Antifungal activity of propolis extract against yeasts isolated from onychomycosis lesions

Anti-Malassezia globosa (MYA-4889, ATCC) activity of Thai propolis from the stingless bee Geniotrigona thoracica

Malassezia globosa, a lipophilic pathogen, is known to be involved in various chronic skin diseases. Unfortunately, the available treatments have unwanted side effects and microbial drug resistance is evolving. As the antimicrobial activity of propolis is outstanding, this study aimed to examine the potential of propolis from the stingless bee Geniotrigona thoracica against the yeast. Anti-M. globosa growth activity was ascertained in agar well diffusion and broth microdilution assays and the inhibitory concentration value at 50 % (IC50) was determined. Since the yeast cannot synthesize its own fatty acids, extracellular lipase is important for its survival. Here, anti-M. globosa extracellular lipase activity was additionally investigated by colorimetric and agar-based methods. Compared to the crude hexane and crude dichloromethane extracts, the crude methanol partitioned extract (CMPE) exhibited the best anti-M. globosa growth activity with an IC50 of 1.22 mg/mL. After CMPE was further enriched by silica gel column chromatography, fraction CMPE1 (IC50 of 0.98 mM or 184.93 μg/mL) presented the highest activity and was later identified as methyl gallate (MG) by nuclear magnetic resonance analysis. Subsequently, MG was successfully synthesized and shown to have a similar activity, and a minimal fungicidal concentration of 43.44 mM or 8.00 mg/mL. However, lipase assay analysis suggested that extracellular lipase might not be the main target mechanism of MG. This is the first report of MG as a new anti-Malassezia compound. It could be a good candidate for further developing alternative therapeutic agents.

Revisiting Oral Antiseptics, Microorganism Targets and Effectiveness

A good oral health status is mostly dependent on good oral hygiene habits, which knowingly impacts systemic health. Although controversial, chemical oral antiseptics can be useful in adjunct use to mechanical dental plaque control techniques in the prevention and management of local and overall health and well-being. This review aims to revisit, gather and update evidence-based clinical indications for the use of the most popular oral antiseptics, considering different types, microorganism targets and effectiveness in order to establish updated clinical recommendations.

Biomaterials with antifungal strategies to fight oral infections

Oral fungal infections pose a threat to human health and increase the economic burden of oral diseases by prolonging and complicating treatment. A cost-effective strategy is to try to prevent these infections from happening in the first place. With this purpose, biomaterials with antifungal properties are a crucial element to overcome fungal infections in the oral cavity. In this review, we go through different kinds of biomaterials and coatings that can be used to functionalize them. We also review their potential as a therapeutic approach in addition to prophylaxis, by going through traditional and alternative antifungal compounds, e.g., essential oils, that could be incorporated in them, to enhance their efficacy against fungal pathogens. We aim to highlight the potential of these technologies and propose questions that need to be addressed in prospective research. Finally, we intend to concatenate the key aspects and technologies on the use of biomaterials in oral health, to create an easy to find summary of the current state-of-the-art for researchers in the field.

Case of Mixed Infection of Toenail Caused by Candida parapsilosis and Exophiala dermatitidis and In Vitro Effectiveness of Propolis Extract on Mixed Biofilm

Onychomycosis is a chronic fungal nail infection caused by several filamentous and yeast-like fungi, such as the genus Candida spp., of great clinical importance. Black yeasts, such as Exophiala dermatitidis, a closely related Candida spp. species, also act as opportunistic pathogens. Fungi infectious diseases are affected by organisms organized in biofilm in onychomycosis, making treatment even more difficult. This study aimed to evaluate the in vitro susceptibility profile to propolis extract and the ability to form a simple and mixed biofilm of two yeasts isolated from the same onychomycosis infection. The yeasts isolated from a patient with onychomycosis were identified as Candida parapsilosis sensu stricto and Exophiala dermatitidis. Both yeasts were able to form simple and mixed (in combination) biofilms. Notably, C. parapsilosis prevailed when presented in combination. The susceptibility profile of propolis extract showed action against E. dermatitidis and C. parapsilosis in planktonic form, but when the yeasts were in mixed biofilm, we only observed action against E. dermatitidis, until total eradication.

Propolis: A Detailed Insight of Its Anticancer Molecular Mechanisms

Cancer is the second most life-threatening disease and has become a global health and economic problem worldwide. Due to the multifactorial nature of cancer, its pathophysiology is not completely understood so far, which makes it hard to treat. The current therapeutic strategies for cancer lack the efficacy due to the emergence of drug resistance and the toxic side effects associated with the treatment. Therefore, the search for more efficient and less toxic cancer treatment strategies is still at the forefront of current research. Propolis is a mixture of resinous compounds containing beeswax and partially digested exudates from plants leaves and buds. Its chemical composition varies widely depending on the bee species, geographic location, plant species, and weather conditions. Since ancient times, propolis has been used in many conditions and aliments for its healing properties. Propolis has well-known therapeutic actions including antioxidative, antimicrobial, anti-inflammatory, and anticancer properties. In recent years, extensive in vitro and in vivo studies have suggested that propolis possesses properties against several types of cancers. The present review highlights the recent progress made on the molecular targets and signaling pathways involved in the anticancer activities of propolis. Propolis exerts anticancer effects primarily by inhibiting cancer cell proliferation, inducing apoptosis through regulating various signaling pathways and arresting the tumor cell cycle, inducing autophagy, epigenetic modulations, and further inhibiting the invasion and metastasis of tumors. Propolis targets numerous signaling pathways associated with cancer therapy, including pathways mediated by p53, β-catenin, ERK1/2, MAPK, and NF-κB. Possible synergistic actions of a combination therapy of propolis with existing chemotherapies are also discussed in this review. Overall, propolis, by acting on diverse mechanisms simultaneously, can be considered to be a promising, multi-targeting, multi-pathways anticancer agent for the treatment of various types of cancers.

