Protection of plasmid DNA by a Ginkgo biloba extract from the effects of stannous chloride and the action on the labeling of blood elements with technetium-99m

Ginkgo biloba extract (EGb) is a phytotherapeutic agent used for the treatment of ischemic and neurological disorders. Because the action of this important extract is not fully known, assays using different biological systems need to be performed. Red blood cells (RBC) are labeled with technetium-99m (Tc-99m) and used in nuclear medicine. The labeling depends on a reducing agent, usually stannous chloride (SnCl2). We assessed the effect of different concentrations of EGb on the labeling of blood constituents with Tc-99m, as sodium pertechnetate (3.7 MBq), and on the mobility of a plasmid DNA treated with SnCl2 (1.2 µg/ml) at room temperature. Blood was incubated with EGb before the addition of SnCl2 and Tc-99m. Plasma (P) and RBC were separated and precipitated with trichloroacetic acid, and soluble (SF-P and SF-RBC) and insoluble (IF-P and IF-RBC) fractions were isolated. The plasmid was incubated with Egb, SnCl2 or EGb plus SnCl2 and agarose gel electrophoresis was performed. The gel was stained with ethidium bromide and the DNA bands were visualized by fluorescence in an ultraviolet transilluminator system. EGb decreased the labeling of RBC, IF-P and IF-RBC. The supercoiled form of the plasmid was modified by treatment with SnCl2 and protected by 40 mg/ml EGb. The effect of EGb on the tested systems may be due to its chelating action with the stannous ions and/or pertechnetate or to the capability to generate reactive oxygen species that could oxidize the stannous ion.

Ginkgo biloba leaf extract (EGb 761) enhances catalepsy induced by haloperidol and L-nitroarginine in mice

Ginkgo biloba extract EGb 761 has been reported to have therapeutic effects which have been attributed to anti-oxidant and free radical-scavenging activities, including a direct action on nitric oxide production. L G-nitro-arginine (L-NOARG), a nitric oxide synthase inhibitor, and haloperidol, a drug that blocks dopamine receptors, are both known to induce catalepsy in rodents. Nitric oxide has been shown to influence dopaminergic transmission in the striatum. The purpose of the present study was to evaluate the effect of the extract obtained from leaves of Ginkgo biloba tree EGb 761 on catalepsy induced by haloperidol or by L-NOARG. Albino Swiss mice (35-45 g, N = 8-12) received by gavage a single or repeated oral dose (twice a day for 4 days) of EGb 761 followed by ip injection of haloperidol or L-NOARG. After the treatments, the animals were submitted to behavioral evaluation using the catalepsy test. Acute treatment with 80 mg/kg EGb did not modify the catalepsy induced by L-NOARG but, the dose of 40 mg/kg significantly enhanced haloperidol-induced catalepsy measured at the 10th min of the test. After repeated treatment with 80 mg/kg EGb 761, a significant increase in the cataleptic effect produced by both haloperidol and L-NOARG was observed. These data show that repeated EGb 761 administration increases the effects of drugs that modify motor behavior in mice. Since the catalepsy test has predictive value regarding extrapyramidal effects, the possibility of pharmacological interactions between haloperidol and Ginkgo biloba extracts should be further investigated in clinical studies.

Effect of Ginkgo biloba on the reproductive outcome and oxidative stress biomarkers of streptozotocin-induced diabetic rats

