Hydrogen sulfide decreases photodynamic therapy outcome through the modulation of the cellular redox state.

Photodynamic therapy (PDT) is a non-surgical treatment that has been approved for its human medical use in many cancers. PDT involves the interaction of a photosensitizer (PS) with light. The amino acid 5- aminolevulinic acid (ALA) can be used as a pro-PS, leading to the synthesis of Protoporphyrin IX. Hydrogen sulfide (H2S) is an endogenously produced gas that belongs to the gasotransmitter family, which can diffuse through biological membranes and have relevant physiological effects such as cardiovascular functions, vasodilatation, inflammation, cell cycle and neuro-modulation. It was also proposed to have cytoprotective effects. We aimed to study the modulatory effects of H2S on ALAPDT in the mammary adenocarcinoma cell line LM2. Exposure of the cells to NaHS (donor of H2S) in concentrations up to 10 mM impaired the response to ALA-PDT in a dose-dependent manner. The addition of 3 doses of NaHS showed the highest effect. This decreased response to the photodynamic treatment was correlated to an increase in the GSH levels, catalase activity, a dose dependent reduction of PpIX and increased intracellular ALA, decreased levels of oxidized proteins and a decrease of PDT-induced ROS. NaHS also reduced the levels of singlet oxygen in an in vitro assay. H2S also protected other cells of different origins against PDT mediated by ALA and other PSs. These results suggest that H2S has a role in the modulation of the redox state of the cells, and thus impairs the response to ALA-PDT through multifactor pathways. These findings could contribute to developing new strategies to improve the effectiveness of PDT particularly mediated by ALA or other ROS-related treatments.

Synthesis and cytotoxicity evaluation of olivacine-indole hybrids tethered by alkyl linkers.

In this work, eleven new derivatives were prepared of the alkaloid olivacine (1), which was isolated from the bark of Aspidosperma australe. These compounds (7a-k) are hybrids of olivacine and indoles or carbazole, tethered by alkyl chains of variable lengths (C-4, C-5 or C-6). Compounds 7a-k showed increased cytotoxicity towards a panel of four cell lines. The subcellular localization of olivacine and of the synthetic derivatives was studied by fluorescence microscopy. The cycles of K562 cells exposed to olivacine or compounds 7a-k were analysed by flow cytometry, and showed, for some of the new derivatives, a different profile of cell distribution among the phases of the cycle when compared to olivacine, which is indicative of lysosomal apoptosis.

Photosensitization of a subcutaneous tumour by the natural anthraquinone parietin and blue light.

Photodynamic therapy (PDT) is an anticancer treatment involving administration of a tumour-localizing photosensitizer, followed by activation by light of a suitable wavelength. In previous work, we showed that the natural anthraquinone (AQ) Parietin (PTN), was a promising photosensitizer for photodynamic therapy of leukemic cells in vitro. The present work aimed to analyze the photosensitizing ability of PTN in the mammary carcinoma LM2 cells in vitro and in vivo in a model of subcutaneously implanted tumours. Photodynamic therapy mediated by parietin (PTN-PDT) (PTN 30 µM, 1 h and 1.78 J/cm2 of blue light) impaired cell growth and migration of LM2 cells in vitro. PTN per se induced a significant decrease in cell migration, and it was even more marked after illumination (migration index was 0.65 for PTN and 0.30 for PTN-PDT, *p < 0.0001, ANOVA test followed by Tukey's multiple comparisons test), suggesting that both PTN and PTN-PDT would be potential inhibitors of metastasis. Fluorescence microscopy observation indicated cytoplasmic localization of the AQ and no fluorescence at all was recorded in the nuclei. When PTN (1.96 mg) dissolved in dimethyl sulfoxide was topically applied on the skin of mice subcutaneously implanted with LM2 cells, PTN orange fluorescence was strongly noticed in the stratum corneum and also in the inner layers of the tumour up to approximately 5 mm. After illumination with 12.74 J/cm2 of blue light, one PDT dose at day 1, induced a significant tumour growth delay at day 3, which was not maintained in time. Therefore, we administered a second PTN-PDT boost on day 3. Under these conditions, the delay of tumour growth was 28% both on days 3 and 4 of the experiment (*p < 0.05 control vs. PTN-PDT, two-way ANOVA, followed by Sidak's multiple comparisons test). Histology of tumours revealed massive tumour necrosis up to 4 mm of depth. Intriguingly, a superficial area of viable tumour in the 1 mm superficial area, and a quite conserved intact skin was evidenced. We hypothesize that this may be due to PTN aggregation in contact with the skin and tumour milieu of the most superficial tumour layers, thus avoiding its photochemical properties. On the other hand, normal skin treated with PTN-PDT exhibited slight histological changes. These preliminary findings encourage further studies of natural AQs administered in different vehicles, for topical treatment of cutaneous malignancies.

