Cellular Structural Changes in Candida albicans Caused by the Hydroalcoholic Extract from Sapindus saponaria L.

Vulvovaginal candidiasis (VVC) is a disease caused by the abnormal growth of yeast-like fungi in the mucosa of the female genital tract. Candida albicans is the principal etiological agent involved in VVC, but reports have shown an increase in the prevalence of Candida non-C. albicans (CNCA) cases, which complicates VVC treatment because CNCA does not respond well to antifungal therapy. Our group has reported the in vitro antifungal activity of extracts from Sapindus saponaria L. The present study used scanning electron microscopy and transmission electron microscopy to further evaluate the antifungal activity of hydroalcoholic extract from S. saponaria (HE) against yeast obtained from VVC and structural changes induced by HE. We observed the antifungal activity of HE against 125 vaginal yeasts that belonged to four different species of the Candida genus and S. cerevisae. The results suggest that saponins that are present in HE act on the cell wall or membrane of yeast at the first moments after contact, causing damage to these structures and cell lysis.

In vitro antifungal activity of curcumin mediated by photodynamic therapy on Sporothrix brasiliensis.

BACKGROUND: Sporothrix brasiliensis is a pathogenic dimorphic fungus that affects humans and animals causing sporotrichosis. The treatment of this disease with conventional antifungals commonly results in therapeutic failures and resistance. Therefore, this study aimed to evaluate the in vitro effect of curcumin (CUR) mediated by photodynamic therapy (PDT) in its pure state and incorporated into pharmaceutical formulation in gel form, on the filamentous and yeast forms of S. brasiliensis. METHODS: Cells from both forms of the fungus were treated with pure curcumin (PDT-CUR). For this, CUR concentrations ranging from 0.09 to 50 µM were incubated for 15 min and then irradiated with blue LED at 15 J/cm². Similarly, it was performed with PDT-CUR-gel, at lower concentration with fungistatic action. After, a qualitative and quantitative (colony forming units (CFU)) analysis of the results was performed. Additionally, reactive oxygen species (ROS) were detected by flow cytometry. Results PDT with 0.78 µM of CUR caused a significant reduction (p < 0.05) in cells of the filamentous and yeast form, 1.38 log10 and 1.18 log10, respectively, in comparison with the control. From the concentration of 1.56 µM of CUR, there was a total reduction in the number of CFU (≥ 3 log10). The PDT-CUR-gel, in relation to its base without CUR, presented a significant reduction (p < 0.05) of 0.83 log10 for the filamentous form and for the yeast form, 0.72 log10. ROS release was detected after the PDT-CUR assay, showing that this may be an important pathway of death caused by photoinactivation. Conclusion PDT-CUR has an important in vitro antifungal action against S. brasiliensis strains in both morphologies.

Analysis of the antifungal potential of Macrocybe titans extract against Candida albicans.

Aim: To investigate the antifungal potential of Macrocybe titans extracts against Candida albicans. Material & methods: Extracts were obtained as aqueous (EfraMat-22 and EfraMat-45) and methanolic/ethyl acetate fractions. Results: Broth microdilution and disk diffusion assays showed that EfraMat-45 provided the best results in terms of minimum inhibitory concentration. Scanning electron microscopy analysis revealed morphological changes and slight damage on the surfaces of cells exposed to EfraMat-45 at the MIC. Fluorescence microscopy analysis of the yeasts showed cell elongation. EfraMat-45 presented high levels of phenolic compounds and flavonoids, high antioxidant activity and absence of in vitro cytotoxicity. Conclusion: The results indicated that the aqueous extract of M. titans is highly promising as an antifungal agent.

Successful treatment of experimental murine vulvovaginal candidiasis with gentian violet.

Aim: This study evaluated the antifungal efficacy of gentian violet (GV) in an experimental vulvovaginal candidiasis (VVC) model. Materials & methods: In vitro susceptibility and cytotoxicity assays were performed to validate the antifungal potential and safety of GV. The antifungal efficacy was then evaluated in vivo through comparative analysis of the fungal burden following treatment with GV or nystatin, as well as assessment of the vaginal tissue by histology and electron microscopy. Results: GV demonstrated a safe antifungal profile against C. albicans, with a significant decrease in fungal burden and an improvement in the inflammatory process evaluated histologically. Conclusion: The results of this study motivate further assessment of GV as a promising alternative for VVC therapy.

Cell wall associated proteins involved in filamentation with impact on the virulence of Candida albicans.

