Antifungal Activity, Mode of Action, and Cytotoxicity of 4-chlorobenzyl p-coumarate: a Promising New Molecule.

Fungal infections represent a serious health problem worldwide. The study evaluated the antifungal activity of 4-chlorobenzyl p-coumarate, an unprecedented semi-synthetic molecule. Docking molecular and assay experiments were conducted to determine the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC), mode of action, effect on growth, fungal death kinetics, drug association, effects on biofilm, micromorphology, and against human keratinocytes. The investigation included 16 strains of Candida spp, including C. albicans, C. krusei, C. glabrata, C. tropicalis, C. dubliniensis, C. lusitaniae, C. utilis, C. rugosa, C. guilhermondi, and C. parapsilosis. Docking analysis predicted affinity between the molecule and all tested targets. MIC and MFC values ranged from 3.9 µg/mL (13.54 µM) to 62.5 µg/mL (217.01 µM), indicating a probable effect on the plasma membrane. The molecule inhibited growth from the first hour of testing. Association with nystatin proved to be indifferent. All concentrations of the molecule reduced fungal biofilm. The compound altered fungal micromorphology. The tested compound exhibited an IC50 of 7.90 ± 0.40 µg/mL (27.45 ± 1.42 µM) for keratinocytes. 4-chlorobenzyl p-coumarate showed strong fungicidal effects, likely through its action on the plasma membrane and alteration of fungal micromorphology, and mildly cytotoxic to human keratinocytes.

An In Silico Approach to Exploring the Antinociceptive Biological Activities of Linalool and its Metabolites.

Pain is characterized by the unpleasant sensory and emotional sensation associated with actual or potential tissue damage, whereas nociception refers to the mechanism by which noxious stimuli are transmitted from the periphery to the CNS. The main drugs used to treat pain are nonsteroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics, which have side effects that limit their use. Therefore, in the search for new drugs with potential antinociceptive effects, essential oils have been studied, whose constituents (monoterpenes) are emerging as a new therapeutic possibility. Among them, linalool and its metabolites stand out. The present study aims to investigate the antinociceptive potential of linalool and its metabolites through a screening using an in silico approach. Molecular docking was used to evaluate possible interactions with important targets involved in antinociceptive activity, such as α2-adrenergic, GABAergic, muscarinic, opioid, adenosinergic, transient potential, and glutamatergic receptors. The compounds in the investigated series obtained negative energies for all enzymes, representing satisfactory interactions with the targets and highlighting the multi-target potential of the L4 metabolite. Linalool and its metabolites have a high likelihood of modulatory activity against the targets involved in nociception and are potential candidates for future drugs.

Mechanisms Involved in the Therapeutic Effect of Cannabinoid Compounds on Gliomas: A Review with Experimental Approach.

INTRODUCTION: Brain tumors have high morbidity and mortality rates, accounting for 1.4% of all cancers. Gliomas are the most common primary brain tumors in adults. Currently, several therapeutic approaches are used; however, they are associated with side effects that affect patients'quality of life. Therefore, further studies are needed to develop novel therapeutic protocols with a more favorable side effect profile. In this context, cannabinoid compounds may serve as potential alternatives. OBJECTIVE: This study aimed to review the key enzymatic targets involved in glioma pathophysiology and evaluate the potential interaction of these targets with four cannabinoid derivatives through molecular docking simulations. METHODS: Molecular docking simulations were performed using four cannabinoid compounds and six molecular targets associated with glioma pathophysiology. RESULTS: Encouraging interactions between the selected enzymes and glioma-related targets were observed, suggesting their potential activity through these pathways. In particular, cannabigerol showed promising interactions with epidermal growth factor receptors and phosphatidylinositol 3- kinase, while Δ-9-tetrahydrocannabinol showed remarkable interactions with telomerase reverse transcriptase. CONCLUSION: The evaluated compounds exhibited favorable interactions with the analyzed enzymatic targets, thus representing potential candidates for further in vitro and in vivo studies.

Antifungal activity against Candida albicans of methyl 3,5-dinitrobenzoate loaded nanoemulsion.