Performance of Two Extracts Derived from Propolis on Mature Biofilm Produced by Candida albicans

Species of the Candida genus represent the third most common cause of onychomycosis, the most frequent and difficult to treat nail infection. Onychomycosis has been attributed to fungi organized in biofilm and some natural products have proved promising for its treatment. This study aimed to evaluate the antibiofilm activity of propolis extract (PE) and its by-product (WPE) on 7-day preformed biofilms produced by Candida albicans in polystyrene microplates, as well as in an ex vivo model on human nail fragments. The cytotoxicity and permeation capacity were also assessed. Firstly, multiple parameters were evaluated over 7 days to elucidate the dynamics of biofilm formation by C. albicans. The cell viability and total biomass did not vary much from the beginning; however, days 3 and 4 were crucial in terms of metabolic activity, which was significantly increased, and the levels of extracellular matrix components, wherein proteins and nucleic acids experienced an increase, but polysaccharide levels dropped. Architecturally, one-day biofilm showed a monolayer of organized cells (blastoconidia, hyphae, and pseudohyphae), while in the seven-day biofilm there was a three-dimensional well-structured and complex biofilm. This yeast was also able to form a biofilm on both surfaces of the nail, without an additional nutritional source. Both extracts showed excellent antibiofilm activity against the 7-day preformed biofilm and were not toxic to Vero cells at concentrations compatible with the antifungal and antibiofilm activities. Both extracts permeated the experimentally infected nail, with WPE being more efficient. The results of this study, taken together, reinforce the potential of these natural products, containing propolis, as a safe option for the topical treatment of onychomycosis.

Efficacy of Propolis Gel on Mature Biofilm Formed by Neocosmospora keratoplastica Isolated from Onychomycosis

This article describes Neocosmospora keratoplastica as an etiological onychomycosis agent. Ex vivo studies were initially performed to demonstrate the ability of this species to grow and form a well-organized characteristic biofilm on sterilized healthy nails. Based on the history of excellent results, both for antifungal and antibiofilm, of propolis resin gum, we evaluated its activity using artificially formed biofilm. In vitro, the minimal biofilm eradication concentration of the propolis extract (PE) was 375 µg of total polyphenol content (TPC) per mL, while for the propolis gel (PG) it was 450 µg of TPC per mL. In biofilm exposed to the propolis products, a decrease in hyphae and conidia was evident, accompanied by a disorganization of the extracellular matrix. Additionally, this low concentration of PE was able to significantly reduce the number of colony-forming units and the metabolic activity. Furthermore, the treatment of a 15-year nail infection due to N. keratoplastica was carried out exclusively using a topical treatment with a gel containing propolis (30%) with a daily dosage. This treatment achieved complete remission of the onychomycosis in 12 months. It is important to point out that some inconveniences previously reported by other patients treated with propolis extract were eliminated, increasing adherence to treatment.

Propolis efficacy on SARS-COV viruses: a review on antimicrobial activities and molecular simulations

This current study review provides a brief review of a natural bee product known as propolis and its relevance toward combating SARS-CoV viruses. Propolis has been utilized in medicinal products for centuries due to its excellent biological properties. These include anti-oxidant, immunomodulatory, anti-inflammatory, anti-viral, anti-fungal, and bactericidal activities. Furthermore, studies on molecular simulations show that flavonoids in propolis may reduce viral replication. While further research is needed to validate this theory, it has been observed that COVID-19 patients receiving propolis show earlier viral clearance, enhanced symptom recovery, quicker discharge from hospitals, and a reduced mortality rate relative to other patients. As a result, it appears that propolis could probably be useful in the treatment of SARS-CoV-2-infected patients. Therefore, this review sought to explore the natural properties of propolis and further evaluated past studies that investigated propolis as an alternative product for the treatment of COVID-19 symptoms. In addition, the review also highlights the possible mode of propolis action as well as molecular simulations of propolis compounds that may interact with the SARS-CoV-2 virus. The activity of propolis compounds in decreasing the impact of COVID-19-related comorbidities, the possible roles of such compounds as COVID-19 vaccine adjuvants, and the use of nutraceuticals in COVID-19 treatment, instead of pharmaceuticals, has also been discussed.

Relevant insights into onychomycosis' pathogenesis related to the effectiveness topical treatment

Onychomycosis (OM) is a fungal infection, responsible for about 50% of nail diseases. OM has been attributed to the ability of fungi to naturally organize themselves into biofilms on nail surfaces. However, little is known about the exact role of the biofilm in the etiopathogenesis of OM, as well as its influence in the permeation of a topical treatment. The objectives of this study were to review the literature for topical OM treatments in clinical trials, assess the efficiency of these treatments, and discuss factors that could affect the success of these treatments. First, a systematic search of articles published in the MEDLINE database (PubMed) between January 2010 and December 2019 was conducted, focusing on drugs under clinical trials for the topical treatment of OM. Of the publications selected, it was clear that none of them had considered the fungi organized in biofilm. Therefore, we reflected on some important variables involved in OM, such as the nail structure and the mechanism of fungal invasion. Some methods, such as histopathologic analysis and spectroscopy techniques, were found to be effective in the detection of nail biofilm, and could be used in future drug permeation studies. This review allowed us to conclude that novel antifungals for the topical treatment of OM must consider the drug to permeate through biofilm. Natural products, such as propolis, seem strong candidates in this respect.

