Ethanolic Extracts Of Propolis Samples Research Articles

Correlation between total phenolic and flavonoid contents and biological activities of 12 ethanolic extracts of Iranian propolis.

Propolis is a resinous substance produced by honey bees that is very popular as a natural remedy in traditional medicine. The current research is the first study on the biological properties of ethanolic extracts of propolis (EEP) from several different regions (12) of Iran. Total phenolic and flavonoid contents (TPC and TFC) of Iranian EEPs were variable between 26.59-221.38 mg GAE/g EEP and 4.8-100.03 mg QE/g EEP. The DPPH scavenging assay showed all the studied EEP samples, except for the sample with the lowest TPC and TFC (P6), have suitable antioxidant activity. All the EEPs inhibited both cholinesterase enzymes (acetylcholinesterase: AChE, butyrylcholinesterase: BuChE) but most of them exhibited a distinct selectivity over BuChE. Evaluation of the antibacterial activity of the EEP samples using four pathogenic bacteria (B. cereus, S. aureus, A. baumannii, and P. aeruginosa) demonstrated that the antibacterial properties of propolis are more effective on the gram-positive bacterium. Spearman correlation analysis showed a strong positive correlation between TPC and TFC of the Iranian EEPs and their antioxidant, anticholinesterase, and antibacterial activities. Considering that there is ample evidence of anticholinesterase activity of flavonoids and a significant correlation between the anticholinesterase activity of the studied Iranian EEPs and their total flavonoid content was observed, the interaction of 17 well-known propolis flavonoids with AChE and BuChE was explored using molecular docking. The results indicated that all the flavonoids interact with the active site gorge of both enzymes with high affinity. Summing up, the obtained results suggest that Iranian propolis possesses great potential for further studies.

Targeting Acanthamoeba proteins interaction with flavonoids of Propolis extract by in vitro and in silico studies for promising therapeutic effects.

Background : Propolis is a natural resinous mixture produced by bees. It provides beneficial effects on human health in the treatment/management of many diseases. The present study was performed to demonstrate the anti- Acanthamoeba activity of ethanolic extracts of Propolis samples from Iran. The interactions of the compounds and essential proteins of Acanthamoeba were also visualized through docking simulation. Methods: The minimal inhibitory concentrations (MICs) of Propolis extract against Acanthamoeba trophozoites and cysts was determined in vitro. In addition, two-fold dilutions of each of agents were tested for encystment, excystment and adhesion inhibitions. Three major compounds of Propolis extract such as chrysin, tectochrysin and pinocembrin have been selected in molecular docking approach to predict the compounds that might be responsible for encystment, excystment and adhesion inhibitions of A. castellanii. Furthermore, to confirm the docking results, molecular dynamics (MD) simulations were also carried out for the most promising two ligand-pocket complexes from docking studies. Results : The minimal inhibitory concentrations (MICs) 62.5 and 125 µg/mL of the most active Propolis extract were assessed in trophozoites stage of Acanthamoeba castellanii ATCC30010 and ATCC50739, respectively. At concentrations lower than their MICs values (1/16 MIC), Propolis extract revealed inhibition of encystation. However, at 1/2 MIC, it showed a potential inhibition of excystation and anti-adhesion. The molecular docking and dynamic simulation revealed the potential capability of Pinocembrin to form hydrogen bonds with A. castellanii Sir2 family protein (AcSir2), an encystation protein of high relevance for this process in Acanthamoeba. Conclusions : The results provided a candidate for the development of therapeutic drugs against Acanthamoeba infection. In vivo experiments and clinical trials are necessary to support this claim.

Targeting Acanthamoeba proteins interaction with flavonoids of Propolis extract by in vitro and in silico studies for promising therapeutic effects.

