Učinkovitost natrijevih soli hidroksiflavona kao hvatača slobodnih radikala u usporedbi s aktivnošću samih hidroksiflavona

Different studies have demonstrated that the bioactivity of hydroxyflavones is due to their antioxidant and free radical scavenging activity. Recently, most interest has been devoted to structure- activity relationships; however, the main problems encountered in these studies are the low solubility of some hydroxyflavones in aqueous solution and the pro-oxidant character of the hydroxyl group at the 3 position. In the present investigation, these problems have been resolved by preparing the corresponding hydroxyflavone sodium salts. In this way, the hydroxyl free radical (OH)• scavenging activity of different hydroxyflavone salts were studied using the Fenton reaction model, and the superoxide (O2)• – scavenging activity was studied using the xanthine oxidase model. The results obtained show clearly that the (OH)• scavenging activity of the hydroxyflavone salt form is at least two times that of the corresponding hydroxyflavone itself. Considering the (O2)• – scavenging activity, the salt form of hydroxyflavone is as good as the corresponding hydroxyflavone. Moreover, it was observed that for a good scavenging activity the hydroxyl at the 3\u27 position must be free, and only the hydroxyl groups of 3 and 4\u27 have to be substituted by sodium when the sodium salt of hydroxyflavone at position 7 does not have an important role in radical scavenging. The salt forms of hydroxyflavones are interesting free radical scavenger compounds showing a hydrophilic character.Različita istraživanja pokazala su da je bioaktivnost hidroksiflavona posljedica njihove antioksidacijske aktivnosti i sposobnosti hvatanja slobodnih radikala. Do sada je mnogo zanimanja iskazano za odnos između strukture i aktivnosti; međutim, osnovni problemi na koje se naišlo u tim istraživanjima slaba je topljivost nekih hidroksiflavona u vodenoj otopini i prooksidacijski karakter hidroksilne skupine u položaju 3. U ovom istraživanju ti problemi razriješeni su pripremom odgovarajućih natrijevih soli hidroksiflavona. Tako su proučavani učinkovitost soli raznih hidroksiflavona kao hvatača slobodnih hidroksilnih radikala (OH)• modelom Fentonove reakcije te kao hvatača superoksid radikala (O2)• – modelom ksantin oksidaze. Dobiveni rezultati jasno pokazuju da soli hidroksiflavona najmanje dva puta učinkovitije hvataju hidroksilne radikale (OH)• nego što to čine odgovarajući hidroksiflavoni. Učinkovitost hvatanja superoksid radikala (O2)• – jednaka je kako za soli hidroksiflavona tako i za same hidroksiflavone. Osim toga opaženo je da za dobar učinak hvatanja radikala, OH skupina u položaju 3\u27 treba biti slobodna, da samo hidroksilne skupine 3 i 4\u27 trebaju biti supstituirane natrijem, dok natrijeva sol hidroksiflavona u položaju 7 nema znatnijega utjecaja na hvatanje radikala. Soli hidroksiflavona, spojevi koji pokazuju hidrofilni karakter, zanimljivi su hvatači slobodnih radikala

Field evaluation of Bt cotton crop impact on nontarget pests: cotton aphid and boll weevil.

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Princípios e práticas ecológicas para o manejo de insetos-praga na agricultura.

bitstream/item/109190/1/1112-05-nco-folderPrincipiosPraticasEcologicas.pd

Modeling of the Temporal Patterns of Fluoxetine Prescriptions and Suicide Rates in the United States

BACKGROUND: To study the potential association of antidepressant use and suicide at a population level, we analyzed the associations between suicide rates and dispensing of the prototypic SSRI antidepressant fluoxetine in the United States during the period 1960–2002. METHODS AND FINDINGS: Sources of data included Centers of Disease Control and US Census Bureau age-adjusted suicide rates since 1960 and numbers of fluoxetine sales in the US, since its introduction in 1988. We conducted statistical analysis of age-adjusted population data and prescription numbers. Suicide rates fluctuated between 12.2 and 13.7 per 100,000 for the entire population from the early 1960s until 1988. Since then, suicide rates have gradually declined, with the lowest value of 10.4 per 100,000 in 2000. This steady decline is significantly associated with increased numbers of fluoxetine prescriptions dispensed from 2,469,000 in 1988 to 33,320,000 in 2002 (r(s) = −0.92; p < 0.001). Mathematical modeling of what suicide rates would have been during the 1988–2002 period based on pre-1988 data indicates that since the introduction of fluoxetine in 1988 through 2002 there has been a cumulative decrease in expected suicide mortality of 33,600 individuals (posterior median, 95% Bayesian credible interval 22,400–45,000). CONCLUSIONS: The introduction of SSRIs in 1988 has been temporally associated with a substantial reduction in the number of suicides. This effect may have been more apparent in the female population, whom we postulate might have particularly benefited from SSRI treatment. While these types of data cannot lead to conclusions on causality, we suggest here that in the context of untreated depression being the major cause of suicide, antidepressant treatment could have had a contributory role in the reduction of suicide rates in the period 1988–2002

