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

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.

Inhibition of pathogenic microbes in oral infectious diseases by natural products: Sources, mechanisms, and challenges

The maintenance of oral health is of utmost importance for an individual's holistic well-being and standard of living. Within the oral cavity, symbiotic microorganisms actively safeguard themselves against potential foreign diseases by upholding a multifaceted equilibrium. Nevertheless, the occurrence of an imbalance can give rise to a range of oral infectious ailments, such as dental caries, periodontitis, and oral candidiasis. Presently, clinical interventions encompass the physical elimination of pathogens and the administration of antibiotics to regulate bacterial and fungal infections. Given the limitations of various antimicrobial drugs frequently employed in dental practice, the rising incidence of oral inflammation, and the escalating bacterial resistance to antibiotics, it is imperative to explore alternative remedies that are dependable, efficacious, and affordable for the prevention and management of oral infectious ailments. There is an increasing interest in the creation of novel antimicrobial agents derived from natural sources, which possess attributes such as safety, cost-effectiveness, and minimal adverse effects. This review provides a comprehensive overview of the impact of natural products on the development and progression of oral infectious diseases. Specifically, these products exert their influences by mitigating dental biofilm formation, impeding the proliferation of oral pathogens, and hindering bacterial adhesion to tooth surfaces. The review also encompasses an examination of the various classes of natural products, their antimicrobial mechanisms, and their potential therapeutic applications and limitations in the context of oral infections. The insights garnered from this review can support the promising application of natural products as viable therapeutic options for managing oral infectious diseases.

Therapeutic Management of Malignant Wounds: An Update

OPINION STATEMENT

Malignant fungating wounds (MFW) are severe skin conditions generating tremendous distress in oncological patients with advanced cancer stages because of pain, malodor, exudation, pruritus, inflammation, edema, and bleeding. The classical therapeutic approaches such as surgery, opioids, antimicrobials, and application of different wound dressings are failing in handling pain, odor, and infection control, thus urgently requiring the development of alternative strategies. The aim of this review was to provide an update on the current therapeutic strategies and the perspectives on developing novel alternatives for better malignant wound management. The last decade screened literature evidenced an increasing interest in developing natural treatment alternatives based on beehive, plant extracts, pure vegetal compounds, and bacteriocins. Promising therapeutics can also be envisaged by involving nanotechnology due to either intrinsic biological activities or drug delivery properties of nanomaterials. Despite recent progress in the field of malignant wound care, the literature is still mainly based on in vitro and in vivo studies on small animal models, while the case reports and clinical trials (less than 10 and only one providing public results) remain scarce. Some innovative treatment approaches are used in clinical practice without prior extensive testing in fungating wound patients. Extensive research is urgently needed to fill this knowledge gap and translate the identified promising therapeutic approaches to more advanced testing stages toward creating multidimensional wound care strategies.

Activity of propolis from Mexico on the proliferation and virulence factors of Candida albicans

BACKGROUND

This research evaluated the anti-Candida albicans effect of Mexican propolis from Chihuahua. Chemical composition of the ethanolic extract of propolis was determined by GC-MS, HPLC-DAD, and HPLC-MS. The presence of anthraquinone, aromatic acid, fatty acids, flavonoids, and carbohydrates was revealed.

RESULTS

The anti-Candida activity of propolis was determined. The inhibitions halos were between 10.0 to 11.8 mm; 25% minimum inhibitory concentration (0.5 mg/ml) was fungistatic, and 50% minimum inhibitory concentration (1.0 mg/ml) was fungicidal. The effect of propolis on the capability of C. albicans to change its morphology was evaluated. 25% minimum inhibitory concentration inhibited to 50% of germ tube formation. Staining with calcofluor-white and propidium iodide was performed, showing that the propolis affected the integrity of the cell membrane. INT1 gene expression was evaluated by qRT-PCR. Propolis significantly inhibited the expression of the INT1 gene encodes an adhesin (Int1p). Chihuahua propolis extract inhibited the proliferation of Candida albicans, the development of the germ tube, and the synthesis of adhesin INT1.

CONCLUSIONS

Given the properties demonstrated for Chihuahua propolis, we propose that it is a candidate to be considered as an ideal antifungal agent to help treat this infection since it would not have the toxic effects of conventional antifungals.

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.

Apitherapy and Periodontal Disease: Insights into In Vitro, In Vivo, and Clinical Studies

Periodontal diseases are caused mainly by inflammation of the gums and bones surrounding the teeth or by dysbiosis of the oral microbiome, and the Global Burden of Disease study (2019) reported that periodontal disease affects 20-50% of the global population. In recent years, more preference has been given to natural therapies compared to synthetic drugs in the treatment of periodontal disease, and several oral care products, such as toothpaste, mouthwash, and dentifrices, have been developed comprising honeybee products, such as propolis, honey, royal jelly, and purified bee venom. In this study, we systematically reviewed the literature on the treatment of periodontitis using honeybee products. A literature search was performed using various databases, including PubMed, Web of Science, ScienceDirect, Scopus, clinicaltrials.gov, and Google Scholar. A total of 31 studies were reviewed using eligibility criteria published between January 2016 and December 2021. In vitro, in vivo, and clinical studies (randomized clinical trials) were included. Based on the results of these studies, honeybee products, such as propolis and purified bee venom, were concluded to be effective and safe for use in the treatment of periodontitis mainly due to their antimicrobial and anti-inflammatory activities. However, to obtain reliable results from randomized clinical trials assessing the effectiveness of honeybee products in periodontal treatment with long-term follow-up, a broader sample size and assessment of various clinical parameters are needed.

