GC-MS analysis and antileishmanial activities of two Turkish propolis types

Effect of Mexican Propolis on Wound Healing in a Murine Model of Diabetes Mellitus

Diabetes mellitus (DM) affects the wound healing process, resulting in impaired healing or aberrant scarring. DM increases reactive oxygen species (ROS) production, fibroblast senescence and angiogenesis abnormalities, causing exacerbated inflammation accompanied by low levels of TGF-β and an increase in Matrix metalloproteinases (MMPs). Propolis has been proposed as a healing alternative for diabetic patients because it has antimicrobial, anti-inflammatory, antioxidant and proliferative effects and important properties in the healing process. An ethanolic extract of Chihuahua propolis (ChEEP) was obtained and fractionated, and the fractions were subjected to High-Performance Liquid Chromatography with diode-array (HPLC-DAD), High-Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) and Gas Chromatography-Mass Spectrometry (GC-MS) analyses and 46 compounds were detected. Deep wounds were made in a murine DM model induced by streptozotocin, and the speed of closure and the wound tensile strength were evaluated by the tensiometric method, which showed that ChEEP had similar activity to Recoveron, improving the speed of healing and increasing the wound tensile strength needed to open the wound again. A histological analysis of the wounds was performed using H&E staining, and when Matrix metalloproteinase 9 (MMP9) and α-actin were quantified by immunohistochemistry, ChEEP was shown to be associated with improved histological healing, as indicated by the reduced MMP9 and α-actin expression. In conclusion, topical ChEEP application enhances wound healing in diabetic mice.

Exploring the Functional Properties of Propolis, Geopropolis, and Cerumen, with a Special Emphasis on Their Antimicrobial Effects

Bee propolis has been touted as a natural antimicrobial agent with the potential to replace antibiotics. Numerous reports and reviews have highlighted the functionalities and applications of the natural compound. Despite much clamor for the downstream application of propolis, there remain many grounds to cover, especially in the upstream production, and factors affecting the quality of the propolis. Moreover, geopropolis and cerumen, akin to propolis, hold promise for diverse human applications, yet their benefits and intricate manufacturing processes remain subjects of intensive research. Specialized cement bees are pivotal in gathering and transporting plant resins from suitable sources to their nests. Contrary to common belief, these resins are directly applied within the hive, smoothed out by cement bees, and blended with beeswax and trace components to create raw propolis. Beekeepers subsequently harvest and perform the extraction of the raw propolis to form the final propolis extract that is sold on the market. As a result of the production process, intrinsic and extrinsic factors, such as botanical origins, bee species, and the extraction process, have a direct impact on the quality of the final propolis extract. Towards the end of this paper, a section is dedicated to highlighting the antimicrobial potency of propolis extract.

Bio-Functional Potential and Biochemical Properties of Propolis Collected from Different Regions of Balochistan Province of Pakistan