Background : Propolis is a natural resinous mixture produced by bees. It provides beneficial effects on human health in the treatment/management of many diseases. The present study was performed to demonstrate the anti- Acanthamoeba activity of ethanolic extracts of Propolis samples from Iran. The interactions of the compounds and essential proteins of Acanthamoeba were also visualized through docking simulation. Methods: The minimal inhibitory concentrations (MICs) of Propolis extract against Acanthamoeba trophozoites and cysts was determined in vitro. In addition, two-fold dilutions of each of agents were tested for encystment, excystment and adhesion inhibitions. Three major compounds of Propolis extract such as chrysin, tectochrysin and pinocembrin have been selected in molecular docking approach to predict the compounds that might be responsible for encystment, excystment and adhesion inhibitions of A. castellanii. Furthermore, to confirm the docking results, molecular dynamics (MD) simulations were also carried out for the most promising two ligand-pocket complexes from docking studies. Results : The minimal inhibitory concentrations (MICs) 62.5 and 125 µg/mL of the most active Propolis extract were assessed in trophozoites stage of Acanthamoeba castellanii ATCC30010 and ATCC50739, respectively. At concentrations lower than their MICs values (1/16 MIC), Propolis extract revealed inhibition of encystation. However, at 1/2 MIC, it showed a potential inhibition of excystation and anti-adhesion. The molecular docking and dynamic simulation revealed the potential capability of Pinocembrin to form hydrogen bonds with A. castellanii Sir2 family protein (AcSir2), an encystation protein of high relevance for this process in Acanthamoeba. Conclusions : The results provided a candidate for the development of therapeutic drugs against Acanthamoeba infection. In vivo experiments and clinical trials are necessary to support this claim.

Targeting Acanthamoeba proteins interaction with flavonoids of Propolis extract by in vitro and in silico studies for promising therapeutic effects.

Background : Propolis is a natural resinous mixture produced by bees. It provides beneficial effects on human health in the treatment/management of many diseases. The present study was performed to demonstrate the anti- Acanthamoeba activity of ethanolic extracts of Propolis samples from Iran. The interactions of the compounds and essential proteins of Acanthamoeba were also visualized through docking simulation. Methods: The minimal inhibitory concentrations (MICs) of Propolis extract against Acanthamoeba trophozoites and cysts was determined in vitro. In addition, two-fold dilutions of each of the agents were tested for encystment, excystment and adhesion inhibitions. Three major compounds of Propolis extract such as chrysin, tectochrysin and pinocembrin have been selected in molecular docking approach to predict the compounds that might be responsible for encystment, excystment and adhesion inhibitions of A. castellanii. Furthermore, to confirm the docking results, molecular dynamics (MD) simulations were also carried out for the most promising two ligand-pocket complexes from docking studies. Results : The minimal inhibitory concentrations (MICs) 62.5 and 125 µg/mL of the most active Propolis extract were assessed in trophozoites stage of Acanthamoeba castellanii ATCC30010 and ATCC50739, respectively. At concentrations lower than their MICs values (1/16 MIC), Propolis extract revealed inhibition of encystation. However, at 1/2 MIC, it showed a potential inhibition of excystation and anti-adhesion. The molecular docking and dynamic simulation revealed the potential capability of Pinocembrin to form hydrogen bonds with A. castellanii Sir2 family protein (AcSir2), an encystation protein of high relevance for this process in Acanthamoeba. Conclusions : The results obtained provided a candidate for the development of therapeutic drugs against Acanthamoeba infection. In vivo experiments and clinical trials are necessary to support this claim.

Optimization of Extraction Parameters of Ethanol Extracts of Propolis Samples Using Artificial Neural Network and Moth-Flame Optimization Algorithm

Abstract In this study, the optimum values of propolis ethanol extracts parameters were determined with the use of single and multi-objective optimization procedures. The euclidean distance approach was used in the multi-objective optimization process. Firstly, propolis was extracted using water with ethanol contents 40, 50, 60, 70 and 80% for 8, 10, 12, 16, 20 and 24 h. Then, total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) activities of all extracts were determined. With the obtained data a prediction model was produced with the use of artificial neural networks (ANN), and optimization was performed using a moth-flame (MFO) algorithm. The best prediction models for the TPC and FRAP were observed in 2-5-1 and 2-5-1 network architecture with the mean absolute percentage error (MAPE) values, 5.126 and 2.451%, respectively. For maximum TPC, the extraction parameters were determined as ethanol content 57.5% and extraction time 13.56 h. To maximize FRAP, the optimized extraction parameters were ethanol content 72.03% and extraction time 18.04 h. The optimum extraction conditions for both maximum values of the studied assays were ethanol content 70.03% and extraction time 16.93 h. The study concluded that the integrated ANN and MFO algorithm system can be used in single and multi-objective optimization of extraction parameters. The established optimization model can save time, money, labor and energy.

