Photodynamic therapy as a new approach to Trichomonas vaginalis inactivation

Fonseca, Thaisa Helena Silva; Alacoque, Marina; Oliveira, Fabrício Marcus Silva; Soares, Betânia Maria; Leite, Henrique Vítor; Caliari, Marcelo Vidigal; Gomes, Maria Aparecida; Busatti, Haendel Gonçalves Nogueira Oliveira

doi:10.1016/j.pdpdt.2018.02.006

Cited by 10 publications

(9 citation statements)

References 36 publications

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“…In previous work, our group confirmed the efficacy and safety of photodynamic treatment with MB on susceptible and resistant strains of T. vaginalis [11]. Among the photosensitizers currently used, MB, a phenothiazine compound, has proven PDT-associated activity [18,19].…”

Section: Discussionmentioning

confidence: 63%

“…Despite being one of the most prescribed medications, patients treated with MTZ have presented several undesirable side effects that can culminate in the discontinuation of the therapeutic scheme, promoting the rise of resistant strains [4]. Thus, therapeutic alternatives, including analogues [15], new agents [16] and regimens such as PDT [11] are desirable.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, parasites of the sensitive strain exposed to PDT presented intense autophagy, numerous vesicles, plasma membrane discontinuity and reduced cytoplasmic electrondensity, associated with large debris amounts were also observed after PDT. The in vitro activity of PDT presented greater inhibitory capacity as compared to MB group (p < 0.05) [11].…”

Section: Discussionmentioning

confidence: 99%

“…In a previous study, our group demonstrated the excellent trichomonacidal activity of PDT using methylene blue [11]. High reduction of trophozoite numbers (approximately 90%) was observed with only one in vitro photodynamic treatment session.…”

Section: Introductionmentioning

confidence: 98%

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Photodynamic therapy effect on the ultrastructure of Trichomonas vaginalis trophozoites and their effectiveness in experimentally infected animals

Fonseca

Gomes²,

Alacoque

et al. 2018

Preprint

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2 Background 3 Trichomonas vaginalis is an amitochondrial parasitic that causes human trichomoniasis, 4 the most common non-viral sexually transmitted infection in the world. The therapy of 5 choice is metronidazole (MTZ). Despite MTZ effectiveness, resistant cases are 6 becoming more frequent. Another point to emphasize are the side effects that may result 7 in treatment discontinuation, leading to further spread of infection and emergence of 8 resistant strains. This scenario reveals the need to develop new therapeutic options. 9 Photodynamic therapy (PDT) is an experimental treatment that involves the activation 10 of photosensitive substances and the generation of cytotoxic oxygen species and free 11 radicals to promote the selective destruction of target tissues. A previous study, from 12 our group, identified an excellent in vitro PDT activity using methylene blue and light 13 emitting diode against MTZ sensitive and resistant strains of T. vaginalis. The aim of 14 this study was to evaluate the efficacy of PDT in vivo and clarify its high 15 trichomonicidal potential by evaluating its action upon T. vaginalis trophozoites through 16 transmission electron microscopy (TEM). 17 18 Methodology 19 Seven-week-old female Balb/c mice were infected intravaginally with T. vaginalis 20 trophozoites. On the third day of infection, methylene blue was introduced into the 21 vaginal canal of the animals, which then received 68.1 J / cm 2 of radiation for 35.6 sec. 22 Control groups without infection and infected, treated with metronidazole were also 23 included for comparison. Twenty-four hours after treatment the vaginal canal of the 24 animals was scraped and the samples processed by the immunocytochemistry technique.3 3 25 After in vitro photodynamic treatment, T. vaginalis trophozoites were processed for 26 TEM. Ultrathin sections were collected in 400-mesh copper grids, contrasted with 5% 27 uranyl acetate and 3% lead citrate, in aqueous solutions for 20 and 5 min., respectively 28 and observed in a Jeol JEM 230 transmission electron microscope. 29 30 Results 31 TEM showed morphological changes such as centripetal displacement of organelles, 32 cannibalism, hydrogenosomal damage, intense cytoplasmic vacuolization, dilated 33 endoplasmic reticulum cisternae and membrane discontinuity, in both resistant and 34 sensitive strains, suggesting that trichomonicidal activity is mainly due to necrosis. 35 PDT significantly reduced infection in animals treated with a single therapy session, 36 compared to control groups, being statistically as efficient as MTZ. 37 38 Conclusions 39 Our results demonstrated high trichomonicidal activity of PDT with morphological 40 alterations compatible with necrosis. Therefore these results indicate that PDT 41 represents not only an alternative therapy for refractory trichomoniasis, but also 42 routinely for this important neglected parasitic disease.43 44