Propolis is a well-known resinous natural substance collected by honeybees (Apis mellifera L.) from plants exudations. Variations in chemical composition of propolis are due to different sources from which it is collected and change in climate and geographical location. In this study, different propolis samples were collected from different regions of Balochistan and examined for its chemical composition, total phenolics and total flavonoid contents, and antioxidant potential by using DPPH radical scavenging assay and antimicrobial activity. Bioactive components analysis revealed the presence of steroids, carbohydrates, flavonoids, coumarins, cardiac glycosides, quinones, anthraquinones, terpenoids, tannins, and phlobatannins at different levels. The total phenolics contents were ranged from $2.9343\pm 1.247$ to $6.0216\pm 2.873$  mg GAE g-1, and flavonoid contents were found to be $0.1546\pm 0.087$ to $0.6586\pm 0.329$  mg QE g-1, respectively. The antioxidant ability of each extract was analyzed by their concentration having 50% inhibition ( $I{C}_{50}$ ). The propolis sample P3 possessed lower $I{C}_{50}$ $27.07\pm 0.73$  mg mL−1 with higher % inhibition of DPPH radical, and P8 showed lower % inhibition by having $I{C}_{50}$ $84.43\pm 2.07$  mg mL−1. The antibacterial activity of all samples was analyzed against a wide group of bacteria including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumonia and propolis extract (P4) was highly active against Klebsiella pneumoniae with the maximum diameter of zone of inhibition $20.33\pm 1.52$  mm, and propolis extract (P3) showed maximum zone of inhibition against Escherichia coli $19.06\pm 1.90,$ while propolis extract (P2) was found less active with minimum diameter of zone of inhibition $7.46\pm 1.50\text{mm}$ . The antifungal activity of extract was considered as active against the fungal species. Propolis extract (P3) showed 82% of zone of inhibition against Aspergillus Niger, and propolis extract (P1) was highly active against Aspergillus parasiticus with 80% of zone of inhibition. By comparing the vibration frequencies in wave numbers of the sample spectrograph acquired from an FTIR spectrophotometer, the functional groups present in the extracts were identified. The presence of seven elements (Fe, Zn, Mn, Ni, Pb, Cd, and Cr) was analyzed through atomic absorption spectrophotometer. The obtained concentrations were within the permissible ranges established by the World Health Organization. The GC-MS analysis revealed the presence of 80 different compounds belonged to different classes. The obtained results confirmed the imperative potential of propolis which can be used in various biological applications.

Computational Study of Asian Propolis Compounds as Potential Anti-Type 2 Diabetes Mellitus Agents by Using Inverse Virtual Screening with the DIA-DB Web Server, Tanimoto Similarity Analysis, and Molecular Dynamic Simulation

Propolis contains a wide range of pharmacological activities because of their various bioactive compounds. The beneficial effect of propolis is interesting for treating type-2 diabetes mellitus (T2DM) owing to dysregulation of multiple metabolic processes. In this study, 275 of 658 Asian propolis compounds were evaluated as potential anti-T2DM agents using the DIA-DB web server towards 18 known anti-diabetes protein targets. More than 20% of all compounds could bind to more than five diabetes targets with high binding affinity (<−9.0 kcal/mol). Filtering with physicochemical and pharmacokinetic properties, including ADMET parameters, 12 compounds were identified as potential anti-T2DM with favorable ADMET properties. Six of those compounds, (2R)-7,4′-dihydroxy-5-methoxy-8-methylflavone; (RR)-(+)-3′-senecioylkhellactone; 2′,4′,6′-trihydroxy chalcone; alpinetin; pinobanksin-3-O-butyrate; and pinocembrin-5-methyl ether were first reported as anti-T2DM agents. We identified the significant T2DM targets of Asian propolis, namely retinol-binding protein-4 (RBP4) and aldose reductase (AKR1B1) that have important roles in insulin sensitivity and diabetes complication, respectively. Molecular dynamic simulations showed stable interaction of selected propolis compounds in the active site of RBP4 and AKR1B1. These findings suggest that Asian propolis compound may be effective for treatment of T2DM by targeting RBP4 and AKR1B1.

Propolis: chemical diversity and challenges in quality control

Propolis is a resinous natural product produced by honeybees using beeswax and plant exudates. The chemical composition of propolis is highly complex, and varies with region and season. This inherent chemical variability presents several challenges to its standardisation and quality control. The present review was aimed at highlighting marker compounds for different types of propolis, produced by the species Apis mellifera, from different geographical origins and that display different biological activities, and to discuss strategies for quality control. Over 800 compounds have been reported in the different propolises such as temperate, tropical, birch, Mediterranean, and Pacific propolis; these mainly include alcohols, acids and their esters, benzofuranes, benzopyranes, chalcones, flavonoids and their esters, glycosides (flavonoid and diterpene), glycerol and its esters, lignans, phenylpropanoids, steroids, terpenes and terpenoids. Among these, flavonoids (> 140), terpenes and terpenoids (> 160) were major components. A broad range of biological activities, such as anti-oxidant, antimicrobial, anti-inflammatory, immunomodulatory, and anticancer activities, have been ascribed to propolis constituents, as well as the potential of these compounds to be biomarkers. Several analytical techniques, including non-separation and separation methods have been described in the literature for the quality control assessment of propolis. Mass spectrometry coupled with separation methods, followed by chemometric analysis of the data, was found to be a valuable tool for the profiling and classification of propolis samples, including (bio)marker identification. Due to the rampant chemotypic variability, a multiple-marker assessment strategy considering geographical and biological activity marker(s) with chemometric analysis may be a promising approach for propolis quality assessment.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11101-022-09816-1.