Potential of propolis antifungal activity for clinical applications

The high incidence of skin diseases of microbial origin along with the widespread increase of microbial resistance demand for therapeutic alternatives. Research on natural compounds has been opening new perspectives for the development of new therapies with health positive impacts. Propolis, a resinous mixture produced by honeybees from plant exudates, is widely used as a natural medicine since ancient times, mainly due to its antimicrobial properties. More recently, antioxidant, anti-tumor, anti-inflammatory, hepatoprotective and immunomodulatory activities were also reported for this natural product, highlighting its high potential pharmacological interest. In the present work, an extensive review of the main fungi causing skin diseases as well as the effects of natural compounds, particularly propolis, against such disease-causing microorganisms was organized and compiled in concise handy tables. This information allows to conclude that propolis is a highly effective antimicrobial agent suggesting that it could be used as an alternative skin treatment against pathogenic microorganisms and also as a cosmeceutic component or as a source of bioactive ingredients.

How diverse is the chemistry and plant origin of Brazilian propolis?

Propolis is a honey bee product containing chiefly beeswax and resins originated from plant buds or exudates. Propolis resin exerts a diversity of biological activities, such as antitumoral, anti-inflammatory, antimicrobial, and defense of the hive against pathogens. Chemical standardization and identification of botanical sources is crucial for characterization of propolis. Types of Brazilian propolis are characteristic of geographical regions and respective biomes, such as savannas (Cerrado), mangroves, dry forest (Caatinga), rain forests (Amazon, Atlantic, and Interior forests), altitudinal fields ("Campos Rupestres"), Pantanal, and Araucaria forests. Despite the wide diversity of Brazilian biomes and flora, relatively few types of Brazilian propolis and corresponding resin plant sources have been reported. Factors accounting for the restricted number of known types of Brazilian propolis and plant sources are tentatively pointed out. Among them, the paper discusses constraints that honey bees must overcome to collect plant exudates, including the characteristics of the lapping-chewing mouthpart of honey bee, which limit their possibilities to cut and chew plant tissues, as well as chemical requirements that plant resins must fulfil, involving antimicrobial activity of its constituents and innocuity to the insects. Although much still needs to be done toward a more comprehensive picture of Brazilian propolis types and corresponding plant origins, the prospects indicate that the actual diversity of plant sources of honey bee propolis will remain relatively low.

The Success of Topical Treatment of Onychomycosis Seems to Be Influenced by Fungal Features

Aim

To evaluate the topical treatment of onychomycosis using a 10% hydroalcoholic propolis extract (PE) in two aleatorily chosen patients and analyze possible risk factors from hosts including some particularities of the isolated fungi that may justify the outcomes achieved.

Materials and Methods

A topical treatment, with PE, was started in two cases of toe onychomycosis due to T. rubrum. The in vitro PE antifungal activity against these isolates was confirmed. Moreover, the ability of the fungi to infect the human nail was evaluated also in an ex vivo study, analyzed by histopathology.

Results

Within four months, both patients showed evident improvement, but with different outcomes. The possible host-related risk factors justifying the poorer outcome in patient 1 include a longer duration time of onychomycosis (50 years). Some particularities in the T. rubrum strain isolated from this patient in relation to that found in patient 2 were observed: (1) the hypha morphology suggesting a major adaptation of the fungus to the host; (2) a 16 times greater propolis concentration was required in vitro; and (3) a faster ability to start a growth using the nail as the only nutritional source. Additionally, this isolate was more efficient in producing a biofilm on the nail surface.

Conclusions

A partial clinical and complete mycological cure for the two patients was achieved after four months of PE daily use. Despite a complete recovery, a different outcome was observed between both cases. A more persistent onychomycosis, added to greater fungal potential to produce biofilm on the nail, seems to influence greatly the success of a topical treatment with PE.

Antimicrobial properties, mechanics, and fluoride release of ionomeric cements modified by red propolis

OBJECTIVES

To evaluate the antimicrobial activity, mechanical properties, and fluoride release capacity of glass ionomer cement (GIC) used for cementing orthodontic bands and modified by ethanolic extract of red propolis (EERP) in different concentrations.

MATERIALS AND METHODS

Two orthodontic GICs containing EERP at 10%, 25%, and 50%, were used. The following assays were carried out: cell viability tests against Streptococcus mutans and Candida albicans, diametral tensile strength, compressive strength, shear bond strength, microhardness, and fluoride release capacity. The statistical analyses of the antimicrobial tests, fluoride release, diametral tensile strength, compressive strength, and microhardness were performed using two-way analysis of variance and Tukey test (P < .05). Shear bond strength data were analyzed using one-way analysis of variance followed by Tukey test (P < .05).

RESULTS

At the concentrations of 25% and 50%, EERP was shown to be a promising antimicrobial agent incorporated into GICs against C albicans (P < .001) and S mutans (P < .001). The fluoride release capacity of the GICs was not affected, and the EERP concentration of 25% was the one that least affected the mechanical properties of the cements (P > .05).

