Genistein as a neuroprotective antioxidant attenuates redox imbalance induced by beta-amyloid peptides 25-35 in PC12 cells.
ABSTRACT Genistein (GEN), a principal component of soybean isoflavones, might possess the neuroprotective role through its antioxidant activity. However, the detailed mechanisms are unknown yet. The purpose of this study was to investigate whether GEN could alleviate oxidative damage induced by beta-amyloid peptides 25-35 (Abeta25-35) in PC12 cells.
The PC12 cells were pre-incubated with or without GEN for 2h following incubation with Abeta25-35 for another 24h. MTT was used to assess the cell viability. Hoechst 33342 staining was applied to determine the apoptotic cells. Confocal laser scanning microscopy was implemented to examine the reactive oxygen species (ROS) levels. Mitochondrial membrane potential (MMP) was measured by flow cytometry. Reduced and oxidized glutathione (GSH/GSSG) ratio was analyzed by using assay kits. Western blot analysis was performed to assess the proteins expression of NF-E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and gamma-glutamylcysteine synthetase (gamma-GCS).
GEN attenuated the cytotoxicity and partially prevented apoptosis induced by Abeta25-35. GEN dramatically attenuated ROS levels induced by Abeta25-35 in PC12 cells. In addition, GEN significantly reversed the reduction of MMP caused by Abeta25-35 to maintain the normal levels of the cells. The GSH/GSSG ratio in GEN pretreated groups significantly increased compared to the groups without GEN pretreatment. GEN reversed Abeta25-35 induced down regulation of the protein expression of gamma-GCS, Nrf2 and HO-1.
GEN could alleviate the oxidative stress caused by Abeta25-35 treatment and maintain redox balance in PC12 cells, which might be associated with the regulation of Nrf2/HO-1 signal pathway.
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ABSTRACT: The objective of this study was to investigate the immobilisation efficiency of soybean β-glucosidase (181.6 U/mL; 23.8 mg protein/mL) on activated chitosan beads. Central Composite Rotational Design (CCDR) 23 was used and the application of immobilised enzyme in commercial soy drink was evaluated. The activation of chitosan beads was achieved with established 2.5% glutaraldehyde, pH 7.5, 8 h incubation time (6 h with agitation and 2 h without agitation) at 37ºC. The highest immobilisation efficiency (%) of soybean β-glucosidase on chitosan beads obtained was 37.74 U/mL and 18.84 mg protein/4 chitosan beads at pH 7.5 and 20 h coupling time of enzyme-matrix (7 h with agitation and 13 h without agitation) at 4ºC. The immobilised enzyme incubated at 50ºC, pH 5.5 resulted in 24% increase in the aglycones content in commercial soy drink after 60 min.Brazilian Archives of Biology and Technology 09/2014; 57(5):766-773. DOI:10.1590/S1516-8913201402331 · 0.45 Impact Factor
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ABSTRACT: To verify the performance of broadband quasioptical mode converters of step-tunable gyrotrons in cold-test experiments, several high order cavity modes at different frequencies have to be excited at low power levels. In order to avoid the huge effort of building a mode generator for each single mode, a broadband quasioptical method was chosen. Here, a Gaussian beam is focused onto a mode specific caustic in a coaxial cavity through a translucent cavity wall. The mode generator can be tuned to different resonances by eventually exchanging the inner conductor of the cavity and by slightly adjusting the position of its quasi-optical components.
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ABSTRACT: Resveratrol, a polyphenol present in red wine, has received much attention lately because of its putative preventive role in the purported link between moderate red wine consumption and lower incidence of neurological disorders such as dementia and stroke. Numerous animal and in vitro studies have shown that this polyphenol is neuroprotective and can reverse various types of cognitive deficits. However, the mechanism(s) of action involved in the multiple effects of resveratrol is not fully understood. In a recent article by Sakata and colleagues in Experimental Neurology (Sakata, Y., Zhuang, H., Kwansa, H., Koehler, R.C., Doré, S., 2010. Resveratrol protects against experimental stroke: putative neuroprotective role of heme oxygenase 1. Exp. Neurol. 224, 325-329.), the authors raise a hypothesis that the induction of heme oxygenase 1, an endogenous enzyme that provides resistance against oxidative stress-related neuronal damage, contributes, at least in part, to the neuroprotective action of resveratrol. Our brief commentary summarizes recent findings on intracellular pathways possibly involved in the effects of a multi-functional molecule, such as resveratrol, and highlights their relevance in various age-related neurological disorders.Experimental Neurology 10/2010; 225(2):237-9. DOI:10.1016/j.expneurol.2010.06.019 · 4.62 Impact Factor