The objective of this study was to evaluate the antifungal activity of free methyl 3,5 dinitrobenzoate (MDNB) and its nanoemulsion (MDNB-NE) against strains of Candida albicans. Additionally, a molecular modeling study was also carried out to propose the mechanism of action and toxicity of MDNB. These results demonstrated the MDNB-NE presented a droplet size of 181.16 ± 3.20 nm and polydispersity index of 0.30 ± 0.03. MDNB and MDNB-NE inhibited the growth of all strains with minimum inhibitory concentrations of 0.27-1.10 mM. The biological results corroborated the molecular model, which pointed to a multi-target antifungal mechanism of action for MDNB in C. albicans. The study could serve as a basis for further research involving compounds with nitro groups with antifungal.

Methyleugenol Has an Antidepressant Effect in a Neuroendocrine Model: In Silico and In Vivo Evidence.

Major depressive disorder is a severe mood disorder characterized by different emotions and feelings. This study investigated the antidepressant activity of the phenylpropanoid methyleugenol (ME) in adult female mice exposed to a stress model induced by dexamethasone. The animals were randomly divided into groups containing eight animals and were pre-administered with dexamethasone (64 µg/kg subcutaneously). After 165 and 180 min, they were treated with ME (25, 50 and 100 mg/kg intraperitoneally) or imipramine (10 mg/kg intraperitoneally) after 45 min and 30 min, respectively; they were then submitted to tests which were filmed. The videos were analyzed blindly. In the tail suspension test, ME (50 mg/kg) increased latency and reduced immobility time. In the splash test, ME (50 mg/kg) decreased grooming latency and increased grooming time. In the open field, there was no statistical difference for the ME groups regarding the number of crosses, and ME (50 mg/kg) increased the number of rearing and time spent in the center. Regarding in silico studies, ME interacted with dopaminergic D1 and α1 adrenergic pathway receptors and with tryptophan hydroxylase inhibitor. In the in vivo evaluation of the pathways of action, the antidepressant potential of ME (50 mg/kg) was reversed by SCH23390 (4 mg/kg intraperitoneally) dopaminergic D1 receptor, Prazosin (1 mg/kg intraperitoneally) α1 adrenergic receptor, and PCPA (4 mg/kg intraperitoneally) tryptophan hydroxylase inhibitor. Our findings indicate that ME did not alter with the locomotor activity of the animals and shows antidepressant activity in female mice with the participation of the D1, α1 and serotonergic systems.

Computational Studies Applied to Linalool and Citronellal Derivatives Against Alzheimer's and Parkinson's Disorders: A Review with Experimental Approach.

Alzheimer's and Parkinson's are neurodegenerative disorders that affect a great number of people around the world, seriously compromising the quality of life of individuals, due to motor and cognitive damage. In these diseases, pharmacological treatment is used only to alleviate symptoms. This emphasizes the need to discover alternative molecules for use in prevention. Using Molecular Docking, this review aimed to evaluate the anti-Alzheimer's and anti-Parkinson's activity of linalool and citronellal, as well as their derivatives. Before performing Molecular Docking simulations, the compounds' pharmacokinetic characteristics were evaluated. For Molecular Docking, 7 chemical compounds derived from citronellal, and 10 compounds derived from linalool, and molecular targets involved in Alzheimer's and Parkinson's pathophysiology were selected. According to the Lipinski rules, the compounds under study presented good oral absorption and bioavailability. For toxicity, some tissue irritability was observed. For Parkinson-related targets, the citronellal and linalool derived compounds revealed excellent energetic affinity for α-Synuclein, Adenosine Receptors, Monoamine Oxidase (MAO), and Dopamine D1 receptor proteins. For Alzheimer disease targets, only linalool and its derivatives presented promise against BACE enzyme activity. The compounds studied presented high probability of modulatory activity against the disease targets under study, and are potential candidates for future drugs.

Effects of long-term cinnamaldehyde immersion on the surface roughness and color of heat-polymerized denture base resin.