Propolis characterization and antimicrobial activities against Staphylococcus aureus and Candida albicans: A review

Propolis is a plant-based sticky substance that is produced by honeybees. It has been used traditionally by ancient civilizations as a folk medicine, and is known to have many pharmaceutical properties including antioxidant, antibacterial, antifungal, anti-inflammatory, antiviral, and antitumour effects. Worldwide, researchers are still studying the complex composition of propolis to unveil its biological potential, and especially its antimicrobial activity against a variety of multidrug-resistant microorganisms. This review explores scientific reports published during the last decade on the characterization of different types of propolis, and evaluates their antimicrobial activities against Staphylococcus aureus and Candida albicans. Propolis can be divided into different types depending on their chemical composition and physical properties associated with geographic origin and plant sources. Flavonoids, phenols, diterpenes, and aliphatic compounds are the main chemicals that characterize the different types of propolis (Poplar, Brazilian, and Mediterranean), and are responsible for their antimicrobial activity. The extracts of most types of propolis showed greater antibacterial activity against Gram-positive bacteria: particularly on S. aureus, as well as on C. albicans, as compared to Gram-negative pathogens. Propolis acts either by directly interacting with the microbial cells or by stimulating the immune system of the host cells. Some studies have suggested that structural damage to the microorganisms is a possible mechanism by which propolis exhibits its antimicrobial activity. However, the mechanism of action of propolis is still unclear, due to the synergistic interaction of the ingredients of propolis, and this natural substance has multi-target activity in the cell. The broad-spectrum biological potentials of propolis present it as an ideal candidate for the development of new, potent, and cost-effective antimicrobial agents.

Chemical Variability and Pharmacological Potential of Propolis as a Source for the Development of New Pharmaceutical Products

This review aims to analyze propolis as a potential raw material for the development and manufacture of new health-promoting products. Many scientific publications were retrieved from the Scopus, PubMed, and Google Scholar databases via searching the word "propolis". The different extraction procedures, key biologically active compounds, biological properties, and therapeutic potential of propolis were analyzed. It was concluded that propolis possesses a variety of biological properties because of a very complex chemical composition that mainly depends on the plant species visited by bees and species of bees. Numerous studies found versatile pharmacological activities of propolis: antimicrobial, antifungal, antiviral, antioxidant, anticancer, anti-inflammatory, immunomodulatory, etc. In this review, the composition and biological activities of propolis are presented from a point of view of the origin and standardization of propolis for the purpose of the development of new pharmaceutical products on its base. It was revealed that some types of propolis, especially European propolis, contain flavonoids and phenolic acids, which could be markers for the standardization and quality evaluation of propolis and its preparations. One more focus of this paper was the overview of microorganisms' sensitivity to propolis for further development of antimicrobial and antioxidant products for the treatment of various infectious diseases with an emphasis on the illnesses of the oral cavity. It was established that the antimicrobial activity of different types of propolis is quite significant, especially to Gram-negative bacteria and lipophilic viruses. The present study could be also of interest to the pharmaceutical industry as a review for the appropriate design of standardized propolis preparations such as mouthwashes, toothpastes, oral drops, sprays, creams, ointments, suppositories, tablets, and capsules, etc. Moreover, propolis could be regarded as a source for the isolation of biologically active substances. Furthermore, this review can facilitate partially overcoming the problem of the standardization of propolis preparations, which is a principal obstacle to the broader use of propolis in the pharmaceutical industry. Finally, this study could be of interest in the area of the food industry for the development of nutritionally well-balanced products. The results of this review indicate that propolis deserves to be better studied for its promising therapeutic effects from the point of view of the connection of its chemical composition with the locality of its collection, vegetation, appropriate extraction methods, and standardization.

Activity of Fusarium oxysporum-Based Silver Nanoparticles on Candida spp. Oral Isolates

Candida spp. resistant to commercially available antifungals are often isolated from patients with oral candidiasis, a situation that points to the need for the development of new therapies. Thus, we evaluated the activity of Fusarium oxysporum-based silver nanoparticles (AgNPs) on Candida spp. isolated from denture stomatitis lesions. Candida isolates were molecularly identified and submitted to susceptibility assays using AgNPs and commercial fungicides. The interference on biofilm formation and the mechanisms of action of AgNPs on Candida spp. were also investigated. Scanning electron microscopy was used to evaluate the morphology of AgNP-treated Candida. Candida albicans was the most frequent species isolated from denture stomatitis cases. All Candida spp. were susceptible to AgNPs at low concentrations, except Candida parapsilosis. AgNPs caused surface damage, cell disruption, and biofilm formation inhibition. The ergosterol supplementation protected C. albicans against the AgNP action. AgNPs are effective against Candida spp. and can be faced as a promising new therapeutic agent against oral candidiasis.

Clinical Anti-aging Efficacy of Propolis Polymeric Nanoparticles Prepared by a Temperature-induced Phase Transition Method

BACKGROUND

Collagen forms a dermal matrix in the skin. Biosynthesis and decomposition of collagen are the major processes in skin aging. Propolis is rich in flavonoids and phenolic compounds, which are known to be effective in preventing skin aging, including the enhancement of fibroblast proliferation, activation, and growth capacity.

