Evaluation of photodynamic therapy on nanoparticles and films loaded-nanoparticles based on chitosan/alginate for curcumin delivery in oral biofilms.

Nanoparticles and nanoparticle-loaded films based on chitosan/sodium alginate with curcumin (CUR) are promising strategies to improve the efficacy of antimicrobial photodynamic therapy (aPDT) for the treatment of oral biofilms. This work aimed to develop and evaluate the nanoparticles based on chitosan and sodium alginate encapsulated with CUR dispersed in polymeric films associated with aPDT in oral biofilms. The NPs were obtained by polyelectrolytic complexation, and the films were prepared by solvent evaporation. The photodynamic effect was evaluated by counting Colony Forming Units (CFU/mL). Both systems showed adequate characterization parameters for CUR release. Nanoparticles controlled the release of CUR for a longer period than the nanoparticle-loaded films in simulated saliva media. Control and CUR-loaded nanoparticles showed a significant reduction of 3 log10 CFU/mL against S. mutans biofilms, compared to treatment without light. However, biofilms of S. mutans showed no photoinactivation effect using films loaded with nanoparticles even in the presence of light. These results demonstrate the potential of chitosan/sodium alginate nanoparticles associated with aPDT as carriers for the oral delivery of CUR, offering new possibilities to improve the treatment of dental caries and infections. This work will contribute to advances in the search for innovative delivery systems in dentistry.

Green nanotechnology for the development of nanoparticles based on alginate associated with essential and vegetable oils for application in fruits and seeds protection.

Aiming to highlight the valorization of the natural products and the green synthesis processes, this work describes the development of a nanoscale system based on the use of alginate to encapsulate a blend of oils (vegetable and essential oils), not previously reported, with antibacterial and antioxidant actions. The study shows the influence of the polymer and surfactant concentrations on the physicochemical properties of the nanoparticles. The formulations were characterized by DLS, zeta potential, efficiency of encapsulation and stability. In addition, the antioxidant and antimicrobial properties of the systems were evaluated using the DPPH method and disk diffusion assays, respectively. The shelf life was studied by coating fruits and seeds. The results showed that the nanostructured system was stable, the efficiency of encapsulation was high and the nanoparticles size range was about 200-400 nm. The coating of fruits and seeds showed that the system was capable of inhibiting the growth of microorganisms and delaying the fruit maturation, indicating its potential for prolonging the shelf-life of fresh food.

Fabrication of Functional bioMOF-100 Prototype as Drug Delivery System for Breast Cancer Therapy.

Breast cancer is the most frequent cause of cancer death in women, representing the fifth leading cause of cancer death overall. Therefore, the growing search for the development of new treatments for breast cancer has been developed lately as well as drug delivery systems such as biocompatible metal-organic Frameworks (bio-MOFs). These may be promising and attractive for drug incorporation and release. The present study aims to develop a drug carrier system RCA (bioMOF-100 submitted to the activation process) containing incorporated curcumin (CCM), whose material surface is coated with folic acid molecules (FA) to promote the targeting of drug carrier systems to the tumor region. They were synthesized and characterized using several characterization techniques. The materials were submitted to drug encapsulation tests, whose encapsulation efficiency was 32.80% for CCM@RCA-1D. Using the 1H nuclear magnetic resonance (NMR) spectroscopy technique, it was possible to verify the appearance of signals referring to folic acid, suggesting success in the functionalization of these matrices. In vitro tests such as cell viability and type of cell death were evaluated in both series of compounds (CCM@RCA-1D, CCM@RCA-1D/FA) in breast tumor lines. The results revealed low toxicity of the materials and cell death by late apoptosis. Thus, these results indicate that the matrices studied can be promising carriers in the treatment of breast cancer.