STATEMENT OF PROBLEM: Cinnamaldehyde has been successfully used for the short-term disinfection of dentures; however, its long-term effects on the surface and color properties of denture base materials remain unknown. PURPOSE: The purpose of this in vitro study was to evaluate the effects of simulated immersion in cinnamaldehyde for up to 5 years on the surface roughness and color parameters of a heat-polymerized denture resin. MATERIAL AND METHODS: Eighty Ø10×5-mm disk-shaped specimens were prepared from microwave heat-polymerized polymethylmethacrylate (PMMA) and immersed in 4 solutions (n=20): TW-tap water (control), SH - 0.5% sodium hypochlorite, PX-alkaline peroxide, and CA-cinnamaldehyde (27 µg/mL). The immersion protocol simulated 104 cycles (3.5 months), 913 cycles (2.5 years), and 1825 immersion cycles (5 years) of a daily immersion cleaning protocol, with immersion times ranging from 10 to 20-minutes. Surface roughness (Sa) and the color parameters of CIELab (L∗ a∗ b∗, ΔEab), CIEDE2000 (ΔE00), and the National Bureau of Standards (NBS) were analyzed at baseline (t=0) and after the immersion cycles. The data were analyzed by 2-way analysis of variance (ANOVA) for repeated measures and the Tukey post hoc test (α=.01). RESULTS: Sa was significantly increased in all groups after 1825 cycles compared with baseline (P<.01), regardless of the solution. Only the time factor significantly affected ΔEab, ΔE00, and NBS parameters, which were below the perceptibility and acceptability thresholds. After a simulated 5-year immersion, the surface roughness and color values of CA-treated specimens were not statistically different from those of the other groups (P>.01). CONCLUSIONS: Cinnamaldehyde solution (27 µg/mL) produced minor effects on the surface roughness and color parameters of a heat-polymerized denture base resin similar to those of 0.5% sodium hypochlorite and alkaline peroxide after a 5-year simulated immersion.

Safety and tolerability of cinnamaldehyde in orabase for oral candidiasis treatment: phase I clinical trial.

OBJECTIVE: To advance studies on the effect of a new pharmaceutical formulation for the treatment of oral fungal infections, we evaluated the safety and tolerability of orabase ointment containing cinnamaldehyde for use on the oral mucosa. MATERIAL AND METHODS: A clinical trial (phase I) was carried out on 35 individuals with healthy oral mucosa divided into three groups: ointments at 200 µg/mL, n = 12; 300 µg/mL, n = 11; and 400 µg/mL, n = 12. Product safety was assessed using three parameters: (a) clinical evolution as recorded by trained examiners; (b) evolution of the inflammatory process as registered by an exfoliative cytology exam and analyzed by trained pathologists; (c) mucosal swab to count Candida spp. colony-forming units (CFU). These parameters were analyzed both beforehand and at 15 days of treatment. RESULTS: The three ointment concentrations evaluated did not trigger inflammatory processes. The mycological analyses revealed a reduction of at least 99% in the number of Candida spp. CFU. In the exfoliative cytology analyses, the cells were found to be healthy. Participants reported a pleasant taste, yet 17% reported a slight burning sensation when applying the product. CONCLUSIONS: The ointment is safe and tolerable for use on healthy oral mucosa. TRIAL REGISTRATION: Registration number: RBR-7zwzs3. CLINICAL RELEVANCE: The ointment proved to be safe and tolerable for use on oral mucosa, encouraging studies to evaluate its clinical efficacy in patients with oral candidiasis, and contributing to a new therapeutic proposal for the treatment of fungal infections caused by Candida spp.

Hydrochlorothiazide use is associated with the risk of cutaneous and lip squamous cell carcinoma: A systematic review and meta-analysis.

PURPOSE: The aim of this study is to investigate the association between hydrochlorothiazide (HCTZ) use and the risk of cutaneous and lip squamous cell carcinoma development. METHODOLOGY: We performed a systematic review and meta-analysis of case-control studies. We searched the Cochrane Library, PubMed, Scopus, Web of Science and LILACS. This study was registered in PROSPERO under protocol CRD42019129710. The meta-analysis was performed using the software Stata (version 12.0). RESULTS: A total of 2181 published studies referring to the theme were identified, from which six were included in this systematic review. Men were more frequently affected by cutaneous and lip squamous cell carcinoma than women, with a 1.42:1 ratio. The mean age for cutaneous and lip squamous cell carcinoma development was 73.7 years. This meta-analysis demonstrated a chance of developing cutaneous and lip squamous cell carcinoma in any region of the body in hydrochlorothiazide users of 1.76-fold higher than in non-users. In addition, a risk factor of 1.80 higher (CI 95% = 1.71-1.89) of cutaneous squamous cell carcinoma in the head and neck region was observed in HCTZ users. Moreover, in the analysis of the dose used, the chance of developing squamous cell carcinoma was 3.37-fold lower when the concentration of HCTZ used was less than 50,000 mg. CONCLUSIONS: Our results confirm the association between the use of hydrochlorothiazide and the cutaneous and lip squamous cell carcinoma development.