OBJECTIVES

The aim of this study was to develop a poorly soluble propolis extract as an active ingredient in cosmetic products for anti-aging efficacy.

METHODS & RESULTS

Polymeric nanoparticles containing propolis extract, polyethylene glycol 400, and poloxamer 407 were prepared via a temperature-induced phase transition method. The particle size of the polymeric nanoparticles was approximately 20.75 nm. The results of an in vitro procollagen type I carboxy-terminal peptide assay and a matrix metalloproteinase-1 inhibition assay showed that the polymeric nanoparticles increased collagen production by 19.81%-24.59% compared to blank (p < 0.05), and significantly reduced intracellular collagenase activity by 7.46%-31.52% compared to blank (p < 0.05). In a clinical trial, polymeric nanoparticles in a cosmetic formulation were applied around the eyes of 24 female subjects for 8 weeks. Five skin parameters were significantly improved after the application of the test ampoule. Visual evaluation using the Global Photo Damage Score showed a significant reduction in wrinkles after the application of the test ampoules (p < 0.001).

CONCLUSIONS

This study outlines the development of stable polymeric nanoparticles containing poorly soluble propolis in a cosmetic formulation, and its efficacy in wrinkle improvement. The developed polymeric nanoparticles were effective for alleviating wrinkles and can be used for pharmaceutical applications that utilize propolis as antiseptic, anti-inflammatory, antimycotic, antifungal, antibacterial, antiulcer, anticancer, and immunomodulatory agents.

Activity of antifungal drugs and Brazilian red and green propolis extracted with different methodologies against oral isolates of Candida spp

Background

Oral candidiasis is an opportunistic disease caused by fungi of the Candida genus. The occurrence of Candida spp. resistance to the commercial antifungal drugs points to the search for alternative treatments. Propolis has been successfully used in the treatment of infectious diseases for centuries. It has been proposed that an ultrasound pretreatment in the propolis extraction protocol can enhance the concentrations of molecules with antimicrobial activities in the final extract. Thus, this study aimed to compare the antifungal activity against oral Candida spp. isolates of green and red propolis extracts submitted or not to an ultrasound pretreatment before the extraction procedure.

Methods

Candida spp. were isolated from denture stomatitis lesions and identified by sequencing. Oral Candida spp. isolates and reference strains were submitted to broth microdilution assays using commercial antifungals and Brazilian green and red propolis extracts submitted or not to an ultrasound pretreatment. Minimal Inhibitory Concentrations (MIC) and Minimal Fungicide Concentrations (MFC) were determined and biofilm formation interference was evaluated for resistant isolates.

Results

C. albicans, Candida tropicalis and Candida dubliniensis were isolated from denture stomatitis lesions. Growth inhibition was observed in all Candida isolates incubated with all green and red propolis extracts. At lower doses, red propolis extracts presented significant antifungal activity. The ultrasound pretreatment did not promote an increase in the antifungal activity of green or red propolis. Three isolates, which were highly resistant to fluconazole and itraconazole, were susceptible to low doses of red propolis extracts. These same three specimens had their biofilm formation inhibted by red propolis ethanolic extract.

Conclusions

Thus, red propolis can be faced as a promising natural product to be used in the auxiliary antifungal therapy of denture stomatitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03445-5.

Natural Compounds for Preventing Ear, Nose, and Throat-Related Oral Infections

Oral health is an essential element in maintaining general well-being. By preserving the complex equilibrium within the oral microbial community, commensal microorganisms can protect against extrinsic pathogenic threats. However, when an imbalance occurs, the organism is susceptible to a broad range of infections. Synthetic drugs can be administered to help the body fight against the fungal, bacterial, or viral burden. Nonetheless, they may produce undesirable consequences such as toxicity, adverse effects, and drug resistance. In this respect, research has focused on finding safer and more efficient alternatives. Particularly, increasing attention has been drawn towards developing novel formulations based on natural compounds. This paper reviews the plant-based, algae-based, and beehive products investigated for their antimicrobial properties, aiming to thoroughly present the state of the art on oral infection prevention in the ear, nose, and throat (ENT) field.

Evaluation of Stabilized Chlorine Dioxide in Terms of Antimicrobial Activity and Dentin Bond Strength

BACKGROUND

Antimicrobial agents are recommended for disinfection of the cavity following mechanical dental caries removal prior to application of restorative material. There is limited information about stabilized chlorine dioxide (ClO2) as a cavity disinfectant.

OBJECTIVE

The objective of this study is to determine the antimicrobial activity and effect on dentin bond strength of ClO2 compared to chlorhexidine digluconate (CHX), sodium hypochlorite (NaOCl) and ethanolic propolis extract (EPE).

METHODS

Antimicrobial activities of agents against oral pathogens (Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, Candida albicans, and Saccharomyces cerevisiae) and analyses of EPE were examined. Seventy-five mandibular third molars were sectioned, prepared and divided into five subgroups (n=15/group). Cavity disinfectants (2% CHX, 2.5% NaOCl, 30% EPE, 0.3% ClO2) were applied to etched dentin prior to adhesive and composite build-up. Shear bond strength (SBS) was evaluated with a universal testing machine at a crosshead speed of 0.5 mm/min. The SBS data were analyzed with one-way analysis of variance (ANOVA) and Tukey's post-hoc test (p <0.05). The failure modes were evaluated with a stereomicroscope.