CONCLUSIONS

The GICs containing EERP at 25% showed a significant increase in their antimicrobial activity against S mutans and C albicans, while mechanical properties and fluoride release remained without significant changes.

Antiviral, Antibacterial, Antifungal, and Antiparasitic Properties of Propolis: A Review

Propolis is a complex phytocompound made from resinous and balsamic material harvested by bees from flowers, branches, pollen, and tree exudates. Humans have used propolis therapeutically for centuries. The aim of this article is to provide comprehensive review of the antiviral, antibacterial, antifungal, and antiparasitic properties of propolis. The mechanisms of action of propolis are discussed. There are two distinct impacts with regards to antimicrobial and anti-parasitic properties of propolis, on the pathogens and on the host. With regards to the pathogens, propolis acts by disrupting the ability of the pathogens to invade the host cells by forming a physical barrier and inhibiting enzymes and proteins needed for invasion into the host cells. Propolis also inhibits the replication process of the pathogens. Moreover, propolis inhibits the metabolic processes of the pathogens by disrupting cellular organelles and components responsible for energy production. With regard to the host, propolis functions as an immunomodulator. It upregulates the innate immunity and modulates the inflammatory signaling pathways. Propolis also helps maintain the host's cellular antioxidant status. More importantly, a small number of human clinical trials have demonstrated the efficacy and the safety of propolis as an adjuvant therapy for pathogenic infections.

Highly efficient antibiofilm and antifungal activity of green propolis against Candida species in dentistry materials

This study evaluated the effect of green propolis extract on the adhesion and biofilm formation of Candida species in dentistry materials. Phytochemical analysis of green propolis extract was performed by high-performance liquid chromatography. Adhesion was quantified by counting the number of yeast cells adherent to dental material fragments in a Neubauer chamber. Biofilm formation was determined by counting colony-forming units recovered from dental material fragments. The intensity of biofilm adhesion was classified as negative, weak, moderate, strong, or very strong. Fifteen compounds, mainly flavonoids, were identified in green propolis extract. All strains adhered to and formed biofilms on the surfaces of the orthodontic materials studied. On steel and resin, yeast cell adhesion intensities were weak at all incubation times, except for those of Candida parapsilosis and C. tropicalis, which were moderate at 12 h. At 24 and 48 h, C. albicans formed biofilms on steel with moderate adhesion affinities; at 24 and 48 h, C. parapsilosis formed biofilms with very strong affinities. C. tropicalis formed biofilms with strong and very strong affinities at 24 and 48 h, respectively. On resin, all species displayed strong affinity for biofilm formation at 24 and 48 h, except for C. tropicalis, which displayed very strong affinity at only 48 h. Green propolis extract displayed antifungal activity and inhibited both adhesion and biofilm formation at 2.5 μg/mL. This study reinforces the idea that green propolis has antifungal activity and interferes with the virulence of Candida species.

In Vitro Antifungal and Antivirulence Activities of Biologically Synthesized Ethanolic Extract of Propolis-Loaded PLGA Nanoparticles against Candida albicans

Propolis is a natural substance and consists of bioactive compounds, which gives it antioxidant and antimicrobial properties. However, the use of propolis is limited by the low solubility in aqueous solutions. Thus, nanoparticles may be likely to accomplish enhanced delivery of poorly water-soluble phytomedicine. The aim of the present study was to fabricate and evaluate the biological activity of ethanolic extract of propolis-loaded poly(lactic-co-glycolic acid) nanoparticles (EEP-NPs). The EEP-NPs were prepared using the oil-in-water (o/w) single-emulsion solvent evaporation technique. The physicochemical properties of EEP-NPs were characterized and tested on their cytotoxicity, antifungal activity, and impact on key virulence factors that contribute to pathogenesis of C. albicans. EEP-NPs were successfully synthesized and demonstrated higher antifungal activity than EEP in free form. Moreover, EEP-NPs exhibited less cytotoxicity on Vero cells and suppressed the virulence factors of C. albicans, including adhesion, hyphal germination, biofilm formation, and invasion. Importantly, EEP-NPs exhibited a statistical decrease in the expression of hyphal adhesion-related genes, ALS3 and HWP1, of C. albicans. The results of this study revealed that EEP-NPs mediates a potent anticandidal activity and key virulence factors by reducing the gene-encoding virulence-associated hyphal- adhesion proteins of C. albicans and, thereby, disrupting the morphologic presence and attenuating their virulence.

Getting the Jump on the Development of Bullfrog Oil Microemulsions: a Nanocarrier for Amphotericin B Intended for Antifungal Treatment

Amphotericin B (AmB), a potent antifungal drug, presents physicochemical characteristics that impair the development of suitable dosage forms. In order to overcome the AmB insolubility, several lipid carriers such as microemulsions have been developed. In this context, the bullfrog oil stands out as an eligible oily phase component, since its cholesterol composition may favor the AmB incorporation. Thus, the aim of this study was to develop a microemulsion based on bullfrog oil containing AmB. Moreover, its thermal stability, antifungal activity, and cytotoxicity in vitro were evaluated. The microemulsion formulation was produced using the pseudo-ternary phase diagram (PTPD) approach and the AmB was incorporated based on the pH variation technique. The antifungal activity was evaluated by determination of minimal inhibitory concentration (MIC) against different species of Candida spp. and Trichosporon asahii. The bullfrog oil microemulsion, stabilized with 16.8% of a surfactant blend, presented an average droplet size of 26.50 ± 0.14 nm and a polydispersity index of 0.167 ± 0.006. This system was able to entrap AmB up to 2 mg mL^-1. The use of bullfrog oil as oily phase allowed an improvement of the thermal stability of the system. The MIC assay results revealed a growth inhibition for different strains of Candida spp. and were able to enhance the activity of AmB against T. asahii. The microemulsion was also able to reduce the AmB toxicity. Finally, the developed microemulsion showed to be a suitable system to incorporate AmB, improving the system's thermal stability, increasing the antifungal activity, and reducing the toxicity of this drug.

