title: DNA analysis of cattle parasitic protozoan Tritrichomonas foetus after photodynamic therapy.
abstract: Photodynamic therapy (PDT) is a modality of therapy that involves the activation of photosensitive substances and the generation of cytotoxic oxygen species and free radicals to promote the selective destruction of target tissues. This study analyzed the application of PDT to Tritrichomonas foetus, a scourged and etiological agent of bovine trichomoniasis, a sexually transmitted infectious disease. As it is an amitochondrial and aerotolerant protozoan, it produces energy under low O2tension via hydrogenosome. T. foetus from an axenic culture was incubated with photosensitizer tetrasulfonated aluminium phthalocyanine and then irradiated with a laser source (InGaAIP) at a density of 4.5Jcm-2. The DNA integrity of the control and treated group parasites was analyzed by conventional gel electrophoresis and comet assay techniques. In previous results, morphological changes characterized by apoptotic cell death were observed after T. foetus was submitted to PDT treatment. In the treated groups, T. foetus DNA showed a higher concentration of small fragments, about 200pb, in gel electrophoresis after PDT. In the comet assay, the DNA tail percentage was significantly higher in the treated groups. These results demonstrate that PDT leads to DNA fragmentation with changes in nuclear morphology and apoptotic features.
authors.affiliation: Research and Development Institute, UNIVAP, São José dos Campos, SP 12244-000, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Margraf-Ferreira
authors.affiliation: Biosciences and Oral Diagnosis Department, ICT/UNESP, São José dos Campos, SP, Brazil.
authors.forename: I C S
authors.initials: ICS
authors.lastname: Carvalho
authors.affiliation: Research and Development Institute, UNIVAP, São José dos Campos, SP 12244-000, Brazil.
authors.forename: S M
authors.initials: SM
authors.lastname: Machado
authors.affiliation: Research and Development Institute, UNIVAP, São José dos Campos, SP 12244-000, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Pacheco-Soares
authors.affiliation: Structural, Molecular and Genetics Biology Department, UEPG, Ponta Grossa, PR, Brazil.
authors.forename: C W
authors.initials: CW
authors.lastname: Galvão
authors.affiliation: Chemistry Department, UEPG, Ponta Grossa, PR, Brazil.
authors.forename: R M
authors.initials: RM
authors.lastname: Etto
authors.affiliation: Research and Development Institute, UNIVAP, São José dos Campos, SP 12244-000, Brazil. Electronic address: nsoares@univap.br.
authors.forename: N S
authors.initials: NS
authors.lastname: da Silva
mesh_terms: D000818:Animals; D002417:Cattle / Q000469:parasitology*; D004249:DNA Damage / Q000235:genetics*; D016054:DNA, Protozoan / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D010778:Photochemotherapy / Q000379:methods*; D011829:Radiation Dosage; D016835:Tritrichomonas foetus / Q000187:drug effects* / Q000235:genetics* / Q000528:radiation effects
chemical_list: D016054:DNA, Protozoan
keywords: AlPcS(4); Cell death; Comet assay; DNA damage