RESULTS

It was determined that the compared disinfectants were showed different inhibition zone values against oral pathogens. ClO2 exhibited the highest antimicrobial activity, followed by CHX, NaOCI and EPE, respectively. No statistically significant difference was observed in the SBS values between the disinfectant treated groups and control group. The failure modes were predominantly mixed.

CONCLUSION

The use of 0.3% stabilized ClO2 as a cavity disinfectant agent exhibited high antimicrobial activity against oral pathogens and no adverse effects on SBS to etched dentin.

Biomaterials for the Prevention of Oral Candidiasis Development

Thousands of microorganisms coexist within the human microbiota. However, certain conditions can predispose the organism to the overgrowth of specific pathogens that further lead to opportunistic infections. One of the most common such imbalances in the normal oral flora is the excessive growth of Candida spp., which produces oral candidiasis. In immunocompromised individuals, this fungal infection can reach the systemic level and become life-threatening. Hence, prompt and efficient treatment must be administered. Traditional antifungal agents, such as polyenes, azoles, and echinocandins, may often result in severe adverse effects, regardless of the administration form. Therefore, novel treatments have to be developed and implemented in clinical practice. In this regard, the present paper focuses on the newest therapeutic options against oral Candida infections, reviewing compounds and biomaterials with inherent antifungal properties, improved materials for dental prostheses and denture adhesives, drug delivery systems, and combined approaches towards developing the optimum treatment.

Antifungal and anti-biofilm activity of a new Spanish extract of propolis against Candida glabrata

Background

Resistance to traditional antifungal agents is a considerable health problem nowadays, aggravated by infectious processes related to biofilm formation, usually on implantable devices. Therefore, it is necessary to identify new antimicrobial molecules, such as natural products, to develop new therapeutic strategies to prevent and eradicate these infections. One promising product is propolis, a natural resin produced by honeybees with substances from various botanical sources, beeswax and salivary enzymes. The aim of this work was to study the effect of a new Spanish ethanolic extract of propolis (SEEP) on growth, cell surface hydrophobicity, adherence and biofilm formation of Candida glabrata, a yeast capable of achieving high levels of resistance to available anti-fungal agents.

Methods

The antifungal activity of SEEP was evaluated in the planktonic cells of 12 clinical isolates of C. glabrata. The minimum inhibitory concentration (MIC) of propolis was determined by quantifying visible growth inhibition by serial plate dilutions. The minimum fungicide concentration (MFC) was evaluated as the lowest concentration of propolis that produced a 95% decrease in cfu/mL, and is presented as MFC₅₀ and MFC₉₀, which corresponds to the minimum concentrations at which 50 and 90% of the C. glabrata isolates were inhibited, respectively. Influence on cell surface hydrophobicity (CSH) was determined by the method of microbial adhesion to hydrocarbons (MATH). The propolis effect on adhesion and biofilm formation was determined in microtiter plates by measurement of optical density (OD) and metabolic activity (XTT-assay) in the presence of sub-MIC concentrations of SEEP.

Results

SEEP had antifungal capacity against C. glabrata isolates, with a MIC₅₀ of 0.2% (v/v) and an MFC₅₀ of 0.4%, even in azole-resistant strains. SEEP did not have a clear effect on surface hydrophobicity and adhesion, but an inhibitory effect on biofilm formation was observed at subinhibitory concentrations (0.1 and 0.05%) with a significant decrease in biofilm metabolism.

Conclusions

The novel Spanish ethanolic extract of propolis shows antifungal activity against C. glabrata, and decreases biofilm formation. These results suggest its possible use in the control of fungal infections associated with biofilms.

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.

Antibacterial, Antifungal, and Antidiabetic Effects of Leaf Extracts from Persea americana Mill. (Lauraceae)

Fruits and leaves of Persia americana are used in traditional medical practices. This study was carried out to determine the antibacterial, antifungal, and antidiabetic effects of the leaf extracts from P. americana. The antibacterial activities of the leaf extracts were evaluated against Klebsiella pneumoniae and Staphylococcus epidermidis while antifungal activities were determined against Candida albicans and Candida tropicalis. The antidiabetic potential of the extracts was determined against mammalian α-glucosidase in vitro. The broth microdilution method was used to investigate the antibacterial and antifungal susceptibility of the microbial strains towards the leaf extracts. S. epidermidis was the most susceptible microbe out of the tested microorganisms. The acetone extract was the most potent extract against S. epidermidis with a minimum inhibitory concentration (MIC) of 50 μg/mL. At 100 μg/mL, the ethanol:water extract 18% of K. pneumoniae cells remained viable. Cell viability after exposure to the dichloromethane (DCM) and methanol extracts was 28% against C. albicans and 8% against C. tropicalis, respectively. The DCM:methanol and acetone extracts caused membrane damage in S. epidermidis exhibited by protein leakage. Only the acetone extract effected nucleic acid leakage. Screening of extracts’ potential to inhibit the activity of α-glucosidase was carried out spectrophotometrically following the production of p-nitrophenol from p-nitrophenol-glucopyranoside (substrate) at a wavelength of 405 nm. Out of all the tested extracts, the methanolic extract showed the best inhibitory activity on α-glucosidase enzyme in a time-dependent and dose-dependent manner.${\mathbf{K}}_i$and${\mathbf{K}}_{\text{inact}}$values were found to be 1.4 mg/mL and 2.4 U/min, respectively, after incubation for 1 hour. It was concluded that the leaf extracts of P. americana contain phytochemicals with antibacterial, antifungal, and α-glucosidase inhibitory effects. Further studies are required for the identification of the active compounds in the leaf extracts responsible for these observed effects.