Toxicological Parameters of a Formulation Containing Cinnamaldehyde for Use in Treatment of Oral Fungal Infections: An In Vivo Study.

OBJECTIVE: We aimed to define the safety and toxicity of both isolated and embedded cinnamaldehyde using a pharmaceutical formulation for the treatment of oral fungal infections in an in vivo study. MATERIALS AND METHODS: Acute toxicity was assessed in studies with Galleria mellonella larvae and Danio rerio embryos (zebrafish), and genotoxicity was assessed in a mouse model. The pharmaceutical formulation (orabase ointment) containing cinnamaldehyde was evaluated for verification of both in vitro antifungal activity and toxicity in keratinized oral rat mucosa. RESULTS: In Galleria mellonella larvae, cinnamaldehyde was not toxic up to the highest dose tested (20 mg/kg) and presented no genotoxicity up to the dose of 4 mg/kg in the model using mice. However, it was found to be toxic in zebrafish embryos up to a concentration of 0.035 µg/mL; LC50 0.311; EC50 0.097 (egg hatching delay); and 0.105 (Pericardial edema). In the orabase antifungal susceptibility test, cinnamaldehyde exhibited activity in concentrations greater than 200 µg/mL. As for safety in the animal model with rats, the orabase ointment proved to be safe for use on keratinized mucosa up to the maximum concentration tested (700 µg/mL). CONCLUSIONS: At the concentrations tested, cinnamaldehyde was not toxic in vertebrate and invertebrate animal models and did not exhibit genotoxic activity. In addition, when used in the form of an ointment in orabase, having already recognized antifungal activity, it was shown to be safe up to the highest concentration tested.

Cytotoxic and Antifungal Amides Derived from Ferulic Acid: Molecular Docking and Mechanism of Action.

Amides derived from ferulic acid have a wide spectrum of pharmacological activities, including antitumor and antifungal activity. In the present study, a series of ten amides were obtained by coupling reactions using the reagents (benzotriazol-1-yloxy) tripyrrolidinophosphonium hexafluorophosphate (PyBOP) and N,N'-dicyclohexylcarbodiimide (DCC). All the compounds were identified on the basis of their IR, 1H- and 13C-NMR, HRMS data, and with yields ranging from 43.17% to 91.37%. The compounds were subjected to cytotoxic tests by the alamar blue technique and antifungal screening by the broth microdilution method to determine the minimum inhibitory concentration (MIC). The amides 10 and 11 displayed the best result in both biological evaluations, and compound 10 was the most potent and selective in HL-60 cancer cells, with no cytotoxicity on healthy cells. This amide had antifungal activity in all strains and had the lowest MIC against Candida albicans and Candida tropicalis. The possible mechanism of antifungal action occurs via the fungal cell wall. Molecular modeling suggested that compounds 10 and 11 interact with the enzymes GWT1 and GSC1, which are essential for the development of C. albicans. The findings of the present study demonstrated that compounds 10 and 11 may be used as a platform in drug development in the future.

Breakpoints for the Classification of Anti-Candida Compounds in Antifungal Screening.

INTRODUCTION: The absence of a standardized classification scheme for the antifungal potency of compounds screened against Candida species may hinder the study of new drugs. This systematic review proposes a scheme of interpretative breakpoints for the minimum inhibitory concentration (MIC) of bioactive compounds against Candida species in in vitro tests. MATERIALS AND METHODS: A literature search was conducted in the PubMed, Scopus, Web of Science, Lilacs, and SciFinder databases for the period from January 2015 to April 2020. The following inclusion criterion was used: organic compounds tested by the microdilution technique according to the Clinical and Laboratory Standards Institute protocol against reference strains of the genus Candida. A total of 545 articles were retrieved after removing duplicates. Of these, 106 articles were selected after applying the exclusion criteria and were evaluated according to the number of synthesized molecules and their chemical classes, the type of strain (reference or clinical) used in the antifungal test, the Candida species, and the MIC (in µg/mL) used. RESULTS: The analysis was performed based on the median, quartiles (25% and 75%), maximum, and minimum values of four groups: all strains, ATCC strains, C. albicans strains, and C. albicans ATCC strains. The following breakpoints were proposed to define the categories: MIC < 3.515 µg/mL (very strong bioactivity); 3.516-25 µg/mL (strong bioactivity); 26-100 µg/mL (moderate bioactivity); 101-500 µg/mL (weak bioactivity); 500-2000 µg/mL (very weak bioactivity); and >2000 µg/mL (no bioactivity). CONCLUSIONS: A classification scheme of the antifungal potency of compounds against Candida species is proposed that can be used to identify the antifungal potential of new drug candidates.

