Prospecção de bioativos farmacológicos em algas marinhas Rhodophyta e Heterokontophyta e avaliação de citotoxicidade / Prospection of pharmaceutical bioactive compounds in marine algae Rhodophyta and Heterokontophyta and cytotoxicity evaluation

Muitas drogas terapêuticas produzidas pela indústria farmacêutica são estruturas químicas isoladas de organismos encontrados na natureza ou moléculas baseadas nelas. Podem ser incluídas nesse grupo drogas isoladas de organismos marinhos, como corais, esponjas e algas marinhas, conhecidos como produtores de grandes quantidades de metabólitos secundários. Com base neste fato o presente estudo teve como objetivo realizar a prospecção de moléculas bioativas com propósito farmacológico, em extratos de algas marinhas vermelhas (Rhodophyta) e pardas (Heterokontophyta) coletadas no litoral brasileiro. A prospecção foi realizada por meio de avaliação de seus potenciais antioxidante, antibacteriano, antifúngico, anticancerígeno, e antiparasitário contra organismos causadores de leishmaniose e esquistossomose. Para as avaliações foram empregadas os extratos supercríticos de 5 espécies diferentes, sendo 2 pardas: Dictyota dichotoma e D. menstrualis e três vermelhas: Chondria littoralis, Spyridia hypnoides e Plocamium brasiliense. Os extratos foram avaliados quanto aos seus potenciais bioativos e os resultados mais promissores foram selecionados para as etapas seguintes do fracionamento. Em uma avaliação geral os extratos apresentaram bons resultados e representam uma potencial fonte de bioativos. Os extratos das espécies de D. dichotoma e D. menstrualis foram então submetidos a um procedimento de fracionamento bioguiado pela atividade esquistossomicida. Incorporou-se ainda um terceiro extrato de D. mertensii aos estudos e todas as etapas do fracionamento foram monitoradas por LC-MS. Comparando-se as massas detectadas em todas as frações que apresentaram atividade, para os 3 extratos, foi verificado que a substância de m/z 271,24 estava presente em todas elas, portanto os procedimentos de isolamento foram direcionados a esta molécula para a qual foi possível isolar 7 mg. Diferentemente do que era esperado a molécula quando avaliada isoladamente não apresentou atividade esquistossomicida, levando a hipótese de que a atividade seja decorrente de uma molécula diferente para cada espécie ou ainda que a mesma seja decorrente de uma interação com outras substâncias por um mecanismo de ação aditivo ou sinérgico. O trabalho avaliado de forma geral apresentou resultados promissores e representa um grande embasamento para servir como base para posteriores trabalho de fracionamento

Several therapeutic drugs manufactured by the pharmaceutical industry are chemical structures isolated from organisms that are found in nature or molecules based on that. May be included at this group drugs isolated from marine organisms, like corals, sponges and seaweeds, known as great secondary metabolites producers. Based on this facts the objective of the present study is to perform a prospection study to achieve bioactive molecules with pharmaceutical purposes, on extracts made from red (Rhodophyta) and brown (Heterokontophyta) seaweed collected in the Brazilian shore. The prospection studies was performed by means of evaluation of the antioxidant, antibacterial, antifungal, anticancer and antiparasitic (against Leishmania and Schistosoma) potential. In the evaluation were tested the supercritical extracts of 5 different species, including 2 brown species: Dictyota dichotoma and D. menstrualis and 3 red species: Chondria littoralis, Spyridia hypnoides and Plocamium brasiliense. The extracts were evaluated by their potential bioactive compounds and the most promising results were selected for the following fractionation steps. Overall the extracts have shown good results and may be represent a potential source of bioactive molecules. The extracts of both D. dichotoma and D. menstrualis were submitted to a bioguided fractionation process by their antischistosomal activities. It was still included a third extract from D. mertensii to the studies and every step was monitored by LC-MS techniques. Comparing the detected mass for each active fraction, it was observed the presence of a substance with m/z 271,24 in all of the extracts, so the isolating procedures were directed to obtain that specific molecule, which was obtained in a biomass of 7 mg. Differently than expected the molecule when evaluated isolated do not show the antischistosomal activity, leading to the hypothesis that the activity was related to different molecules for each species or even the observed effect is resulted by an interaction mechanism with another substances by an additive or synergist mechanism. The overall evaluation of the whole work show some promising results and it represent a great support for future fractionation works

Histopathologic changes following neoadjuvant chemotherapy in locally advanced breast cancer.

Aims: To compare the clinical and pathologic assessment of response to neoadjuvant chemotherapy and describe the various histopathologic changes observed. Materials and Methods: We studied a group of 40 patients with locally advanced breast cancer who had their initial workup in the form of clinico-imaging assessment of the size and pretreatment biopsy from the lesion. All the patients received two to six cycles of neoadjuvant chemotherapy, either cyclophosphamide 50 to 60 mg/m 2 IV, doxorubicin 40 to 50 mg/m 2 IV and 5-fluorouracil 500 to 800 mg/m 2 IV (CAF) or cyclophosphamide, epirubicin, and 5-fluorouracil (CEF). Clinical and pathologic assessment of response to chemotherapy was done based on the UICC guidelines. Result: Complete clinical response (cCR) was seen in 10% cases (4/40), thirty percent patients had (12/40) partial response and 60% (24/40) had stable disease after neoadjuvant chemotherapy. Pathologic complete response (pCR) with no evidence of viable tumor was observed in 20% patients (8/40). Fifteen patients (37.5%) showed partial response and 42.5% patients (17/40) had a stable disease. No patient progressed during the course of chemotherapy. Changes in the tumor type were observed following chemotherapy, most common being the mucinous change. Histologic changes like dyscohesion, shrinkage of tumor cells, elastosis, collagenization, necrosis, lymphocytic reaction, giant cell response are some of the common observations seen following treatment with neoadjuvant chemotherapy. Conclusion: Pathologic assessment of response to neoadjuvant chemotherapy is a better predictor than the clinical response. The chemotherapy drugs can be modified based on the response observed after 1-2 cycles of neoadjuvant, the response being based on both tumor and patient's responsiveness.