Antimicrobial Therapeutics in Regenerative Endodontics: A Scoping Review

INTRODUCTION

This review aimed to provide a critical appraisal of alternative antimicrobial strategies in lieu of traditional triple antibiotic paste (TAP).

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The literature search was performed in 8 databases (PubMed/Medline, Embase, LILACS, Web of Science, Scopus, BVS, SciELO, and the Cochrane Library), selecting clinical, in vitro, in vivo, and in situ studies that evaluated antimicrobial alternatives to TAP in regenerative endodontics. Studies lacking an experimental TAP group were excluded.

RESULTS

A total of 1705 potentially relevant records were initially identified. From the 38 studies retrieved for full-text reading, 16 fulfilled all selection criteria and were included in the qualitative analysis. According to the study design, 11 studies were solely in vitro, 1 study was both in vitro and in vivo (animal model), 2 studies were solely animal experiments, and 2 studies were clinical trials. The alternative antimicrobial agents to TAP consisted of modified TAP formulations (eg, a combination of TAP with chitosan); TAP-eluting nanofibers; propolis; chlorhexidine (CHX) gels/solutions; double antibiotic pastes composed of distinct combinations of antibiotics; Ca(OH)₂-based formulations; and sodium hypochlorite. Overall, most of the alternative agents performed similarly to TAP, although some strategies (eg, Ca(OH)₂- and CHX-based formulations) seemed to present dubious importance in the control of infection.

CONCLUSIONS

TAP still remains an excellent option in terms of the complete elimination of microorganisms. This review points to the use of electrospun fibers as a drug delivery system to offer a controlled release of the antimicrobial agent, as well as the use of natural compounds, deserving future investigation.

Phytol-Loaded Solid Lipid Nanoparticles as a Novel Anticandidal Nanobiotechnological Approach

Phytol is a diterpene alcohol and can be found as a product of the metabolism of chlorophyll in plants. This compound has been explored as a potential antimicrobial agent, but it is insoluble in water. In this study, we describe a novel approach for an interesting anticandidal drug delivery system containing phytol. Different formulations of phytol-loaded solid lipid nanoparticles (SLN) were designed and tested using a natural lipid, 1,3-distearyl-2-oleyl-glycerol (TG1). Different compositions were considered to obtain three formulations with 1:10, 1:5, and 1:3 w/w phytol/TG1 ratios. All the formulations were prepared by emulsification solvent evaporation method and had their physicochemical properties assessed. The biocompatibility assay was performed in the HEK-293 cell line and the antifungal efficacy was demonstrated in different strains of Candida ssp., including different clinical isolates. Spherical and uniform SLN (<300 nm, PdI < 0.2) with phytol-loading efficiency >65% were achieved. Phytol-loaded SLN showed a dose-dependent cytotoxic effect in the HEK-293 cell line. The three tested formulations of phytol-loaded SLN considerably enhanced the minimal inhibitory concentration of phytol against 15 strains of Candida spp. Considering the clinical isolates, the formulations containing the highest phytol/TG1 ratios showed MICs at 100%. Thus, the feasibility and potential of phytol-loaded SLN was demonstrated in vitro, being a promising nanocarrier for phytol delivery from an anticandidal approach.

Novel Bi-Factorial Strategy against Candida albicans Viability Using Carnosic Acid and Propolis: Synergistic Antifungal Action

The potential fungicidal action of the natural extracts, carnosic acid (obtained from rosemary) and propolis (from honeybees’ panels) against the highly prevalent yeast Candida albicans, used herein as an archetype of pathogenic fungi, was tested. The separate addition of carnosic acid and propolis on exponential cultures of the standard SC5314 C. albicans strain caused a moderate degree of cell death at relatively high concentrations. However, the combination of both extracts, especially in a 1:4 ratio, induced a potent synergistic pattern, leading to a drastic reduction in cell survival even at much lower concentrations. The result of a mathematical analysis by isobologram was consistent with synergistic action of the combined extracts rather than a merely additive effect. In turn, the capacity of SC5314 cells to form in vitro biofilms was also impaired by the simultaneous presence of both agents, supporting the potential application of carnosic acid and propolis mixtures in the prevention and treatment of clinical infections as an alternative to antibiotics and other antifungal agents endowed with reduced toxic side effects.

"Inhibitory effect of Brazilian red propolis on Candida biofilms developed on titanium surfaces"

BACKGROUND

Peri-implant inflammation resulting from the presence of Candida biofilms may compromise the longevity of implant-supported dentures. This study evaluated the inhibitory effect of Brazilian red propolis on mono-species biofilms of C. albicans (ATCC 90028) and co-culture biofilms of C. albicans (ATCC 90028) and C. glabrata (ATCC 2001), developed on titanium surfaces.

METHODS

Titanium specimens were pre-conditioned with artificial saliva and submitted to biofilm formation (1 × 106 CFU/mL). After 24 h (under microaerophilic conditions at 37 °C) biofilms were submitted to treatment for 10 min, according to the groups: sterile saline solution (growth control), 0.12% chlorhexidine and 3% red propolis extract. Treatments were performed every 24 h for 3 days and analyses were conducted 96 h after initial adhesion. After that, the metabolic activity (MTT assay) (n = 12/group), cell viability (CFU counts) (n = 12/group) and surface roughness (optical profilometry) (n = 6/group) were evaluated. Data from viability and metabolic activity assays were evaluated by ANOVA and Tukey tests. Surface roughness analysis was determined by Kruskal Wallis e Mann Whitney tests.

