Green propolis may represent a promising therapeutic alternative against dental anaerobic pathogens because of its antimicrobial action. This study aimed to evaluate the antimicrobial and antibiofilm actions of Brazilian green propolis aqueous extract (BGP-AqExt) against dental anaerobic bacteria. The minimum inhibitory concentration (MIC) and minimum microbicide concentration (MMC) of the extract were determined against the standard strains (ATCC) of Fusobacterium nucleatum, Parvimonas micra, Prevotella intermedia, Porphyromonas gingivalis and Porphyromonas endodontalis. BGP-AqExt was chemically characterized by high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis. Antibiofilm action was measured by MTT and crystal violet tests. The data were statistically analyzed by ANOVA and Tukey (5%) tests. The extract had antimicrobial action against all tested anaerobic bacteria, with an MIC value of 55 mg/mL for all bacteria, an MMC of 27.5 mg/mL for F. nucleatum and P. micra and 55 mg/mL for P. intermedia. Chemically, BGP-AqExt is composed of quercetin, gallic acid, caffeic and p-coumaric acid, drupani, kaempferol and Artepillin C. Significant reductions in biomass and metabolic action of biofilms were found after BGP-AqExt application. Therefore, BGP-AqExt has an antimicrobial and antibiofilm effect against dental anaerobic bacteria.
Candida auris is an emerging Candida sp. that has rapidly spread all over the world. The evidence regarding its origin and emerging resistance is still unclear. The severe infection caused by this species results in significant mortality and morbidity among the elderly and immunocompromised individuals. The development of drug resistance is the major factor associated with the therapeutic failure of existing antifungal agents. Previous studies have addressed the antifungal resistance profile and drug discovery for C. auris. However, complete coverage of this information in a single investigation is not yet available. In this review, we have mainly focused on recent developments in therapeutic strategies against C. auris. Based on the available information, several different approaches were discussed, including existing antifungal drugs, chemical compounds, essential oils, natural products, antifungal peptides, immunotherapy, antimicrobial photodynamic therapy, drug repurposing, and drug delivery systems. Among them, synthetic chemicals, natural products, and antifungal peptides are the prime contributors. However, a limited number of resources are available to prove the efficiency of these potential therapies in clinical usage. Therefore, we anticipate that the findings gathered in this review will encourage further in vivo studies and clinical trials.
Cryptococcal infection commonly begins as an opportunistic infection in humans, however, this can escalate to a systemic or life-threatening form in immunocompromised individuals. Here, we aim to identify novel antifungal molecules from plants resources. Sclareolide, a phytochemical classified as a sesquiterpene lactone, was assessed against Cryptococcus neoformans H99. Sclareolide exhibited promising antifungal properties with a minimum inhibitory concentration (MIC) of 16 µg/mL. Additionally, the C. neoformans growth rate was significantly affected by sclareolide treatment in a concentration-dependent manner, as observed through a time killing assay, with a significant reduction at MIC × 8 compared to the control by 48 h. To elucidate the underlying mechanisms of sclareolide antifungal activity, fluorescence-based methods were employed. Propidium iodide (PI) accumulation assay indicated a reduction in C. neoformans membrane integrity, with values as low as 6.62 ± 0.18% after treatment. Moreover, sclareolide at MIC × 4 and MIC × 8 significantly increased the production of reactive oxygen species (ROS) and reduced the mitochondrial membrane potential (MMP), suggesting oxidative stress and mitochondrial dysfunction in C. neoformans. Sclareolide did not induce caspase-dependent apoptosis, suggesting a non-apoptotic mechanism. Further, a checkerboard experiment was performed to assess potential synergistic interaction with Amphotericin B, however, no synergism was observed. Moving on, sclareolide at 128 µg/mL did not exhibit toxicity in Galleria mellonella, further supporting its potential as a safe antifungal agent. These findings suggest that the antifungal activity of sclareolide against C. neoformans is mediated by oxidative stress. Further in vivo and pharmacokinetic studies are recommended to explore the potential of sclareolide as a prototype for the development of novel anti-cryptococcal therapies.