Curcumin-Loaded Mesoporous Silica Nanoparticles Dispersed in Thermo-Responsive Hydrogel as Potential Alzheimer Disease Therapy.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive and behavioral impairment. Curcumin-loaded mesoporous silica nanoparticles (MSN-CCM) can overcome the drawbacks related to the free curcumin (CCM) clinical application, such as water insolubility and low bioavailability, besides acting over the main causes associated to AD. A thermo-responsive hydrogel is an interesting approach for facilitating the administration of the nanosystem via a nasal route, as well as for overcoming mucociliary clearance mechanisms. In light of this, MSN-CCM were dispersed in the hydrogel and evaluated through in vitro and in vivo assays. The MSNs and MSN-CCM were successfully characterized by physicochemical analysis and a high value of the CCM encapsulation efficiency (EE%, 87.70 ± 0.05) was achieved. The designed thermo-responsive hydrogel (HG) was characterized by rheology, texture profile analysis, and ex vivo mucoadhesion, showing excellent mechanical and mucoadhesive properties. Ex vivo permeation studies of MSN-CCM and HG@MSN-CCM showed high permeation values (12.46 ± 1.08 and 28.40 ± 1.88 µg cm-2 of CCM, respectively) in porcine nasal mucosa. In vivo studies performed in a streptozotocin-induced AD model confirmed that HG@MSN-CCM reverted the cognitive deficit in mice, acting as a potential formulation in the treatment of AD.

Exploiting Polymeric Films as a Multipurpose Drug Delivery System: a Review.

Polymeric films are drug delivery systems that maintain contact with the delivery tissue and sustain a controlled release of therapeutic molecules. These systems allow a longer time of drug contact with the target site in the case of topical treatments and allow the controlled administration of drugs. They can be manufactured by various methods such as solvent casting, hot melt extrusion, electrospinning, and 3D bioprinting. Furthermore, they can employ various polymers, for example PVP, PVA, cellulose derivatives, chitosan, gelling gum, pectin, and alginate. Its versatility is also applicable to different routes of administration, as it can be administered to the skin, oral mucosa, vaginal canal, and eyeballs. All these factors allow numerous combinations to obtain a better treatment. This review focuses on exploring some possible ways to develop them and some particularities and advantages/disadvantages in each case. It also aims to show the versatility of these systems and the advantages and disadvantages in each case, as they bring the opportunity to develop different medicines to facilitate therapies for the most diverse purposes .

Natural product-based nanomedicine applied to fungal infection treatment: A review of the last 4 years.

Fungal infections are one of the main public health problems, especially in immunocompromised patients, nosocomial environments, patients with chronic diseases, and transplant recipients. These diseases are increasingly frequent and lethal because the microorganism has a high capacity to acquire resistance to available therapy. The main resistance factors are the emergence of new strains and the uncontrolled use of antifungals. It is, therefore, important to develop new methods that contribute to combating fungal diseases in the clinical area. Natural products have considerable potential for the development of new drugs with antifungal activity, mainly due to their biocompatibility and low toxic effect. This promising antimicrobial activity of natural products is mainly due to the presence of flavonoids, terpenes, and quinones, which explains their antifungal potential. Pharmaceutical nanotechnology has been explored to enhance the delivery, selectivity, and clinical efficacy of these products. Nanotechnological systems provide a safe and selective environment for various substances, such as natural products, improving antifungal activity. However, further safety experiments (in vivo or clinical trials) need to be carried out to prove the therapeutic action of natural products, since they may have undesirable, toxic, and mutagenic effects. Therefore, this review article addresses the main nanotechnological methods using natural products for effective future treatment against the main fungal diseases.

Potential of curcumin-loaded cubosomes for topical treatment of cervical cancer.

Cervical cancer is one of the most common cancers affecting women worldwide. There are an estimated 570.000 new cases of cervical cancer each year and conventional treatments can cause severe side effects. In this work, we developed a platform for vaginal administration of lipophilic drugs for cervical cancer treatment. We formulated mucoadhesive cubosomes for the delivery of curcumin, a lipophilic drug for cervical cancer treatment, to increase its bioavailability and local absorption. This study tests the use of cubosomes for vaginal drug administration and assesses their potential efficiency using the CAM (chick embryo chorioallantoic membrane) model. SAXS (small-angle X-ray scattering), cryo-TEM (cryo-transmission electron microscopy), and dynamic light scattering (DLS) were employed to characterise the system. With ex vivo permeation and retention studies, we find that the curcumin released from our system is retained in the vaginal mucosa. In vitro cytotoxicity assay and cellular uptake showed an increased cytotoxic effect of curcumin against HeLa cell line when incorporated into the cubosomes. The curcumin-loaded cubosomes also demonstrated an antiangiogenic effect evaluated in vivo by the CAM model.

Piperine for treating breast cancer: A review of molecular mechanisms, combination with anticancer drugs, and nanosystems.

Piperine (PIP) is an alkaloid found primarily in Piper longum, and this natural compound has been shown to exert effects on proliferation and survival against various types of cancer. In particular, PIP has potent inhibitory effects on breast cancer (BC), the most prevalent type of cancer in women worldwide. PIP targets numerous signaling pathways associated with the therapy of BC cells through the following mechanisms: (a) induction of arrest of the cell cycle and apoptosis; (b) alteration of the signaling protein expression; (c) reduction in transcription factors; and (d) inhibition of tumor growth. BC cells have the ability to resist conventional drugs, so one of the strategies is the combination of PIP with other phytochemicals such as paclitaxel, thymoquinone, hesperidin, bee venom, tamoxifen, mitoxantrone, piperlongumin, and curcumin. Nanotechnology-based drug encapsulation systems are currently used to enhance the release of PIP. This includes polymer nanoparticles, carbon nanotubes, and liposomes. In the present review, the chemistry and bioavailability of PIP, its molecular targets in BC, and nanotechnological strategies are discussed. Future research directions are also discussed to further understand this promising natural product.

Hydroalcoholic Extract of Myrcia bella Loaded into a Microemulsion System: A Study of Antifungal and Mutagenic Potential.

Myrcia bella is a medicinal plant used for the treatment of diabetes, hemorrhages, and hypertension in Brazilian folk medicine. Considering that plant extracts are attractive sources of new drugs, the aim of the present study was to verify the influence of incorporating 70% hydroalcoholic of M. bella leaves in nanostructured lipid systems on the mutagenic and antifungal activities of the extract. In this work, we evaluated the antifungal potential of M. bella loaded on the microemulsion against Candida sp for minimum inhibitory concentration, using the microdilution technique. The system was composed of polyoxyethylene 20 cetyl ether and soybean phosphatidylcholine (10%), grape seed oil, cholesterol (10%: proportion 5/1), and purified water (80%). To investigate the mutagenic activity, the Ames test was used with the Salmonella Typhimurium tester strains. M. bella, either incorporated or free, showed an important antifungal effect against all tested strains. Moreover, the incorporation surprisingly inhibited the mutagenicity presented by the extract. The present study attests the antimicrobial properties of M. bella extract, contributing to the search for new natural products with biological activities and suggesting caution in its use for medicinal purposes. In addition, the results emphasize the importance of the use of nanotechnology associated with natural products as a strategy for the control of infections caused mainly by the genus Candida sp.

Mycobacterium tuberculosis and Paracoccidioides brasiliensis Formation and Treatment of Mixed Biofilm In Vitro.