RESULTS

Regarding the mono-species biofilm, the cell viability and the metabolic activity showed that both chlorhexidine and red propolis had inhibitory effects and reduced the metabolism of biofilms, differing statistically from the growth control (p < 0.05). With regards the co-culture biofilms, chlorhexidine had the highest inhibitory effect (p < 0.05). The metabolic activity was reduced by the exposure to chlorhexidine and to red propolis, different from the growth control group (p < 0.05). The surface roughness (Sa parameter) within the mono-species and the co-culture biofilms statistically differed among groups (p < 0.05).

CONCLUSIONS

Brazilian red propolis demonstrated potential antifungal activity against Candida biofilms, suggesting it is a feasible alternative for the treatment of peri-implantitis.

The beneficial effect of Indonesian propolis wax from Tetragonula sp. as a therapy in limited vaginal candidiasis patients

Vaginal candidiasis characterized by abnormal vaginal discharge and itching usually treated by azole’s drug or nystatin; however, some results of treatment are unsatisfied and become recurrent. Propolis containing polyphenols and flavonoids is known to have anti-inflammatory and antimicrobial activity. This study investigated the effect of Indonesian propolis wax from Tetragonula sp. as a therapy in limited vaginal candidiasis patients. The subjects were women who came to the Tasik Community Health Centre met the inclusion criteria such as clinical complaint and laboratory evaluation (positive hyphae/pseudohyphae and culture on Sabouraud Dextrose Agar (SDA) medium) from a vaginal swab. Evaluation of anti-candida effect of propolis was determined by clinical remission and the absence of Candida’s growth on SDA medium. Forty subjects were randomly assigned to those receiving treatment by ovule propolis (n = 20) and that treatment by nystatin (n = 20) as a control, once daily, for seven days, respectively. All methods have been approved by the Ethics Commission of the Faculty of Medicine, Universitas Indonesia. Our results indicated no significant difference in the laboratory evaluation of patients who have treated ovule propolis compared to standard therapy. This study suggests that propolis wax has a beneficial effect to develop as an anti-candida agent for vaginal candidiasis therapy.

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.

Description of Streptococcus mutans, Streptococcus sanguinis, and Candida albicans biofilms after exposure to propolis dentifrice by using OpenCFU method

Context

Dental caries is a major and chronic dental public health problem, which can usually be prevented by regular oral hygiene. The most common oral hygiene practice is brushing teeth with a dentifrice. Propolis has emerged as a promising anti-cariogenic agent, which is considered to be a good oral antiseptic for prevention of caries. Several studies have shown that the use of C has an influence in the growth of oral biofilms. There are several standard methods used to count bacterial colonies, such as crystal violet and CFU Count assays. OpenCFU method is a technique that can be used to calculate biofilm colonies more faster, precisely, and accurately.

Aim

To compare several methods for evaluating the number of biofilm colonies formed with exposure to a standard dentifrice and propolis.

Methods and materials

Biofilm assays were carried out on 96-well microplates. Reference strains of oral Streptococcus species (S. mutans ATCC 25175^T and S. sanguinis ATCC 10566^T) and yeast (Candida albicans ATCC 10231^T) were inoculated into wells, and 200 µL of standard and propolis dentifrice solution were added to each well and incubated for 18 h at 37 °C. Bacteria and yeast were then sub-cultured on respective media and the colony-forming units (CFU) were counted manually. The other wells were stained by crystal violet and incubated for 15 min, followed by observation using an inverted microscope and evaluated using crystal violet analysis and the OpenCFU automated method.

Results

The numbers of CFUs determined for all strains were similar in the standard-dentifrice group and propolis-dentifrice group, and were similar among the three methods: crystal violet staining, manual CFU count, and OpenCFU analysis.

Conclusion

OpenCFU analysis can be reliably used as a rapid and a more practical method to analyse the growth of oral microorganism biofilms. However, high digital image quality is required to provide an accurate analysis for colony counting.

Evidence-Based Studies and Perspectives of the Use of Brazilian Green and Red Propolis in Dentistry

This review analyzes the evidence and perspectives of dental use of the green and red propolis produced in Brazil by Apis mellifera L. Multiple applications of propolis were found considering its antibacterial, antifungal, anti-inflammatory, immunomodulatory, antiviral, and healing properties. Its therapeutic effects are mainly due to the presence of alcohols, aldehydes, aliphatic acids, aliphatic esters, amino acids, aromatic acids, aromatic esters, flavonoids, hydrocarbyl esters, ethers, fatty acids, ketones, terpenes, steroids, and sugars. Propolis has been mainly used in dentistry in the composition of dentifrices and mouthwashes. Studies have also demonstrated promising use against dentin hypersensitivity, root canal treatment, Candida albicans, and other microorganisms. Overall review of the literature presented here demonstrated that both Brazilian green and red propolis are effective for the problems of multiple etiologies that affect the oral cavity in different dental specialties.

