The luteinizing hormone receptor (LHR), one of the three glycoprotein hormone receptors, is necessary for critical reproductive processes, including gonadal steroidogenesis, oocyte maturation and ovulation, and male sex differentiation. Moreover, it has been postulated to contribute to certain neoplasms, particularly ovarian cancer. A member of the G protein-coupled receptor family, LHR contains a relatively large extracellular domain responsible for high affinity hormone binding; transmembrane activation then leads to G protein coupling and subsequent second messenger production. This review deals with recent advances in our understanding of LHR structure and structure-function relationships, as well as hormone-mediated changes in gene expression in ovarian cancer cells expressing LHR. Suggestions are also made for critical gaps that need to be filled as the field advances, including determination of the three-dimensional structure of inactive and active receptor, elucidation of the mechanism by which hormone binding to the extracellular domain triggers the activation of Gs, clarification of the putative roles of LHR in non-gonadal tissues, and the role, if any, of activated receptor in the development or progression of ovarian cancer.

SUMMARYThe objective of this study was to extract and concentrate calcium oxalate (CaOx) crystals from plant leaves that form the above mentioned crystals. The chemical and physical studies of CaOx from plant to be performed depend on an adequate amount of the crystals. The plant used in this study was croton (Codiaeum variegatum). The leaves were ground in a heavy duty blender and sieved through a 0.20 mm sieve. The suspension obtained was suspended in distilled water. The crystals were concentrated at the bottom of a test tube. The supernatant must be washed until it is free of plant pigments and other organic substances. Biogenic CaOx crystals have well-defined and sharp peaks, indicating very high crystallinity. Moreover, the CaOx crystals were not damaged during the extraction procedure, as can be seen on the scanning electron microscope images. The porposed method can be considered efficient to extract and concentrate biogenic calcium oxalate.Index terms: biogenic calcium oxalate, biomineral, extraction of calcium oxalate. RESUMO: EXTRAÇÃO E CONCENTRAÇÃO DE OXALATO DE CÁLCIO BIOGÊNICO DE FOLHAS DE PLANTASO objetivo deste estudo foi extrair e concentrar cristais de oxalato de cálcio (CaOx) a partir de folhas de plantas que formam os cristais mencionados. Os estudos químicos e físicos de CaOx de plantas a serem realizados demandam uma massa adequada dos cristais. A planta usada neste estudo foi o cróton (Codiaeum variegatum). As folhas foram trituradas por um liquidificador industrial e peneiradas em peneira de 0,20 mm. Ao suco obtido foi adicionada água destilada. Os cristais foram concentrados no fundo da proveta. É necessário manter a lavagem dos cristais até que o sobrenadante fique livre de pigmentos de plantas e outras substâncias orgânicas. Os cristais de CaOx apresentaram picos bem formados e estreitos, indicando que sua cristalinidade é muito alta; além disso, esses cristais não foram danificados durante o procedimento de extração, o que pode ser visto observando-se as fotos obtidas pelo microscópio eletrônico de varredura. O método apresentado pode ser considerado eficiente para extrair e concentrar cristais de oxalato de cálcio biogênico.Termos de indexação: oxalato de cálcio biogênico, biomineral , extração de oxalato de cálcio.

Cerebrovascular accidents and coronary artery disease are the leading causes of cardiovascular mortalities in Brazil and high levels of LDL cholesterol are one of the main risk factors. In this context, several plant extracts and natural substances have shown promise as cholesterol-lowering. The objective of this study was to evaluate the potential of the hydroalcoholic extract of the fruit of H. dulcis and of dihydromyricetin in cholesterol reduction in hypercholesterolemic rats. Forty-two Wistar male rats were distributed into seven groups of six animals that received diets supplemented with 1% cholesterol and 0.3% cholic acid, with the exception of the control group, which received conventional diets. Animals were treated with oral suspensions containing: atorvastatin 1.0 mg/kg; H. dulcis extract at 50.0 and 100.0 mg/kg and dihydromyricetin at 25.0 and 50.0 mg/kg vehicle (control group). The following biochemical markers were evaluated; total cholesterol, HDL-C, LDL-C, triglycerides, AST, ALT, and alkaline phosphatase. The hypercholesterolemic diet was effective in inducing hypercholesterolemia, increasing total cholesterol by 112.7% relative to the control group. The treatments with two doses of the extract proved to be promising hypocholesterolemic agents, as they were able to substantially reduce total cholesterol and LDL-C, without significantly altering triglycerides, hepatic transaminases, and alkaline phosphatase, thereby encouraging the studies with the plant H. dulcis. The groups treated with the flavonoid dihydromyricetin, although they showed a significant reduction in total cholesterol and LDL-C, and found increases in triglycerides and hepatic transaminases, which is unwanted in the context of hypercholesterolaemia.Uniterms: Hovenia dulcis/pharmacognosy. Hovenia dulcis/hydroalcoholic extract/ cholesterol reduction. Hovenia dulcis/flavonoid dihydromyricetin/cholesterol reduction. Dihydromyricetin/cholesterol reduction. Hypercholesterolemia/experimental study. Medicinal plants.No Brasil, o acidente vascular cerebral e a doença arterial coronariana constituem as principais causas de mortalidade cardiovascular, sendo os altos níveis de colesterol LDL um dos principais fatores de risco. Nesse contexto, diversos extratos vegetais e substâncias naturais isoladas têm se mostrado promissoras como hipocolesterolemiantes. O objetivo do trabalho foi avaliar o potencial do extrato hidroalcoólico dos frutos de Hovenia dulcis e do flavonóide diidromiricetina na redução do colesterol em ratos hipercolesterolêmicos. Quarenta e dois ratos Wistar machos, foram distribuídos em 7 grupos de 6 animais, que receberam dieta suplementada com 1% de colesterol e 0,3% de ácido cólico, à exceção do grupo controle, que recebeu ração convencional. Posteriormente, os animais foram tratados com suspensões orais contendo: atorvastatina 1,0 mg/kg; extrato de H. dulcis de 50,0 e 100,0 mg/kg; diidromiricetina de 25,0 e 50,0 mg/kg e veículo (grupo controle). Avaliaram-se os parâmetros bioquímicos: colesterol total, HDL-C, LDL-C, trigl...

RESUMO As leucemias são neoplasias malignas que acometem as células do sangue e têm origem na medula óssea. São cânceres de grande incidência e de difícil tratamento, havendo, portanto, a uma constante procura por terapias

The present study investigated the possibility of apoptosis-inducing activity in human leukemia U-937 and THP-1 cells by the flavonoid morin. The treatments were evaluated by using the MTT and LDH assays; analysis of mitochondrial membrane potential (ΔΨm) was evaluated by flow cytometry, cell death by apoptosis was confirmed by fluorescence microscopy and by assessing the activity of caspases-3 and -6. The data indicated that the flavonoid morin has promoted a decrease in cell viability in a concentration-dependent way for both of the cancerous cell lines. An increase in the percentage of cell death caused by apoptosis was associated to a potential alteration in the mitochondrial membrane (ΔΨm) suggesting the involvement of cell death in intrinsic apoptotic pathways. Activation of caspases-3 and -6 confirmed the presence of apoptotic activity from morin.The results reinforce the antileukemic potential of flavonol morin.