Navegando por Assunto "Mitochondrial membrane potential"

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    Cellular and metabolic changes after photodynamic therapy in leishmania promastigotes
    (Elsevier) Marcolino, Luciana Maria Cortez; Pereira, André Henrique Correia; Pinto, Juliana Guerra; Mamone, Leandro Ariel; Ferreira-Strixino, Juliana
    Leishmaniasis is a zoonotic disease, regarded by WHO as a public health problem that has presented a significant increase in the recent years. Conventional treatment is toxic and leads to serious side effects. Photodynamic therapy has been studied as a treatment to cutaneous leishmaniasis. This study aimed to evaluate the cell viability, morphological changes, type of cell death, production of reactive oxygen species, and changes in the mitochondrial membrane and DNA fragmentation in Leishmania braziliensis and Leishmania major promastigotes. Confocal microscopy was used to quantify the fluorescence emitted by JC-1, Annexin V, and propidium iodide reagents. The trypan blue exclusion test was used to evaluate the viability of the cells, the mitochondrial activity was verified with MTT, and the morphological changes were analyzed for SEM and DNA damage using the comet assay. PDT using curcumin at 500, 125, and 31,25 μg/mL decreased the viability of the parasites and induced changes in the mitochondrial membrane potential. The production of reactive oxygen species was dose- dependent and was observed only in the groups submitted to PDT. DNA damage was also observed in the parasite cells. The morphology of the cells was affected mainly at the highest curcumin concentration, resulting in rounded cells with a shortened flagellum. When the type of cell death was analyzed, the prevalence of apoptosis was noted. The results support the use of curcumin as photosensitizer in PDT against Leishmania promastigotes in the treatment for cutaneous leishmaniasis.
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    In vitro evaluation of red and near infrared LED photobiomodulation on L929 fibroblasts metabolic activity and morphology
    (Springer) Segismondi, Larissa Cavallieri; Soares, Luís Eduardo Silva; Soares, Cristina Pacheco
    Purpose Fibroblasts, the main cells of connective tissue, are highly susceptible to oxidative stress caused by reactive oxygen species (ROS). Photobiomodulation (PBM) has emerged as a promising therapy capable of modulating biological tissues, enhancing cellular metabolic activity, and promoting the proliferation and survival of fibroblasts. In this study, we aimed to investigate the potential in vitro photoprotective effect of cellular photomodulation using 660 and 850 nm LEDs in L929 fibroblast cells treated with hydrogen peroxide as a model of oxidative stress. Methods Changes in cell viability were observed using the Alamar Blue colorimetric assay, and cell morphology was assessed by inverted microscopy. Mitochondria and nuclei were also labeled in living cells using fluorescence with TMRM and Hoechst, in addition to ROS detection with CellRox Green. Results Our results indicate that pretreatment with LED exerts a cytoprotective effect against oxidative stress, promoting an increase in mitochondrial activity, mitochondrial membrane potential, and a reduction in intracellular reactive oxygen spe- cies (ROS) generation while inducing improvements in the morphological characteristics of cells. Conclusion The findings from the present study indicate that Photobiomodulation (PBM) with LED contributes to maintain- ing cellular homeostasis and can help prevent and mitigate damage resulting from oxidative stress in fibroblasts.
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    In vitro evaluation of red and near infrared LED photobiomodulation on L929 fibroblasts metabolic activity and morphology
    (Springer) Segismondi, Larissa Cavallieri; Soares, Luís Eduardo Silva; Pacheco-Soares, Cristina
    Purpose Fibroblasts, the main cells of connective tissue, are highly susceptible to oxidative stress caused by reactive oxygen species (ROS). Photobiomodulation (PBM) has emerged as a promising therapy capable of modulating biological tissues, enhancing cellular metabolic activity, and promoting the proliferation and survival of fibroblasts. In this study, we aimed to investigate the potential in vitro photoprotective effect of cellular photomodulation using 660 and 850 nm LEDs in L929 fibroblast cells treated with hydrogen peroxide as a model of oxidative stress. Methods Changes in cell viability were observed using the Alamar Blue colorimetric assay, and cell morphology was assessed by inverted microscopy. Mitochondria and nuclei were also labeled in living cells using fluorescence with TMRM and Hoechst, in addition to ROS detection with CellRox Green. Results Our results indicate that pretreatment with LED exerts a cytoprotective effect against oxidative stress, promoting an increase in mitochondrial activity, mitochondrial membrane potential, and a reduction in intracellular reactive oxygen species (ROS) generation while inducing improvements in the morphological characteristics of cells. Conclusion The findings from the present study indicate that Photobiomodulation (PBM) with LED contributes to maintaining cellular homeostasis and can help prevent and mitigate damage resulting from oxidative stress in fibroblasts.