The new buzz: Investigating the antimicrobial interactions between bioactive compounds found in South African propolis

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis, a resinous substance produced by the Apis mellifera bee, contains a number of flavonoids sourced from plants found in the surrounding region. Whilst bees use this substance to seal off and protect the beehive, humans have used propolis therapeutically for centuries, making use of its antibacterial, antiseptic, antipyretic and wound healing properties, among others. South African propolis is rich in the flavonoids pinocembrin, galangin, and chrysin and very little previous research has been conducted on the antimicrobial effects of these compounds.

AIM OF THE STUDY

To obtain an understanding of the antimicrobial activity of the compounds pinocembrin, galangin, and chrysin, both independently and in combination.

MATERIALS AND METHODS

The compounds pinocembrin, galangin and chrysin were investigated for interactive antimicrobial activity by determining the minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), anti-quorum sensing activity, biofilm studies, and toxicity studies (brine shrimp lethality assay).

RESULTS

Minimum inhibitory concentration results demonstrated that combinations of compounds showed better inhibitory activity than single compounds. When the flavonoids were tested in combination using the MIC assay, synergy was noted for 22% of the 1:1 ratio combinations and for 66% of the triple 1:1:1 ratio combinations. Similarly, MBC results showed bactericidal activity from selected combinations, while the compounds on their own demonstrated no cidal activity. Quorum sensing studies showed that compound combinations are more effective at inhibiting bacterial communication than the individual compounds. Biofilm assays showed that the highest percentage inhibition was observed for the triple combination against E. coli at 24 h. Finally, brine shrimp lethality studies revealed that combinations of the three compounds had reduced cytotoxicity when compared to the individual compounds.

CONCLUSION

The results obtained in this study demonstrate that the compounds found in South African propolis work synergistically to achieve an optimal antimicrobial effect, whilst simultaneously minimizing cytotoxicity.

Photometric Analysis of Propolis from the Island of Samothraki, Greece. The Discovery of Red Propolis

Propolis presents notable and variable antioxidant activity depending on the territory and the local flora. As a result, propolis collected from areas presenting botanical diversity can become an intriguing research field. In the present study, we examined propolis from different areas of Samothraki, a small Greek island in the north-eastern Aegean Sea, considered a hot-spot of plant biodiversity. The analysis of propolis samples presented huge variability in the antioxidant activity, the total polyphenol content and the total flavonoids content. Propolis from two areas presented high antioxidant activity with a maximum at 1741.48 μmol of Trolox equivalents per gram of dry propolis weight, very high polyphenol content, 378.73 mg of gallic acid equivalents per gram of dry propolis weight, and high flavonoid content with a maximum concentration of 70.31 mg of quercetin equivalents per gram of dry propolis weight. The samples that presented the best qualitative characteristics were all red propolis which is a type that has never been reported in any part of Europe.

Antifungal Activity and Synergism with Azoles of Polish Propolis

The aim of our work was to check if one of the products of natural origin, namely honey bee propolis, may be an alternative or supplement to currently used antifungal agents. The activity of 50 ethanolic extracts of propolis (EEPs), harvested in Polish apiaries, was tested on a group of 69 clinical isolates of C. albicans. Most of the EEPs showed satisfactory activity, with minimum fungicidal concentrations (MFC) mainly in the range of 0.08⁻1.25% (v/v). Eradication of biofilm from polystyrene microtitration plates in 50% (MBEC₅₀, Minimum Biofilm Eradication Concentration) required concentrations in the range of 0.04% (v/v) to more than 1.25% (v/v). High activity was also observed in eradication of biofilm formed by C. glabrata and C. krusei on the surfaces of PVC (Polyvinyl Chloride) and silicone catheters. EEPs at subinhibitory concentrations inhibited yeast-to-mycelia morphological transformation of C. albicans in liquid medium and mycelial growth on solid medium. A synergistic effect was observed for the action of EEP in combination with fluconazole (FLU) and voriconazole (VOR) against C. albicans. In the presence of EEP at concentrations as low as 0.02%, the MICs of FLU and VOR were 256 to 32 times lower in comparison to those of the drug alone. Evidence for the fungal cell membrane as the most probable target of EEPs are presented.

Curcumin-mediated Photodynamic Therapy for the treatment of oral infections-A review

BACKGROUND

Recent evidences show the promising applications of Curcumin (CUR) against different diseases, including some of the main oral pathologies. The objective of this review paper was to catalog articles that investigated the photodynamic effect of CUR for oral diseases in the last 15 years.

METHODS

The establishment of defined criteria for data collection was proposed and a total of 173 articles were identified, but only 26 were eligible for full text reading. Their main findings were critically reviewed to provide a state-of-the-art overview of the use of CUR in Dentistry.

RESULTS

Antimicrobial potential of CUR was the subject of the majority of the articles. CUR showed great potential for photodynamic action against oral bacteria, fungi, and strains resistant to conventional drugs. Some authors indicated the efficacy of CUR-mediated Photodynamic Therapy to reduce tumor cells while others observed low cytotoxicity in mammalian cells and healthy oral mucosa. However, CUR solubility and stability is still a problem for the photodynamic technique, and to overcome these drawbacks, biocompatible vehicles need to be better explored.

CONCLUSIONS

Investigations have used different CUR concentrations and formulations, as well as different light parameters. This fact, together with the lack of in vivo studies, clearly shows that clinical protocols have not been established yet. Investigations are necessary in order to establish the best concentrations and safe vehicles to be used for this technique.

