Avaliação do potencial mutagênico, genotóxico, estrogênico e modulação da expressão gênica pelo nemorosone, isolado da resina de Clusia rosea

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of nemorosone, isolated from the plant Clusia rosea, on the cell cycle and gene expression in MCF-7 BUS breast cancer cell lines

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification of a bioactive compound isolated from Brazilian propolis type 6

A prenylated benzophenone, hyperibone A, was isolated from the hexane fraction of Brazilian propolis type 6. Its structure was determined by spectral analysis including 2D NMR. This compound exhibited cytotoxic activity against HeLa tumor cells (IC(50) = 0.1756 mu M), strong antimicrobial activity (MIC range-0.73-6.6 mu g/mL; MBC range-2.92-106 mu g/mL) against Streptococcus mutans, Streptococcus sobrinus, Streptococcus oralis, Staphylococcus aureus, and Actinomyces naeslundii, and the results of its cytotoxic and antimicrobial activities were considered good. (C) 2009 Elsevier Ltd. All rights reserved.

Assessment of estrogenic, mutagenic and antimutagenic activity of nemorosone

Currently, a wide range of research involving natural products is focused on the discovery of new drugs in many different therapeutic areas. A great number of the synthetic compounds on the market were derived from natural products, especially plants. Nemorosone is the major constituent of the floral resin of Clusia rosea Jacq., Clusiaceae, and in Cuban propolis. In vitro studies have shown cytotoxic activity in this substance against various tumor cell lines, including those resistant to various cytotoxic drugs, whereas it has low cytotoxicity to non-tumoral cells. Therefore, in order to characterize the biological activity of nemorosone, a substance with potential antitumor activity, and in view of preclinical testing of the toxicity of drug candidate compounds, the main aim of this study was to determine the mutagenic and antimutagenic activity of nemorosone by the Ames test, using the strains TA97a, TA98, TA100 and TA102 of Salmonella typhimurium. Secondly, to characterize the estrogenic activity in an experimental recombinant yeast model (Recombinant Yeast Assay) mutagenic activity was observed at in any of the concentrations in any of the test strains. To evaluate the antimutagenic potential, direct and indirect mutagenic agents were used: 4 nitro-o-phenylenediamine (NPD), mitomycin C (MMC) and aflatoxin B1 (AFL). Nemorosone showed moderate antimutagenic activity (inhibition level 31%), in strain TA100 in the presence of AFL, and strong antimutagenic activity in TA102 against MMC (inhibition level 53%). Estrogenic activity was observed, with an EEq of 0.41±0.16 nM at various tested concentrations.

Evaluation of estrogenic, antiestrogenic and genotoxic activity of nemorosone, the major compound found in brown Cuban propolis

Background: Brown propolis is the major type of propolis found in Cuba; its principal component is nemorosone, the major constituent of Clusia rosea floral resins. Nemorosone has received increasing attention due to its strong in vitro anti-cancer action. The citotoxicity of nemorosone in several human cancer cell lines has been reported and correlated to the direct action it has on the estrogen receptor (ER). Breast cancer can be treated with agents that target estrogen-mediated signaling, such as antiestrogens. Phytoestrogen can mimic or modulate the actions of endogenous estrogens and the treatment of breast cancer with phytoestrogens may be a valid strategy, since they have shown anti-cancer activity.Methods: The aim of the present investigation was to assess the capacity of nemorosone to interact with ERs, by Recombinant Yeast Assay (RYA) and E-screen assays, and to determine by comet assay, if the compound causes DNA-damaging in tumoral and non-tumoral breast cells.Results: Nemorosone did not present estrogenic activity, however, it inhibited the 17-β-estradiol (E2) action when either of both methods was used, showing their antiestrogenicity. The DNA damage induced by the benzophenone in cancer and normal breast cells presented negative results.Conclusion: These findings suggest that nemorosone may have therapeutic application in the treatment of breast cancer. © 2013 Camargo et al.; licensee BioMed Central Ltd.

Endocarditis By Kocuria Rosea In An Immunocompetent Child.

