Evaluation of propolis. I. Evaluation of Brazilian and Chinese propolis by enzymatic and physico-chemical methods

Potential Effects of Romanian Propolis Extracts against Pathogen Strains

The impact of globalization on beekeeping brings new economic, scientific, ecological and social dimensions to this field The present study aimed to evaluate the chemical compositions of eight propolis extracts from Romania, and their antioxidant action and antimicrobial activity against seven species of bacteria, including pathogenic ones: Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Listeria monocytogenes and Salmonella enterica serovar Typhimurium. The phenolic compounds, flavonoids and antioxidant activity of propolis extracts were quantified; the presence of flavones and aromatic acids was determined. Quercetin and rutin were identified by HPLC analysis and characterized using molecular descriptors. All propolis samples exhibited antibacterial effects, especially against P. aeruginosa and L. monocytogenes. A two-way analysis of variance was used to evaluate correlations among the diameters of the inhibition zones, the bacteria used and propolis extracts used. Statistical analysis demonstrated that the diameter of the inhibition zone was influenced by the strain type, but no association between the propolis origin and the microbial activity was found.

The effects of phytochemicals and herbal bio-active compounds on tumour necrosis factor-α in overweight and obese individuals: a clinical review

Obesity is abnormal fat accumulation in the body which acts as a risk factor for various cardiometabolic states. Adipose tissue in excess can release inflammatory factors, including TNF-α and IL-6, and suppress adiponectin production. TNF-α increases the levels of IL-6 and acute phase reactants such as C-reactive protein. Inflammation has a crucial role in developing and progressing various cardiometabolic diseases and a wide range of obesity-related complications. It has been shown that TNF-α has a significant role in the development of insulin resistance. Recently, a growing body of evidence has focused on herbal medicine, phytochemicals and natural bioactive compounds as inexpensive, relatively easy accessible agents with low adverse effects to reduce inflammatory markers such as TNF-α and simultaneously decrease insulin resistance, glucose intolerance, and dyslipidemia in obesity. The main focus of the current review is to summarize the results of the studies, which assessed the effects of phytochemicals and herbal bio-active compounds on serum TNF-α in subjects with overweight or obesity. This review suggests that herbal medicine have favorable effects on the reduction of TNF-α concentration; however, the results were not uniform for different products. Among the reviewed plants, ginger, ginseng, resveratrol, and flaxseed had more promising effects.

Propolis: types, composition, biological activities, and veterinary product patent prospecting

Propolis is a resinous substance composed of a mixture of different plant parts and molecules secreted by bees. Chemically, it is defined as a complex matrix containing biologically active molecules with antibacterial, antifungal, antiviral, antiparasitic, hepatoprotective, and immunomodulatory activities. It is widely employed in cosmetic formulations and pharmaceutical products and is one of the most widely used natural products. However, the effects and strength of these biological activities depend on the chemical profile and composition of each propolis type. This composition is associated with the diversity of local flora, the place and period of collection, and the genetics of the bees. In this context, the objective of this review was to investigate the biological, chemical, and microbiological properties of propolis. A technological prospection was also performed on patents for products designed to be used in animal health. Our investigation shows that the literature contains diverse studies dedicated to comparing and describing the composition and therapeutic properties of propolis. These studies demonstrate the potential biological use of propolis in veterinary medicine, showing the applications of propolis extracts in different formulations. However, there are a low number of propolis-based veterinary products with a registered patent. Thus, the development of products based on propolis is a promising market to be exploited. © 2019 Society of Chemical Industry.

Chemical Composition, Antioxidant and Anti-inflammatory Activity Evaluation of the Lebanese Propolis Extract

Background:

Propolis is a resinous substance produced by bees and known to possess antioxidant, antimicrobial, antiproliferative and anti-inflammatory activities.

Objective:

This study is aimed at evaluating the in vivo and in vitro anti-inflammatory potential of the Crude Ethanolic Extract (CE) of Lebanese propolis and its Ethyl Acetate Fraction (EAF).

Method:

Chemical content of propolis was characterized using high-performance liquid chromatography and LC-MS/MS. COX-2 and iNOS protein expression, nitric oxide (NO) and prostaglandin (PGE2) release in LPS-activated RAW monocytes were achieved respectively by western blot and spectrophotometry. Antioxidant activity was evaluated by DPPH free radical scavenging assay. Measurement of paw thickness in carrageenan-induced paw edema in mice and pathologic assessment of inflammation in paw sections were used to judge the anti-inflammatory properties of propolis.

Results:

Pathology analysis revealed in the treated group significant reduction of immune cell infiltration and edema. Both extract and ethyl acetate fraction showed significant anti-inflammatory and antioxidant effects in LPS-treated RAW cells characterized by the inhibition of COX-2 and iNOS protein expression, as well as PGE2 and NO release. Chemical analysis of the crude extract and its ethyl acetate fraction identified 28 different compounds of which two phenolic acids and nine other flavonoids were also quantified. Ferulic acid, caffeic acid, chrysin, galangin, quercetin, and pinocembrin were among the most representative compounds.