Effects of Propolis on Infectious Diseases of Medical Relevance

Infectious diseases are a significant problem affecting the public health and economic stability of societies all over the world. Treatment is available for most of these diseases; however, many pathogens have developed resistance to drugs, necessitating the development of new therapies with chemical agents, which can have serious side effects and high toxicity. In addition, the severity and aggressiveness of emerging and re-emerging diseases, such as pandemics caused by viral agents, have led to the priority of investigating new therapies to complement the treatment of different infectious diseases. Alternative and complementary medicine is widely used throughout the world due to its low cost and easy access and has been shown to provide a wide repertoire of options for the treatment of various conditions. In this work, we address the relevance of the effects of propolis on the causal pathogens of the main infectious diseases with medical relevance; the existing compiled information shows that propolis has effects on Gram-positive and Gram-negative bacteria, fungi, protozoan parasites and helminths, and viruses; however, challenges remain, such as the assessment of their effects in clinical studies for adequate and safe use.

Promising Anti-Protozoan Activities of Propolis (Bee Glue) as Natural Product: A Review

PURPOSE

Propolis (bee glue) is a resinous mixture of different plant exudates that possesses a wide range of biological and antimicrobial activities and has been used as a food supplement and in complementary medicine for centuries. Some researchers have proposed that propolis could be a potential curative compound against microbial agents such as protozoan parasitic infections by different and occasionally unknown mechanisms due to the immunoregulatory function and antioxidant capacity of this natural product.

METHODS

In this review, we concentrate on in vitro and in vivo anti-protozoan activities of propolis extracts/fractions in the published literature.

RESULTS

In Leishmania, propolis inhibits the proliferation of promastigotes and produces an anti-inflammatory effect via the inhibition of nitric oxide (NO) production. In addition, it increases macrophage activation, TLR-2, TNF-α, IL-4, IL-17 production, and downregulation of IL-12. In Plasmodium and Trypanosoma, propolis inhibits the parasitemia, improving anemia and increasing the IFN-γ, TNF-α, and GM-CSF cytokines levels, most likely due to its strong immunomodulatory activity. Moreover, propolis extract arrests proliferation of T. cruzi, because it has aromatic acids and flavonoids. In toxoplasmosis, propolis increases the specific IgM and IgG titers via decreasing the serum IFN-γ, IL-1, and IL-6 cytokines levels in the rats infected with T. gondii. In Cryptosporidium and Giardia, it decreases oocysts shedding due to phytochemical constituents, particularly phenolic compounds, and increases the number of goblet cells. Propolis inhibits the growth of Blastocystis, possibly by apoptotic mechanisms like metronidazole. Unfortunately, the mechanism action of propolis' anti-Trichomonas and anti-Acanthamoeba is not well-known yet.

CONCLUSION

Reviewing the related literature could highlight promising antimicrobial activities of propolis against intracellular and extracellular protozoan parasites; this could shed light on the exploration of more effective drugs for the treatment of protozoan parasitic infections in the near future.

Quantification and Characterization of Phenolic Compounds from Northern Indian Propolis Extracts and Dietary Supplements

BACKGROUND

Propolis is a resinous substance produced by bees. Propolis extracts have been used for anti-inflammatory and antimicrobial activities. The use of propolis dietary supplements has been increasing in the United States and the rest of the world.

OBJECTIVE

A simple, economic, and valid analytical method is needed for quality assessment of dietary supplements and extracts claiming to contain propolis.