Spectroscopic Discrimination and Characterization of Bee Propolis from the Philippines

Propolis or bee glue is gaining popularity in the market as a potential source of bioactive components that can be used in different health products. In this study, the ethanolic extracts of propolis samples from stingless bee (Tetragonula biroi Friese) colonies collected from Los Baños (in Laguna), Tayabas (in Quezon), and San Roque (in Albay) were characterized using various spectroscopic techniques such as absorbance, fluorescence, and infrared. Spectroscopic results showed differences in the chemical composition of the propolis samples. Infrared (IR) spectroscopy showed similarities and differences in terms of the functional groups present in the samples. Lastly, the phenol content of the ethanolic extracts was obtained using the FolinCiocalteu assay. Samples from Laguna yielded the highest phenolic content, followed by Albay and Quezon. Differences in chemical composition specifically in phenolic content will have an effect on the biological activities of the propolis extracts. The results of this study can be used as an initial screening for propolis samples for possible use in different health products.

Synergistic Effects of Propolis Combined with 2-Phenoxyethanol and Antipyretics on the Growth of Staphylococcus aureus.

The present investigation aimed to assess the combinational effect of commonly used antipyretics and antiseptics with ethanolic extracts of propolis (EEPs) on the growth inhibition of Staphylococcus aureus. The broth microdilution checkerboard assay revealed synergistic interactions between all investigated antipyretics, namely acetylsalicylic acid, ibuprofen, and acetaminophen, with EEPs samples. The values of the fractional inhibitory concentration (ΣFIC) index for all these combinations were <0.5. While, in the case of considered antiseptics, namely chlorhexidine, octenidine dihydrochloride, and 2-phenoxyethanol, the positive interaction was confirmed only for the last one (values of ΣFIC in the range 0.0625–0.25). Combinations of two other agents with all four samples of EEPs resulted in an important antagonistic effect (values of ΣFIC ≥ 4.5). Propolis is mostly dedicated to the treatment of skin/wound infections; thus, these findings are of particular practical importance. The outcomes of the study also support the hypothesis that the propolis’s antimicrobial effect is due to the combined (synergistic) action of several ingredients rather than the presence of one component of high antibacterial activity. The composition of 13 ingredients of EEPs (at a concentration below the MIC (minimum inhibitory concentration) of the most active agent) exhibited considerably high anti-staphylococcal efficiency with MIC = 128 µg/mL.

Antibacterial and DPPH free radical-scavenging activities of the ethanol extract of propolis collected in Taiwan

In the present study, ethanolic extracts of propolis (EEP) collected from various regions (Taipei, Mingchen and Fangliao) in Taiwan during different time periods (June, August and October-November, 2000) were tested for their antibacterial and antioxidative activities. In addition, the thermal stabilities of these activities exerted by EEP were also investigated. It was found that the EEP samples, depending on collecting location and time period, exerted various antioxidative activities in terms of scavenging α,α-diphenyl-2-piorylhydrasyl (DPPH) free radicals and showed various extents of antibacterial activity against Staphylococcus aureus and Listeria monocytogenes, but not against Escherichia coli and Salmonella typhimurium. In general, the Taiwanese propolis extract collected in June showed the most profound antibacterial and free radical-scavenging activities than those collected during other time periods. Among all of the samples tested, EEP collected from the Mingchien area in June exhibited the highest antibacterial activity, while that collected from the Taipei area during the same time period showed the highest free radical-scavenging activity. Further tests of EEP collected from Taipei in June revealed that its DPPH free radical-scavenging effects reduced significantly after heating at 50, 80 or 100°C for 1 hr, while its antibacterial activity remained unchanged.