Apoptotic cell death induced by dendritic derivatives of aminolevulinic acid in endothelial and foam cells co-cultures.

Photodynamic therapy (PDT) is an effective procedure for the treatment of lesions diseases based on the selectivity of a photosensitising compound with the ability to accumulate in the target cell. Atherosclerotic plaque is a suitable target for PDT because of the preferential accumulation of photosensitisers in atherosclerotic plaques. Dendrimers are hyperbranched polymers conjugated to drugs. The dendrimers of ALA hold ester bonds that inside the cells are cleaved and release ALA, yielding PpIX production. The dendrimer 6m-ALA was chosen to perform this study since in previous studies it induced the highest porphyrin macrophage: endothelial cell ratio (Rodriguez et al. in Photochem Photobiol Sci 14:1617-1627, 2015). We transformed Raw 264.7 macrophages to foam cells by exposure to oxidised LDLs, and we employed a co-culture model of HMEC-1 endothelial cells and foam cells to study the affinity of ALA dendrimers for the foam cells. In this work it was proposed an in vitro model of atheromatous plaque, the aim was to study the selectivity of an ALA dendrimer for the foam cells as compared to the endothelial cells in a co-culture system and the type of cell death triggered by the photodynamic treatment. The ALA dendrimer 6m-ALA showed selectivity PDT response for foam cells against endothelial cells. A light dose of 1 J/cm2 eliminate foam cells, whereas less than 50% of HMEC-1 is killed, and apoptosis cell death is involved in this process, and no necrosis is present. We propose the use of ALA dendrimers as pro-photosensitisers to be employed in photoangioplasty to aid in the treatment of obstructive cardiovascular diseases, and these molecules can also be employed as a theranostic agent.

Photodynamic therapy of tumour cells mediated by the natural anthraquinone parietin and blue light.

Photodynamic therapy (PDT) is a treatment for superficial tumours involving the administration of a photosensitiser followed by irradiation. The potential of the natural anthraquinone parietin (PTN) in PDT is still relatively unexploited. In the present work, PTN isolated from the lichen Teoloschistes nodulifer (Nyl.) Hillman (Telochistaceae) was evaluated as a potential photosensitiser on tumour cells employing UVA-Vis and blue light. Blue light of 2 J/cm2 induced 50% death of K562 leukaemic cells treated 1 h with 30 µM PTN (Protocol a). Higher light doses (8 J/cm2) were needed to achieve the same percentage of cell death employing lower PTN concentrations (3 µM) and higher exposure times (24 h) (Protocol b). Cell cycle analysis after both protocols of PTN-PDT revealed a high percentage of sub-G1 cells. PTN was found to be taken up by K562 cells mainly by passive diffusion. Other tumour cells such as ovary cancer IGROV-1 and LM2 mammary carcinoma, as well as the normal keratinocytes HaCaT, were also photosensitised with PTN-PDT. We conclude that PTN is a promising photosensitiser for PDT of superficial malignancies and purging of leukaemic cells, when illuminated with blue light. Thus, this light wavelength is proposed to replace the Vis-UVA lamps generally employed for the photosensitisation of anthraquinones.

Disaccharides obtained from carrageenans as potential antitumor agents.

Carrageenans are sulfated galactans found in certain red seaweeds with proven biological activities. In this work, we have prepared purified native and degraded κ-, ι-; and λ-carrageenans, including the disaccharides (carrabioses) and disaccharide-alditols (carrabiitols) from seaweed extracts as potential antitumor compounds and identified the active principle of the cytotoxic and potential antitumor properties of these compounds. Both κ and ι-carrageenan, as well as carrageenan oligosaccharides showed cytotoxic effect over LM2 tumor cells. Characterized disaccharides (carrabioses) and the reduced product carrabiitols, were also tested. Only carrabioses were cytotoxic, and among them, κ-carrabiose was the most effective, showing high cytotoxic properties, killing the cells through an apoptotic pathway. In addition, the cells surviving treatment with κ-carrabiose, showed a decreased metastatic ability in vitro, together with a decreased cell-cell and cell-matrix interactions, thus suggesting possible antitumor potential. Overall, our results indicate that most cytotoxic compounds derived from carrageenans have lower molecular weights and sulfate content. Potential applications of the results emerging from the present work include the use of disaccharide units such as carrabioses coupled to antineoplasics in order to improve its cytotoxicity and antimetastatic properties, and the use of ι-carrageenan as adjuvant or carrier in anticancer treatments.