Effect of neoadjuvant chemotherapy on stromal CD10 antigens in breast cancer - A preliminary study.

Introduction: CD10 is a zinc-dependent peptidase (metalloproteinase). Stromal CD10 expression in breast cancer correlates with poor prognosis, oestrogen receptor negativity and higher grade. CD10 may be a potential target of new cancer therapies as it is involved in cleavage of doxorubicin. Aim: To evaluate the effect of neo-adjuvant anthracycline-based chemotherapy on status of stromal CD10 antigens in breast cancer. Materials and Methods: Patients with invasive breast cancer scheduled for anthracycline-based neo-adjuvant chemotherapy were included in the study. Tumor stromal CD10 expression was estimated before and after 3 cycles of chemotherapy, and change in its status was correlated with clinical response to chemotherapy. Results: 16 out of the 29 patients had strong CD10 expression; in these 16 patients, 14 (87.5%) were hormone receptor negative, and 14 (87.5%) had HER-2/neu overexpression. Stromal CD10 expression remained same in 13 out of 29 cases (44.83%) after chemotherapy. There was a change in CD10 expression in the remaining 16 cases (55.17%); in 13 cases (44.83%) it decreased from its pre-chemotherapy status, while its expression increased in 3 cases (10.34%). In cases of complete and partial clinical response, there was no increase in CD10 expression. Where CD10 expression had increased after chemotherapy, there was either a minor response or no response to chemotherapy. In 13 cases where CD10 expression had decreased, 12 cases had a clinical response to chemotherapy. Conclusions: Strong CD10 expression correlates with hormone receptor negativity and HER-2/neu overexpression. Stromal CD10 expression in breast cancer is not static and changes with neo-adjuvant anthracycline-based chemotherapy. A stable or decrease in CD10 expression correlates with complete or partial clinical response, while an increase in CD10 expression appears to correlate with poor clinical response. A larger series is required to determine the clinical significance of these changes. As stromal CD10 expression and its change with chemotherapy may have a prognostic significance, they should be documented in breast cancer patients before and after chemotherapy.

Evaluación de marcadores moleculares asociados con resistencia a gota (Phytophthora infestans L) en papas diploides y tetraploides / Evaluation of molecular markers associated with resistance to late blight (Phytophthora infestans L) in diploid and tetraploid potatoes

La papa, cultivo de importancia a nivel mundial es gravemente afectado por gota, enfermedad ocasionada por el oomycete Phytophthora infestans. Actualmente la forma más efectiva para combatir la enfermedad es mediante el desarrollo de cultivares resistentes al patógeno. Para esto, una estrategia es identificar genes que confieran resistencia al patógeno, para lo cual se buscan marcadores asociados con el carácter de resistencia. En este estudio se evaluaron marcadores moleculares tipo SCAR (Sequence Characterized Amplified Region): CosA, GP179, BA47f2 y Prp1 asociados con resistencia a P. infestans y el gen de resistencia R1, en 22 cultivares tetraploides pertenecientes a la subespecie andigena y cinco especies silvestres. Se evaluó el polimorfismo y se determinó si los alelos polimórficos permitían diferenciar genotipos resistentes de susceptibles. Se comparó el tamaño de los fragmentos obtenidos con los fragmentos esperados asociados con resistencia de acuerdo a reportes. El análisis se realizó considerando presencia/ausencia de los fragmentos: CosA210, CosA250, R11400, R11800, BA47f2500, GP179570, Prp1300, Prp1600, y Prp1900. Los resultados indicaron que en los cultivares tetraploides y silvestres, se presentaron polimorfismos en todos los marcadores evaluados, con excepción del marcador GP179. No se encontró correlación entre el rasgo de resistencia y los alelos. Los resultados de este estudio muestran que hay repuesta diferencial a los marcadores entre las subsp. tuberosum y subsp. Andigena.

Potato is an important worldwide crop seriously affected by late blight disease caused by the oomycete Phytophthora infestans. Currently, the most effective way to control the disease is developing resistant cultivars to the pathogen by identifying genes that confer resistance to the pathogen. For this purpose it is important to find molecular markers associated with the trait. In this study, the SCAR (Sequence Characterized Amplified Region) markers: CosA, GP179, BA47f2 y Prp1, associated with late blight and the resistant gen R1 were evaluated in 22 tetraploid cultivars from subspecie andigena and five wild potato species. Polymorphism was evaluated and it was evaluated if polymorphic alleles allow differentiating resistant from susceptible genotypes. The fragment length for each marker was compared to the allele size reported associated to resistance. The analysis considered the presence/absence of the fragments: CosA210, CosA250, R11400, R11800, BA47f2500, GP179570, Prp1300, Prp1600 and Prp1900. The results indicated that both, tetraploid cultivars and wild potatoes, showed polymorphisms with all these markers, except with the GP179 marker. It was not found correlation between resistance and the presence of specific alleles. Evidence found in this study indicates that results obtained with molecular markers differed between subsp. tuberosum and subsp. andigena.