METHODS

A ultra-high performance liquid chromatography (UHPLC) quadropole time-of-flight-MS method was used to characterize the chemical composition of northern Indian propolis. Fourteen major phenolic compounds were quantified using a UHPLC-DAD method. An HPTLC method was used to develop chemical fingerprinting profiles for propolis extracts and dietary supplements. The seven propolis extracts and 14 dietary supplements purchased in the U.S. were analyzed using the UHPLC-DAD-QToF method.

RESULTS

Fifty-seven compounds belonging to phenolic, coumarin, fatty acid, and terpene classes were identified in propolis extracts. Based on quantification results, the content of 14 phenolic compounds in propolis extracts varied from 19-32% in dietary supplements, a significant variation to the recommended daily intake (0.2-94 mg/day).

CONCLUSIONS/HIGHLIGHTS

The developed analytical methods can be used for quality assessment of propolis extracts and dietary supplements.

Chemical characterization and biological activity of six different extracts of propolis through conventional methods and supercritical extraction

Propolis is a natural product with many demonstrated biological activities and propolis extract has been used in the food, pharmaceutical and cosmetics industries. Different works have showed the variations in the chemical composition, and consequently, on the biological activity of the propolis that are associated with its type and geographic origin. Due to this study evaluated propolis extracts obtained through supercritical extraction and ethanolic extraction (conventional) in three samples of different types of propolis (red, green and brown), collected from different regions in Brazil (state of Bahia). Analyses were performed to determine the humidity, water activity, the content of total ash, proteins, lipids and fiber in raw propolis samples. The content of phenolic compounds, flavonoids, in vitro antioxidant activity (DPPH), catechin, ferulic acid and luteolin and antimicrobial activity against two bacteria (Staphylococcus aureus and Escherichia coli) were determined for all extracts. For the green and red ethanolic extracts the anti-leishmanicidal potential was also evaluated. The physicochemical profiles showed agreement in relation to the literature. The results identified significant differences among the extracts (p>0.05), which are in conformity with their extraction method, as well as with type and botanical origin of the samples. The extraction with supercritical fluid was not efficient to obtain extracts with the highest contents of antioxidants compounds, when compared with the ethanolic extracts. The best results were shown for the extracts obtained through the conventional extraction method (ethanolic) indicating a higher selectivity for the extraction of antioxidants compounds. The red variety showed the largest biological potential, which included the content of antioxidants compounds. The results found in this study confirm the influence of the type of the raw material on the composition and characteristics of the extracts. The parameters analysis were important to characterize and evaluate the quality of the different Brazilian propolis extracts based on the increased use of propolis by the natural products industry.

Antitrypanosomal, antileishmanial and cytotoxic activities of Brazilian red propolis and plant resin of Dalbergia ecastaphyllum (L) Taub

The treatment for leishmaniasis and Chagas disease can be hard and painful, such that many patients give up on the treatment. In order to find an alternative path for the treatment of these diseases, researchers are using natural products to fight these parasites. The aim of this study was to evaluate the antiprotozoan and cytotoxic activities of red propolis samples collected from different Brazilian states and seasons whilst searching for possible activity differences. We also compared the red propolis results with the ones obtained for the plant resin extract collected from Dalbergia ecastaphyllum trees. The hydroethanolic red propolis extracts from Pernambuco and Alagoas, and the D. ecastaphyllum resin were evaluated regarding their antileishmanial, antitrypanosomal and cytotoxic activity. All extracts showed antiprotozoan and cytotoxic activity. RP-PER showed to be more cytotoxic against protozoan parasites and fibroblast cells. All propolis extracts showed a higher cytotoxic activity when compared to resin extracts. The propolis sample collected in Pernambuco during the rainy season killed the parasites with lower concentrations than the sample collected in the dry season. The IC₅₀ observed against the parasites could be used without high fibroblast cell damage.