The aim of the present study was to evaluate the effect of Ginkgo biloba treatment (EGb 761, 200 mg kg-1 day-1) administered from day 0 to 20 of pregnancy on maternal reproductive performance and on the maternal and fetal liver antioxidant systems of streptozotocin-induced diabetic Wistar rats. On day 21 of pregnancy, the adult rats (weighing approximately 250 ± 50 g, minimum number = 13/group) were anesthetized to obtain maternal and fetal liver samples for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total glutathione (GSH-t) determinations. The uterus was weighed with its contents. The diabetic (G3) and treated diabetic (G4) groups of rats presented significant maternal hyperglycemia, reduced term pregnancy rate, impaired maternal reproductive outcome and fetal-placental development, decreased GSH-Px (G3 = G4 = 0.6 ± 0.2) and SOD (G3 = 223.0 ± 84.7; G4 = 146.1 ± 40.8), and decreased fetal CAT activity (G3 = 22.4 ± 10.6; G4 = 34.4 ± 14.1) and GSH-t (G3 = G4 = 0.3 ± 0.2), compared to the non-diabetic groups (G1, untreated control; G2, treated). For G1, maternal GSH-Px = 0.9 ± 0.2 and SOD = 274.1 ± 80.3; fetal CAT = 92.6 ± 82.7 and GSH-t = 0.6 ± 0.5. For G2, G. biloba treatment caused no toxicity and did not modify maternal or fetal-placental data. EGb 761 at the nontoxic dose used (200 mg kg-1 day-1), failed to modify the diabetes-associated increase in maternal glycemia, decrease in pregnancy rate, decrease in antioxidant enzymes, and impaired fetal development when the rats were treated throughout pregnancy (21 days).

Beneficial effects of Ginkgo biloba extract on insulin signaling cascade, dyslipidemia, and body adiposity of diet-induced obese rats

Ginkgo biloba extract (GbE) has been indicated as an efficient medicine for the treatment of diabetes mellitus type 2. It remains unclear if its effects are due to an improvement of the insulin signaling cascade, especially in obese subjects. The aim of the present study was to evaluate the effect of GbE on insulin tolerance, food intake, body adiposity, lipid profile, fasting insulin, and muscle levels of insulin receptor substrate 1 (IRS-1), protein tyrosine phosphatase 1B (PTP-1B), and protein kinase B (Akt), as well as Akt phosphorylation, in diet-induced obese rats. Rats were fed with a high-fat diet (HFD) or a normal fat diet (NFD) for 8 weeks. After that, the HFD group was divided into two groups: rats gavaged with a saline vehicle (HFD+V), and rats gavaged with 500 mg/kg of GbE diluted in the saline vehicle (HFD+Gb). NFD rats were gavaged with the saline vehicle only. At the end of the treatment, the rats were anesthetized, insulin was injected into the portal vein, and after 90s, the gastrocnemius muscle was removed. The quantification of IRS-1, Akt, and Akt phosphorylation was performed using Western blotting. Serum levels of fasting insulin and glucose, triacylglycerols and total cholesterol, and LDL and HDL fractions were measured. An insulin tolerance test was also performed. Ingestion of a hyperlipidic diet promoted loss of insulin sensitivity and also resulted in a significant increase in body adiposity, plasma triacylglycerol, and glucose levels. In addition, GbE treatment significantly reduced food intake and body adiposity while it protected against hyperglycemia and dyslipidemia in diet-induced obesity rats. It also enhanced insulin sensitivity in comparison to HFD+V rats, while it restored insulin-induced Akt phosphorylation, increased IRS-1, and reduced PTP-1B levels in gastrocnemius muscle. The present findings suggest that G. biloba might be efficient in preventing and treating obesity-induced insulin signaling impairment.

Adição de extratos de Ginkgo biloba e Panax ginseng em néctares mistos de frutas tropicais

O estudo objetivou desenvolver formulações de néctares mistos de frutas tropicais, acrescidos de diferentes concentrações de extratos de Ginkgo biloba, Panax ginseng e misturas de Ginkgo biloba e Panax ginseng, avaliar características sensoriais, físico-químicas e químicas dos néctares selecionados. As formulações dos néctares tiveram a seguinte composição de polpa: caju (Anacardium occidentale), 12,25%; manga (Mangifera indica L), 21%; e acerola (Malpighia emarginata D.C.), 1,75%. Foram desenvolvidas diferentes formulações, com a adição dos extratos nas concentrações variando de 15 a 30 mg.100 mL-1 de néctar. A avaliação sensorial da impressão global, sabor e aroma foi feita por meio de teste de aceitação. Para as bebidas formuladas com Panax ginseng, somente o atributo sabor apresentou variação com o aumento da concentração do extrato. Para as bebidas acrescidas de Ginkgo biloba, observou-se um decréscimo linear para todos os atributos avaliados com o aumento da concentração do extrato. Para a mistura de extratos, não se observou variação das médias com o aumento da concentração dos extratos. Conclui-se que a adição de extrato de Panax ginseng até a concentração de 20 mg.100 mL-1 de néctar e a mistura dos extratos, em concentrações de 7,5 mg.100 mL-1 de néctar de cada extrato, apresentam boa aceitação sensorial. A adição dos extratos não afetou a composição química dos néctares que apresentaram quantidades elevadas de vitamina C, carotenoides, fenólicos totais e antocianinas.