Embarazo Ectópico Cornual: Reporte de un Caso / Ectopic Pregnancy: a Case Report

En el embarazo ectópico cornual el saco gestacional se implanta en el cuerno uterino. Son factores de riesgo: infecciones genitales, tabaquismo, cirugía abdomino-pélvica previa, embarazo ectópico previo, tratamientos de esterilidad, técnicas de reproducción, fármacos, endometriosis, edad materna y la enfermedad inflamatoria pélvica. Se diagnostica por: anamnesis clínica, exploración física, marcadores plasmáticos placentarios, ecografía transvaginal y punción saco de Douglas. En el tratamiento médico se recomienda administrar metotrexate, si se acompaña de hemorragia se realiza laparotomía con resección cornual o histerectomía. Les presentamos un caso clínico de una paciente de sexo femenino de 28 años, con diagnóstico de embarazo cornual de 16 semanas de gestación, con antecedentes de presentar dos abortos y un embarazo ectópico previo. Presentaba: taquicardia, taquipnea e hipotensión. Al examen físico se evidencia sangrado transvaginal. La paciente fue sometida a cirugía, donde se interrumpió la gestación y se procedió a regularizar bordes y tejido desvitalizado.

In the cornual pregnancy the gestational sac is implanted in the uterine horn. Risk factors for the existence of ectopic pregnancy include: genital infections, smoking, previous abdomino-pelvic surgery, contraceptive use, previous ectopic pregnancy, infertility treatment and reproductive techniques, drug administration, luteal insufficiency, endometriosis, maternal age and pelvic inflammatory disease. Cornual pregnancy is diagnosed by anamnesis, clinical examination, placental plasma markers, transvaginal ultrasound and Douglas sac puncture. The medical treatment recommended for interstitial pregnancy is the administration of methotrexate. In case of bleeding caused by the cornual pregnancy is recommended laparotomy surgery whit cornual resection or hysterectomy. We present the case of 28 years old female patient diagnosed with a 16 weeks cornual ectopic pregnancy. With a history of four pregnancies; two of them end in abortion and one in a previous ectopic pregnancy.The review of vital sign showed tachycardia, tachypnea and hypotension. Physical examination evidence transvaginal bleeding. The patient was submitted to surgery where the ectopic pregnancy was interrupted and proceeded to regularize the edges and devitalized tissue.

Pancreatitis Aguda como consecuencia del uso de Orlistat / Acute Pancreatitis as consequence of the use of Orlistat

La pancreatitis aguda es un proceso inflamatorio del páncreas desencadenada por la auto digestión ante la activación de sus pro fermentos, tiene un manejo urgente ya que pone en peligro la vida del paciente. El reciente ingreso de Orlistat, un fármaco inhibidor de la lipasa gástrica y pancreática para tratar la obesidad, a través de su venta creciente sin receta se ha estado traduciendo en una mayor frecuencia de eventos adversos sobre todo gastrointestinales (diarrea grasa, esteatorrea, incontinencia, pero con insignificantes efectos sistémicos) con complicaciones por un mal uso, entre éstos la pancreatitis cuyo mecanismo causal no está aún determinado en su totalidad. Hasta la fecha se han reportado a la Administración de Alimentos y Medicamentos de Estados Unidos (FDA) 99 casos de pancreatitis aguda relacionadas con el uso de Orlistat, no habiéndose encontrado reportes de casos similares en América Latina. En el caso clínico una adolescente de 15 años de edad, desencadenó un cuadro típico de severa pancreatitis aguda con necrosis de más del 50% asociada a colección peripancrática clasificada como Baltazar D- E, Ranson de 5 a 6, secundaria al consumo de Orlistat para su obesidad grado III, apoyando esto con los criterios de probabilidad de Naranjo.

Acute pancreatitis is an inflammatory process of the pancreas, triggered by self digestión before activation of their pro ferments, it has a urgent management because it endangers the life of the patient.The recent accession of Orlistat, an inhibitor drug of lipase gastric and pancreatic to treat obesity, through its growing sale without a prescription has been translated in a greater frequency of especially gastrointestinal adverse events (fatty diarrhea, steatorrhea, incontinence, but with negligible systemic effects) with complications from misuse, among these pancreatitis whose causal mechanism is not yet determined in its entirety.To date, the U S Food and Drug Administration (FDA) have been reported 99 cases of acute pancreatitis associated with the use of Orlistat, not having found reports of similar cases in Latin America. In the clinical case a 15-year-old teenager, triggered a typical pattern of severe acute pancreatitis with more than 50% necrosis associated with peripancreática collection classified as Baltazar D-E, Ranson of 5-6, secondary to the use of Orlistat for his obesity grade III, supporting this with the criteria of probability of Naranjo.