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Section: Discussionmentioning

confidence: 63%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

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Photodynamic therapy effect on the ultrastructure of Trichomonas vaginalis trophozoites and their effectiveness in experimentally infected animals

Fonseca

Gomes²,

Alacoque

et al. 2018

Preprint

Self Cite

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show abstract

“…The associated morphological changes in the cells included membrane projections, nucleus fragmentation, endoplasmic reticulum proliferation, and cytoplasmic vacuolization, suggesting the possible value of the treatment for bovine trichomoniasis. Silva Fonseca, Alacoque [119] exposed metronidazole sensitive and resistant T. vaginalis strains to methylene blue as the light-emitting diode (LED). They found that light alone was ineffective, but the sensitized light inhibited up to 81% of the nonresistant and 91.1% of the resistant strains, respectively.…”

Section: Photodynamic Therapymentioning

confidence: 99%

Anti-trichomonad activities of different compounds from foods, marine products, and medicinal plants: a review

Friedman

Tam

Cheng

et al. 2020

BMC Complement Med Ther

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Human trichomoniasis, caused by the pathogenic parasitic protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease that contributes to reproductive morbidity in affected women and possibly to prostate cancer in men. Tritrichomonas foetus strains cause the disease trichomoniasis in farm animals (cattle, bulls, pigs) and diarrhea in domestic animals (cats and dogs). Because some T. vaginalis strains have become resistant to the widely used drug metronidazole, there is a need to develop alternative treatments, based on safe natural products that have the potential to replace and/or enhance the activity of lower doses of metronidazole. To help meet this need, this overview collates and interprets worldwide reported studies on the efficacy of structurally different classes of food, marine, and medicinal plant extracts and some of their bioactive pure compounds against T. vaginalis and T. foetus in vitro and in infected mice and women. Active food extracts include potato peels and their glycoalkaloids α-chaconine and α-solanine, caffeic and chlorogenic acids, and quercetin; the tomato glycoalkaloid α-tomatine; theaflavin-rich black tea extracts and bioactive theaflavins; plant essential oils and their compounds (+)-α-bisabolol and eugenol; the grape skin compound resveratrol; the kidney bean lectin, marine extracts from algae, seaweeds, and fungi and compounds that are derived from fungi; medicinal extracts and about 30 isolated pure compounds. Also covered are the inactivation of drug-resistant T. vaginalis and T. foetus strains by sensitized light; anti-trichomonad effects in mice and women; beneficial effects of probiotics in women; and mechanisms that govern cell death. The summarized findings will hopefully stimulate additional research, including molecular-mechanism-guided inactivations and human clinical studies, that will help ameliorate adverse effects of pathogenic protozoa.

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Transmission electron microscopy revealing the mechanism of action of photodynamic therapy on Trichomonas vaginalis

Fonseca

Gomes²,

Alacoque

et al. 2019

Acta Tropica

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Photodynamic therapy as a new approach to Trichomonas vaginalis inactivation

Cited by 10 publications

References 36 publications

Photodynamic therapy effect on the ultrastructure of Trichomonas vaginalis trophozoites and their effectiveness in experimentally infected animals

Photodynamic therapy effect on the ultrastructure of Trichomonas vaginalis trophozoites and their effectiveness in experimentally infected animals

Anti-trichomonad activities of different compounds from foods, marine products, and medicinal plants: a review

Transmission electron microscopy revealing the mechanism of action of photodynamic therapy on Trichomonas vaginalis

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