Impact of sterilization process on chemical composition and antimicrobial activity of propolis

Hygiene of the bee products, especially for the use of people, is very important. Although many studies have been done to prevent bacterial contamination of honey and pollen, there is a lack of research on the hygiene of propolis. Although the risk of contamination by spore-forming bacteria is high, bees use propolis to clean hives. In order to determine the standard propolis quality, the sterilization process will be a matter of scientific interest in near future. Thus, this study examines the impact of sterilization process on chemical composition and antimicrobial activity of propolis. In this study, 250 grams of propolis was collected, and the sample was divided into three parts. Raw propolis (RP) was sterilized without any pretreatment, but sterilization made it sticky and hard, and it burned during the process. Both sterilized (SEEP) and non-sterilized (NSEEP) ethanol extracts of propolis samples were analyzed by GC-MS for their chemical contents. Susceptibility patterns of three bacteria (Escherichia coli, Staphyllococcus aureus, Pseudomonas aeruginosa) and one yeast (Candida albicans) strains to NSEEP and SEEP were assessed by the disc diffusion method. The MIC values were determined for both NSEEP and SEEP. The results show that NSSEP contains far more chemical components than SEEP, and its antimicrobial activity is much higher. It is easy to say that the sterilization process changes the chemical composition of propolis and leads to the loss of some substances and its antimicrobial activity. Therefore, it is not considered necessary. Instead of microbial contamination, chemical contamination constitutes a greater risk for human consumption.

Propolis extracts from the northern region of Thailand suppress cancer cell growth through induction of apoptosis pathways

The continual increase in mortality rates and number of cancer cases is a matter of serious concern in developing countries. The incorporation of natural products into classical cancer treatment approaches is a promising direction. The mechanisms of A549 and HeLa cancer cell death induction by ethanolic extracts of propolis samples from Phayao, Chiang Mai, and Nan provinces in northern Thailand were investigated in this study. The propolis extract from Chiang Mai showed the highest antioxidant activity and the greatest total phenolic content. The propolis extract from Nan also exhibited the highest total flavonoid content. The proliferation of A549 and HeLa cells grown in the presence of the propolis extracts was suppressed in a dose- and time-dependent manner. Moreover, treatment of both cancer cells with the propolis extracts showed DNA fragmentation and significantly increased the number of the apoptotic cells. On A549 cells, the extrinsic and intrinsic pathways of caspase enzymes were activated by the propolis extracts from Phayao and Chiang Mai. In the case of the propolis extract from Nan, the mechanisms involved apoptosis on the A549 cells were caspase-independent pathway. The extrinsic pathway of the caspase enzyme was triggered by all of the propolis extracts on HeLa cells. Finally, oral administration of the propolis granule produced from the propolis extract from Nan resulted in extended survival of tumour-bearing mice. Therefore, propolis extracts from the northern region of Thailand demonstrated pharmacological properties, both antioxidant and anticancer activities. From these findings, it is evident that propolis extracts can be considered as a naturally obtained agent extremely useful in cancer treatment.

Relationship between total phenolic contents and biological properties of propolis from 20 different regions in South Korea

