A Novel Synthesis Route of Mesoporous γ-Alumina from Polyoxohydroxide Aluminum

Mesoporous gamma-aluminas (gamma-Al2O3) were synthesized starting from an unusual precursor of polyoxohydroxide aluminum (POHA). This precursor was obtained from aluminum oxidation in alkaline water-ethanol solvent in the presence of d-glucose that induces the formation of a gel, which leads to the POAH powder after ethanolic treatment Precipitated POHAs were calcined at different temperatures (300, 400, 700 and 900 degrees C) resultmg m the metastable gamma-Al(2)0(3) phase. Whereas at 300 degrees C no gamma-Al(2)0(3) phase was formed, unexpectedly, mesoporous gamma-Al(2)0(3) was obtained at 400 degrees C having a high specific surface area (282 m(2)/g) and a narrow pore size distribution At higher temperatures, the aluminas had the expected decrease in surface area 166 m(2)/g (700 degrees C) and 129 m(2)/g (900 degrees C), respectively The structural change from POHA to alumina calcined at 400 degrees C occurs directly without the need to isolate the hydroxide or oxyhydroxide aluminum precursors Both POHA and transition aluminas were characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), N-2 sorption and Scanning Electron Microscopy (SEM) These findings show an alternative route to produce high standard aluminas.Fundacao de Apoio a Pesquisa do Estado de Sao Paulo - FAPESPCAPESCNPqUniv Sao Paulo, Dept Engn Quim DEQ, Escola Engn Lorena, Estr Municipal Campinho S-N, BR-12602810 Lorena, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Ciencias Exatas & Terra, Rua Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilUniv Fed ABC, Ctr Engn Modelagem & Ciencias Sociais Aplicadas, Santo Andre, SP, BrazilUniv Sao Paulo, Inst Quim, Ave Prof Lineu Prestes 748, BR-05508900 Sao Paulo, SP, BrazilUniv Sao Paulo, Escola Engn Lorena, Polo Ind, Dept Engn Mat DEMAR, Gleba Al-6 S-N, BR-12602810 Lorena, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Ciencias Exatas & Terra, Rua Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilFAPESP: 2015/06064-6, 2013/08166-5, 2016/05496-2Web of Scienc

Effects of lutein and chlorophyll b on GSH depletion and DNA damage induced by cisplatin in vivo

Recent studies have proposed the use of low concentrations of phytochemicals and combinations of phytochemicals in chemoprevention to reduce cytotoxicity and simulate normal ingestion through diet. The purpose of the present study was to evaluate whether the DNA damage, chromosome instability, and oxidative stress induced by cisplatin (cDDP) are modulated by a combination of the natural pigments lutein (LT) and chlorophyll b (CLb). The protective effects observed for synergism between phytochemicals have not been completely investigated. The comet assay and micronucleus test were performed and the catalase activities and glutathione (GSH) concentrations were measured in the peripheral blood, bone marrow, liver, and kidney cells of mice. The comet assay and micronucleus test results revealed that the pigments LT and CLb were not genotoxic or mutagenic and that the pigments presented antigenotoxic and antimutagenic effects in the different cell types evaluated. This protective effect is likely related to antioxidant properties in peripheral blood cells through the prevention of cDDP-induced GSH depletion. Altogether our results show that the combination of LT and CLb, which are both usually present in the same foods, such as leafy green vegetables, can be used safely.32882883

The effects of oral glutamine on cisplatin-induced genotoxicity in Wistar rat bone marrow cells

Several studies have suggested that dietary supplementation with antioxidants can influence the response to chemotherapy as well as the development of adverse side effects that result from treatment with antineoplastic agents. The emphasis of the present study was to investigate whether the administration of a single dose of oral glutamine had any protective effect against cisplatin-induced clastogenicity. Cisplatin was administered to Wistar rats either alone or after treatment with glutamine. The rats were treated with glutamine (300 mg/kg b.w.) by gavage 24 h before the administration of cisplatin (5 mg/kg b.w., i.p.) and then sacrificed 24h after treatment with cisplatin. Glutamine significantly reduced (by about 48%) the clastogenicity of cisplatin in rat bone marrow cells. The antioxidant action of glutamine presumably modulates the clastogenic action of cisplatin. (C) 2002 Elsevier B.V. B.V. All rights reserved

In Vivo Genotoxicity and Oxidative Stress Evaluation of an Ethanolic Extract from Piquia (Caryocar villosum) Pulp

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)In this study, the ethanolic extract obtained from piquia pulp was assessed for genotoxicity and oxidative stress by employing the micronucleus test in bone marrow and peripheral blood cells in addition to comet, thiobarbituric-acid-reactive substances (TBARS), and reduced glutathione assays in the liver, kidney, and heart. Additionally, phytochemical analyses were performed to identify and quantify the chemical constituents of the piquia extract. Wistar rats were treated by gavage with an ethanolic extract from piquia pulp (75 mg/kg body weight) for 14 days, and 24 h prior to euthanasia, they received an injection of saline or doxorubicin (15 mg/kg body weight, intraperoneally). The results demonstrated that piquia extract at the tested dose was genotoxic but not mutagenic, and it increased the TBARS levels in the heart. Further studies are required to fully elucidate how the properties of ethanolic extract of piquia pulp can affect human health.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.163268271Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2009/15692-0, 2005/59552-6

Surface area, crystal morphology and characterization of transition alumina powders from a new gibbsite precursor

A new procedure was used to prepare a microcrystalline powder constituted by thin euhedral hexagonal gibbsite plates, 0.2 to 0.6 µm in diameter and 32 nm thick. The powder, fired between 200 and 1000 °C, produced chi and kappa transition aluminas. Alpha-alumina is formed from 1000 °C and recrystallized up to 1500 °C. At 1000 °C, kappa- and alpha-alumina coexisted, but kappa-alumina could only be characterized by SAED. The details of the internal organization of the transition alumina pseudomorphs were clearly observable in TEM due to the great thinness of the I-gibbsite plates. The specific surface area varied from pristine I-gibbsite (24.9 m².g-1) to chi- and kappa transition aluminas (25.4 m².g-1) at 1000 °C to alpha-alumina (4.0 m².g-1) at 1500 °C. The maximum value of specific surface area is 347 m².g-1 in chi-alumina powder at 300 °C, a difference from Bayer gibbsite, in which the chi-alumina highest surface area is 370 m².g-1 at 400 °C