scholarly journals Photodynamic Therapy Using Toluidine Blue O (TBO) Dye as a Photosensitizer against Leishmania major

Author(s):  
Mehdi Najm ◽  
Maryam Pourhajibagher ◽  
Alireza Badirzadeh ◽  
Elham Razmjou ◽  
Maryam Alipour ◽  
...  

Background: Photodynamic therapy (PDT) is alternative treatment of cutaneous leishmaniasis (CL), and phenolthiazine dyes such as Toluidine Blue O (TBO) have the potential role in PDT and notably affect parasites inactivation. This study aimed to evaluate the effectiveness of PDT by using TBO and a light-emitting diode (LED) in the treatment of zoonotic CL (ZCL). Methods: The study was conducted in Iran University of Medical Sciences, Tehran, Iran in 2018-2020. Different concentration (7.8 µg/ mL up to 500 µg/ mL) of TBO as a photosensitizer and a 630 nm LED light as a source of light were used for antileishmanial activity against both forms of Leishmania major promastigotes and intracellular amastigotes. Effective concentration (EC50) and cell cytotoxicity (CC50) were calculated in both infected and non-infected J774.A1 macrophages, respectively. As well as inhibitory concentration (IC50) was quantified in L. major promastigotes for 2 h, 24 h, and 48 h after incubation using a MTT colorimetric assay. Results: TBO dye in combination with the PDT significantly decreases the L. major promastigotes and intracellular amastigotes viability when compared with TBO alone. Both TBO dye in combination with the PDT and TBO alone had no toxic effects on the mice macrophages; however, it significantly killed the entered parasites inside the cells. Our results in the current study established satisfactory findings in clearing intracellular L. major parasites in in-vitro conditions. Conclusion: TBO dye in combination with the PDT can be considered as a harmless, effective and importantly perfect treatment against L. major, causative agent of ZCL, in an in-vitro situation without any negative toxicity to the mice macrophages.

2015 ◽  
Vol 08 (04) ◽  
pp. 1550017 ◽  
Author(s):  
Xuewei Jiang ◽  
Zhichao Fan ◽  
Yili Yu ◽  
Chenying Shao ◽  
Yuanzhen Suo ◽  
...  

Photodynamic therapy (PDT) has been commonly used in treating many diseases, such as cancer and infectious diseases. We investigated the different effects of PDT on three main pathogenic bacteria of periodontitis — Prevotella melaninogenica (P.m.), Porphyromonas gingivalis (P.g.) and Aggregatibacter actinomycetemcomitans (A.a.). The portable red light-emitting diode (LED) phototherapy device was used to assess the exogenous PDT effects with different light doses and photosensitizer concentrations (Toluidine blue O, TBO). The portable blue LED phototherapy device was used to assess the endogenous PDT effects with the use of endogenous photosensitizers (porphyrin) under different light doses. We found out that both exogenous and endogenous PDT were able to restrict the growth of all the three bacteria significantly. Moreover, the optimal PDT conditions for these bacteria were obtained through this in vitro screening and could guide the clinical PDT on periodontitis.


2012 ◽  
Vol 87 (2) ◽  
pp. 250-255 ◽  
Author(s):  
José Cláudio Faria Amorim ◽  
Betania Maria Soares ◽  
Orley Araújo Alves ◽  
Marcus Vinícius Lucas Ferreira ◽  
Gerdal Roberto Sousa ◽  
...  

BACKGROUND: Trichophyton rubrum is the most common agent of superficial mycosis of the skin and nails causing long lasting infections and high recurrence rates. Current treatment drawbacks involve topical medications not being able to reach the nail bed at therapeutic concentrations, systemic antifungal drugs failing to eradicate the fungus before the nails are renewed, severe side effects and selection of resistant fungal isolates. Photodynamic therapy (PDT) has been a promising alternative to conventional treatments. OBJECTIVES: This study evaluated the in vitro effectiveness of toluidine blue O (TBO) irradiated by Light emitting diode (LED) in the reduction of T. rubrum viability. METHODS: The fungal inoculums' was prepared and exposed to different TBO concentrations and energy densities of Light emitting diode for evaluate the T. rubrum sensibility to PDT and production effect fungicidal after photodynamic treatment. In addition, the profiles of the area and volume of the irradiated fungal suspensions were also investigated. RESULTS: A small reduction, in vitro, of fungal cells was observed after exposition to 100 µM toluidine blue O irradiated by 18 J/cm² Light emitting diode. Fungicidal effect occurred after 25 µM toluidine blue O irradiation by Light emitting diode with energy density of 72 J/cm². The analysis showed that the area and volume irradiated by the Light emitting diode were 52.2 mm² and 413.70 mm³, respectively. CONCLUSION: The results allowed to conclude that Photodynamic therapy using Light emitting diode under these experimental conditions is a possible alternative approach to inhibit in vitro T. rubrum and may be a promising new treatment for dermatophytosis caused by this fungus.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1176
Author(s):  
Vanesa Pérez-Laguna ◽  
Yolanda Barrena-López ◽  
Yolanda Gilaberte ◽  
Antonio Rezusta