Propolis Extract for Onychomycosis Topical Treatment: From Bench to Clinic

Onychomycosis is a chronic fungal infection of nails, commonly caused by dermatophyte fungi, primarily species of Trichophyton. Because of the limited drug arsenal available to treat general fungal infections and the frequent failure of onychomycosis treatment, the search for new therapeutic sources is essential, and topical treatment with natural products for onychomycosis has been encouraged. Propolis, an adhesive resinous compound produced by honeybees (Apis mellifera), has shown multiple biological properties including significant antifungal and anti-biofilm activities in vitro. In spite of promising in vitro results, in vivo results have not been reported so far. This study assessed an ethanol propolis extract (PE) as a topical therapeutic option for onychomycosis, including its characterization in vitro and its applicability as a treatment for onychomycosis (from bench to clinic). The in vitro evaluation included analysis of the cytotoxicity and the antifungal activity against the planktonic cells and biofilm formed by Trichophyton spp. We also evaluated the capacity of PE to penetrate human nails. Patients with onychomycosis received topical PE treatments, with a 6-month follow-up period. The results of the in vitro assays showed that PE was non-toxic to the cell lines tested, and efficient against both the planktonic cells and the biofilm formed by Trichophyton spp. The results also showed that PE is able to penetrate the human nail. The results for PE applied topically to treat onychomycosis were promising, with complete mycological and clinical cure of onychomycosis in 56.25% of the patients. PE is an inexpensive commercially available option, easy to obtain and monitor. Our results indicated that PE is a promising natural compound for onychomycosis treatment, due to its ability to penetrate the nail without cytotoxicity, and its good antifungal performance against species such as Trichophyton spp. that are resistant to conventional antifungals, both in vitro and in patients.

Propolis: A natural biomaterial for dental and oral healthcare

The field of health has always emphasised on the use of natural products for curing diseases. There are varieties of natural products (such as silk, herbal tea, chitosan) used today in the biomedical application in treating a large array of systemic diseases. The natural product "Propolis" is a non-toxic resinous material having beneficial properties such as antimicrobial, anticancer, antifungal, antiviral and anti-inflammatory; hence gain the attention of researchers for its potential for bio-dental applications. The study aims to explore the properties and chemistry of propolis concerning biomedical and dental applications. In addition, status and scope of propolis for current and potential future in bio-dental applications have been discussed. This review gives an insight to the reader about the possible use of propolis in modern-day dentistry.

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.

Antifungal activity and influence of propolis against germ tube formation as a critical virulence attribute by clinical isolates of Candida albicans

OBJECTIVE

The potentiality to switch between yeast and hyphal morphologies plays an important role in the virulence of Candida albicans (C. albicans). The objective of the present study was to evaluate the chemical composition, antifungal activity and influence of propolis upon germ tube formation of C. albicans clinical isolates.

METHODS

The major compounds of propolis ethanolic extract (PEE) was revealed by gas chromatography-mass spectrometry (GC/MS) analysis. Broth microdilution method was used for determination of minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of this extract. C. albicans isolates were exposed to sub-MIC concentrations of propolis and germ tube reduction percent (GRP) and morphological transition from yeast to filamentous form were monitored microscopically.

RESULTS

Phenolic compounds, aromatic acids, aliphatic acids, sugars and polycyclic aromatic hydrocarbons were the major compound classes in PEE. Mean of MIC and MFC values of PEE against C. albicans isolates were 360.6μg·mL^-1 and 1250.1μg·mL^-1, respectively. The increase in concentration led to a significant reduction in germ tube formation, so mean of GRP was 36.7±11.1 and 22±10.1 at concentration of ½ MIC and ¼ MIC of PEE, respectively.

CONCLUSIONS

In conclusion, the present study indicated that PEE has interesting potential as a therapeutic agent that targets germ tube formation by C. albicans as a critical virulence factor.

Antifungal activity of propolis against Candida species isolated from cases of chronic periodontitis

This research evaluated the fungistatic and fungicidal activities of red propolis alcoholic extract (RPAE) against different Candida species isolated from chronic periodontitis cases, and compared with chlorhexidine (CHX). Nineteen samples of Candida species (C. albicans [n = 12], C. tropicalis [n = 5] and C. glabrata [n = 2]) isolated from chronic periodontitis cases were analyzed. The fungistatic and fungicidal activity of both RPAE and CHX were evaluated using fluconazole and C. parapsilosis (ATCC 6258) as a control. Fungistatic activity was analyzed based on the Clinical and Laboratory Standards Institute (CLSI) reference procedure to determine the minimum inhibitory concentrations. Fungicidal activity was established according to the absence of fungal growth on Sabouraud Dextrose Agar medium. The fungistatic and fungicidal activities of RPAE were observed, respectively, at 32-64 μg/mL and 64-512 μg/mL for C. albicans, 64 μg/mL and 64-256 μg/mL for C. glabrata, and 32-64 μg/mL and 64 µg/mL for C. tropicalis. CHX fungistatic activity was observed at concentrations of 0.003-1.92 µg/mL for C. albicans, 1.92 µg/mL for C. glabrata, and 0.03-1.92 µg/mL for C. tropicalis. Fluconazole fungistatic activity ranged between 1-64 μg/mL, and fungicidal activity occurred at 8-64 μg/mL, for the three Candida species analyzed. All the Candida species were susceptible to RPAE antifungal activity, but five samples of C. albicans, one of C. tropicalis and one of C. glabrata were resistant to fluconazole antifungal activity. CHX showed fungistatic activity against all the Candida species analyzed. The antifungal potential of these substances suggests that they can be applied as an alternative treatment for diseases affected by these species.