Conclusion:

Lebanese propolis is rich in a various amount of flavonoids which showed promising antiinflammatory and antioxidant properties. Additionally, chemical analysis showed unique chemical compositions with the potential of identifying ingredients with interesting anti-inflammatory activities.

Evaluation of the antimicrobial activity and cytotoxic effect of hydroxyapatite containing Brazilian propolis

The aim of this work was to produce hydroxyapatite powder (HA) containing the dry extract of green and red propolis, and to evaluate the possible bactericidal activity of these materials over a short period of time through a fast release system. The ethanolic extracts of green and red propolis (EEP) were incorporated into the material by spray drying. After release tests, powders containing dry EEP were characterized regarding the content of total phenolics and flavonoids. Material characterization was undertaken by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The antimicrobial activity was evaluated by plate colony counting, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against Staphylococcus aureus (S. aureus). The cytotoxicity of the materials was determined by the neutral red incorporation method. The materials showed apparently spherical morphology, indicating a decrease in the degree of agglomeration with the addition of propolis. Characteristic HA and propolis functional groups were observed in the FTIR. The materials showed a higher release of phenolics and lower amounts of flavonoids when compared to the EEP, with the higher amounts of flavonoids observed for HA with red propolis. A bactericidal effect was observed for all materials within the interval of 0.5 and 1 h, showing lower inhibitory activity (MIC) and higher bactericidal activity (MBC) when compared to the EEP, with the best results attributed to HA with red propolis. The IC₅₀ values (which is the concentration needed to inhibit cell growth by 50%) obtained from the cytotoxicity assay for HA with the green and red propolis lay between MIC and MCB. Considering these results, it is suggested that HA and propolis may be used as a possible antimicrobial agent, inhibiting the growth of S. aureus, although further in vivo biocompatibility should be investigated before using this material as a medical device with bactericidal potential.

Ginger and Propolis Exert Neuroprotective Effects against Monosodium Glutamate-Induced Neurotoxicity in Rats

Central nervous system cytotoxicity is linked to neurodegenerative disorders. The objective of the study was to investigate whether monosodium glutamate (MSG) neurotoxicity can be reversed by natural products, such as ginger or propolis, in male rats. Four different groups of Wistar rats were utilized in the study. Group A served as a normal control, whereas group B was orally administered with MSG (100 mg/kg body weight, via oral gavage). Two additional groups, C and D, were given MSG as group B along with oral dose (500 mg/kg body weight) of either ginger or propolis (600 mg/kg body weight) once a day for two months. At the end, the rats were sacrificed, and the brain tissue was excised and levels of neurotransmitters, ß-amyloid, and DNA oxidative marker 8-OHdG were estimated in the brain homogenates. Further, formalin-fixed and paraffin-embedded brain sections were used for histopathological evaluation. The results showed that MSG increased lipid peroxidation, nitric oxide, neurotransmitters, and 8-OHdG as well as registered an accumulation of ß-amyloid peptides compared to normal control rats. Moreover, significant depletions of glutathione, superoxide dismutase, and catalase as well as histopathological alterations in the brain tissue of MSG-treated rats were noticed in comparison with the normal control. In contrast, treatment with ginger greatly attenuated the neurotoxic effects of MSG through suppression of 8-OHdG and β-amyloid accumulation as well as alteration of neurotransmitter levels. Further improvements were also noticed based on histological alterations and reduction of neurodegeneration in the brain tissue. A modest inhibition of the neurodegenerative markers was observed by propolis. The study clearly indicates a neuroprotective effect of ginger and propolis against MSG-induced neurodegenerative disorders and these beneficial effects could be attributed to the polyphenolic compounds present in these natural products.

Antifungal Activity of Propolis Against Yeasts Isolated From Blood Culture: In Vitro Evaluation

BACKGROUND

Due to the failure of available antifungal agents in the treatment of candidemia and the toxic activities of these drugs, a lot of researches are being conducted to develop new nontoxic and effective antifungal agents for optimal control of fungal pathogens. The aim of this study is to evaluate the in vitro antifungal activity of propolis against yeasts isolated from the blood cultures of intensive care unit patients.

METHODS

Seventy-six strains were included in this study. The in vitro antifungal activity of propolis, fluconazole (FLU), and itraconazole (ITR) was investigated by the microdilution broth methods (CLSI guidelines M27-A3 for yeast). The propolis sample was collected from Kayseri, Turkey.

RESULTS

Of the 76 isolates, 33 were identified as Candida albicans while 37 were C. parapsilosis, three were C. tropicalis, and three were identified as C. glabrata. The geometric mean range for MIC (μg/ml) with regard to all isolates was 0.077 to 3 μg/ml for FLU and ITR, and 0.375 to 0.70 μg/ml for propolis. It was shown that propolis had significant antifungal activity against all Candida strains and the MIC range of propolis was determined as 0185 to 3 μg/ml.