Otimizando o componente farmacológico da terapia integrada da vertigem

A farmacoterapia é opção importante no tratamento das vestibulopatias periféricas. OBJETIVO: Identificar a medicação que otimiza a terapia integrada da vertigem (TIV) na doença de Ménière e em outras vestibulopatias periféricas. MATERIAL E MÉTODO: Estudo de casos em que pacientes com doença de Ménière ou outras vestibulopatias periféricas receberam TIV com betaistina, cinarizina, clonazepam, flunarizina, Ginkgo biloba ou sem medicação durante 120 dias. RESULTADOS: Na doença de Ménière, TIV com qualquer um dos medicamentos foi mais eficaz do que TIV sem medicação, após 60 dias; a betaistina foi mais efetiva que todas as outras drogas, após 60 e 120 dias. Nas outras vestibulopatias periféricas, diferenças significantes foram observadas entre TIV com betaistina, cinarizina, clonazepam ou flunarizina e TIV sem medicação após 60 dias e todas as drogas foram mais efetivas que TIV sem medicação após 120 dias; betaistina, cinarizina ou clonazepam foram igualmente efetivos e betaistina foi mais efetiva que flunarizina e Ginkgo biloba. Os tratamentos foram bem tolerados. CONCLUSÕES: TIV incluindo medicação é mais efetiva que sem medicação na doença de Ménière ou em outras vestibulopatias periféricas. Betaistina foi o medicamento mais efetivo na doença de Ménière e tão eficaz quanto cinarizina ou clonazepam em outras vestibulopatias periféricas.

Métodos de preparação e atividade biológica do ácido quinolínico e derivados

In 1981 2,3-pyridine dicarboxylic acid (quinolinic acid) was discovery to be a selective agonist for the N-methyl -D-aspartic acid (NMDA) receptor. As a consequence it possesses neurotoxic activity resulting from overstimulation of the receptor. Quinolinic acid is implicated as an etiological factor in a range of neurodegenerative disease including AIDS related dementia, Huntington´s disease and Lyme disease. In the design of novel therapies to treat these diseases, some molecules have been identified as an important target. In this paper we described different methods to prepare quinolinic acid and derivatives.

Estudo da utilização no pré-operatório de medicamentos ou drogas fitoterápicas que alteram a coagulação sangüínea

OBJETIVO: Verificar com que freqüência medicamentos e\ou drogas fitoterápicas que interferem na coagulação sangüínea são utilizados por pacientes que serão submetidos à intervenção cirúrgica e cujo uso não é relatado ao cirurgião; ou quando este é informado não se recomenda a sua interrupção antes da operação. MÉTODO: Estudo quantitativo com variáveis qualitativas, transversal, sobre o uso de medicamentos (AAS e Vitamina E) e fitoterápicos (Ginkgo biloba, Alho, Ginseng e Gengibre) por parte de 416 pacientes em programação pré-operatória. Desenvolvido no Hospital Universitário de Taubaté (HUT) no Hospital Regional de Taubaté (HRT) e em um Consultório Particular de Cirurgia Plástica. Estes dados foram obtidos por meio de questionário com perguntas relacionadas ao uso ou não das drogas referidas no último ano e nos 10 dias que antecediam a operação, se o cirurgião foi informado do fato e se houve recomendação médica para a sua suspensão. RESULTADOS: do total pesquisado 58,89% não fizeram uso de alguma das drogas em questão, 39% as usaram no último ano e 13,83% usaram nos últimos 10 dias. O AAS foi o medicamento mais utilizado e dentre os fitoterápicos, o Ginkgo biloba. Do total pesquisado 73,69% dos pacientes não informaram ao cirurgião o uso destas drogas. CONCLUSÕES: Na população estudada é elevada a porcentagem do uso de drogas que interferem na coagulação sanguínea, sendo as mais utilizadas o AAS, a vitamina E e o Ginkgo biloba. A maioria dos pacientes pesquisados não informou ao cirurgião a sua utilização. Deve-se enfatizar a necessidade de pesquisar o uso dessas drogas no pré-operatório, com o objetivo de reduzir possíveis complicações hemorrágicas per e pós-operatórias, pelas suas complicações médicas e eventuais implicações legais.