Candida albicans is a commensal microorganism of the human microbiota that can be associated with superficial to disseminated infections. This species possesses several attributes that contribute to pathogenesis and virulence, such as the ability to transition from yeast to hyphae forms. During this transition, several changes occur in the fungal cell wall, which is the first point of contact between the pathogen and the host. The cell wall is a bi-layered structure, containing chitin, glucan, and proteins, the latter of which play important roles in pathogenesis. Given the importance of this structure, particularly in filamentation, this review focuses on the studies of C. albicans mutants for genes that encode cell wall-associated proteins that have an important role in the virulence, and also have a role in hyphal morphogenesis. Thus, we highlight some proteins whose mutation is associated with attenuated virulence in vivo and have defective filamentation. We also provide examples of proteins whose inactivation does not impair the filamentation yet are still important for C. albicans virulence.

The zoonosis sporotrichosis can be successfully treated by photodynamic therapy: A scoping review.

Sporotrichosis is a worldwide zoonosis, prevalent in tropical and subtropical regions. In recent years, there has been a substantial increase in human and feline cases reported in Brazil. Despite this, the antifungal treatment for sporotrichosis is still limited, and thus, research into new therapeutic modalities must be encouraged. Recently, photodynamic therapy has been introduced as a treatment for sporotrichosis. This work presents an overview of both in vitro and in vivo studies that have used photodynamic therapy in the context of photoinactivation of Sporothrix species. Until now, as far as the authors are aware, this is the first scope review specifically on photodynamic therapy for the treatment of sporotrichosis. A systematic electronic search was conducted in two databases: Web of Science and PubMed. Seven original articles published from 2010 to July 2021 were selected, six of which met the proposed inclusion and exclusion criteria and were considered in this scoping review. Concerning the photoinactivation of Sporothrix spp. the results have been promising as studies, in both animals and humans, have reported significant clinical and mycological effects. The most used photosensitizers were methylene blue and its derivatives, and aminolevulinic acid and its methyl derivative, methyl aminolevulinic acid. In conclusion, photodynamic therapy has great potential in treatment of sporotrichosis, as its fungicidal effect both in vitro and in vivo has clearly been demonstrated. Photodynamic therapy could be used in conjunction with classic antifungal agents to optimize treatment outcomes.

Hypericin-P123-photodynamic therapy in an ex vivo model as an alternative treatment approach for onychomycosis caused by Fusarium spp.

BackgroundFusarium has been considered an opportunistic pathogen, causing several infections in humans, including onychomycosis. In addition, a high resistance to conventional antifungals has been linked to this genus. Photodynamic Therapy (PDT), known as a non-invasive therapy, can be an alternative treatment for fungal infections, based on the excitation of a photosensitizing compound (PS) by a specific length of light, causing damage to the target. The aim of this study was to evaluate the effects of a formulation of Hypericin (Hyp) encapsulated in Pluronic™ (P123), via photodynamic therapy (PDT), on planktonic cells and biofilms in Fusarium spp. using in vitro and ex vivo assays. Materials & Methods epidemiology studies about Fusarium spp. in onychomycosis was perfomed, carried out molecular identification, compared the antifungal activity of the conventional antifungals with PDT with encapsulated Hypericin (Hyp-P123), carried out detection of reactive oxygen species, and measured the antibiofilm effect of the Hyp-P123-PDT in vitro and in an ex vivo model of onychomycosis. Results Hyp-P123-PDT exhibited a fungicidal effect in vitro with reductions ≥ 3 log10. ROS generation increased post-Hyp-P123-PDT in Fusarium spp. Hyp-P123-PDT showed a potent inhibitory effect on adhesion-phase and mature biofilms in vitro tests and an ex vivo model of onychomycosis (p<0.0001). Conclusion Hyp-P123-PDT had a potent effect against Fusarium spp., suggesting that photodynamic therapy with Hyp-P123 is a safe and promising treatment for onychomycosis in clinical practice.

A systematic review of photodynamic therapy as an antiviral treatment: Potential guidance for dealing with SARS-CoV-2.

BACKGROUND: SARS-CoV-2, which causes the coronavirus disease (COVID-19), presents high rates of morbidity and mortality around the world. The search to eliminate SARS-CoV-2 is ongoing and urgent. This systematic review seeks to assess whether photodynamic therapy (PDT) could be effective in SARS-CoV-2 inactivation. METHODS: The focus question was: Can photodynamic therapy be used as potential guidance for dealing with SARS-CoV-2?". A literature search, according to PRISMA statements, was conducted in the electronic databases PubMed, EMBASE, SCOPUS, Web of Science, LILACS, and Google Scholar. Studies published from January 2004 to June 2020 were analyzed. In vitro and in vivo studies were included that evaluated the effect of PDT mediated by several photosensitizers on RNA and DNA enveloped and non-enveloped viruses. RESULTS: From 27 selected manuscripts, 26 publications used in vitro studies, 24 were exclusively in vitro, and two had in vitro/in vivo parts. Only one analyzed publication was exclusively in vivo. Meta-analysis studies were unfeasible due to heterogeneity of the data. The risk of bias was analyzed in all studies. CONCLUSION: The in vitro and in vivo studies selected in this systematic review indicated that PDT is capable of photoinactivating enveloped and non-enveloped DNA and RNA viruses, suggesting that PDT can potentially photoinactivate SARS-CoV-2.