CONCLUSION

This study demonstrated that propolis had significant antifungal activity against yeasts isolated from blood culture compared with FLU and ITR. The propolis MIC in azole-resistant strains such as C. glabrata was found lower than the FLU MIC.

Propolis reduces Leishmania amazonensis-induced inflammation in the liver of BALB/c mice

Experimental models of mouse paw infection with L. amazonensis show an induction of a strong inflammatory response in the skin, and parasitic migration may occur to secondary organs with consequent tissue injury. There are few studies focusing on the resolution of damage in secondary organs caused by Leishmania species-related cutaneous leishmaniasis. We investigated the propolis treatment effect on liver inflammation induced by Leishmania amazonensis infection in the mouse paw. BALB/c mice were infected in the hind paw with L. amazonensis (10(7)) promastigote forms. After 15 days, animals were treated daily with propolis (5 mg/kg), Glucantime (10 mg/kg), or with propolis plus Glucantime combined. After 60 days, mice were euthanized and livers were collected for inflammatory process analysis. Liver microscopic analysis showed that propolis reduced the inflammatory process compared to untreated infected control. There was a decrease of liver myeloperoxidase and N-acetyl-β-glucosaminidase activity levels, collagen fiber deposition, pro-inflammatory cytokine production, and plasma aspartate transaminase and alanine transaminase levels. Furthermore, propolis treatment enhanced anti-inflammatory cytokine levels and reversed hepatosplenomegaly. Our data demonstrated that daily low doses of Brazilian propolis reduced the secondary chronic inflammatory process in the liver caused by L. amazonensis subcutaneous infection in a susceptible mice strain.

Impact of supplementing diets with propolis on productive performance, egg quality traits and some haematological variables of laying hens

One hundred and twenty eight, 28-weeks-old Lohmann LSL hybrid layers were used in this experiment, which lasted 12 weeks to investigate the effect of propolis supplementation on the productive performance, egg quality traits and haematological variables of laying hens. All hens were randomly classified into four equal experimental groups, eight replicates (4 birds/each). Hens in group 1 were fed on a commercial diet and considered as control group, while those in groups 2, 3 and 4 were fed on the same commercial diet and supplemented with 250, 500 and 1000 mg propolis/kg diet. The obtained results revealed that daily feed consumption/hen increased insignificantly with increasing propolis level than that of the control group. Regarding the means of egg mass and egg production rate, it was observed that the laying hens fed diets containing 250 and 1000 mg propolis/kg significantly (p < 0.05) produced more and heaver egg in comparison with control group. External egg quality traits have not affected with increasing the level of propolis, while eggshell weight was significantly (p < 0.05) increased. The internal egg quality traits except albumen and yolk percentages increased significantly (p < 0.05) with increasing propolis level for treated hens as compared to those in the control. Concerning the haematological parameters, the results showed that the levels of total protein and globulin increased significantly with increasing propolis level, while cholesterol and liver enzymes were significantly decreased (p < 0.05). Heterophils count of hens in the treated groups significantly decreased, whereas the lymphocyte count significantly increased, resulting in a decreased H/L ratio than that of the control group. Thus, it could be concluded that the supplementation of 250 mg propolis/kg diet is highly recommended to improving egg production, blood constituent and haematological parameters of the commercial laying hens.

Effect of Ethanol/Water Solvents on Phenolic Profiles and Antioxidant Properties of Beijing Propolis Extracts

Propolis is a natural substance known to be beneficial for human health and used as a folk medicine in many parts of the world. In this study, phenolic profiles and antioxidant properties of Beijing propolis extracted by different ethanol/water solvents were analyzed. Our results reveal that phenolic compounds and antioxidant properties of propolis extracts were significantly dependent on the concentration of ethanol/water solvents. Totally, 29 phenolic compounds were identified: 12 phenolic acids, 13 flavonoids, and 4 phenolic acid esters. In particular, 75 wt.% ethanol/water solvent may be the best for the highest extraction yield and the strongest antioxidant properties. Caffeic acid, benzyl caffeate, phenethyl caffeate, 5-methoxy pinobanksin, pinobanksin, pinocembrin, pinobanksin-3-O-acetate, chrysin, and galangin were the characteristic compounds of Beijing propolis, and these compounds seem to verify that Beijing propolis may be poplar-type propolis. In addition, the presence of high level of pinobanksin-3-O-acetate in Chinese propolis may be a novel finding, representing one-third of all phenolics.

Topical Brazilian propolis improves corneal wound healing and inflammation in rats following alkali burns

Background

The objective of this study was to investigate the effects of the Brazilian Scaptotrigona sp propolis, a widely used folk medicine, in corneal wound healing and inflammation.

Methods

Corneal epithelial defects of 1 mm in diameter were made in the right eyes of Wistar male adult rats by cauterization with silver nitrate sticks. Subsequently, they were divided in two groups (n = 40 rats/group): Brazilian propolis (BP) group was topically treated with a microemulsion containing 1% Brazilian propolis; vehicle (VH) group received the same formulation without propolis. The epithelial defect area was photographed and measured at t = 0 (wound induction), and after 12, 24, 48 and 120 h of treatment. The inflammatory response was evaluated based on counting of neutrophils. Epithelial regeneration rates were determined based on Ki-67 expression in basal epithelial cells. Comparisons were made using the Kruskal-Wallis and the Mann–Whitney U test.

