Comparative analysis of different doses of coherent light (laser) and non-coherent light (light-emitting diode) on cellular necrosis and apoptosis: a study in vitro

Introduction Threshold doses of electromagnetic radiation can initiate necrosis and apoptosis in cells. The purpose of this study was to evaluate cellular apoptosis and necrosis immediately (t0) and 24 hours (t24) after irradiation with different doses of coherent light (laser) or non-coherent light (LED). Methods CHO-K1 lineage cells were irradiated with laser (810nm) or LED (945±20nm), with 24mW, contact area of 1cm2 and doses of 10, 20, 30, 40 and 50J/cm2 for 300, 660, 960, 1230 and 1620s, respectively, at both wavelengths. Cells were evaluated by fluorescence microscopy, differentiating viable, apoptotic and necrotic cells immediately and 24 hours after irradiation. Results The number of necrotic cells at t0 was higher in the LED 40 and 50J/cm2 groups (86±14 and 84±16% respectively, p <0.05), than in the 10 and 20J/cm2 laser (5±2 and 5±3%, p<0.05) and LED (5±3 and 4±1%, p<0.05) conditions. At t24, the LED 40J/cm2 (80±20%, p<0.05) group also showed more necrosis than the control and lower dose groups (laser 10, 20, and 30J/cm2 percentage of 6±4, 10±3 and 7±3%, p<0.05; LED 10 and 20J/cm2 percentage of 3±1 and 17±10%, p<0.05). A decrease in apoptotic cells was observed in the laser group with doses of 10, 40, and 50J/cm2 (6±4, 3±1 and 1±1% respectively, not significant), as well as in the LED 40J/cm2 (2±2%, not significant) group versus control. The cells had a higher percentage of apoptosis cells in the control group and with laser doses of 10 and 30J/cm2 (percentage of 20±1 and 20±4%, not significant), while only the LED 40J/cm2 (10±10%, not significant) had a lower percentage compared the control group. Conclusion Laser or LED stimulation promoted an increase in cell necrosis in a high energy density condition as characterized in a dose-dependent inhibition therapy. Laser or LED infrared irradiation in low doses (up to 20J/cm2) reduced the percentage of apoptosis in CHO-K1 cells, while high doses (30J/cm2) elevated apoptosis.

Efeito da terapia ultrassônica de baixa intensidade em cultura celular de fibroblastos / Efecto del ultrasonido de baja intensidad en cultivo celular de fibroblastos / Effect of low-intensity pulsed ultrasound therapy on a fibroblasts cell culture

Dentro da prática fisioterápica verifica-se a ampla utilização do ultrassom terapêutico para tratamento das diversas afecções musculoesqueléticas. O objetivo deste estudo foi avaliar o efeito da irradiação Ultrassônica de Baixa Intensidade, com diferentes regimes de pulsos e intensidade, em cultura celular de fibroblastos L929 (ATCC CCL-1 NCTC), de modo a verificar a viabilidade celular e definir parâmetros de dosimetria. Para isso, utilizou-se a aplicação de ultrassom pulsado, com frequência de 1Mhz, em cultura de células fibroblásticas, divididas em cinco grupos (controle e com intensidade instantâneas de 0,3W/cm2-10%; 0,3W/cm2 -20 %; 0,5W/cm2 -10% e US 0,5W/cm2 -20 % - 100Hz). A irradiação ocorreu com intervalos de 24, 48 e 72 horas, por dois minutos, e após 24 horas de cada irradiação foi realizado teste de MTT Brometo de [3-(4,5-dimetiltiazol)-2,5-difeniltetrazólio]. Os resultados revelaram que ao compararem-se os valores de células viáveis pelo método MTT nos cinco grupos, não foi possível encontrar diferença estatisticamente significativa em nenhum deles, nos três momentos avaliados (24, 48 e 72 horas); enquanto que, ao se realizar a análise de medida repetida nos diferentes grupos, encontrou-se diferença estatisticamente significativa apenas no grupo irradiado com ultrassom a 0,5W/ cm2com regime de pulso de 10% (p=0,003). Com base nesses resultados, conclui-se que a irradiação Ultrassônica de Baixa Intensidade em cultura celular de fibroblastos L929, somente no grupo com intensidade de 0,5W/cm2-10% obteve o crescimento numérico, com significância estatística em todos os períodos de avaliação.