Atividade antiviral e virucida de extratos hidroalcoólicos de própolis marrom, verde e de abelhas Jataí (Tetragonisca angustula) frente ao herpersvírus bovino tipo 1 (BoHV-1) e ao vírus da diarreia viral bovina (BVDV)

RESUMO: Dentre as propriedades biológicas da própolis, a atividade antimicrobiana tem merecido destacada atenção. No presente trabalho, descreve-se a ação antiviral e virucida de três extratos hidroalcoólicos de própolis (marrom, verde e de abelhas jataí (Tetragonisca angustula), frente ao Herpesvírus Bovino tipo (BoHV-1) e ao Vírus da Diarreia Viral Bovina (BVDV). Os três extratos hidroalcoólicos foram obtidos de extração etanólica e são oriundos do sul do Brasil. A composição química dos extratos de própolis foi determinada pela cromatografia líquida de alta eficiência acoplada a espectrômetro de massas (UFLC-PDA-ESI-TOF/MS) que identificou e quantificou compostos como: ácido cafeico e ácido p-cumárico, ácido clorogênico, ácido ferúlico, além de flavonoides como a rutina. A toxicidade celular bem como a atividade antiviral dos extratos de própolis em monocamadas de células MDBK (Madin-Darby Bovine Kidney) foi avaliada através de observação microscópica e quantificada pelo teste de MTT (3-(4,5 dimetiltiazol-2yl)-2-5-difenil-2H tetrazolato de bromo). O extrato de própolis de abelhas jataí demonstrou ser menos citotóxico (1,57μg/mL), quando comparado aos extratos verde (0,78μg/mL) e marrom (0,39μg/mL). Quanto a atividade antiviral, a própolis verde demostrou maior eficácia em ambos os tratamentos celulares (pós e pré-exposição) frente ao BoHV-1 em relação aos outros extratos, ou seja, houve maior viabilidade celular quando comparada aos controles de células e vírus. Já a de jataí apresentou atividade frente aos dois vírus (BoHV-1 e BVDV) no método pré-infecção, enquanto a própolis marrom demonstrou ação apenas frente ao BoHV-1 também no método pré-infecção. Para determinação da atividade virucida foram utilizadas diferentes diluições dos vírus, bem como temperaturas e tempos distintos de incubação. A própolis verde a 37°C propiciou a maior redução no título viral (4,33log) em relação a marrom (log = 3,5log) e de jataí (log = 3,24log). No entanto, frente ao BVDV a própolis jataí apresentou os melhores resultados em ambas as temperaturas (22oC e 37oC). Portanto, os extratos avaliados apresentaram atividade antiviral e virucida frente ao BoHV-1 e BVDV, o que os torna alvo para o desenvolvimento de novos biofármacos como alternativa ao uso de antivirais comerciais em Medicina Veterinária.

Chemical profile and anti-leishmanial activity of three Ecuadorian propolis samples from Quito, Guayaquil and Cotacachi regions

Three propolis samples were collected from different regions of Ecuador (Quito, Guayaquil and Cotacachi) and their methanolic extracts were prepared. Preliminary information supplied by TLC and NMR data, allowed us to define two main types of propolis: Cotacachi propoli sample (CPS), rich in flavonoids and Quito and Guayaquil samples (QPS and GPS) containing triterpenic alcohols and acetyl triterpenes as the main constituents. Two different approaches based on RP-HPLC preparative procedure and NMR structural determination (CPS) and GC-MS analysis (QPS and GPS) were successfully used for the chemical characterization of their major compounds. All three propolis extracts were able to inhibit Leishmania amazonensis growth but propolis sample rich in flavonoids was the most active (IC₅₀=17.1±1.7μg/mL). In the literature this is the first study on propolis from Ecuador.

Chemical Composition and Antimicrobial Activities of Iranian Propolis

Background

With considering the importance of natural products for their remedial and therapeutic value, this research was aimed to analyze the chemical compositions and antimicrobial activity of four propolis samples from different areas of Iran (Chenaran, Taleghan, Morad Beyg, and Kalaleh) with various climates and flora.

Methods

Ethanolic (70% EtOH) and dichlromethane (DCM) extracts of Iranian propolis were analyzed by gas chromatography-mass spectrometry (GC-MS) methods, and antimicrobial activity was evaluated against Candida albicans, Escherichia coli, and Staphylococcus aureus using disk diffusion antimicrobial method.

Results

The results of GC-MS analysis showed the presence of fatty acids, flavonoids, terpenes, aromatic-aliphatic acids, and their related esters. The total flavonoids in DCM extract of Chenaran, Taleghan, Morad Beyg, and Kalaleh propolis were pinocembrin and pinostrobin chalcone. The common phenolic and terpene compounds detected in all four tested EtOH extracts were P-cumaric acid and dimethyl -1,3,5,6-tetramethyl-[1,3-(13C2)] bicycloce [5.5.0] dodeca-1,3,5,6,8,10-hexaene-9,10-dicarboxylate, respectively. The highest inhibitory diameter zone of the Iranian propolis against C. albicans, E. coli, and S. aureus was for DCM extract of Kalaleh propolis (13.33 mm), Morad Beyg propolis (12 mm), and Kalaleh (11.67 mm), respectively.

Conclusion

Iranian propolis showed antimicrobial activities against C. albicans, E. coli, and S. aurous, perhaps due to the presence of flavonoids, phenolic acids, and terpenes as active components that can be used alone or in combination with the selected antibiotics to synergize antibiotic effect, as well as to prevent microbial resistance to available antimicrobial drugs.

Biological properties of propolis extracts: Something new from an ancient product

Natural products are an interesting source of new therapeutics, especially for cancer therapy as 70% of them have botany origin. Propolis, a resinous mixture that honey bees collect and transform from tree buds, sap flows, or other botanical sources, has been used by ethnobotany and traditional practitioners as early in Egypt as 3000 BCE. Enriched in flavonoids, phenol acids and terpene derivatives, propolis has been widely used for its antibacterial, antifungal and anti-inflammatory properties. Even though it is a challenge to standardize propolis composition, chemical analyses have pointed out interesting molecules that also present anti-oxidant and anti-proliferative properties that are of interest in the field of anti-cancer therapy. This review describes the various geographical origins and compositions of propolis, and analyzes how the main compounds of propolis could modulate cell signaling. A focus is made on the putative use of propolis in prostate cancer.

Polymeric Nanoparticles of Brazilian Red Propolis Extract: Preparation, Characterization, Antioxidant and Leishmanicidal Activity

The ever-increasing demand for natural products and biotechnology derived from bees and ultra-modernization of various analytical devices has facilitated the rational and planned development of biotechnology products with a focus on human health to treat chronic and neglected diseases. The aim of the present study was to prepare and characterize polymeric nanoparticles loaded with Brazilian red propolis extract and evaluate the cytotoxic activity of "multiple-constituent extract in co-delivery system" for antileishmanial therapies. The polymeric nanoparticles loaded with red propolis extract were prepared with a combination of poly-ε-caprolactone and pluronic using nanoprecipitation method and characterized by different analytical techniques, antioxidant and leishmanicidal assay. The red propolis nanoparticles in aqueous medium presented particle size (200-280 nm) in nanometric scale and zeta analysis (-20 to -26 mV) revealed stability of the nanoparticles without aggregation phenomenon during 1 month. After freeze-drying method using cryoprotectant (sodium starch glycolate), it was possible to observe particles with smooth and spherical shape and apparent size of 200 to 400 nm. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermal analysis revealed the encapsulation of the flavonoids from the red propolis extract into the polymeric matrix. Ultra performance liquid chromatography coupled with diode array detector (UPLC-DAD) identified the flavonoids liquiritigenin, pinobanksin, isoliquiritigenin, formononetin and biochanin A in ethanolic extract of propolis (EEP) and nanoparticles of red propolis extract (NRPE). The efficiency of encapsulation was determinate, and median values (75.0 %) were calculated using UPLC-DAD. 2,2-Diphenyl-1-picryhydrazyl method showed antioxidant activity to EEP and red propolis nanoparticles. Compared to negative control, EEP and NRPE exhibited leishmanicidal activity with an IC50 value of ≅38.0 μg/mL and 31.3 μg/mL, 47.2 μg/mL, 154.2μg/mL and 193.2 μg/mL for NRPE A1, NRPE A2, NRPE A3 and NRPE A4, respectively. Nanoparticles loaded with red propolis extract in co-delivery system and EEP presented cytotoxic activity on Leishmania (V.) braziliensis. Red propolis extract loaded in nanoparticles has shown to be potential candidates as intermediate products for preparation of various pharmaceutical dosage forms containing red propolis extract in the therapy against negligible diseases such as leishmaniasis. Graphical Abstract Some biochemical mechanisms of cellular debridement of Leishmania (V.) braziliensis species by the flavonoids of red propolis extract (EEP) or NRPE loaded with red propolis extract.

Antiviral Activity of Hatay Propolis Against Replication of Herpes Simplex Virus Type 1 and Type 2

Background

Propolis is a bee product widely used in folk medicine and possessing many pharmacological properties. In this study we aimed to investigate: i) the antiviral activities of Hatay propolis samples against HSV-1 and HSV-2 in HEp-2 cell line, and ii) the presence of the synergistic effects of propolis with acyclovir against these viruses.

Material/Methods

All experiments were carried out in HEp-2 cell cultures. Proliferation assays were performed in 24-well flat bottom microplates. We inoculated 1×10⁵ cells per ml and RPMI 1640 medium with 10% fetal calf serum into each well. Studies to determine cytotoxic effect were performed. To investigate the presence of antiviral activity of propolis samples, different concentrations of propolis (3200, 1600, 800, 400, 200, 100, 75, 50, and 25 μg/mL) were added into the culture medium. The amplifications of HSV-1 and HSV-2 DNA were performed by real-time PCR method. Acyclovir (Sigma, USA) was chosen as a positive control. Cell morphology was evaluated by scanning electron microscopy (SEM).

Results

The replication of HSV-1 and HSV-2 was significantly suppressed in the presence of 25, 50, and 100 μg/mL of Hatay propolis. We found that propolis began to inhibit HSV-1 replication after 24 h of incubation and propolis activity against HSV-2 was found to start at 48 h following incubation. The activity of propolis against both HSV-1 and HSV-2 was confirmed by a significant decrease in the number of viral copies.

Conclusions

We determined that Hatay propolis samples have important antiviral effects compared with acyclovir. In particular, the synergy produced by antiviral activity of propolis and acyclovir combined had a stronger effect against HSV-1 and HSV-2 than acyclovir alone.

Metabolite profiling, antioxidant and antibacterial activities of Brazilian propolis: Use of correlation and multivariate analyses to identify potential bioactive compounds

The production of propolis by honeybees results from a selective collection of exudates from various plant species and present many potentialities in the pharmaceutical industry. The objective of this study was to investigate the chemical profile of Brazilian propolis, as well as their in vitro antioxidant and antibacterial activities. Gas chromatography-mass spectrometry was applied for chemical profiling of propolis extracts. Total phenolic compounds were quantified by Folin-Ciocalteu and antioxidant properties were assessed by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Antibacterial activity was assessed against Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteus. Correlation and multivariate statistical analysis were used to identify potential bioactive compounds in the extracts. Twenty-nine metabolites were identified along with 34 other metabolites that were classified into the following classes: triterpenoids (12), acetyltriterpenoids (3), sesquiterpenes (6), steroids (4), and hydrocarbons (9). The antioxidant capacity (IC₅₀) ranged from 21.50 to 78.77μg/mL, whereas the content of total phenolic compounds ranged from 31.88 to 204.30mg GAE/g of dry weight. Total phenolic compounds and methyl retinoate showed a positive correlation with the antioxidant capacity, whereas tetradecanal, γ-palmitolactone and ethyl hydrocinnamate showed a negative correlation. Different sets of metabolites are shown to correlate with the antibacterial activity of the extracts, which is largely dependent on the type of microorganism. This innovative approach allowed us to identify likely bioactive compounds in the extracts, although the mechanism(s) underlying antibacterial activity encompass a complex trait, which might involve synergistic effects.

Propolis: A Complex Natural Product with a Plethora of Biological Activities That Can Be Explored for Drug Development

The health industry has always used natural products as a rich, promising, and alternative source of drugs that are used in the health system. Propolis, a natural resinous product known for centuries, is a complex product obtained by honey bees from substances collected from parts of different plants, buds, and exudates in different geographic areas. Propolis has been attracting scientific attention since it has many biological and pharmacological properties, which are related to its chemical composition. Several in vitro and in vivo studies have been performed to characterize and understand the diverse bioactivities of propolis and its isolated compounds, as well as to evaluate and validate its potential. Yet, there is a lack of information concerning clinical effectiveness. The goal of this review is to discuss the potential of propolis for the development of new drugs by presenting published data concerning the chemical composition and the biological properties of this natural compound from different geographic origins.

The isolation of antiprotozoal compounds from Libyan propolis

Propolis is increasingly being explored as a source of biologically active compounds. Until now, there has been no study of Libyan propolis. Two samples were collected in North East Libya and tested for their activity against Trypanosoma brucei. Extracts from both samples had quite high activity. One of the samples was fractionated and yielded a number of active fractions. Three of the active fractions contained single compounds, which were found to be 13-epitorulosal, acetyl-13-epi-cupressic acid and 13-epi-cupressic acid, which have been described before in Mediterranean propolis. Two of the compounds had a minimum inhibitory concentration value of 1.56 µg/mL against T. brucei. The active fractions were also tested against macrophages infected with Leishmania donovani, and again moderate to strong activity was observed with the compounds having IC50 values in the range 5.1-21.9 µg/mL.

In vitro evaluation of Portuguese propolis and floral sources for antiprotozoal, antibacterial and antifungal activity

Propolis is a beehive product with a very complex chemical composition, used since ancient times in several therapeutic treatments. As a contribution to the improvement of drugs against several tropical diseases caused by protozoa, we screened Portuguese propolis and its potential floral sources Populus x Canadensis and Cistus ladanifer against Plasmodium falciparum, Leishmania infantum, Trypanosoma brucei and Trypanosoma cruzi. The toxicity against MRC-5 fibroblast cells was evaluated to assess selectivity. The in vitro assays were performed following the recommendations of WHO Special Programme for Research and Training in Tropical Diseases (TDR) and revealed moderate activity, with the propolis extracts presenting the relatively highest inhibitory effect against T. brucei. Additionally, the antimicrobial activity against Staphylococcus aureus, Candida albicans, Trichophyton rubrum and Aspergillus fumigatus was also verified with the better results observed against T. rubrum. The quality of the extracts was controlled by evaluating the phenolic content and antioxidant activity. The observed biological activity variations are associated with the variable chemical composition of the propolis and the potential floral sources under study.

The effect of propolis on CCL5 and IFN-γ expression by peripheral blood mononuclear cells from leishmaniasis patients

Objectives

Mucocutaneous leishmaniasis is associated with a strong Th1 immune response to Leishmania, which modulates chemokines and their receptors expression, affecting their migratory capacity. There are no antileishmanial vaccines available and chemotherapy still relies on the potentially toxic pentavalent antimonials. Propolis is a bee product with immunomodulatory and antiparasite activities, and researchers have been attracted to its potential for the development of new drugs. This work investigated the effects of propolis on CCL5 and IFN-γ expression by peripheral blood mononuclear cells (PBMC) in order to evaluate a possible immunomodulatory action of propolis in patients with leishmaniasis compared to healthy control subjects.

Methods

PBMC were incubated in the absence or presence of propolis and the evaluation of a possible cytotoxicity of propolis was carried out using MTT assay. The expression level of CCL5 and IFN-γ was determined by real-time PCR.

Key findings

Our data indicated that propolis modulates the immune response of leishmaniasis patients in vitro, affecting CCL5 and IFN-γ expression by PBMC.

Conclusions

Data suggested that propolis drives an anti-inflammatory response depending on concentration. Although propolis is a potential source of new and selective drugs for the treatment of leishmaniasis, its usefulness in the therapeutics should be further investigated.