Impact of serial systemic infection on Candida albicans virulence factors.

Aim: To evaluate changes in virulence and pathogenicity approaches from Candida albicans after successive passages in a murine model of systemic candidiasis. Materials & methods: Phenotypic assays were performed using colonies recovered from animals infected serially, totalizing five passages. Results: A progressive infection was observed along the passages, with increased fungal burden and the presence of greater inflammatory areas in the histopathological findings. Recovered strains exhibited increased filamentation and biofilm abilities, along with modulation of phospholipase and proteinase activities. Conclusion: Repeated contact between yeast and host increased the expression of virulence factors. Furthermore, a correspondence between phenotypic profile and proteomic data obtained previously was observed.

Copolymeric micelles as efficient inert nanocarrier for hypericin in the photodynamic inactivation of Candida species.

Aim: To evaluate the efficacy of photodynamic inactivation (PDI) mediated by hypericin encapsulated in P-123 copolymeric micelles (P123-Hyp) alone and in combination with fluconazole (FLU) against planktonic cells and biofilm formation of Candida species Materials & methods: PDI was performed using P123-Hyp and an LED device with irradiance of 3.0 mW/cm2 . Results: Most of isolates (70%) were completely inhibited with concentrations up to 2.0 µmol/l of HYP and light fluence of 16.2 J/cm2. FLU-resistant strains had synergic effect with P123-HYP-PDI and FLU. The biofilm formation was inhibited in all species, in additional the changes in Candida morphology observed by scanning electron microscopy. Conclusion: P123-Hyp-PDI is a promising option to treat fungal infections and medical devices to prevent biofilm formation and fungal spread.

Artepillin C Induces Selective Oxidative Stress and Inhibits Migration and Invasion in a Comprehensive Panel of Human Cervical Cancer Cell Lines.

BACKGROUND: Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) is the main bioactive component of Brazilian green propolis, and possesses, among other things, anticancer properties. However, to the best of our knowledge, there are no studies of artepillin C in cervical cancer. METHOD: To explore a new therapeutic candidate for cervical cancer, we have evaluated the effects of artepillin C on cellular viability in a comprehensive panel of human cervical cancer-derived cell lines including HeLa (human papillomavirus/HPV 18-positive), SiHa (HPV 16-positive), CaSki (HPV 16- and 18-positive) and C33A (HPV-negative) cells compared to a spontaneously immortalized human epithelial cell line (HaCaT). RESULTS: Our results demonstrated that artepillin C had a selective effect on cellular viability and could induce apoptosis possibly by intrinsic pathway, likely a result of oxidative stress, in all cancer-derived cell lines but not in HaCaT. Additionally, artepillin C was able to inhibit the migration and invasion of cancer cells. CONCLUSION: Thus, artepillin C appears to be a promising new candidate as an anticancer drug for cervical cancer induced by different HPV types.

γ-irradiation from radiotherapy improves the virulence potential of Candida tropicalis.

AIM: To evaluate if radiation used in radiotherapy can cause changes in the virulence potential of Candida tropicalis ATCC 750. MATERIALS & METHODS: C. tropicalis was exposed in vitro to identical dose and scheme of irradiation would be used in patients with head and neck cancer. Some virulence parameters were analyzed before and after irradiation. RESULTS: Colony morphologies were irreversibly affected by irradiation. Increase in growth rate, filamentation, adhesion on cell lines and phagocytosis process were also observed. Overall the irradiated C. tropicalis cells became more efficient at causing systemic infection in mice. CONCLUSION: γ-radiation induced important changes in C. tropicalis increasing its virulence profile, which could directly affect the relationship between yeasts and hosts.

Propolis: a potential natural product to fight Candida species infections.

AIM: To evaluate the effect of propolis against Candida species planktonic cells and its counterpart's biofilms. MATERIALS & METHODS: The MIC values, time-kill curves and filamentation form inhibition were determined in Candida planktonic cells. The effect of propolis on Candida biofilms was assessed through quantification of CFUs. RESULTS: MIC values, ranging from 220 to 880 µg/ml, demonstrated higher efficiency on C. albicans and C. parapsilosis than on C. tropicalis cells. In addition, propolis was able to prevent Candida species biofilm's formation and eradicate their mature biofilms, coupled with a significant reduction on C. tropicalis and C. albicans filamentation. CONCLUSION: Propolis is an inhibitor of Candida virulence factors and represents an innovative alternative to fight candidiasis.