Kocuria rosea belongs to genus Kocuria (Micrococcaceae family, suborder Micrococcineae, order Actinomycetales) that includes about 11 species of bacteria. Usually, Kocuria sp are commensal organisms that colonize oropharynx, skin and mucous membrane; Kocuria sp infections have been described in the last decade commonly affecting immunocompromised patients, using intravenous catheter or peritoneal dialysis. These patients had mainly bacteremia/recurrent sepsis. We hereby describe the case of a 10-year-old girl, immunocompetent, who had endocarditis/sepsis by K. rosea which was identified in five different blood cultures by Vitek 2 ID-GPC card (BioMérieux, France). Negative HIV serology, blood count within normal range of leukocytes/neutrophils and lymphocytes, normal fractions of the complement, normal level of immunoglobulins for the age; lymphocyte immunophenotyping was also within the expected values. Thymus image was normal at chest MRI. No catheters were required. Identification of K. rosea was essential to this case, allowing the differentiation of coagulase-negative staphylococci and use of an effective antibiotic treatment. Careful laboratory analysis of Gram-positive blood-born infections may reveal more cases of Kocuria sp infections in immunocompetent patients, which may collaborate for a better understanding, prevention and early treatment of these infections in pediatrics.

A mosaic of beach bean (Canavalia rosea) caused by an isolate of Cowpea aphid-borne mosaic virus (CABMV) in Brazil

Beach bean (Canavalia rosea) plants showing mosaic symptoms were found at Massaguacu beach, Caraguatatuba, Brazil. A potyvirus was found to be responsible for the symptoms, based on transmission assays and electron microscopy. A positive reaction in ELISA was obtained against cowpea aphid-borne mosaic (CABMV) antisera. Viral identity was confirmed by RT-PCR using specific primers to amplify part of the NIb and the entire CP coding region of the genome and the 3`NTR. Comparison of the amplified sequences with that of CABMV showed a nucleotide sequence identity of 97% for the CP coding region. Thus, the potyvirus from beach bean should be considered a CABMV isolate, referred to as CABMV-Cr.

Bees visitors of three species of Clusia (Clusiaceae) flowers in Central Amazonia

Observations on bees visitors to three species of Clusia (Clusiaceae) flowers in the Reserva Adolpho Ducke, Manaus, Amazonas, Brazil were made during three two-week periods. The three species of Clusia, namely C. grandiflora, C. panapanari and C. insignis, presented variations regarding the species of bee visitors. A total of 23 bee species visited the three species of Clusia. The Euglossini and Meliponinae bees were the most frequent visitors of the Clusia flowers. Bee collecting behavior of floral resources is described.

Larvas de insetos associadas a Clusia hilariana Schltdl. (Clusiaceae) na Restinga de Jurubatiba, RJ, Brasil

Clusia hilariana é uma das espécies de plantas mais abundantes no Parque Nacional, desempenhando um papel importante na dinâmica sucessional desse ecossistema de restinga. Esse trabalho apresenta a composição e aspectos ecológicos das espécies de larvas de mariposas encontradas em C. hilariana. Em 40 plantas, mensalmente vistoriadas, foram obtidas quatorze espécies de lepidópteros. Chloropaschia granitalis foi a espécie de larva mais abundante alimentando-se nessa espécie de planta.

Contrôle biologique de la pourriture cendrée (Macrophomina phaseolina) du niébé par l’enrobage des semences avec Clonostachys rosea: Impact des conditions de conservation des semences traitées sur la performance du bioagent.

Dans les sols infestés avec Macrophomina phaseolina les semences de niébé ne germent pas ou bien la plantule est détruite plus ou moins rapidement après la germination. Clonostachys rosea est un champignon commun du sol reconnu comme un saprophyte avec une haute capacité de compétition sur les racines et dans le sol. Notre étude a pour objectif d’évaluer l’effet de C. rosea en traitement de semences du niébé conservées à 40°C sur le développement de la pourriture charbonneuse. L’effet de la durée de conservation sur la viabilité des spores et le pouvoir antagonique du bioagent a également été étudié dans les conditions semi contrôlé et au champ. Les isolats de C. rosea proviennent de la collection du laboratoire de phytopathologie de AGRHYMET. La production des spores a été effectuée sur le milieu PDA pendant 4 semaines. Les semences du niébé ont été traitées avec une suspension de spores à la concentration de 108 spores / ml à raison de 5 ml de suspension par kg de semences. Les semences traitées ont été séchées sous la hotte à flux laminaire pendant 2 h avant d’être semées ou conservées à 40°C. Des tests de viabilité des spores de C. rosea sur le milieu de culture PDA ont été effectués au laboratoire tous les 15 jours de conservation. Le taux de germination des semences sur papier buvard, évalué au cinquième jour après semis au laboratoire a été de 99 %. La forte moyenne de spores viables au jour de l’enrobage (J0) (>4,5 105), a chuté à 1700 spores par graines après 75 jours de conservation. En serre, le niveau de colonisation des tissus des plants de niébé se développant sur le sol infesté a été significativement plus faible chez les plants issus de graines enrobées (1009 microsclérotes/g tissus) que chez ceux issus de graines non enrobées (2356 microsclérotes/g tissus). Par rapport a la sévérité de la maladie, exprimée sur une échelle de 1-5, ont été notées une forte infection des plants du témoin Macrophomina (graines non traitées semées dans un sol infesté) et des attaques moins sévères sur les traitements G3M et G4M (graines traitées semées dans un sol infesté). Au champ dans l’essai semé avec des graines enrobées mais non conservées, l’association des isolats G3 et G4 a été nettement supérieure aux autres traitements par rapport aux rendements en fane et en graines. Par contre, par rapport au rendement, aucun effet des traitements n’a été observé dans l’essai semé avec les graines conservées pendant 30 jours.