Integrated oral care contributes positively to the course of treatment of oncopediatric patients.

The purpose of this study was to implement a model of permanent oral health care for oncopediatric patients and to observe its effects on severe oral mucositis and subsequent treatment interruptions. We performed a quasi-experimental study in the Pediatric Department of Napoleão Laureano Hospital, in the city of João Pessoa, Brazil. A integrated oral care was implemented by a dentistry team for prevention of comorbidities, such as infections, oral pain, oral function maintenance, oral mucositis, and interventions for lesions due to severe oral mucositis. The oral comorbidities were compared before and after the implementation. The duration of severe oral mucositis (SOM) before and after the interventions and the interruptions in treatment due to SOM were the main outcome measures. Permanent oral health care reduced the duration of SOM and reduced pediatric chemotherapy interruptions due to SOM by 81.8%.Conclusion: The permanent oral health care to offer to oncopediatric patients increased surveillance regarding oral comorbidities and reduced chemotherapy interruptions due to severe oral mucositis. This care plan could be adopted anywhere around the world. What is Known: • Several studies on oral care for pediatric oncology patients, especially regarding both prevention of and treatment for oral mucositis during antineoplastic therapy, have been published. What is New: • This study describes the benefits of permanent oral care with daily oral surveillance for pediatric patients, which reduced the duration of severe oral mucositis, increased surveillance and the efficiency in diagnostic for signs of oral mucositis, enabling early intervention, and decreased chemotherapy interruptions, contributing positively to the course of treatment.

Efficacy of essential oil of cinnamon for the treatment of oral candidiasis: A randomized trial.

AIM: It was analyzed the efficacy of mouthwash and spray containing essential oil (EO) of Cinnamomum zeylanicum Blume for the treatment of oral candidiasis. METHODS AND RESULTS: A randomized, controlled, and blinded clinical trial was conducted with 36 individuals (probabilistic sample) with oral candidiasis who were divided into two treatment groups: C. zeylanicum (0.5 mg/mL), n = 18; nystatin (100,000IU/mL), n = 18. The efficacy of the products was evaluated by two parameters: (a) clinical evolution recorded by calibrated examiners (Kappa = 0.822) according to Newton's classification and (b) reduction of colony-forming units/mL. Mycological and clinical parameters were analyzed before and at 15 days after treatment. Clinical examination of the mucosa showed that C. zeylanicum (p < 0.0339) and nystatin (p < .0139) had efficacy, resulting in a reduction of signs and symptoms (Mann-Whitney test). Mycological analysis showed that C. zeylanicum caused a reduction of 61% and 33% of Candida spp., isolates oral mucosa and dentures, respectively. Candida tropicalis strains were eliminated after C. zeylanicum, in both sites. The participants reported a pleasant taste and few product-related complaints. CONCLUSION: C. zeylanicum EO and nystatin exhibited clinical efficacy, according to the Newton classification, and reducing in Candida spp. The clinical trial has been registered (Registration number: NBR-33s6 × 5, ensaiosclinicos.gov.br).

Risk factors for anterior open bite: A case-control study.

