Antioxidant peptides obtained from snakehead (Channa argus) soup (SHS) after simulated gastrointestinal (GI) digestion were separated, identified and characterized. Results showed that the fraction with MW < 3 kDa had the highest antioxidant capacity. Four novel antioxidant peptides were identified after RP-HPLC and UPLC-MS/MS. PGMLGGSPPGLLGGSPP and SDGSNIHFPN had the highest DPPH radical scavenging activity (IC50 = 1.39 mM) and Fe 2+ chelating ability (IC50 = 4.60 mM), respectively. Structures in silico for IVLPDEGK, PGMLGGSPPGLLGGSPP and SDGSNIHFPN suggest that at least one β-turn and/or α-helix, are associated with antioxidant activity. Moreover, our results showed that these three peptides docked with a recombinant Kelch-like ECH-associated protein 1 (Keap1) with a binding score greater than TX6, a good ligand of Keap1. The cell viability assay also showed significant cytoprotective effects against H2O2-induced cellular oxidative damage. This information implies that antioxidant mechanisms of novel peptides occurred via activation of cellular anti-oxidation Keap1-Nrf2 signaling pathway.

It has been reported that chronic and acute alcohol exposure decreases cerebral glucose metabolism and increases acetate oxidation. However, it remains unknown how much ethanol the living brain can oxidize directly and whether such a process would be affected by alcohol exposure. The questions have implications for reward, oxidative damage, and long-term adaptation to drinking. One group of adult male Sprague-Dawley rats was treated with ethanol vapor and the other given room air. After 3 wk the rats received i.v. [2-13 C]ethanol and [1, 2-13 C 2 ]acetate for 2 h, and then the brain was fixed, removed, and divided into neocortex and subcortical tissues for measurement of 13 C isotopic labeling of glutamate and glutamine by magnetic resonance spectroscopy. Ethanol oxidation was seen to occur both in the cortex and the subcortex. In ethanol-naïve rats, cortical oxidation of ethanol occurred at rates of 0.017 ± 0.002 μmol/min/g in astroglia and 0.014 ± 0.003 μmol/min/g in neurons, and chronic alcohol exposure increased the astroglial ethanol oxidation to 0.028 ± 0.002 μmol/min/g (P = 0.001) with an insignificant effect on neuronal ethanol oxidation. Compared with published rates of overall oxidative metabolism in astroglia and neurons, ethanol provided 12.3 ± 1.4% of cortical astroglial oxidation in ethanol-naïve rats and 20.2 ± 1.5% in ethanol-treated rats. For cortical astroglia and neurons combined, the ethanol oxidation for naïve and treated rats was 3.2 ± 0.3% and 3.8 ± 0.2% of total oxidation, respectively. 13C labeling from subcortical oxidation of ethanol was similar to that seen in cortex but was not affected by chronic ethanol exposure.T he liver is the major organ for the oxidation of ethanol (Etoh) (1, 2), followed by the stomach and other organs. Acetate (Ac) generated from Etoh by the liver is consumed by the brain (3, 4), where it replaces a significant portion of cerebral glucose metabolism in humans and animals (5-8), either decreasing glucose consumption directly or compensating for glucose consumption decreased by some other effect. However, the brain may also oxidize Etoh (9-14), and that capacity is important with respect to several perspectives. The first step of Etoh oxidation generates acetaldehyde (AA), which is toxic, reactive, and potentially carcinogenic. AA is aversive systemically, as has been observed from the unpleasant effects of disulfuram, an inhibitor of AA dehydrogenase, but it has been shown to be rewarding in parts of the brain (12,15,16) especially in the posterior ventral tegmental area (17-19) by activating dopamine neurons (20)(21)(22). The liver maintains circulating levels of AA at levels of 20-155 μM (23, 24), and AA has been reported not to penetrate the blood-brain barrier or to penetrate very slowly (23,25). Thus, if the brain can oxidize Etoh, then intracerebral AA may mediate behavioral, neurochemical, and toxic effects of Etoh in the brain, possibly playing a role in the development of alcohol dependence (6,16,26).AA is difficult to measure in living systems. The ...

Ultrafine fish bone powder (UFBP) from silver carp (Hypohthalmichthyxtitrix molitrix) was prepared using dry media milling. The characteristics of UFBP were investigated by laser particle size analyzer, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and inductively coupled plasma (ICP) spectrometry. The size and specific surface area of UFBP particles were significantly (p<0.05) affected by rotation speed, media/powder weight ratio, media diameter, and milling time. With the following conditions: rotation speed of 400 revolutions per minute, Downloaded by [University of Tennessee, Knoxville] at 13:38 01 June 2016A c c e p t e d M a n u s c r i p t 2 ratio of media to fish bone powder at 4:1, media diameter of 2 mm and 2.5 h of milling time, the optimal values of particle size (1.75 µm) and specific surface area (7.75 m 2 /g) were obtained.The SEM results confirmed that the particle became smaller and more uniform after milling treatment. Ash (63.71 %) and protein (20.52 %) were the main components of UFBP, and total calcium content was determined to be 236. 90 mg/g in dried UFBP. As UFBP particle size decreased, calcium solubility significantly increased (p<0.05), calcium content on the surface layer decreased, but the chemical compositions and structure did not change.

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Three machine learning methods, genetic algorithm-multilinear regression (GA-MLR), least-squares support vector machine (LS-SVM), and project pursuit regression (PPR), were used to investigate the relationship between thiazoline derivatives and their fungicidal activities against the rice blast disease. The GA-MLR method was used to select the most appropriate molecular descriptors from a large set of descriptors, which were only calculated from molecular structures, and develop a linear quantitative structure-activity relationship (QSAR) model at the same time. On the basis of the selected descriptors, the other two more accurate models (LS-SVM and PPR) were built. Both the linear and nonlinear modes gave good prediction results, but the nonlinear models afforded better prediction ability, which meant that the LS-SVM and PPR methods could simulate the relationship between the structural descriptors and fungicidal activities more accurately. The results show that the nonlinear methods (LS-SVM and PPR) could be used as good modeling tools for the study of rice blast. Moreover, this study provides a new and simple but efficient approach, which should facilitate the design and development of new compounds to resist the rice blast disease.