Candida albicans can cause various types of oral infections, mainly associated with denture stomatitis. Conventional therapy has been linked to high recurrence, toxicity, and fungal resistance, necessitating the search for new drugs and delivery systems. In this study, caffeic acid phenethyl ester (CAPE) and gellan gum (GG) were studied as an antifungal agent and carrier system, respectively. First, we observed that different GG formulations (0.6 to 1.0% wt/vol) were able to incorporate and release CAPE, reaching a controlled and prolonged release over 180 min at 1.0% of GG. CAPE-GG formulations exhibited antifungal activity at CAPE concentrations ranging from 128 to >512 µg/mL. Furthermore, CAPE-GG formulations significantly decreased the fungal viability of C. albicans biofilms at short times (12 h), mainly at 1.0% of GG (p < 0.001). C. albicans protease activity was also reduced after 12 h of treatment with CAPE-GG formulations (p < 0.001). Importantly, CAPE was not cytotoxic to human keratinocytes, and CAPE-GG formulations at 1.0% decreased the fungal burden (p = 0.0087) and suppressed inflammation in a rat model of denture stomatitis. Altogether, these results indicate that GG is a promising delivery system for CAPE, showing effective activity against C. albicans and potential to be used in the treatment of denture stomatitis.
1 January 2021 in Research, Society and Development
Objective: Treponema denticola “T. denticola” is a pathogen associated with periodontal diseases that exhibits capacity for adherence, invasion, and colonization of host tissues, which allows alternating its location and damage in different sites of human body. This review aimed to discuss different studies that detected T. denticola in atherosclerotic plaques, demonstrating the importance of periodontal disease on the systemic health and the necessity of exploring the outcome of this colonization apart from the oral cavity. Methodology: Fifty-five studies were identified and gathered in this review according to the following topics: Periodontal disease, atherosclerosis and T. denticola. In vitro and in vivo studies published between 2002 and 2020 were searched on PubMed, raising relevant insights about the role of T. denticola and its association with the systemic disease, atherosclerosis, focusing on the bacterial tissue invasion and development of atherosclerosis. Results: After bibliographic review, it was possible to identify studies demonstrating the presence of T. denticola and other oral pathogens in cardiac or vascular tissues and in blood serum, as well, there is research in which other evidence of a relationship with atherosclerosis is shown. Conclusion: The invasion of periodontal pathogens and its toxins associated to the host’s immune and inflammatory response may contribute to the development of atherosclerosis.
Enterococcus faecalis and Enterococcus faecium are frequently associated with persistent endodontic infections due to their ability to form biofilms and resist conventional treatments. The aim of this study was to evaluate the antibacterial and antibiofilm effects of Lavandula dentata L. essential oil at 100% against the standard and clinical strains of Enterococcus spp. The minimum bactericidal concentration (MBC) of L. dentata essential oil for each bacterial strain was determined. The antibiofilm effect was evaluated by an MTT assay. Data were statistically analyzed by the ANOVA and Tukey test, with a significance level of 5%. The MBC value was 32% (292.8 mg/mL) against all the tested strains. L. dentata significantly reduced E. faecalis and E. faecium biofilms at 16–64% (146.4–585.6 mg/mL) concentrations, with effects comparable to 2% chlorhexidine (CHX) (p ≥ 0.05). Biofilm reduction was strain-dependent at 30 min but showed broader efficacy after 24 h, particularly against E. faecium clinical strains (p ≤ 0.001). L. dentata demonstrated effective antimicrobial activity against planktonic and biofilm forms of E. faecalis and E. faecium as it reduced biofilm formation at a concentration of 16% and 64% (146.4 and 585.6 mg/mL), with results comparable to 2% CHX after 30 min and 24 h. L. dentata EO may serve as a potential alternative or adjunctive antimicrobial agent in endodontic treatment. However, the study’s limitations included the in vitro design and lack of cytotoxicity assessment.