Results

The BP group presented both smaller epithelial defect areas at 12, 24 and 48 h and fewer corneal infiltrating neutrophils at 24 and 48 h (P < 0.01) than the VH group. These effects were associated with more pervasive Ki-67 staining in the BP group at 12 and 24 h (P < 0.05).

Conclusions

Topically applied BP accelerated wound healing and reduced the inflammatory response to silver nitrate-induced corneal alkali burns in rats.

Propolis protects against high glucose-induced vascular endothelial dysfunction in isolated rat aorta

While propolis is known to have abundant bioactive constituents and a variety of biological activities, it is not clear whether propolis has beneficial effects on high glucose-mediated vascular endothelial impairment. The aim of the present study was to investigate the potential protective effect of propolis extract against the acute vascular endothelial dysfunction resulting from exposure to high glucose load and to elucidate its underlying mechanism. Rat aortic rings were incubated with normal glucose (11 mM), high glucose (44 mM), or mannitol (44 mM) for 3 h with or without propolis extract (400 μg/ml). Contraction to phenylephrine (Phe, 10(-9)-10(-5) M) and relaxation to acetylcholine (ACh, 10(-9)-10(-5) M) and sodium nitroprusside (SNP, 10(-9)-10(-5) M) were measured before and after incubation. Changes in malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) were also measured. Phe-induced contraction was impaired by high glucose as the E(max) decreased from 138.87 ± 11.43 to 103.65 ± 11.5 %. In addition, ACh-induced relaxation was impaired as the E(max) decreased from 99.80 ± 7.25 to 39.20 ± 6.5 %. SNP-induced relaxation was not affected. Furthermore, high glucose decreased the levels of both SOD (by 6 U/ml) and GSH (by 68 %) and increased levels of MDA (by 85 %). Propolis extract prevented high glucose-induced impairment of Phe and ACh responses and increased both SOD and GSH, leading to decreased MDA levels. In conclusion, propolis can protect against high glucose-induced vascular dysfunction by reducing oxidative stress.

Use of propolis hydroalcoholic extract to treat colitis experimentally induced in rats by 2,4,6-trinitrobenzenesulfonic Acid

This study focused on the therapeutic effect of a propolis SLNC 106 (PI) extract on experimental colitis. Wistar adult rats received 0.8 mL rectal dose of one of the following solutions: saline (group S), 20 mg TNBS in 50% ethanol (group TNBS), 20 mg TNBS in 50% ethanol and propolis extract in saline (group TNBS-P), propolis extract in saline (group SP), and 20 mg TNBS in 50% ethanol and 50 mg/kg mesalazine (group TNBS-M). The animals were euthanized 7 or 14 days after the colitis induction. Samples of the distal colon were harvested for the analysis of myeloperoxidase (MPO) enzyme activity and for morphometric analysis in paraffin-embedded histological sections with hematoxylin-eosin or histochemical staining. The animals treated with TNBS exhibited the typical clinical signs of colitis. Increased MPO activity confirmed the presence of inflammation. TNBS induced the development of megacolon, ulceration, transmural inflammatory infiltrate, and thickened bowel walls. Treatment with propolis moderately reduced the inflammatory response, decreased the number of cysts and abscesses, inhibited epithelial proliferation, and increased the number of goblet cells. The anti-inflammatory activity of the propolis SLNC 106 extract was confirmed by the reductions in both the inflammatory infiltrate and the number of cysts and abscesses in the colon mucosa.

Anti-Tumor Effects of Water-Soluble Propolis on a Mouse Sarcoma Cell Line In Vivo and In Vitro

The honeybee product propolis and its extracts are known to have biological effects such as antibiotic, anti-viral, anti-inflammatory and anti-tumor activities. This study was designed to investigate whether water-soluble propolis (WSP) inhibits tumor growth. The tumor cell line used was mouse sarcoma 180 (S-180), and its growth was determined in vitro and in vivo with exposure to different concentrations of WSP.

The effects of WSP on tumor cells in vitro were evaluated by measuring the intracellular uptake of 3 H -thymidine. 3 H -thymidine uptake was inhibited in accordance with the concentration of WSP. The minimum concentration of WSP necessary for 3 H -thymidine uptake inhibition was 1.0 μg/ml and uptake was suppressed to 88% of the level in non-treated cells at this concentration.

In an experiment using tumor-bearing mice, oral administration of WSP was begun 24 hours after transplantation of S-180 cells. WSP was administered to the mice 5 times, every other day for 10 days. The doses were 320 mg/kg (10 mg/mouse) or 960 mg/kg (30 mg/mouse) of body weight. All mice were sacrificed 10 days after transplantation, and tumor growth was evaluated. The orally administered WSP significantly inhibited the growth of transplanted tumors ( p < 0.05). Furthermore, histological findings revealed a significant reduction in mitotic cells and tumor invasion of the muscular tissue at both dose-levels of WSP.