BackgroundPropolis (or bee glue), collected from botanical sources by honey bee, has been used as a popular natural remedies in folk medicine throughout the world. This study was conducted to assess growth inhibitory effects of ethanol extracts of propolis (EEPs) from 20 different regions in South Korea on human intestinal bacteria as well as their human β-amyloid precursor cleavage enzyme (BACE-1), acetylcholinesterase (AChE) inhibitory, antioxidant, antiproliferative, and anti-human rhinovirus activities.MethodsThe Bonferroni multiple-comparison method was used to test for significant differences in total polyphenol and flavonoid contents among EEP samples using SAS 9.13 program. Correlation coefficient (r) analysis of the biological activities of EEP samples was determined using their 50 % inhibition concentration or minimal inhibitory concentration values and their polyphenol or flavonoid contents in 20 native Korean EEP samples.ResultsThe amounts of total polyphenol and flavonoids in the Korean EEP samples ranged from 49 to 239 mg gallic acid equivalent (GAE)/g EEP (Brazilian, Chinese, and Australian samples, 127–142 mg GAE/g EEP) and from 21 to 50 mg quercetin equivalent (QE)/g EEP (Brazilian, Chinese, and Australian samples, 33–53 mg QE/g EEP), respectively. Correlation coefficient analysis showed that total polyphenol contents may be negatively correlated with 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (r = −0.872) and total flavonoid content has no correlation with the activity (r = 0.071). No direct correlation between BACE-1 inhibition, AChE inhibition, or antiproliferative activity and total polyphenol or total flavonoid content in Korean EEP samples was found. Gram-positive and Gram-negative bacteria were observed to have different degrees of antimicrobial susceptibility to the EEP samples examined, although ciprofloxacin susceptibility among the bacterial groups did not differ greatly.ConclusionsFurther studies will warrant possible applications of propolis as potential therapeutic BACE-1 blocker, antioxidant, antiproliferative agent, and antimicrobial agent.

Chemical composition and antimicrobial activity of propolis collected from some localities of Western Algeria

The chemical analysis and antibacterial activity of propolis collected from some parts of Western Algeria were investigated. The ethanolic extracts of propolis (EEP) were evaluated for further investigation. The major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis. All EEP samples were active against Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus), but no activity was found against Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli). The mean diameters of growth inhibition of the EEP ranged between 8.05 and 21.4 mm. The propolis extract obtained from Sidi bel Abbés (SFS-SBA) was more active than other samples as well as showed unique HPLC profile. These results support the idea that propolis can be a promising natural food preservative in food industry and alternative candidate for management of bacterial infections caused by drug-resistant microorganisms.

Pentacyclic triterpenes and crude extracts with antimicrobial activity from Cameroonian brown propolis samples

The aim of this study was to isolate compounds from Cameroonian propolis extracts and to test their antibacterial activities against bacteria isolated from carcass at the Yaound� slaughterhouse. The n-hexane, ethyl acetate and ethanol extracts of propolis samples from Ngaoundal and Tala-Mokolo were separated by successive silica gel column chromatography to give six triterpenes. Their structures were determined as 25-cyclopropyl-3β-hydroxyurs-12-ene (7), cycloart-3β-hydroxy-12, 25(26)-diene (8), lup-20(29)-en-3-one (9), olean-12-en-3β, 28-diol (10), lup-20(29)-en-3β-oate (13) and 3β-hydroxylup-20(29)-ene (14). Compounds 7 and 8 were new triterpene derivatives while 10 and 13 were isolated for the first time from propolis. The structures of all the compounds were established on the basis of spectroscopic analysis. Phytochemical screening of the methanol extract (5) revealed the presence of alkaloids, reducing compounds, coumarins, saponins and tannins accounting for its broad spectrum antibacterial activities. The six isolated compounds and crude extracts were tested for antimicrobial activity against some Gram negative bacteria. The methanol extract (5) of propolis samples was active against Escherichia coli and Pseudomonas aeruginosa (MIC: 0.2 mg/ml) whereas the isolated compounds 7, 8 and 10 exclusively exhibited antimicrobial activity against Salmonellas pp (MIC: 0.1-0.15 mg/ml). The MIC values of all the four propolis products were greater than that of the standard drug (Amoxicillin): 0.1-0.2 mg/ml versus 0.4 mg/ml. Nevertheless, further pharmacological and toxicity studies on experimental animals are necessary to establish the safety of the propolis products for its use as topical antimicrobial agents.