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.

An Update on Candida tropicalis Based on Basic and Clinical Approaches

Candida tropicalis has emerged as one of the most important Candida species. It has been widely considered the second most virulent Candida species, only preceded by C. albicans. Besides, this species has been recognized as a very strong biofilm producer, surpassing C. albicans in most of the studies. In addition, it produces a wide range of other virulence factors, including: adhesion to buccal epithelial and endothelial cells; the secretion of lytic enzymes, such as proteinases, phospholipases, and hemolysins, bud-to-hyphae transition (also called morphogenesis) and the phenomenon called phenotypic switching. This is a species very closely related to C. albicans and has been easily identified with both phenotypic and molecular methods. In addition, no cryptic sibling species were yet described in the literature, what is contradictory to some other medically important Candida species. C. tropicalis is a clinically relevant species and may be the second or third etiological agent of candidemia, specifically in Latin American countries and Asia. Antifungal resistance to the azoles, polyenes, and echinocandins has already been described. Apart from all these characteristics, C. tropicalis has been considered an osmotolerant microorganism and this ability to survive to high salt concentration may be important for fungal persistence in saline environments. This physiological characteristic makes this species suitable for use in biotechnology processes. Here we describe an update of C. tropicalis, focusing on all these previously mentioned subjects.

Efficacy of Propolis on the Denture Stomatitis Treatment in Older Adults: A Multicentric Randomized Trial

Our hypothesis tested the efficacy and safety of a mucoadhesive oral gel formulation of Brazilian propolis extract compared to miconazole oral gel for the treatment of denture stomatitis due to Candida spp. infection in older adults. Forty patients were randomly allocated in a noninferiority clinical trial into two groups. The control group (MIC) received 20 mg/g miconazole oral gel and the study group (PROP) received mucoadhesive formulation containing standardized extract of 2% (20 mg/g) propolis (EPP-AF®) during 14 days. Patients were examined on days 1, 7, and 14. The Newton's score was used to classify the severity of denture stomatitis. The colony forming unity count (CFU/mL) was quantified and identified (CHROMagar Candida®) before and after the treatment. Baseline characteristics did not differ between groups. Both treatments reduced Newton's score (P < 0.0001), indicating a clinical improvement of the symptoms of candidiasis with a clinical cure rate of 70%. The microbiological cure with significant reduction in fungal burden on T14 was 70% in the miconazole group and 25% in the EPP-AF group. The EPP-AF appears to be noninferior to miconazole considering the clinical cure rate and could be recommended as an alternative treatment in older patients.

"Nature cures:" An alternative herbal formulation as a denture cleanser

BACKGROUND

Candida albicans is one of the microorganisms which harbor the oral cavity, especially in elderly. However, the incidence of existence of this increases in patients using removable dental prosthesis. There is therefore a need to test the anticandidal efficacy of these cost-effective, easily available products to be used as routine denture cleansers.

AIM AND OBJECTIVES

(1) To evaluate antifungal properties of triphala churna on the heat cure denture base material. (2) To evaluate the antifungal effect of chlorhexidine gluconate on the heat cure denture base material. (3) To compare the antifungal effect of triphala churna and chlorhexidine gluconate with a control. (4) To evaluate which among triphala churna and chlorhexidine gluconate has a better antifungal property on the heat cure denture base material.

MATERIALS AND METHODS

Study population consisted of sixty dentures wearers from those attending the Outpatient Department of Prosthodontics of the School of Dentistry, Krishna Institute of Medical Sciences Deemed University, Karad. Swabs were collected from the dentures before and after the use of triphala and chlorhexidine. The swabs were cultured on Sabouraud dextrose agar and the total Candida counts were determined.

CONCLUSION

Triphala as an antifungal is shown to have more efficacy than the conventional chlorhexidine mouthwash. Résumé Arrière-plan: Candida albicans est l'un des micro-organismes qui abritent la cavité buccale surtout chez les personnes âgées. Cependant, l'incidence de l'existence de cette augmentation chez les patients utilisant des prothèses dentaires amovibles. Il est donc nécessaire de tester l'efficacité anticancédique de ces produits rentables et faciles à utiliser pour être utilisés comme nettoyants de routine pour prothèses dentaires. Buts et Objectifs: (1) Évaluer les propriétés antifongiques de Triphala churna sur le matériau de base de la prothèse thermo-durcissable. (2) Évaluer l'effet antifongique du gluconate de chlorhexidine sur le matériau de base de la prothèse thermo-durcissable. (3) Comparer l'effet antifongique de Triphala churna et du gluconate de chlorhexidine avec un témoin. (4) Évaluer lequel parmi Triphala churna et le gluconate de chlorhexidine a une meilleure propriété antifongique sur le matériel de base de la prothèse de durcissement à chaud. Matériaux et Méthode: La population de l'étude était constituée de soixante porteurs de prothèses dentaires de ceux qui fréquentaient le Département de Prosthodontie de l'École des Sciences Dentaires de l'Institut Krishna des Sciences Médicales de l'Université de Karad. Des prélèvements ont été effectués sur les prothèses avant et après l'utilisation de Triphala et de chlorhexidine. On a cultivé les écouvillons sur de l'agar Sabouraud dextrose et on a déterminé le nombre total de candida.

CONCLUSION

Triphala comme un anti fongique est démontré pour avoir plus d'efficacité que le lavage de la bouche classique chlorhexidine.