BACKGROUND: Anterior open bite (AOB) is noteworthy because it is a complex dysplasia, and clinical studies on this malocclusion are usually epidemiological studies or experimental models with small samples and no control group, which renders the data on AOB incomplete and therefore inconclusive. The objective this study was to assess the risk factors involved in developing AOB. MATERIALS AND METHODS: A case-control study was provided with a total of 96 lateral cephalometric radiographs of male and female patients aged between 8 and 14 years were used, regardless of facial type. The dependent variable was the presence or absence of AOB, which divided the participants into case and control groups, respectively; these groups were matched for gender and age. The case and control groups data were analyzed by descriptive and inferential analysis by binary logistic regression using at the 5% significance level. RESULTS: The occurrence of AOB was associated with the presence of deleterious oral habits (P = 0.014; Chi-square test) and was approximately three times (odds ratio = 3.04) more likely to occur in participants with AOB. No significant association between the presence of mouth breathing and the occurrence of AOB was found (P = 0.151; Chi-square test). The odds associated with tongue interposition were 10.51 times higher than those of participants with no such deglutition. The odds associated with the dolichofacial pattern were 5.74 times those of participants with a nondolichofacial pattern. CONCLUSION: Tongue interposition and dolichocephalic facial pattern were risk factors for developing AOB.

Cinnamaldehyde is a biologically active compound for the disinfection of removable denture: blinded randomized crossover clinical study.

BACKGROUND: Fungal infections associated with the use of dentures, like denture stomatitis, are difficult to prevent and treat. This in situ study aimed to investigate the efficacy of cinnamaldehyde for the disinfection of complete removable dentures, and the effect on the physical and mechanical properties (Vickers microhardness, color, and surface roughness) of the acrylic resin. METHODS: Acrylic resin disks were inserted into the dentures of a probabilistic sample of 33 complete denture users, that used cinnamaldehyde (27 µg/mL) and 0.5% sodium hypochlorite solutions in a 20 min/7-days protocol of dentures immersion in each solution, with a wash-out period of 7 days, to constitute a crossover-study. The disks were analyzed before and after the immersion, for the presence of microorganisms (CFU/mL) and by scanning electron microscope (SEM). Also, the surface roughness (Ra) and Vickers microhardness were measured, and color parameters were analyzed using the National Bureau of Standards (NBS) method. Data was analyzed by Wilcoxon and Friedman (microbiological evaluation), paired t-test (color and roughness) and independent t-test (Vickers hardness) (α = 0.05). RESULTS: A significant reduction (P < 0.05) in the number of microorganisms was observed for each species (total microorganisms, Streptococcus mutans, and Candida spp.), with no significant differences (P > 0.05) between hypochlorite and cinnamaldehyde. There was an increase in the roughness and a decrease in the hardness of the test specimens, with no difference between the two disinfectant substances (P > 0.05). Both hypochlorite and cinnamaldehyde also caused changes in color, considered as "perceptible" by the NBS classification, but with no significant difference between disinfectant substances (P < 0.05), and under the clinically acceptable limit (ΔE ≤ 3.7). CONCLUSION: The 27 µg/mL cinnamaldehyde solution was effective against all evaluated microorganisms and caused minor alterations in hardness, surface roughness, and color parameters, with no clinical relevance.

Antifungal activity of Punicalagin-nystatin combinations against Candida albicans.

OBJECTIVES: Oral candidiasis is the most common opportunistic fungal infection of oral mucosa and results from an overgrowth of Candida, especially Candida albicans. The potential anti-C. albicans and cytotoxicity of punicalagin (PCG), isolated from Punica granatum, alone or with nystatin (NYS) were evaluated. METHODS: Activity of compounds alone or in combinations was determined against two C. albicans strains (ATCC 90028 and SC5314). Minimal inhibitory concentration (MIC)-50 and Minimum Fungicidal Concentration (MFC) were assessed by XTT assay and CFU counts, respectively. For combinations, determination of fractional inhibitory concentration index was performed. Ergosterol pathway was investigated as a possible PCG antifungal mechanism. Cytotoxicity assays were undertaken on human primary oral keratinocytes and gingival fibroblasts incubated with antifungal concentrations of PCG and/or NYS for 24 hr. RESULTS: Combination of NYS and PCG increased antifungal efficacy, compared with compounds tested alone. Combinations 4 (PCG-6.25 µg/ml; NYS-3.9 µg/ml) and 5 (PCG-12.5 µg/ml; NYS-1.95 µg/ml) were more effective since they reduced the MIC-50 of PCG (50 µg/ml) by 8 and 4 times, respectively, increased the candidal inhibition and nullified the PCG cytotoxicity for keratinocytes. PCG antifungal mechanism did not involve ergosterol biosynthesis pathway. CONCLUSIONS: The favorable outcomes for combination of PCG and NYS encourage further testing this therapeutic strategy against C. albicans.