En la práctica fisioterápica se utiliza bastante el ultrasonido como terapia para el tratamiento de diversos trastornos muscoloesqueléticos. Este artículo tiene por objetivo evaluar el efecto de la irradiación ultrasónica de baja intensidad, con diferentes regímenes de pulsos y de intensidades, en cultivo celular de fibroblastos L929 (ATCC CCL-1 NCTC), para verificar la viabilidad celular y establecer los parámetros de dosimetría. Se utilizó el ultrasonido pulsado, con frecuencia de 1Mhz, en un cultivo de células fibroblásticas, divididas en cinco grupos (con control y con la intensidad instantánea del 0,3W/cm2-10%; 0,3W/cm2 -20%; 0,5W/cm2 -10% y US 0,5W/cm2-20 % - 100Hz). La irradiación se llevó a cabo en intervalos de 24, 48 y 72 horas, durante dos minutos y después de las 24 horas de cada irradiación se realizó la prueba de MTT {Bromuro de [3-(4,5-dimetiltiazol)-2,5-difeniltetrazólio]}. Los resultados mostraron que en la comparación entre los valores de células viables por el método MTT en los cinco grupos evaluados no ha sido posible encontrar ninguna diferencia estadísticamente significativa en los tres momentos evaluados (24, 48 y 72 horas). En cambio, al llevar a cabo el análisis de medida repetida en los diferentes grupos, se obtuvo una diferencia estadísticamente significativa solamente en el grupo irradiado con ultrasonido a 0,5W/cm2 con el régimen de pulso del 10% (p=0,003). Basándose en estos resultados se concluyó que la irradiación ultrasónica de baja intensidad en cultivo celular de fibroblastos L929 obtuvo el aumento sólo en el grupo con intensidad de 0,5W/cm2-10%, con significancia en todos los periodos de evaluación.

Within the physiotherapy practice there is a wide use of therapeutic ultrasound for the treatment of various musculoskeletal disorders. The aim of this study was to evaluate the effect of Low Intensity Ultrasonic irradiation with differents forms of pulse and intensity in cell culture of L929 fibroblasts (ATCC CCL-1 NCTC), in order to check cell viability and define parameters of dosimetry. For this purpose, it was used the application of pulsed ultrasound with a frequency of 1MHz in cultured fibroblast cells divided into five groups (control and instantaneous intensity of 0.3W/cm2-10%, 0.3W/cm2 -20%, 0.5W/cm2-10% and US 0.5W/cm2-20% - 100Hz). Irradiation occurred at intervals of 24, 48 and 72 hours for two minutes and 24 hours after each irradiation test MTT [3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide] was performed. Results showed that when comparing the values of viable cells by MTT method in the five groups, we could not find statistically significant difference in any of them, in these three conditions (24, 48 and 72 hours); while. Whereas, when performing the analysis of repeated measures in the different groups, it was found a statistically significant difference only in the group irradiated with ultrasound at 0.5W/cm2 with pulse regime of 10% (p=0.003). Based on these results, it is concluded that the Low Intensity Ultrasonic irradiation in L929 fibroblast cell culture, only in the group with an intensity of 0.5W/cm2 -10% obtained numerical growth, with statistical significance in all periods evaluation.

Wound healing properties and mucilage content of Pereskia aculeata from different substrates

Physiologic growth parameters Wound healing Pereskia aculeata Mill., Cactaceae, is a cactus with high mucilage production, well-known for its nutritional properties. Folk use consists on skin injuries, and mucilage is probably involved in the wound healing activity. This work studied some aspects of its cultivation, specifically regarding soil (substrate), to correlate the effects of nutritional content to mucilage production and to the wound-healing property. Plants were grown under five different soil treatment (sand, crude soil, sand and soil, sand and cattle manure, soil and cattle manure), and after eight months extracts were prepared by turbo-extraction to obtain a crude hydroethanolic extract. We evaluated the effects of these extracts on swelling index, cytotoxicity, and in vitro wound healing property. The results show that the substrate used in cultivation may interfere with mucilage production, but not with cytotoxicity and wound healing, this shows the safety of its use, despite the soil treatment received along the various biomes where P. aculeata is cultivated. Furthermore, morphological studies demonstrated the beneficial effect of the mucilage-containing extract on the fibroblast cell culture, corroborating its folk use for wound healing.