Chemical compositions and antioxidant activities of water extracts of Chinese propolis

The present study investigated the chemical composition and antioxidant activity of the water extract of propolis (WEP) collected from 26 locations in China. Spectrophotometry was used to determine the physicochemical properties and the chemical constituents of WEP. Phenolic compounds in WEP were identified by RP-HPLC-DAD with reference standards. The antioxidant activities [characterized by reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability] of WEP were also measured. Results show that epicatechin, p-coumaric acid, morin, 3,4-dimethoxycinnamic acid, naringenin, ferulic acid, cinnamic acid, pinocembrin, and chrysin are the major functional phenolic compounds in Chinese WEPs. Furthermore, most WEPs show strong antioxidant activities, which are significantly correlated with E(1cm)(1%), an index for the estimation of the quality of WEP. WEPs also contain many more active constituents than ethanol extracts of propolis.

Effect of ethanolic extract of propolis on growth performance and plasma biochemical parameters of rainbow trout (Oncorhynchus mykiss)

This study was conducted to evaluate the effect of ethanolic extract of propolis (EEP) on growth performance and plasma biochemical parameters of rainbow trout (Oncorhynchus mykiss). Graded levels of EEP [0 (control), 1, 2, and 4 g kg(-1) diet] were fed to trout juveniles (mean weight 7.73 ± 0.17 g) for 10 weeks. Dietary EEP supplementation regardless of inclusion level significantly improved the specific growth rate of fish. Similarly, supplemental EEP generally improved the feed efficiency ratio and protein efficiency ratio, but no significant differences were observed between the 1 g kg(-1) EEP group and the control group. In addition, dietary EEP supplementation generally increased the plasma superoxide dismutase, lysozyme, total antioxidant capacity, glutathione peroxidase, and catalase activities, but decreased the plasma malondialdehyde level. The plasma triglycerides level was significantly lower in the 1 or 4 g kg(-1) EEP group as compared with the control group. Dietary EEP supplementation generally decreased the plasma aspartate aminotransferase and alanine aminotransferase activities, but increased the hepatic aspartate aminotransferase and alanine aminotransferase activities. These results indicate the potential to use the EEP as a growth promoter, hepatoprotective agent, and immunostimulant for rainbow trout.

Analytical methods applied to diverse types of Brazilian propolis

Propolis is a bee product, composed mainly of plant resins and beeswax, therefore its chemical composition varies due to the geographic and plant origins of these resins, as well as the species of bee. Brazil is an important supplier of propolis on the world market and, although green colored propolis from the southeast is the most known and studied, several other types of propolis from Apis mellifera and native stingless bees (also called cerumen) can be found. Propolis is usually consumed as an extract, so the type of solvent and extractive procedures employed further affect its composition. Methods used for the extraction; analysis the percentage of resins, wax and insoluble material in crude propolis; determination of phenolic, flavonoid, amino acid and heavy metal contents are reviewed herein. Different chromatographic methods applied to the separation, identification and quantification of Brazilian propolis components and their relative strengths are discussed; as well as direct insertion mass spectrometry fingerprinting.Propolis has been used as a popular remedy for several centuries for a wide array of ailments. Its antimicrobial properties, present in propolis from different origins, have been extensively studied. But, more recently, anti-parasitic, anti-viral/immune stimulating, healing, anti-tumor, anti-inflammatory, antioxidant and analgesic activities of diverse types of Brazilian propolis have been evaluated. The most common methods employed and overviews of their relative results are presented.

Propolis: is there a potential for the development of new drugs?

INTRODUCTION

Propolis has plenty of biological and pharmacological properties and its mechanisms of action have been widely investigated in the last years, using different experimental models in vitro and in vivo. Researchers have been interested in the investigation of isolated compounds responsible for propolis action; however, there is lack of clinical research on the effects of propolis.

STRATEGY AND OBJECTIVES

Since propolis-containing products have been marketed and humans have used propolis for different purposes, the goal of this review is to discuss the potential of propolis for the development of new drugs, by comparing data from the literature that suggest candidate areas for the establishment of drugs against tumors, infections, allergy, diabetes, ulcers and with immunomodulatory action.

CONCLUSIONS

The efficacy of propolis in different protocols in vitro and in vivo suggests its therapeutic properties, but before establishing a strategy using this bee product, it is necessary to study: (a) the chemical nature of the propolis sample. (b) Propolis efficacy should be compared to well-established parameters, e.g. positive or negative controls in the experiments. Moreover, possible interactions between propolis and other medicines should be investigated in humans as well. (c) Clinical investigation is needed to evaluate propolis potential in patients or healthy individuals, to understand under which conditions propolis may promote health. Data point out the importance of this research field not only for the readers and researchers in the scientific community waiting for further clarification on the potential of propolis but also for the pharmaceutical industry that looks for new drugs.