Red Propolis Antifungal Action on Species of Candida of the Oral Cavity

Introduction: propolis is a substance that has aroused the interest of many researchers because of its numerous therapeutic properties, antibacterial and antifungal.Objectives: identifying the species of Candida and evaluate the antifungal effect of red propolis yeast oral cavity.Method: this is a clinical in vitro study with saliva samples collected from 152 patients treated at the dental office of the Family Health Strategy in the city of São Bento-PB. The identification of Candida species was made through the Chrom Ãgar Candida. The antifungal activity of the propolis extract was analyzed in four different concentrations: 100%, 75%, 50% and 25%, through the agar diffusion test.Results: The most prevalent species was C. albicans; antifungal action as to the concentration of 25% of the propolis extract was that apparently demonstrated greater efficacy, compared to the highest concentration.Conclusion: The inhibitory effect of propolis against Candida may have been influenced by the concentration of alcohol present in the extract. To test this hypothesis suggests that search is performed with extracts of propolis and at the same time with the alcohol, in both concentrations and different environmental conditions. This study offers subsidies for other professionals employ different methodologies and propolis concentrations with other substances in order to test the antimicrobial action of these

A Randomized, Double Blind, Placebo-Controlled Trial of Pioglitazone in Combination with Riluzole in Amyotrophic Lateral Sclerosis

BACKGROUND: Pioglitazone, an oral anti-diabetic that stimulates the PPAR-gamma transcription factor, increased survival of mice with amyotrophic lateral sclerosis (ALS). METHODS/PRINCIPAL FINDINGS: We performed a phase II, double blind, multicentre, placebo controlled trial of pioglitazone in ALS patients under riluzole. 219 patients were randomly assigned to receive 45 mg/day of pioglitazone or placebo (one: one allocation ratio). The primary endpoint was survival. Secondary endpoints included incidence of non-invasive ventilation and tracheotomy, and slopes of ALS-FRS, slow vital capacity, and quality of life as assessed using EUROQoL EQ-5D. The study was conducted under a two-stage group sequential test, allowing to stop for futility or superiority after interim analysis. Shortly after interim analysis, 30 patients under pioglitazone and 24 patients under placebo had died. The trial was stopped for futility; the hazard ratio for primary endpoint was 1.21 (95% CI: 0.71-2.07, p = 0.48). Secondary endpoints were not modified by pioglitazone treatment. Pioglitazone was well tolerated. CONCLUSION/SIGNIFICANCE: Pioglitazone has no beneficial effects on the survival of ALS patients as add-on therapy to riluzole. TRIAL REGISTRATION: Clinicaltrials.gov NCT00690118

Pre- and postsynaptic mechanisms underlying inhibition of hypoglossal motor neuron excitability by riluzole

Riluzole is the sole treatment for amyotrophic lateral sclerosis (ALS), but its therapeutically relevant actions on motor neurons are not well defined. Whole cell patch-clamp recordings were made from hypoglossal motor neurons (HMs, n = 25) in brain stem slices from 10- to 23-day-old rats anesthetized with pentobarbital sodium to investigate the hypothesis that riluzole inhibits HMs by multiple mechanisms. Riluzole (20 mu M) hyperpolarized HMs by decreasing an inward current, inhibited voltage-gated persistent Na+ and Ca2+ currents activated by slow voltage ramps, and negatively shifted activation of the hyperpolarization-activated cationic current (I H). Repetitive firing of HMs was strongly inhibited by riluzole, which also increased action potential threshold voltage and rheobase and decreased amplitude and maximum rise slope but did not alter the maximal afterhyperpolarization amplitude or decay time constant. HM rheobase was inversely correlated with persistent Na+ current density. Glutamatergic synaptic transmission was inhibited by riluzole by both pre- and postsynaptic effects. Riluzole decreased activity-dependent glutamate release, as shown by decreased amplitude of evoked and spontaneous excitatory postsynaptic currents (EPSCs), decreased paired-pulse ratio, and decreased spontaneous, but not miniature, EPSC frequency. However, riluzole also decreased miniature EPSC amplitude and the inward current evoked by local application of glutamate onto HMs, suggesting a reduction of postsynaptic glutamate receptor sensitivity. Riluzole thus has a marked inhibitory effect on HM activity by membrane hyperpolarization, decreasing firing and inhibiting glutamatergic excitation by both pre- and postsynaptic mechanisms. These results broaden the range of mechanisms controlling motor neuron inhibition by riluzole and are relevant to researchers and clinicians interested in understanding ALS pathogenesis and treatment