Avaliação da atividade mitocondrial no processo de morte celular em células tumorais de mama após tratamento com Ciclosporina A e Photosan3® / Evaluation of mitochondrial activity in the cell death process in breast tumor cells after treatment with Cyclosporine A and Photosan3®

INTRODUÇÃO: A terapia fotodinâmica (PDT) é uma modalidade terapêutica para o tratamento de doenças neoplásicas e não neoplásicas tendo como alvo a mitocôndria, organela que tem atraído maior atenção devido ao seu envolvimento direto no processo de morte celular. Inibindo a atividade mitocondrial é possível estudar outras organelas envolvidas no processo de morte celular. O objetivo deste estudo foi avaliar a importância da mitocôndria no processo de morte celular na linhagem celular M3, induzida após a fotossensibilização com Photosan3®. MÉTODOS: Para os experimentos foram utilizados os seguintes grupos: grupo controle I, células sem nenhum tratamento; grupo II PDT, células incubadas com Photosan3®; grupo III PDT, células incubadas com CsA e Photosan3®; grupo IV células tratadas somente com Estaurosporina (STS). Após a incubação com o fotossensibilizador os grupos II e III foram irradiados com diodo laser semicondutor (λ 670 nm). Todos os grupos foram incubados a 37 ºC em estufa com atmosfera de 5% de CO2, por 24 h e 48 h. No final destes períodos todos os grupos foram submetidos ao ensaio de citotoxicidade, pelo teste de MTT (brometo de 3-[4,5-dimetil-tiazol-2-il]-2,5-difeniltetrazólio) e corados com anexina V e iodeto de propídio para determinar a proporção de morte celular, sendo as análises realizadas por microscopia de fluorescência. RESULTADOS: Os resultados mostraram que as células realizaram apoptose por via independente de mitocôndria. A CsA apresentou-se eficiente na inativação da mitocôndria no processo apoptótico durante a fotossensibilização com Photosan3®. CONCLUSÃO: A associação de CsA e Photosan3® na terapia fotodinâmica demonstrou a presença de morte celular por apoptose independente da participação mitocondrial.

INTRODUCTION: Photodynamic therapy (PDT) is a therapeutic modality for the treatment of neoplastic and non-neoplastic diseases. Mitochondria have attracted great attention due to their direct involvement in the cell death process. By inhibiting the mitochondrial activity, it is possible to study other organelles involved in the cell death process. The objective of this study was to evaluate the involvement of mitochondria in induced cell death process in M3 cell line after photosensitization with Photosan3®. METHODS: The experiments involved the following groups: control group I, cells with no treatment; group II PDT, cells incubated with Photosan3®; group III PDT, cells incubated with CsA and Photosan3®; group IV, cells treated only with treated only Staurosporine (STS). After incubation with the photosensitizer, the groups II and III were irradiated using a semiconductor laser diode (λ 670 nm). All groups were incubated at 37 ºC in an atmosphere of 5% CO2 for 24 and 48 h. After this period, all groups were subjected to the MTT (3 - [4,5-dimethyl-thiazol-2-yl] -2,5-diphenyltetrazolium bromide) cytotoxicity assay and labeled with Annexin V and Iodide Propidium to determine the rate of cell death. The analyses were performed by fluorescence microscopy. RESULTS: The results show that PDT Photosan leads to apoptosis of breast cell line M3 by a route independent of the mitochondria. CONCLUSION: The association of CsA and Photosan3® in photodynamic therapy showed the occurrence of cell death (apoptosis) independent of mitochondrial participation.