The influence of propolis application to meat utility on ROSS 308 broiler chickens

The aim of the experiment was to monitor the impact of propolis extract (experimental group) for meat utility of the Ross 308 chicken. The dosage of propolis was 0.2 g.kg KKZ-1 throught the fattening (40 days). Application of propolis increased (P≤0.01) slaughter weight (+76.80 g) and carcass weight (+67.90 g) in hens compared to the control group (1790.60 g, resp. 1266.54 g). In group with roosters slaughter weight (+70.80 g) and carcass weight (+56.00 g) were also increased (P≥0.05) in the experimental group compared to control (2086.20 g, resp. 1475.20 g). Offal weight in both sexes was lower (P≥0.05) in the experimental group (135.55 g - ♀, 158.21 g - ♂) compared to control (140.75 g - ♀, 168.55 g - ♂). Carcass yield was higher in hens (P≥0.05) in the experimental group (78.71 %) versus control (78.60 %).The evaluation of meat utility Ross 308 chickens  without distinction of sex did not show significant differences (P≥0.05), but a slight increase in slaughter weight and in the carcass weight in group with application of propolis extract in their fattening. Contrary slightly lower offal weight (-7.77 g) and carcass yield (-0.21 %) were found in the experimental group of chickens without distinction of sex (P≥0.05) compared to control group (weight of offal - 154.65 g, carcass yield - 78.69 %). We recommend the application of propolis as a possible supplement in the fattening of chickens, as it increases the performance parameters of meat and may also positively affect the economy of production.

Cytotoxic phenolic compounds in leaf buds of Populus tremuloides

Phytochemical investigations of the EtOH extract of Populus tremuloides leaf buds led to the isolation of 19 phenolic compounds. Among them, (1S,2S)-1-[4-O-E-coumaroyl-β-d-glucopyranosyloxy]cyclohexanediol was reported for the first time, and its structure was determined by spectroscopic (NMR and MS) and chemical methods. Seventeen of the isolated compounds were tested for their cytotoxicity against lung carcinoma (A549) and colorectal adenocarcinoma (DLD-1) human cell lines. Antibacterial activity was also evaluated against Escherichia coli and Staphylococcus aureus .

IMUNOMODULAÇÃO PELA PRÓPOLIS

RESUMO A própolis, uma substância resinosa produzida pelas abelhas melíferas a partir de exsudatos coletados em diferentes partes das plantas, tem sido utilizada há séculos na medicina popular devido as suas propriedades terapêuticas. Esta substância apresenta atividade antiinflamatória, antitumoral, antioxidante e imunomoduladora, embora muitos dos seus mecanismos de ação sejam desconhecidos. A imunomodulação pela própolis pode estar associada tanto com a estimulação quanto com a supressão de determinados eventos da resposta imune. Os efeitos antagônicos e muitas vezes não complementares sobre o sistema imunológico podem ser decorrentes da grande variabilidade química existente entre diferentes amostras de própolis, bem como das diferentes metodologias adotadas nos estudos científicos, resultando em variada ação farmacológica. Este artigo teve como objetivo revisar e discutir alguns aspectos relacionados à ação da própolis sobre o sistema imunológico.

Propolis and the immune system: a review

Propolis has been used empirically for centuries and it was always mentioned as an immunomodulatory agent. In recent years, in vitro and in vivo assays provided new information concerning its mechanisms of action, thus a review dealing with propolis and the immune system became imperative. This review compiles data from our laboratory as well as from other researchers, focusing on its chemical composition and botanical sources, the seasonal effect on its composition and biological properties, its immunomodulatory and antitumor properties, considering its effects on antibody production and on different cells of the immune system, involving the innate and adaptive immune response. In vitro and in vivo assays demonstrated the modulatory action of propolis on murine peritoneal macrophages, increasing their microbicidal activity. Its stimulant action on the lytic activity of natural killer cells against tumor cells, and on antibody production was demonstrated. Propolis inhibitory effects on lymphoproliferation may be associated to its anti-inflammatory property. In immunological assays, the best results were observed when propolis was administered over a short-term to animals. Propolis antitumor property and its anticarcinogenic and antimutagenic potential are discussed. Since humans have used propolis for different purposes and propolis-containing products have been marketed, the knowledge of its properties with scientific basis is not only of academic interest but also of those who use propolis as well. This review opens a new perspective on the investigation of propolis biological properties, mainly with respect to the immune system.

Adjuvant effect of green propolis on humoral immune response of bovines immunized with bovine herpesvirus type 5

Despite recent technological advances in vaccine production, most vaccines depend on the association with adjuvant substances. In this study, propolis, which has been attracting the attention of researchers due to its bioactive properties, was evaluated as an immunological adjuvant. The association of 40mg/dose of an ethanolic extract of green propolis with an inactivated oil vaccine against bovine herpesvirus type 5 (BoHV-5), resulted in a significant increase (P<0.01) in the neutralizing antibody levels, comparing to the bovines that received the same vaccine without propolis. Besides, propolis increased the percentage of animals with high antibody titers (above 32). Phenolic compounds such as artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) and the derivatives of cinnamic acid besides other flavonoid substances were abundant in the propolis extract used, and they could be the main substances with adjuvant action. The effect of the green propolis extract on the humoral immune response can be exploited in the development of new vaccines.

