin, acacetin, galanguin, izalpin, kaempferide, prenyletin and diarytheptane were isolated from propolis from Central Chile.

Effects of Apis mellifera Propolis on the Activities of Streptococcal Glucosyltransferases in Solution and Adsorbed onto Saliva–Coated Hydroxyapatite

Propolis, a resinous hive product collected by Apis mellifera bees, has been used for thousands of years in folk medicine. Ethanolic extracts of propolis (EEP) have been shown to inhibit the activity of a mixture of crude glucosyltransferase (Gtf) enzymes in solution. These enzymes synthesize glucans from sucrose, which are important for the formation of pathogenic dental plaque. In the present study, the effects of propolis from two different regions of Brazil on the activity of separate, purified Gtf enzymes in solution and on the surface of saliva–coated hydroxyapatite (sHA) beads were evaluated. The EEP from Minas Gerais (MG; Southeastern Brazil) and Rio Grande do Sul (RS; Southern Brazil) were tested for their ability to inhibit the enzymes GtfB (synthesis of insoluble glucan), GtfC (insoluble/soluble glucan) and GtfD (soluble glucan). The effects of propolis on Gtf from Streptococcus sanguis (soluble glucan synthesis) was also explored. The EEP from both regions effectively inhibited the activity of all Gtfs in solution (75–95%) and on the surface of sHA beads (45–95%) at concentrations between 0.75 and 3.0 mg of propolis/ml. However, the two samples of propolis showed different levels of inhibition on each of the enzymes tested. In general, EEP RS demonstrated a significantly higher inhibitory activity on GtfB and C activities (both solution and surface assays) than EEP MG at concentrations between 0.047 and 0.187 mg/ml (p<0.05). EEP MG, on the other hand, exhibited a greater inhibitory effect on the activities of surface GtfD (at 0.375, 0.75 and 1.5 mg/ml) and S. sanguis Gtf (at 1.5 and 3.0 mg/ml; p<0.05). These data indicate that EEP is a potent inhibitor of Gtf enzymes in solution and adsorbed on an experimental pellicle; however, its effect on Gtf activity is variable depending on the geographical origin of the propolis samples. There is a need to identify the active compounds of propolis.

Isolation and Identification of Antimicrobial Compounds in Brazilian Propolis

Three distinct antimicrobial compounds were isolated from Brazilian propolis. These compounds were identified as 3,5-diprenyl-4-hydroxycinnamic acid (1), 3-prenyl-4-dihydrocinnamoloxycinnamic acid (2), and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (3).The respective antimicrobial activity, expressed as MIC in μg/ml, 1–3 against Bacillus cereus was 15.6, 31.3, and 125; that against Enterobacter aerogenes was 31.3, 62.5, and 125; and that against Arthroderma benhamiae was 15.6, > 250, and 62.5. Compound 1 is likely to be one of the major antimicrobial compounds in Brazilian propolis.

Identification by Gas Chromatography-Mass Spectrometry of 150 Compounds in Propolis

Abstract Propolis was analyzed by gas chromatography-mass spectrometry for both its headspace volatiles and for the less volatile components of its alcoholic extract (propolis balsam). 181 peaks were located of which 171 representing 150 compounds were identified, including 28 identified in propolis for the first time. The majority of compounds were typical of poplar bud exudate.