Co-infection of Mycobacterium tuberculosis and Paracoccidioides brasiliensis, present in 20% in Latin America, is a public health problem due to a lack of adequate diagnosis. These microorganisms are capable of forming biofilms, mainly in immunocompromised patients, which can lead to death due to the lack of effective treatment for both diseases. The present research aims to show for the first time the formation of mixed biofilms of M. tuberculosis and P. brasiliensis (Pb18) in vitro, as well as to evaluate the action of 3'hydroxychalcone (3'chalc) -loaded nanoemulsion (NE) (NE3'chalc) against monospecies and mixed biofilms, the formation of mixed biofilms of M. tuberculosis H37Rv (ATCC 27294), 40Rv (clinical strains) and P. brasiliensis (Pb18) (ATCC 32069), and the first condition of formation (H37Rv +Pb18) and (40Rv + Pb18) and second condition of formation (Pb18 + H37Rv) with 45 days of total formation time under both conditions. The results of mixed biofilms (H37Rv + Pb18) and (40Rv + Pb18), showed an organized network of M. tuberculosis bacilli in which P. brasiliensis yeasts are connected with a highly extracellular polysaccharide matrix. The (Pb18 + H37Rv) showed a dense biofilm with an apparent predominance of P. brasiliensis and fragments of M. tuberculosis. PCR assays confirmed the presence of the microorganisms involved in this formation. The characterization of NE and NE3'chalc displayed sizes from 145.00 ± 1.05 and 151.25 ± 0.60, a polydispersity index (PDI) from 0.20± 0.01 to 0.16± 0.01, and zeta potential -58.20 ± 0.92 mV and -56.10 ± 0.71 mV, respectively. The atomic force microscopy (AFM) results showed lamellar structures characteristic of NE. The minimum inhibitory concentration (MIC) values of 3'hidroxychalcone (3'chalc) range from 0.97- 7.8 µg/mL and NE3'chalc from 0.24 - 3.9 µg/mL improved the antibacterial activity when compared with 3'chalc-free, no cytotoxicity. Antibiofilm assays proved the efficacy of 3'chalc-free incorporation in NE. These findings contribute to a greater understanding of the formation of M. tuberculosis and P. brasiliensis in the mixed biofilm. In addition, the findings present a new possible NE3'chalc treatment alternative for the mixed biofilms of these microorganisms, with a high degree of relevance due to the lack of other treatments for these comorbidities.

Curcumin-loaded Pluronic® F-127 Micelles as a Drug Delivery System for Curcumin-mediated Photodynamic Therapy for Oral Application.

Antimicrobial photodynamic therapy (aPDT) is promising for oral decontamination. Curcumin has been used as photosensitizer; however, the hydrophobic properties can negatively affect aPDT. This study evaluated the aPDT efficacy using Cur-loaded Pluronic® F-127 micelles against Streptococcus mutans and Candida albicans biofilms. Micelles characterization was performed by zeta potential, dynamic light scattering, transmission electron microscopy, absorption and fluorescence spectroscopy. Cur concentrations, cell viability by CFU mL-1 and confocal microscopy were determined. Data were analyzed by parametric and nonparametric tests under 5%. Cur-loaded Pluronic® F-127 exhibited spherical shape, suitable particle size (≤100 nm), adequate polydispersity index, best stability, lower photodegradation and autoaggregation compared to unloaded-Cur. Both microorganisms were sensitive to Cur-loaded Pluronic® F-127 micelles aPDT, with minimum inhibitory concentration (MIC) of 270 µm and 2.1093 µm for S. mutans and C. albicans suspended culture, respectively. Cur-loaded Pluronic® F-127 aPDT exhibited antibacterial/antifungal effect against the biofilms (~3 log10 reduction; P ≤ 0.05); however, similar to unloaded (P ≥ 0.05). Confocal images confirmed these results. Cur-loaded Pluronic® F-127 micelles exhibited good photo-chemical properties and may be a viable alternative to deliver Cur and to improve aPDT effect during the treatment of dental caries. Moreover, Pluronic® micelles can enhance the solubility, stability, permeability and control the release of Cur.

Nanostructured lipid carriers containing chitosan or sodium alginate for co-encapsulation of antioxidants and an antimicrobial agent for potential application in wound healing.

The high incidence and costs of chronic wounds in the elderly have motivated the search for innovations to improve product performance and the healing process while reducing costs. In this study, bioadhesive nanostructured lipid carriers (NLC) were developed for the co-encapsulation of compounds with antioxidant (α-tocopherol and quercetin) and antimicrobial (tea tree oil) activity for management of wounds. The NLC was produced with shea butter and argan oil, and modified with sodium alginate or chitosan to confer bioadhesive properties. Spherical nanoparticles of ~307-330 nm and zeta potential varying from -21.2 to +11.8 mV were obtained. Thermal analysis demonstrated that the lipid matrix reduced tea tree oil thermal loss (~1.8-fold). Regardless of the type of polysaccharide employed, the NLCs promoted cutaneous localization of antioxidants in damaged (subjected to incision) skin, with a ~74 to 180-fold higher delivery into the skin compared to percutaneous delivery. This result is consistent with the similar bioadhesive properties of chitosan or sodium alginate-modified NLC. Nanoencapsulation of tea tree oil did not preclude its antimicrobial effects against susceptible and resistant strains of S. aureus and P. aeruginosa, while co-encapsulation of antioxidants increased the NLC-induced fibroblasts migration, supporting their potential usefulness for management of wounds.

The role of polysaccharides from natural resources to design oral insulin micro- and nanoparticles intended for the treatment of Diabetes mellitus: A review.

Oral administration of insulin (INS) would represent a revolution in the treatment of diabetes, considering that this route mimics the physiological dynamics of endogenous INS. Nano- and microencapsulation exploiting the advantageous polysaccharides properties has been considered an important technological strategy to protect INS against harsh conditions of gastrointestinal tract, in the same time that improve the permeability via transcellular and/or paracellular pathways, safety and in some cases even selectivity for targeting delivery of INS. In fact, some polysaccharides also give to the systems functional properties such as pH-responsiveness, mucoadhesiveness under specific physiological conditions and increased intestinal permeability. In general, all polysaccharides can be functionalized with specific molecules becoming more selective to the cells to which INS is delivered. The present review highlights the advances in the past 10 years on micro- and nanoencapsulation of INS exploiting the unique natural properties of polysaccharides, including chitosan, starch, alginate, pectin, and dextran, among others.

Current applications of drug delivery nanosystems associated with antimicrobial photodynamic therapy for oral infections.

The oral cavity is colonized by several species of microorganisms that can cause dental caries, periodontal diseases, candidiasis, endodontic infections, and, among other diseases related to the dental field. Conventional treatment consists of mechanical removal associated with systemic administration of antimicrobials, which can cause various side effects and microbial resistance. In this context, alternative therapies have been developed, including Antimicrobial Photodynamic Therapy (aPDT). For the improvement of therapy, the implementation of nanotechnology is very important to optimize the delivery system of the dyes or photosensitizers on biological targets. Besides, this combination provides a non-invasive treatment, better solubility and bioavailability, delivery to the target site, controlled release and protection against external and physical-chemical factors, low side effects, and, unlikely resistant species. Although, there are numerous researches on aPDT and nanotechnology, few review articles based on the combination of these three aspects: nanosystems, aPDT and oral infections are available. For this reason, this article aims to discuss the advances and advantages of this combination. Therefore, this article was divided into different types of nanosystems (organic and inorganic nanoparticles) associated with aPDT bringing a description of it is definitions, properties, and, applications in oral infections.

Terpinen-4-ol and nystatin co-loaded precursor of liquid crystalline system for topical treatment of oral candidiasis.

This study was performed to develop a liquid crystalline system (LCS) incorporated with terpinen-4-ol and nystatin to evaluate its antifungal, antibiofilm, and synergistic/modulatory activity against Candida albicans. The LCS was composed of a dispersion containing 40% propoxylated and ethoxylated cetyl alcohol, 40% oleic acid, and 0.5% chitosan dispersion. According to analysis by polarized light microscopy, rheology, and mucoadhesion studies, the incorporation of 100% artificial saliva increased the pseudoplasticity, consistency index, viscosity, and mucoadhesion of the formulation. The minimum inhibitory concentration, minimum fungicidal concentration, and rate of biofilm development were used to evaluate antifungal activity; the LCS containing terpinen-4-ol and nystatin effectively inhibited C. albicans growth at a lower concentration, displaying a synergistic action. Therefore, LCS incorporated with terpinen-4-ol and nystatin is a promising alternative for preventing and treating infections and shows potential for the development of therapeutic strategies against candidiasis.

A Review of Analytical Methods for the Determination of Hypericin in Foods, Herbal, Biological and Pharmaceutical Matrices.

AIMS: A review of analytical methods for the determination of hypericin in foods, herbal, biological and pharmaceutical matrices. BACKGROUND: Hypericin (HYP) is a naturally-occurring pigment obtained from some plants of the genus Hypericum. Although HYP has been known for many years, it has recently attracted attention due to its varied biological properties, such as anti-inflammatory and antidepressant activity and it is also an efficient photosensitizer. OBJECTIVE: The objective of this review is to provide insights into the physicochemical properties of HYP, as well as to report the analytical methods existing in the literature and official compendia for different matrices. METHODS: The survey data were collected by Google Scholar® and Scopus® using keys terms. RESULT: Analytical methods involving HYP are mainly concerned with the quality control of pharmaceutical preparations, foods, beverages, biological samples and drug delivery systems using different types of analysis methods. Some difficulties have also been identified due to the physicochemical properties of HYP. It presents great solubility in alkaline solutions, organic bases and common polar organic solvents. CONCLUSION: It can be analyzed by thin layer chromatography, spectrophotometry in the ultraviolet region, but the most commonly used method is by HPLC. HYP presents monographs in the American, British and European Pharmacopoeias, however, the methods of analysis are not yet harmonized.

Syngonanthus nitens (Bong.) Ruhland Derivatives Loaded into a Lipid Nanoemulsion for Enhanced Antifungal Activity Against Candida parapsilosis.

BACKGROUND: Vaginal infections caused by non-albicans species have become common in women of all age groups. The resistance of species such as Candida parapsilosis to the various antifungal agents is a risk factor attributed to these types of infections, which instigates the search for new sources of active compounds in vulvovaginal candidiasis (VCC) therapy. OBJECTIVE: This study evaluated the antifungal activity of Syngonanthus nitens Bong. (Ruhland) derivatives and employed a lipid nanoemulsion as a delivery system.' METHODS: In this study, a lipid nanoemulsion was employed as a delivery system composed of Cholesterol (10%), soybean phosphatidylcholine: Brij 58 (1: 2) and PBS (pH 7.4) with the addition of 0.5% of a chitosan dispersion (80%), and evaluated the antifungal activity of S. nitens Bong. (Ruhland) derivatives against planktonic cells and biofilms of Candida parapsilosis. By a biomonitoring fractionation, the crude extract (EXT) and one fraction (F2) were selected and incorporated into a lipid nanoemulsion (NL) composed of cholesterol (10%), a 1:2 mixture of soybean phosphatidylcholine:polyoxyethylene -20- cetyl ether (10%), and phosphate buffer solution (pH 7.4) with a 0.5% chitosan dispersion (80%). The NL presented a diameter size between 50-200 nm, pseudoplastic behavior, and positive charge. The EXT and five fractions were active against planktonic cells. RESULTS AND DISCUSSION: The incorporation of EXT and F2 into the NL increased antifungal activity and enhanced the anti-biofilm potential. This study classified the use of an NL as an important tool for the administration of S. nitens derivatives in cases of infections caused by this C. parapsisilosis. CONCLUSION: This work concluded that S. nitens derivatives were important sources of active molecules against C. parapsilosis and the use of a lipid nanoemulsion was an important tool to promote more effective F2 release and to improve the antifungal activity aiming the control of C. parapsilosis infections.

Mucoadhesive films based on gellan gum/pectin blends as potential platform for buccal drug delivery.