Immunomodulation produced by a green propolis extract on humoral and cellular responses of mice immunized with SuHV-1

Despite recent technological advances in vaccine production, most the vaccines depend on the association with adjuvant substances. This work evaluated the adjuvant capacity of an ethanol extract of green propolis associated to inactivated Suid herpesvirus type 1 (SuHV-1) vaccine preparations. Mice inoculated with SuHV-1 vaccine plus aluminum hydroxide and 5mg/dose of propolis extract presented higher levels of antibodies when compared to animals that received the same vaccine without propolis. The use of SuHV-1 vaccine with propolis extract alone did not induce significant levels of antibodies, however it was able to increase the cellular immune response, evidenced by the increase in the expression of mRNA to IFN-gamma. Besides, propolis increased the percentage of protected animals against challenge with a lethal dose of SuHV-1. The effect of green propolis extract on the humoral and cellular immune responses may be exploited for the development of effective vaccines.

Water extract of propolis and its main constituents, caffeoylquinic acid derivatives, exert neuroprotective effects via antioxidant actions

We investigated whether water extract of Brazilian green propolis (WEP) and its main constituents [caffeoylquinic acid derivatives (3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, chlorogenic acid) and cinnamic acid derivatives (p-coumaric acid, artepillin C, drupanin, baccharin)] exert neuroprotective effects against the retinal damage induced by oxidative stress. Additionally, their neuroprotective effects were compared with their antioxidant effects. WEP, 3,4-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, chlorogenic acid, and p-coumaric acid (but not artepillin C, baccharin, or drupanin) concentration-dependently inhibited oxidative stress-induced neurotoxicity [achieved using L-buthionine-(S,R)-sulfoximine (BSO) to deplete glutathione in combination with glutamate to inhibit cystine uptake] in cultured retinal ganglion cells (RGC-5, a rat ganglion cell line transformed using E1A virus). At their effective concentrations against oxidative stress-induced retinal damage, WEP, 3,4-di-caffeoylquinic acid, 3,5-di-caffeoylquinic acid, and chlorogenic acid (but not cinnamic acid derivatives) inhibited lipid peroxidation (LPO) in mouse forebrain homogenates. Thus, the neuroprotective effects of WEP and caffeoylquinic acid derivatives paralleled those against LPO. These findings indicate that WEP and caffeoylquinic acid derivatives have neuroprotective effects against retinal damage in vitro, and that these effects may be partly mediated via antioxidant effects.

Comparative study of in vitro methods to analyse the antifungal activity of propolis against yeasts isolated from patients with superficial mycoses

AIM

To test a total of 15 strains belonging to four species of yeasts by different in vitro methods against propolis and itraconazole (ITC).

METHODS AND RESULTS

Three methods were compared for susceptibility testing of yeast isolates to propolis: disc diffusion method, agar dilution method and National Committee for Clinical Laboratory Standards (NCCLS, M27A) broth microdilution method. ITC was selected as the antifungal agent for comparison study. Using the broth microdilution method, the geometric mean for MIC (microg ml(-1)) with regard to all isolates was < or =0.06 for propolis and < or =0.35 for ITC. The broth microdilution and the agar dilution methods were in good agreement (75%) for propolis against yeasts isolated from patients with superficial mycoses. Using the diffusion method, all strains showed a broad zone of inhibition at the first available reading time (24 or 48 h). An increase of MIC values was accompanied by a decrease of growth inhibition zone diameter. A favourable correlation was found between MIC and inhibition zone around the disc for propolis sample and the correlation coefficient was: r = -0.626 (P < 0.01).

CONCLUSIONS

This study suggests the potential value of the agar dilution and disc diffusion method as a convenient alternative method for testing of yeasts to propolis.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrated that propolis and ITC were very active against yeasts from patients with superficial mycoses. The other prominent finding in this study is that RPMI 1640 with L-glutamine was the available broth for the in vitro susceptibility testing of yeasts.

The anticarcinogenic effect of propolis in human lymphocytes culture

The in vitro anticarcinogenic potential of propolis in human lymphocytes was investigated. Blood samples were obtained from ten healthy males, non-smoking volunteers, which were incubated and exposed to increasing concentrations of propolis (0.01, 0.05, 0.1, 0.2, 0.5, 0.7 and 1.0 ml). The mean micronucleus rates were 1.47 +/- 0.38 - 4.02 +/- 0.64. Mitotic index rates were between 19.45 +/- 2.22 and 0.28 +/- 0.33. The differences between the control and exposed cells were statistically significant (p < or = 0.05). We conclude that exposure to different concentrations of propolis cannot produce a carcinogenic effect in peripheral human lymphocytes in vitro. However, increasing micronucleus (MN) rates showed that propolis could have a carcinogenic effect in high concentrations. Also chemical analysis of propolis sample was evaluated by GC/MS. Propolis sample mainly contains flavonoids, fatty and aromatic acids and their esters.