Amides Derived from Vanillic Acid: Coupling Reactions, Antimicrobial Evaluation, and Molecular Docking.

A series of amides derived from vanillic acid were obtained by coupling reactions using PyBOP ((Benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate) and DCC (Dicyclohexylcarbodiimide) coupling reagents. These were submitted to biological evaluation for species of Candida, Staphylococcus, and Pseudomonas. The microdilution method in broth was used for the antimicrobial testing to determine the Minimum Inhibitory Concentration (MIC) and to verify the likely mechanism of action for antifungal activity. The ten amides were obtained with yields ranging from 28.81 to 86.44%, and three compounds were novel. In the antibacterial evaluation, the amides (in their greatest concentrations) were bioactive against Staphylococcus aureus strain ATCC 25925. Meanwhile, all of the tested amides presented antifungal activity against at least one strain. The amide with best antifungal profile was compound 7, which featured an MIC of 0.46 µmol/mL, and a mechanism of action involving the plasma membrane and fungal cell wall. The presence of a methyl group in the para position of the aromatic ring is suggested which enhances the activity of the compound against fungi. Docking studies of the ten compounds using the protein 14α-demethylase as a biological target were also performed. The biological results presented good correlation with molecular docking studies demonstrating that a possible site of antifungal action for bioactive amides is the enzyme 14α-demethylase.

Antifungal Activity, Mode of Action, Docking Prediction and Anti-biofilm Effects of (+)-ß-pinene Enantiomers against Candida spp.

AIMS: The objective of this study was to investigate the effectiveness of (+)-ß-pinene inhibition on Candida spp. growth, aiming at elucidation of the mechanism of action; to determine fungal cell enzyme binding activity (through molecular docking simulations) and its effects on biofilm reduction. METHODS: Candida strains (n=25) from referenced and clinical origins, either susceptible or resistant to standard clinical antifungals, were tested for determination of Minimum Inhibitory Concentration (MIC); Minimum Fungicidal Concentration (MFC); and microbial death curves upon treatment with (+)-ß-pinene; the effects of (+)-ß-pinene on the cell wall (sorbitol assay), membrane ergosterol binding, and effects on biofilm were evaluated by microdilution techniques. We also evaluated the interactions between (+)-ß-pinene and cell wall and membrane enzymes of interest. RESULTS: The MIC values of (+)-ß-pinene ranged from <56.25 to 1800 µmol/L. The MIC of (+)-ß-pinene did not increase when ergosterol was added to the medium, however it did increase in the presence of sorbitol, leading to a doubled MIC for C. tropicalis and C. krusei. The results of the molecular docking simulations indicated better interaction with delta-14-sterol reductase (-51 kcal/mol). (+)-ß-pinene presents anti-biofilm activity against multiples species of Candida. CONCLUSION: (+)-ß-pinene has antifungal activity and most likely acts through interference with the cell wall; through molecular interaction with Delta-14-sterol reductase and, to a lesser extent, with the 1,3-ß- glucan synthase. This molecule was also found to effectively reduce Candida biofilm adhesion.

In Vitro Effect of Cinnamomum zeylanicum Blume Essential Oil on Candida spp. Involved in Oral Infections.

The present study demonstrates the antifungal potential of chemically characterized essential oil (EO) of Cinnamomum zeylanicum Blume on Candida spp. biofilm and establishes its mode of action, effect on fungal growth kinetics, and cytotoxicity to human cells. The minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values varied from 62.5 to 1,000 µg/mL, and the effect seems to be due to interference with cell wall biosynthesis. The kinetics assay showed that EO at MICx2 (500 µg/mL) induced a significant (p < 0.05) reduction of the fungal growth after exposure for 8 h. At this concentration, the EO was also able to hinder biofilm formation and reduce Candida spp. monospecies and multispecies in mature biofilm at 24 h and 48 h (p < 0.05). A protective effect on human red blood cells was detected with the EO at concentrations up to 750 µg/mL, as well as an absence of a significant reduction (p > 0.05) in the viability of human red blood cells at concentrations up to 1,000 µg/mL. Phytochemical analysis identified eugenol as the main component (68.96%) of the EO. C. zeylanicum Blume EO shows antifungal activity, action on the yeast cell wall, and a deleterious effect on Candida spp. biofilms. This natural product did not show evidence of cytotoxicity toward human cells.