Potentiating antimicrobial efficacy of propolis through niosomal-based system for administration

Background

Propolis is a multicomponent active, complex resinous substance collected by honeybees (Apis mellifera) from a variety of plant sources. This study was designed to improve the antimicrobial efficacy of propolis by engineering a niosomal-based system for topical application.

Methods

Propolis was extracted in ethanol and screened for total polyphenol content. Propolis-loaded niosomes (PLNs) were prepared with varying concentrations of Span 60 and cholesterol. The PLNs were evaluated for physicochemical parameters, namely, vesicle size, entrapment efficiency, zeta potential, surface topography and shape, and stability, followed by screening for in vitro antimicrobial activity. The PLNs were formulated into propolis niosomal gel (PNG) using Carbopol P934 base and subjected to ex vivo skin deposition study.

Results

The ethanolic extract of propolis had high polyphenolic content (270 ± 9.2 mg GAE/g). The prepared PLNs showed vesicle size between 294 nm and 427 nm, and the percent entrapment in the range of 50.62–71.29% with a significant enhancement in antimicrobial activity against Staphylococcus aureus and Candida albicans. Enhanced antimicrobial activity of PLNs was attributed to the ability of niosomes to directly interact with the bacterial cell envelop thereby facilitating the diffusion of propolis constituents across the cell wall. The formulated PNG exhibited a twofold better skin deposition due to improved retention of niosomes in the skin.

Conclusion

The findings indicate that the engineering of a niosomal-based system for propolis enhanced its antimicrobial potential through topical application.

Early state research on antifungal natural products

Nosocomial infections caused by fungi have increased greatly in recent years, mainly due to the rising number of immunocompromised patients. However, the available antifungal therapeutic arsenal is limited, and the development of new drugs has been slow. Therefore, the search for alternative drugs with low resistance rates and fewer side effects remains a major challenge. Plants produce a variety of medicinal components that can inhibit pathogen growth. Studies of plant species have been conducted to evaluate the characteristics of natural drug products, including their sustainability, affordability, and antimicrobial activity. A considerable number of studies of medicinal plants and alternative compounds, such as secondary metabolites, phenolic compounds, essential oils and extracts, have been performed. Thus, this review discusses the history of the antifungal arsenal, surveys natural products with potential antifungal activity, discusses strategies to develop derivatives of natural products, and presents perspectives on the development of novel antifungal drug candidates.

Propolis: a wonder bees product and its pharmacological potentials

Propolis is a natural resinous mixture produced by honey bees from substances collected from parts of plants, buds, and exudates. Due to its waxy nature and mechanical properties, bees use propolis in the construction and repair of their hives for sealing openings and cracks and smoothing out the internal walls and as a protective barrier against external invaders like snakes, lizards, and so forth, or against weathering threats like wind and rain. Bees gather propolis from different plants, in the temperate climate zone mainly from poplar. Current antimicrobial applications of propolis include formulations for cold syndrome (upper respiratory tract infections, common cold, and flu-like infections), wound healing, treatment of burns, acne, herpes simplex and genitalis, and neurodermatitis. Worldwide propolis has a tremendous popularity, but in India the studies over propolis have just started, not extensively reported except few regions of India like Maharashtra, West Bengal, Tamil Nadu, Gujrat, and Madhya Pradesh.

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.

Comparison of diagnostic methods in the evaluation of onychomycosis

Onychomycosis is a common nail problem, accounting for up to half of all nail diseases. Several nail disorders may mimic the onychomycosis clinically. Therefore, a sensitive, quick, and inexpensive test is essential for screening nail specimens for the administration of the proper drug. The aim of this study was to compare 4 different diagnostic methods in the evaluation of onychomycosis and to determine their sensitivity, specificity, positive predictive value, and negative predictive value. In a cross-sectional study, nail specimens were collected from 101 patients suspected to have onychomycosis during a 14-month period. The nail specimens were examined using potassium hydroxide (KOH) 20 %, KOH-treated nail clipping stained with periodic acid-Schiff (KONCPA), and calcofluor white (CFW) stain, and grew a fungal culture. The culture was chosen as the gold standard for statistical analysis using the McNemar and chi-square tests. Out of 101 patients, 100 (99 %) patients had at least 1 of the 4 diagnostic methods positive for the presence of organisms. The positive rates for the fungal culture, KOH preparation, CFW, and KONCPA were 74.2, 85.1, 91.09, and 99.01 %, respectively. The sensitivity and negative predictive value of KONCPA was 100 %. KONCPA was the most sensitive among the tests and was also superior to other methods in its negative predictive value. KONCPA was easy to perform, rapid, and gave significantly higher rates of detection of onychomycosis compared to the standard methods of KOH preparation and fungal culture. Therefore, KONCPA should be the single method of choice for the evaluation of onychomycosis.