Films of gellan gum:pectin blends were prepared by solvent casting method. Gellan gum:pectin mass ratios were varied (4:1; 1:1; 1:4) at different concentrations (3% or 4%) and glycerol was used as plasticizer (1 or 2%). The films were thin (18-30 µm), translucent, flexible, and homogeneous. The surface pH was suitable for buccal application. All films reached high mechanical resistance and the mucoadhesive ability of them was evidenced. High ratio of gellan gum improved the mechanical resistance and the mucoadhesion of the films as well as the control of drug release rates. The films did not disintegrate in simulate saliva up to 24 h and curcumin release could be sustained up to 12 h. The set of data evidence that the films designed in this work represent a potential platform for buccal drug delivery.

Improved in vitro and in vivo Anti-Candida albicans Activity of Cymbopogon nardus Essential Oil by Its Incorporation into a Microemulsion System.

PURPOSE: Vulvovaginal candidiasis (VVC) is an opportunistic fungal infection that adversely affects a woman's health, due to unpleasant symptoms, therapeutic challenges, and the emergence of resistant strains. The association of natural products and nanotechnology is important to improve the antifungal potential of medicinal plants. We aimed to evaluate the in vitro and in vivo anti-Candida albicans activity of unloaded (EO) and loaded (ME+EO) essential oil of Cymbopogon nardus in the microemulsion (ME). METHODS: The chemical analysis of the EO was performed by gas chromatography-mass spectrometry. The ME and ME+EO were characterized by scattering, zeta potential, polarized light microscopy, rheological assays, mucoadhesiveness and transmission electronic microscopy. The in vitro antifungal activity of the EO and ME+EO were evaluated by microdilution technique. The toxicity of EO and ME+EO was analyzed on human cell line HaCat and using alternative model assay with Artemia salina. The experimental in vivo VVC was performed in female mice (C57BL/6). RESULTS: The main compounds of the EO were found to be citronellal, geranial, geraniol, citronellol, and neral. The formulations exhibited suitable size, homogeneity, negative charge, isotropic behavior, highly organized structure, and pseudoplastic behavior, for vaginal application. TEM photomicrographs showed possible EO droplets inside the spherical structures. The EO, when loaded into the ME, exhibited an improvement in its antifungal action against C. albicans. The EO was not toxic against brine shrimp nauplii. An in vivo VVC assay showed that the use of the ME significantly improved the action of the EO, since only the ME+EO promoted the eradication of the fungal vaginal infection on the third day of treatment. CONCLUSION: The EO and ME+EO are promising alternatives for the control of fungal infections caused by C. albicans, once the use of nanotechnology significantly improved the antifungal action of the EO, especially in an in vivo model of VVC.

Antifungal Activity of a Hydroethanolic Extract From Astronium urundeuva Leaves Against Candida albicans and Candida glabrata.

We have previously reported on the activity of different extracts from Astronium sp. against Candida albicans, with the hydroethanolic extract prepared from leaves of A. urundeuva, an arboreal species widely distributed in arid environments of South America and often used in folk medicine, displaying the highest in vitro activity. Here we have further evaluated the antifungal activity of this extract against strains of C. albicans and C. glabrata, the two most common etiological agents of candidiasis. The extract was tested alone and loaded into a nanostructured lipid system (10% oil phase, 10% surfactant and 80% aqueous phase, 0.5% Poloxamer 407®). In vitro susceptibility assays demonstrated the antifungal activity of the free extract and the microemulsion against both Candida species, with increased activity against C. glabrata, including collection strains and clinical isolates displaying different levels of resistance against the most common clinically used antifungal drugs. Checkerboard results showed synergism when the free extract was combined with amphotericin B against C. albicans. Serial passage experiments confirmed development of resistance to fluconazole but not to the free extract upon prolonged exposure. Although preformed biofilms were intrinsically resistant to treatment with the extract, it was able to inhibit biofilm formation by C. albicans at concentrations comparable to those inhibiting planktonic growth. Cytotoxicity assays in different cell lines as well as an alternative model using Artemia salina L. confirmed a good safety profile of the both free and loaded extracts, and an in vivo assay demonstrated the efficacy of the free and loaded extracts when used topically in a rat model of vaginal candidiasis. Overall, these results reveal the promise of the A. urundeuva leaves extract to be further investigated and developed as an antifungal.