Chemical compositions and antimicrobial activities of four different Anatolian propolis samples

Propolis means a gum that is gathered by bees from various plants. It is known for its biological properties, having antibacterial, antifungal and healing properties. The aims of this study were to evaluate the antimicrobial activity of four different Anatolian propolis samples on different groups of microorganisms including some oral pathogens and comparison between their chemical compositions. Ethanol extracts of propolis (EEP) were prepared from four different Anatolian propolis samples and examined whether EEP inhibit the growth of the test microorganisms or not. For the antimicrobial activity assays, minimum inhibitory concentrations (MIC) were determined by using macrodilution method. The MIC values of the most effective propolis (TB) were 2 microg/ml for Streptococcus sobrinus and Enterococcus faecalis, 4 microg/ml for Micrococcus luteus, Candida albicans and C. krusei, 8 microg/ml for Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis and Enterobacter aerogenes, 16 microg/ml for Escherichia coli and C. tropicalis and 32 microg/ml for Salmonella typhimurium and Pseudomonas aeruginosa. The chemical compositions of EEP's were determined by high-temperature high-resolution gas chromatography coupled to mass spectrometry. The main compounds of four Anatolian propolis samples were flavonoids such as pinocembrin, pinostropin, isalpinin, pinobanksin, quercetin, naringenin, galangine and chrysin. Although propolis samples were collected from different regions of Anatolia all showed significant antimicrobial activity against the Gram positive bacteria and yeasts. Propolis can prevent dental caries since it demonstrated significant antimicrobial activity against the microorganisms such as Streptococcus mutans, Streptococcus sobrinus and C. albicans, which involves in oral 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.

Antifungal Activities of Propolis Collected by Different Races of Honeybees Against Yeasts Isolated From Patients With Superficial Mycoses

Yeasts isolated from patients with superficial mycoses were tested against propolis samples collected from different regions and honeybee races. The minimum inhibitory concentration (MIC) values obtained using the agar dilution methods were compared to the diameters of growth inhibition zones by using the disk diffusion method. The results showed that Candida albicans, C. glabrata, Trichosporon spp., and Rhodotorula sp. were susceptible to low concentrations of propolis, the latter showing a higher susceptibility. Relative to the other propolis tested, the propolis sample collected by Apis mellifera caucasica possessed the highest antifungal activity against all of the superficial mycoses. In contrast, the propolis samples collected by A.m. carnica and A.m. anatolica were the least active samples. Also, the propolis sample from the Adana region is more active than samples from other regions. An increase of MIC values was accompanied by a decrease of growth inhibition zone diameters.

Effect of Brazilian propolis on scratching behavior induced by compound 48/80 and histamine in mice

We studied the effect of Brazilian propolis on scratching behavior induced by compound 48/80 and histamine in ICR mice. Propolis granular A.P.C dose-related inhibited scratching behavior induced by compound 48/80 and significant inhibition were observed at 1000 mg/kg. However, histamine-induced scratching behavior was not inhibited by propolis granular A.P.C even at 1000 mg/kg. Propolis ethanol extract at 10 microg/ml or more inhibited histamine release from rat mast cells induced by compound 48/80. In addition, it blocked increased vascular permeability induced by compound 48/80. The inhibitory effect of propolis on scratching behavior induced by compound 48/80 was gradually enhanced by repeated administration, and 500 mg/kg propolis granular A.P.C, which caused no effect through single administration, significantly inhibited scratching behavior after repeated administration for 4 weeks. From these findings, it is assumed that the inhibition of scratching behavior induced by propolis occurs through a mast cell-dependent mechanism.

Protective effects of caffeic acid phenethyl ester against experimental allergic encephalomyelitis-induced oxidative stress in rats

Because oxidative damage has been known to be involved in inflammatory and autoimmune-mediated tissue destruction, modulation of oxygen free radical production represents a new approach to the treatment of inflammatory and autoimmune diseases. Central nervous system tissue is particularly vulnerable to oxidative damage, suggesting that oxidation plays an important role in the pathogenesis of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Caffeic acid phenethyl ester (CAPE), an active component of honeybee propolis, has been determined to have antioxidant, anti-inflammatory, antiviral, and anticancer activities. We have previously reported that CAPE inhibits ischemia-reperfusion injury and oxidative stress in rabbit spinal cord tissue. The present study, therefore, examined effects of CAPE on oxidative tissue damage in EAE in rats. Treatment with CAPE significantly inhibited reactive oxygen species (ROS) production induced by EAE, and ameliorated clinical symptoms in rats. These results suggest that CAPE may exert its anti-inflammatory effect by inhibiting ROS production at the transcriptional level through the suppression of nuclear factor kappaB activation, and by directly inhibiting the catalytic activity of inducible nitric oxide synthase.