Candidiasis is very common and complicated to treat in some cases due to increased resistance to antifungals. Antimicrobial photodynamic therapy (aPDT) is a promising alternative treatment. It is based on the principle that light of a specific wavelength activates a photosensitizer molecule resulting in the generation of reactive oxygen species that are able to kill pathogens. The aim here is the in vitro photoinactivation of three strains of Candida spp., Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 and Candida krusei ATCC 6258, using aPDT with different sources of irradiation and the photosensitizer methylene blue (MB), alone or in combination with chlorhexidine (CHX). Irradiation was carried out at a fluence of 18 J/cm2 with a light-emitting diode (LED) lamp emitting in red (625 nm) or a white metal halide lamp (WMH) that emits at broad-spectrum white light (420–700 nm). After the photodynamic treatment, the antimicrobial effect is evaluated by counting colony forming units (CFU). MB-aPDT produces a 6 log10 reduction in the number of CFU/100 μL of Candida spp., and the combination with CHX enhances the effect of photoinactivation (effect achieved with lower concentration of MB). Both lamps have similar efficiencies, but the WMH lamp is slightly more efficient. This work opens the doors to a possible clinical application of the combination for resistant or persistent forms of Candida infections.


2019 ◽  
Vol 9 (24) ◽  
pp. 5414 ◽  
Author(s):  
Sofia Friães ◽  
Eurico Lima ◽  
Renato E. Boto ◽  
Diana Ferreira ◽  
José R. Fernandes ◽  
...  

The search to replace conventional cancer treatment therapies, such as chemotherapy, radiotherapy and surgery has led over the last ten years, to a substantial effort in the development of several classes of photodynamic therapy photosensitizers with desired photophysicochemical and photobiological properties. Herein we report the synthesis of 6-iodoquinoline- and benzothiazole-based unsymmetrical squaraine cyanine dyes functionalized with amine groups located in the four-membered central ring. Their photodegradation and singlet oxygen production ability, as well as their in vitro photocytotoxicity against Caco-2 and HepG2 cell lines using a 630.8 ± 0.8 nm centered light-emitting diode system, were also investigated. All photosensitizer candidates displayed strong absorption within the tissue transparency spectral region (650–850 nm). The synthesized dyes were found to have moderate light stability. The potential of these compounds is evidenced by their cytotoxic activity against both tumor cell lines, highlighting the zwitterionic unsubstituted dye, which showed more intense photodynamic activity. Although the singlet oxygen quantum yields of these iodinated derivatives are considered low, it could be concluded that their introduction into the quinoline heterocycle was highly advantageous as it played a role in increasing selective cytotoxicity in the presence of light. Thus, the novel synthesized dyes present photophysicochemical and in vitro photobiological properties that make them excellent photosensitizer candidates for photodynamic therapy.


2006 ◽  
Vol 114 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Iriana C. J. Zanin ◽  
Maristela M. Lobo ◽  
Lidiany K. A. Rodrigues ◽  
Luiz A. F. Pimenta ◽  
Jose F. Hofling ◽  
...  

2014 ◽  
Vol 08 (04) ◽  
pp. 509-514 ◽  
Author(s):  
Liliana Guimarães Oliveira Ricatto ◽  
Luis Augusto Lopato Conrado ◽  
Cecilia Pedroso Turssi ◽  
Fabiana Mantovani Gomes França ◽  
Roberta Tarkany Basting ◽  
...  

ABSTRACT Objective: The aim of this study was to evaluate in vitro the effect of photodynamic therapy (PDT) using LASER or light emitting diode (LED) on cariogenic bacteria (Streptococcus mutans [SM] and Lactobacillus casei [LC]) in bovine dentin. Materials and Methods: Twenty five fragments of dentin were contaminated with SM and LC strands and divided into five experimental groups according to the therapy they received (n = 5): C – control (no treatment), SCLED – no dye/LED application (94 J/cm2), SCLASER – no dye/LASER application (94 J/cm2), CCLED – dye/LED application (94 J/cm2) and CCLASER – dye/LASER application (94 J/cm2). The dye used was methylene blue at 10 mM. Dentin scrapes were harvested from each fragment and prepared for counts of colony forming units (CFU)/mL. The data were analyzed using Kruskal–Wallis, followed by Student–Newman–Keuls (⍺ =0.05). Results: Regarding SM, groups CCLASER and CCLED showed a significant reduction in CFU/mL, which was statistically superior to the SCLASER, SCLED and C groups. Regarding LC, the groups CCLASER and CCLED caused a significant reduction in CFU/mL when compared with SCLASER, which showed intermediate values. SCLED and C had a lesser effect on reducing CFU/mL, where the former showed values similar to those of SCLASER. Conclusions: In conclusion, PDT combined with LASER or LED and methylene blue had a significant antimicrobial effect on cariogenic bacteria in the dentin.


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