Antimicrobial activity of Citrox bioflavonoid preparations against oral microorganisms

BACKGROUND

Citrox is a formulation of soluble bioflavonoids obtained from citrus fruits. The non-toxic and antimicrobial properties of natural bioflavonoids are well documented, and consequently there has been interest in the therapeutic application of these substances.

OBJECTIVE

To determine the antimicrobial activity of two Citrox formulations (BC30 and MDC30) with different bioflavonoid combinations against a range of oral microorganisms.

METHODS

The antimicrobial activity of both formulations was tested against 14 bacterial species and six Candida species. The two Citrox formulations (dilution range 0.007-8% v/v) were firstly evaluated by determining the in vitro Minimal Inhibitory Concentration (MIC) against planktonic microorganisms in a broth microdilution assay. Secondly, the ability of the same serial dilutions to inhibit microbial growth was assessed in a modified microtitre biofilm assay.

RESULTS

Both Citrox formulations exhibited antimicrobial activity. The BC30 formulation demonstrated greater activity than MDC30 and significantly inhibited growth of all bacterial species and most candidal species tested at a concentration of 1% (v/v) in both the broth and the biofilm assay.

CONCLUSION

Bioflavonoid preparations of Citrox have a broad-spectrum of antimicrobial activity against oral microorganisms, and as such have the potential to be used within therapeutic preparations for the control of the oral microflora.

Antifungal Activity of Brazilian Propolis Microparticles against Yeasts Isolated from Vulvovaginal Candidiasis

Propolis, a resinous compound produced by Apis mellifera L. bees, is known to possess a variety of biological activities and is applied in the therapy of various infectious diseases. The aim of this study was to evaluate the in vitro antifungal activity of propolis ethanol extract (PE) and propolis microparticles (PMs) obtained from a sample of Brazilian propolis against clinical yeast isolates of importance in the vulvovaginal candidiasis (VVC). PE was used to prepare the microparticles. Yeast isolates (n = 89), obtained from vaginal exudates of patients with VVC, were exposed to the PE and the PMs. Moreover, the main antifungal drugs used in the treatment of VVC (Fluconazole, Voriconazole, Itraconazole, Ketoconazole, Miconazole and Amphotericin B) were also tested. Minimum inhibitory concentration (MIC) was determined according to the standard broth microdilution method. Some Candida albicans isolates showed resistance or dose-dependent susceptibility for the azolic drugs and Amphotericin B. Non-C. albicans isolates showed more resistance and dose-dependent susceptibility for the azolic drugs than C. albicans. However, all of them were sensitive or dose-dependent susceptible for Amphotericin B. All yeasts were inhibited by PE and PMs, with small variation, independent of the species of yeast. The overall results provided important information for the potential application of PMs in the therapy of VVC and the possible prevention of the occurrence of new symptomatic episodes.

Antifungal activity of propolis extract against yeasts isolated from vaginal exudates

OBJECTIVE

The objective of this study was to evaluate the in vitro antifungal activity of propolis extract against yeasts Candida albicans and Candida non-albicans isolated from vaginal exudates, in comparison with nystatin.

DESIGN

Ninety-seven (97) vaginal yeasts strains were evaluated. These strains were obtained from different clinical conditions, isolated and stored at the Sector of Medical Mycology of the State University of Maringá (Paraná, Brazil). The assays of susceptibility to nystatin and propolis extracts (PE) were conducted through microdilution in broth (National Committee for Clinical Laboratory Standards-NCCLS, M-27A Document of 1997).

RESULTS

All the yeasts tested were inhibited by low concentrations of PE (maximum of 393.19 mug/mL of the total flavonoid content), including an isolate resistant to nystatin, regardless of the clinical conditions of the women and the species of yeast isolated.

CONCLUSIONS

The PE showed an outstanding performance against the tested vaginal yeast strains, and could be included among the novel therapeutic options for the treatment of vulvovaginal candidiasis.

Candida parapsilosis: a review of its epidemiology, pathogenesis, clinical aspects, typing and antimicrobial susceptibility

The Candida parapsilosis family has emerged as a major opportunistic and nosocomial pathogen. It causes multifaceted pathology in immuno-compromised and normal hosts, notably low birth weight neonates. Its emergence may relate to an ability to colonize the skin, proliferate in glucose-containing solutions, and adhere to plastic. When clusters appear, determination of genetic relatedness among strains and identification of a common source are important. Its virulence appears associated with a capacity to produce biofilm and production of phospholipase and aspartyl protease. Further investigations of the host-pathogen interactions are needed. This review summarizes basic science, clinical and experimental information about C. parapsilosis.

Ação terapêutica da própolis em lesões cutâneas

Trata-se de uma revisão integrativa da literatura que teve como objetivo analisar os estudos que abordam o uso terapêutico da própolis em lesões cutâneas. Os dados foram obtidos por meio de busca nas bases de dados LILACS, MEDLINE, e BDENF, abrangendo o período de 1980 a 2007, nos idiomas português, inglês e espanhol. Identificaram-se 1127 artigos, dos quais 38 atenderam aos critérios de inclusão deste estudo. Destes artigos, 7 (18,4%) eram estudos clínicos e 31 (81,6%) experimentais "in vitro" e em animais. Quanto à abordagem, foram classificados em dois focos temáticos: atuação terapêutica da própolis na cicatrização das lesões e ação antimicrobiana da própolis. A análise dos trabalhos destacou a eficácia da própolis no tratamento de feridas, atuando como agente cicatrizante e antimicrobiano natural, cujas propriedades dependem diretamente da forma e local de extração e concentração do produto.