Nutritional and Functional Properties of Aqueous and Hydroalcoholic Extracts from Argentinean Propolis

Bee propolis is a natural product extensively used as an ingredient in functional foods in amounts that may confer health benefits. The aim of this study was to investigate the nutritional and functional properties (antioxidant activity) of aqueous and ethanolic extracts of propolis samples from Santiago del Estero province, northern Argentina. All propolis extracts contained macronutrients (glucose, fructose, sucrose and proteins), micronutrients (Na, K, Ca, P and Mg) and trace elements (Fe). Spectrophotometric, TLC and HPLC-DAD analyses showed the presence of several phenolic, flavonoid and non-flavonoid compounds, but in all cases the flavonoids prevailed. The PCA of polyphenolic content provided a clear separation of propolis in Group 1 (SE1, 2, 3, 4 and 7) and Group 2 (SE5 and 6) associated with phenolic compound content and collection regions. Two compounds, pinocembrin and chrysin, which could be used as chemical markers of Santiago del Estero propolis, were identified in all samples. Propolis samples extracted with water presented better radical scavenging ability than ethanolic extracts, independent of the antioxidant method (scavenging activity of ABTS*+, DPPH*, HO* and O2(-)* and beta-carotene bleaching test). Such results correlated closely with the levels of total phenols and flavonoids in samples. The results justify the use of Argentine propolis as a functional dietary supplement.

Chemical composition, cytotoxic and antioxidative activities of ethanolic extracts of propolis on HCT-116 cell line

Propolis is a complex resinous sticky substance that honeybees collect from buds and exudates of various plants. Owing to its versatile biological and pharmacological activities, propolis is widely used in medicines, cosmetics and foods. The aim of this study was to evaluate the cytotoxic and antioxidative effects of various ethanolic extracts of propolis (EEPs) on human colon cancer cell line HCT-116 and compare them with their composition determined by HPLC-DAD. The most abundant flavonoids in all samples were chrysin, pinocembrin and galangin (12.697-40.811 µg mg⁻¹), while the main phenolic acids were caffeic acid, ferulic acid and isoferulic acid. Dose- and time-dependent inhibition of growth of HCT-116 cells was observed for all propolis samples, with IC₅₀ values ranging from 26.33 to 143.09 µg mL⁻¹. Differences in cytotoxic activity of propolis samples were associated with differences in their composition. All EEP samples reduced both superoxide anion radical and nitrite levels and also had strong DPPH-scavenging activity. All tested propolis samples had pronounced cytotoxic and antioxidative activities.

GC-MS analysis of propolis of Indian origin

More than 300 constituents have been identiÞ ed in different propolis samples. This study investigated the composition of ethanolic extracts of propolis samples collected from the Gujarat zone. A gas chromatographymass spectrometry was carried out on a Agilent GC-MS 5975 under electron impact ionization (70 eV). The chromatographic column for the analysis was done by the HP5MS capillary column (30 m x 0.25 mm internal diameter). The carrier gas used was helium at a s ow rate of 1 ml/min. The oven temperature was 100°C to 280°C with a constant increase of 10°C. Propolis samples were analyzed with the column held initially at 60°C for 2 min and then increased to 230°C with a 2°C/ min heating ramp and then kept at 230°C for 3 min. Finally, the temperature was increased to 280°C with a 3°C/min heating ramp. The injection was performed in split mode at 220°C. Sample volumes of 1 μl were injected and analyzed by GC-MS. The following compounds were identiÞ ed for the Þ rst time in the propolis sample: p-coumeric acid, Benzyl cinnamate, 4-pentanoic acid, and Ferulic acid. The main type of the compound identiÞ ed was fatty acids derivatives. Similar results were found by Silici, et al. [5] for the turkey propolis. Key words: GC-MS analysis, propolis, Honeycomb .

In vitro antimicrobial activity of propolis samples from different geographical origins against certain oral pathogens