Genetic divergence in cocoa progenies for backcrossing program to witches' broom disease resistance

Backcrossing has been little used in cacao breeding, particularly due to the long time required to transfer genes and recover the genetic background of the recurrent parent. The objective of this study was to select individuals, resulting from the backcross CEPEC-42 x SIC-19, genetically related to the recurrent parent SIC-19 by using RAPD molecular markers, among those with resistance to witches' broom. Of the 31 plants that clustered with SIC-19, 18 from the replanted material remained free of the disease in the field, with good vegetative aspect and, therefore can be used for backcross to reach the desired objective.

Prevalence of periodontal disease in dogs and owners' level of awareness - a prospective clinical trial

Periodontal disease (PD) is widely known among veterinarians for its high prevalence and serious consequences to the dogs. The objective of this study was to assess the occurrence of PD in dogs that live in the micro-region of Viçosa, treated at the Veterinary Hospital of the Federal University of Viçosa (HVT - Hospital Veterinário da Universidade Federal de Viçosa), as well as to assess how aware of this disease dog owners are. In order to do so, all dogs treated at the HVT from March 10th, 2009 to November 30th, 2009, on alternate days, had their oral cavities examined. Medical history data, such as age, type of food, main complaint and owner consent, halitosis, presence of dental calculus, inflammation and gingival recession and tooth loss, were collected. A prevalence of 88.67% was found for PD in dogs referred to the HVT, and 2.67% were referred due to this disease. Of all the owners who participated in the study, 43.83% knew about periodontal disease and of these 17.46% made use of some type of prevention or treatment. Therefore, periodontal disease is highly prevalent and the owners are not aware of the disease. Thus, a dog owner clarification program on periodontal disease is needed in the area where HVT-UFV operates.

Prediction of genetic gain from selection indices for disease resistance in papaya hybrids

In order to select superior hybrids for the concentration of favorable alleles for resistance to papaya black spot, powdery mildew and phoma spot, 67 hybrids were evaluated in two seasons, in 2007, in a randomized block design with two replications. Genetic gains were estimated from the selection indices of Smith & Hazel, Pesek & Baker, Williams, Mulamba & Mock, with selection intensity of 22.39%, corresponding to 15 hybrids. The index of Mulamba & Mock showed gains more suitable for the five traits assessed when it was used the criterion of economic weight tentatively assigned. Together, severity of black spot on leaves and on fruits, characteristics considered most relevant to the selection of resistant materials, expressed percentage gain of -44.15%. In addition, there were gains for other characteristics, with negative predicted selective percentage gain. The results showed that the index of Mulamba & Mock is the most efficient procedure for simultaneous selection of papaya hybrid resistant to black spot, powdery mildew and phoma spot.

Agronomic performance of 27 cocoa progenies and plant selection based on productivity, self-compatibility and disease resistance

The objective of the present work was to evaluate 27 progenies of cocoa crosses considering the agronomic traits and select F1 plants within superior crosses. The experiment was installed in March 2005, in the Experimental Station Joaquim Bahiana (ESJOB), in Itajuipe, Bahia. The area of the experiment is of approximately 3 ha, with a total of 3240 plants. Thirteen evaluations of vegetative brooms, five of cushion brooms and 15 of number of pods per plant were accomplished. Thirty pollinations were made for each selected plant to test for self-compatibility. The production, based on the number of pods per plant, and resistance to witches´ broom indicated CEPEC 94 x CCN 10, RB 39 x CCN 51 and CCN 10 x VB 1151 as superior progenies. All selections tested were self-compatible. The analyses of progenies and individual tree data, associated to visual field observations, allowed the selection of 17 plants which were included in a network of regional tests to determine the phenotypic stability.

Silicon in plant disease control

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.