Trichophyton species susceptibility to green and red propolis from Brazil

AIMS

The in vitro antifungal activity of Brazilian green and red propolis was tested against different species of Trichophyton.

METHODS AND RESULTS

The antifungal activity of the Brazilian aqueous and alcoholic extracts of the green propolis and the alcoholic extract of red propolis was observed against Trichophyton rubrum, Trichophyton tonsurans and Trichophyton mentagrohytes samples, using as controls itraconazole and terbinafine. The minimal inhibitory concentration was determined following the microdilution method indicated by the 'Clinical and Laboratory Standards Institute'. The minimal fungicide concentration was determined by the absence of growth in liquid sabouraud culture medium. The data obtained showed that the green propolis alcoholic extract's antifungal activity was from 64 to 1024 microg ml(-1), whereas the red propolis alcoholic extract was from 8 to 1024 microg ml(-1).

CONCLUSIONS

The antifungal activity of the red propolis alcoholic extract was more efficient than the green propolis alcoholic extract for all three species studied. The T. rubrum samples were shown to be more sensitive to the antifungal activity of the alcoholic extracts of the propolis.

SIGNIFICANCE AND IMPACT OF THE STUDY

The antifungal potential of the alcoholic extracts of green and red propolis demonstrated suggest an applicable potential as an alternative treatment for dermatophytosis caused by these species.

Synthesis and antifungal activity of some new 3-hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl) chromones

Seven new 3-hydroxy-2-(1-phenyl-3-aryl-4-pyrazolyl) chromones 4a-g have been synthesized by the oxidation of 2-hydroxychalcone analogues of pyrazole 3a-g with hydrogen peroxide (H(2)O(2)) in KOH-MeOH by Algar Flynn Oymanda (AFO) reaction. The structures of the compounds 4 were established by the combined use of (1)H NMR, IR and mass spectra. All the seven compounds were tested in vitro for their antifungal activity against three phytopathogenic fungi, namely Helminthosporium species, Fusarium oxysporum and Alternaria alternata. Five compounds 4a, 4b, 4c, 4e and 4f were associated with substantially higher antifungal activity than commercial antifungal compound Actidione (cycloheximide) against all three phytopathogenic fungi.

Brazilian green propolis on Helicobacter pylori infection. a pilot clinical study

Recent in vitro studies suggest that propolis and some of its phenolic components are able to inhibit Helicobacter pylori growth. To date, there are no clinical studies.

AIMS

To evaluate the effect of Brazilian green propolis on H. pylori-infected individuals.

PATIENTS AND METHODS

Eighteen (11 females, 7 males, mean age 47 years) participants were included. Before treatment, all participants were submitted to gastroscopy, and H. pylori infection was confirmed by histology, urease test, and (13)C-urea breath test (UBT). Participants with UBT showing a delta over baseline (DOB) value higher than 4 per thousand were considered positive for H. pylori infection. Twenty drops from an alcoholic preparation of Brazilian green propolis were administered three times a day for 7 days. Clinical evaluation and UBT were performed at 1-3 days and at 40 days after the end of therapy to evaluate H. pylori suppression or eradication, respectively.

RESULTS

All participants took all medication and completed the study. Eighty-three percent of the subjects did not succeed in suppressing or eradicating H. pylori. Two participants reached partial suppression after treatment, but became positive again at UBT performed 40 days after treatment. Another participant presented negative at UBT 40 days after treatment, not confirmed by a second UBT performed 100 days after treatment.

CONCLUSIONS

Brazilian green propolis used in popular dose showed minimal effect on H. pylori infection. Larger studies with longer duration, larger dose, and different frequency of administration of propolis extract should be undertaken to define its role on H. pylori therapy.

Freqüência de onicomicoses por leveduras em Maringá, Paraná, Brasil

FUNDAMENTOS: Onicomicoses são afecções ungueais de origem infecciosa causadas por fungos e estão entre as principais onicopatias em todo o mundo. OBJETIVOS: Determinar a freqüência de leveduras como agentes etiológicos de onicomicoses na cidade de Maringá, PR, Brasil. MATERIAL E MÉTODOS: Realizou-se um estudo retrospectivo do período entre janeiro de 1997 e dezembro de 2004, em que foram avaliados os resultados de 1.295 pacientes com suspeita de onicomicose, recebidos no Laboratório de Ensino e Pesquisa em Análises Clínicas da Universidade Estadual de Maringá, Paraná, Brasil. RESULTADOS: A confirmação micológica de onicomicose ocorreu em 761 (58,76%) desses pacientes. As mulheres foram responsáveis por 71% das onicomicoses, e os homens, por 29%. A prevalência nas unhas das mãos foi de 28,67% e nas unhas dos pés, 71,33%. Em relação aos agentes, as leveduras foram mais freqüentemente isoladas (46,39%), seguidas pelos dermatófitos (40,60%) e pelos fungos filamentosos não dermatófitos (13,01%). CONCLUSÃO: A alta freqüência de fungos leveduriformes em onicomicoses indica aprimoramento nas técnicas diagnósticas de confirmação laboratorial de fungos oportunistas. Esses resultados, associados à abordagem clínica do paciente, possibilitam maior segurança no diagnóstico e tratamento.