Propolis is an agent having antimicrobial properties, however, its composition can vary depending on the area where it is collected. In the present study, the antimicrobial activity of five propolis samples, collected from four different regions in Turkey and from Brazil, against nine anaerobic strains was evaluated. Ethanol extracts of propolis (EEP) were prepared from propolis samples and we determined minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of EEP on the growth of test microorganisms by using agar dilution method. All strains were susceptible and MIC values ranged from 4 to 512 μg/ml for propolis activity. Propolis from Kazan-Ankara showed most effective MIC values to the studied microorganisms. MBC values of Kazan-Ankara EEP samples were ranged from 8 to 512 μg/ml. Death was observed within 4 h of incubation for Peptostreptococcus anaerobius and micros and Lactobacillus acidophilus and Actinomyces naeslundii, while 8 h for Prevotella oralis and Prevotella melaninogenica and Porphyromonas gingivalis, 12 h for Fusobacterium nucleatum, 16 h for Veillonella parvula. It was shown that propolis samples were more effective against Gram positive anaerobic bacteria than Gram negative ones. The organic chemical compositions of EEPs were determined by high-resolution gas chromatography coupled to mass spectrometry (GC–MS). The main compounds of EEPs were flavonoids such as pinobanksin, quercetin, naringenin, galangine, chrysin and aromatic acids such as cafeic acid. Because of increased antimicrobial resistance, propolis may be kept in mind in the treatment of oral cavity diseases.

Antioxidant power of Iranian propolis extract

Propolis is a resinous natural hive product derived from plant exudates collected by honey bees. Due to biological and pharmacological activities, it has been extensively used in folk medicine. The present study was designed to measure the antioxidant power of ethanolic extracts of propolis samples from different parts of Iran with “ferric reducing ability of plasma” (FRAP) assay and compare the results with Trolox at concentrations of 100, 1000 and 2000 μg/ml. FRAP values of propolis ethanolic extracts were in the range of 31.5 ± 14.6 to 1650 ± 72 μM, whereas the values of Trolox ranged from 125.25 ± 9.95 to 3381.64 ± 113.83 μM. The FRAP values of Tehran propolis ethanolic extract and Trolox at concentration of 100 μg/ml did not show any significant difference ( P > 0.05). Total flavonoid and polyphenol contents of ethanolic extracts of propolis samples, determined by using aluminum nitrate and Folin–Ciocalteu colorimetric methods, were in the range of 1.22 ± 0.33–7.79 ± 0.39 g/100 g and 3.08 ± 0.02–8.46 ± 0.03 g/100 g crude extract of propolis, respectively. The result of this experiment may show that propolis as a natural source of antioxidant compounds may be of use in prevention of free radical-related diseases.

Chemical composition and antibacterial activity of propolis collected by three different races of honeybees in the same region

The chemical analysis and antibacterial activity of three types of propolis collected three different races of Apis mellifera bee in the same apiary were investigated. Propolis samples were investigated by GC/MS, 48 compounds were identified 32 being new for propolis. The compounds identified indicated that the main plant sources of propolis were Populus alba, Populus tremuloides and Salix alba. The antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans was evaluated. Ethanolic extracts of propolis samples showed high antibacterial activity against Gram-positive cocci ( Staphylococcus aureus), but had a weak activity against Gram-negative bacteria ( Escherichia coli and Pseudomonas aeruginosa) and yeast ( Candida albicans). Propolis sample collected by Apis mellifera caucasica showed a higher antibacterial activity than collected by Apis mellifera anatolica and Apis mellifera carnica.

Antioxidant Activity and Constituents of Propolis Collected in Various Areas of Japan

Propolis is a resinous substance collected by honeybees from various plant sources. We examined the antioxidant activity of Japanese propolis from various areas of Japan: Hokkaido, Akita (Minamiakita and Kazuno), Fukushima (Aizuwakamatsu and Futaba), Gifu, Nagano, Tokyo, Kanagawa, Shizuoka, Okayama, Tottori, Fukuoka and Okinawa. We prepared ethanol extracts of propolis (EEP), and evaluated the antioxidant activity of EEP samples by the β-carotene bleaching and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay systems. Further, we identified the major constituents in EEP by HPLC analysis by a photodiode array (PDA) and mass spectrometric (MS) detection, and quantitatively analyzed each component. EEP from Akita (Minamiakita) and Okinawa had relatively strong antioxidant activity, and was correlated with total polyphenol contents. Propolis from Akita (Minamiakita) contained large amounts of the antioxidative compounds, caffeic acid and phenethyl caffeate. Propolis from Okinawa appeared to have antioxidants not seen in propolis from other areas.