Germinação de sementes e emergência de plântulas de Tabebuia rosea (Bertoloni) a.p. de Candolle (Bignoniaceae), uma espécie exótica com potencial invasor

Este estudo teve por objetivo determinar os efeitos da temperatura e da luz na germinação de sementes de Tabebuia rosea, bem como avaliar a influência dos ambientes de pleno sol e sob dossel na emergência de suas plântulas. Foram testadas temperaturas constantes de 10 a 45 ºC com intervalos de 5 ºC, sob luz branca e escuro. Verificou-se que a faixa ótima de temperatura para a germinação foi de 20 a 40 ºC na luz e de 20 a 35 ºC no escuro. As sementes apresentaram maior sincronização da germinação a 25 ºC na luz e 30 ºC no escuro. Os resultados indicam que as sementes de Tabebuia rosea podem germinar em ampla faixa de temperatura, tanto em ambientes abertos, com disponibilidade de luz, quanto em locais com ausência de luz, enterradas no solo ou, mesmo, no interior das florestas. Essa germinação, bem como o recrutamento das plântulas, tanto a pleno sol quanto sob a sombra da vegetação, indica o potencial invasor da espécie.

Early detection of injuries in leaves of Clusia hilariana Schltdl. (Clusiaceae) caused by particulate deposition of iron

This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1) for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.

Polinização e biologia floral de Clusia arrudae Planchon & Triana (Clusiaceae) na Serra da Calçada, município de Brumadinho, MG

A biologia floral e a polinização de Clusia arrudae foi estudada na Serra da Calçada. C. arrudae não apresenta apomixia mesmo com a deposição de resina nos estigmas. Frutos desenvolvidos a partir de flores polinizadas manualmente produziram mais sementes (6,3 sementes por lóculo) do que frutos desenvolvidos a partir de flores polinizadas naturalmente (4,3 sementes por lóculo). O pico de floração ocorre de dezembro a meados de fevereiro. Plantas masculinas e femininas produzem flores diariamente; todavia, a cada três dias ocorre um pico de anteses que é sincronizado na população. A razão sexual da população é de 1:1, com plantas masculinas produzindo uma maior quantidade de flores que plantas femininas. Flores masculinas produzem cerca de 11 × 10(6) grãos de pólen no decorrer de três dias. A maioria dos grãos (66%) é apresentada no primeiro dia. Os estigmas das flores femininas permanecem receptivos por três dias ou quatro dias quando não ocorre polinização entre o primeiro e o terceiro dias. Flores de C. arrudae foram visitadas por seis espécies de abelhas para coleta de pólen e/ou resina. Operárias de Apis mellifera e Trigona spinipes, fêmeas de Xylocopa frontalis e Neocorynura sp. visitaram flores masculinas para coleta de pólen; operárias de T. spinipes foram também observadas coletando resina em flores femininas. Operárias de Melipona quadrifasciata e fêmeas de Eufriesea nigrohirta foram observadas coletando resina em flores femininas e masculinas. Devido à sua freqüência e comportamento nas flores femininas e masculinas, E. nigrohirta é o polinizador principal de C. arruda na Serra da Calçada.

Étude moléculaire des populations de Rhodiola rosea L. du nunavik (Québec, Canada)

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal