•Synthesized CeO2 nanorods are covered by high energy surfaces ((110) and (100)).•The preparation process is simple and can be enlarged easily.•CeO2 supports change the electronic structure of Pt ...nanoparticles.•High energy surfaces facilitate the electrooxidation reaction of methanol.
Uniform CeO2 nanorods (CeO2-r) and CeO2 nanoparticles (CeO2-p) are synthesized by hydrothermal method and are used as supports to load Pt nanoparticles (indexed as Pt/CeO2-r & Pt/CeO2-p) for methanol electrooxidation. HRTEM images indicate that the synthesized CeO2-r are covered by (100) and (110) facets which own higher surface energy compared to CeO2-p with (111) facets. Electrochemical characterizations demonstrate Pt/CeO2-r shows excellent specific activity which is 1.6 and 10 times higher than Pt/CeO2-p and commercial Pt/C (indexed as Pt/C-JM) towards electrooxidation of methanol. By in-situ FTIR spectroscopic investigation, much higher CO2 productivity is observed at low potential on Pt/CeO2-r that implies strong anti-poisoning ability during methanol electrooxidation. The significant improved electrocatalytical performance is attributed to the existence of CeO2 nanorods with high energy surfaces.
Seleno-polysaccharides possess a variety of biological activities. In the present study, we further investigated the immunomodulatory effects of low molecular-weight seleno-aminopolysaccharides (LSA) ...in intestinal porcine epithelial cells (IPEC-1), and the molecular mechanisms of these effects. Analysis by ELISAs revealed that LSA could significantly increase the secretion of nitric oxide (NO), interleukin- 6 (IL-6), interleukin- 10 (IL-10), and tumor necrosis factor alpha (TNF-α). Moreover, LSA dramatically increased the gene expression levels of TNF-α, IL-6, IL-10, and iNOS in IPEC-1 cells, as determined by qRT-PCR. Western blot analysis further determined that LSA promotes inhibitor kappa B α (IĸBα), nuclear factor- kappa B (NF-κB) p65 phosphorylation. Taken together, these findings suggested that LSA has immunomodulatory activity on IPEC-1 cells, and its mechanism may be related to activation of the NF-ĸB signaling pathway.
This study was carried out to investigate the protective effects of chitosan nanoparticles (CNP) against hydrogen peroxide (H₂O₂)-induced oxidative damage in murine macrophages RAW264.7 cells. After ...24 h pre-incubation with CNP (25-200 μg/mL) and chitosan (CS) (50-200 μg/mL, as controls), the viability loss in RAW264.7 cells induced by H2O2 (500 μM) for 12 h was markedly restored in a concentration-dependent manner as measured by MTT assay (P < 0.05) and decreased in cellular LDH release (P < 0.05). Moreover, CNP also exerted preventive effects on suppressing the production of lipid peroxidation such as malondialdehyde (MDA) (P < 0.05), restoring activities of endogenous antioxidant including superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) (P < 0.05), along with increasing total antioxidant capacity (T-AOC) (P < 0.05). In addition, pre-incubation of CNP with RAW264.7 cells for 24 h resulted in the increase of the gene expression level of endogenous antioxidant enzymes, such as MnSOD and GSH-Px (P < 0.05). At the same concentration, CNP significantly decreased LDH release and MDA (P < 0.05) as well as increased MnSOD, GSH-Px, and T-AOC activities (P < 0.05) as compared to CS. Taken together, our findings suggest that CNP can more effectively protect RAW264.7 cells against oxidative stress by H₂O₂ as compared to CS, which might be used as a potential natural compound-based antioxidant in the functional food and pharmaceutical industries.
An efficient microwave-assisted extraction (MAE) technique was developed to extract polysaccharides from Enteromorpha prolifera (PEP). The operating parameters, such as microwave power, ...liquid/material ratio, temperature and extraction time, were optimized using orthogonal array design coupled with single factor method. PEP yield was determined by the phenol-sulfuric acid method. The optimum extraction conditions were determined as follows: microwave power, 700 W; liquid/material ratio, 40:1 (mL/g); temperature, 70 °C; and extraction time, 25 min. Under such conditions, PEP yield reached to 10.79 %. In comparison with conventional hot water extraction and ultrasonic-assisted extraction, MAE showed obvious advantages in terms of high extraction efficiency, saving energy, rapidity, solvent consumption, and so on. The data demonstrated that MAE could be a fast and reliable method for quantitative analysis of PEP. The scavenging capability of PEP to DPPH/hydroxyl radical reached to 65.2 % and 41.2 % at the concentration of 0.5 mg/mL. The reducing power of PEP was 0.354. Compared with butylated hydroxytoluene (BHT) and gallic acid (GA), the experimental results showed that DPPH radical scavenging activity of PEP was higher than that of BHT. Thus, PEP had good potential as a natural antioxidant used in functional food or medicine industries.
In this study, we examined a series of 2′,4′,6′-trihydroxychalcone derivatives for their inhibitory activity as inhibitors of CDC25B and PTP1B. The pharmacological results showed that all of the ...tested compounds significantly inhibited CDC25B and PTP1B phosphatase in vitro. Among them, three compounds
2
,
6
, and
7
had the best inhibition activity, with inhibition rates against CDC25B were 99.56, 99.68, and 99.63 %, respectively, and with inhibition rates against PTP1B were 98.99, 99.37, and 98.08 %, respectively, which is similar to reference drugs Na
3
VO
4
and Oleanolic acid, respectively. Cytotoxic activity assays showed compounds
2
,
6,
and
7
are potent against HeLa and HCT116. Moreover, compound
6
delayed the potent antitumor inhibitory activity in a colo205 xenograft model in vivo.
In this study, a novel series of 7-substituted-1,2,4triazolo4,3-fpyrimidine derivatives was synthesized as potential anticonvulsant agents. Their anticonvulsant activities were evaluated by the ...maximal electroshock (MES) test, and their neurotoxicities were evaluated by the rotarod neurotoxicity test. The pharmacological results showed that the compound 3i (7-(4-chlorophenoxy)-1,2,4triazolo4,3-fpyrimidine) was among the most active agent with median effective dose (ED(50)) value of 34.7 mg/kg, median toxicity dose (TD(50)) of 262.9 mg/kg, and providing a protective index (PI=TD(50)/ED(50)) value of 7.6. The compound 3i also showed oral activity against MES-induced seizures and lower oral neurotoxicity. The compound 3i demonstrated antagonistic activity against seizures induced by PTZ, ISN, 3-MP and thiosemicarbazide.
A series novel of
N
-palmitoylethanolamide derivatives was synthesized and screened for their anticonvulsant and antidepressant activities. Anticonvulsant activities and neurotoxicities of compounds ...when injected intraperitoneally (i.p.) were determined by maximal electroshock seizure (MES) test and a rotarod test, respectively, in mice. Only four of the synthesized compounds (
3a
,
3b
,
3c
, and
3d
) showed anticonvulsant activity at a dose of 100 mg/kg. Six compounds showed reduced immobility durations during the forced swimming test at a dose of 10 mg/kg, indicative of antidepressant activity. Among the compounds,
N
-(3-hydroxypropyl)cinnamamide (
3a
) was the most promising compound and significantly reduced the duration of immobility duration by 23.36% at a dose of 10 mg/kg compared with the control (
P
< 0.01).
To meet the demand of food, pharmaceutical and cosmetics industry, study on the oligosaccharide- collagen peptide complexes has both scientific significance and application values. In the text, the ...preparation process and antioxidant capacity of oligochitosan-collagen peptides complexes were reported. The resultes indicated that the maximum DPPH radical-scavenging activity of oligochitosan-collagen peptide complexe was reached to 19.26 % when the ratio of oligochitosan to collagen peptide was 80:20, and the activity was stronger than the oligochitosan and collagen peptide at the same concentration in the detection range. In combination with the results of ion-exchange chromatography, we could concluded that the intermolecular chain associations were formed between oligochitosan chains and collagen peptide molecules driven by the electrostatic, intermolecular hydrogen bond and hydrophobic interactions. The results opened a new perspective on the utilization of oligochitosan-collagen peptide complexes as drug, food or cosmetic additives.
In order to evaluate the high-value application of squid by-products yielded hydrolysate, the process of preparation and purification technology, chemical composition and in vitro antioxidant ...activity of the hydrolysate were investigated. The optimal conditions of papain hydrolysis were obtained by single-factor experiments and orthogonal test with the DPPH• scavenging ratio as index, amino acid composition was analysed by automatic amino acid analyzer, the hydrolysate was isolated with a Sephadex G-25 column. Based on single-factor experiments, the hydrolysate with the DPPH• scavenging ratio being 53.96 % was gained under the optimal condition of enzymolysis temperature of 45 °C, enzymolysis time of 3 h, total enzyme dose of 1.2 %, and the pH value of 7. The protein content of the hydrolysate reached up to 17.53 %, and the essential amino acids were accounted for 51.06 % of total amino acids. The largest content amino acid was glutamic acid, which accounted for 10.74 % of total amino acids. Compared with the amino acid profiles recommended by FAO/WHO, the quality of the protein hydrolysate was high, as it was rich in essential amino acids, including isoleucine, leucine, lysine, methionine and cystine, threonine, tryptophan, and valine, which covered 88 %-100 % of the FAO/WHO recommended. The hydrolysate was divided into three fractions (F1-F3) using a Sephadex G-25 column, the F1 possessed the highest antioxidation activity with the reducing power, •OH and DPPH• scavenging ratio being 0.236, 18.13 % and 63.85 % at the concentration of 5 mg/mL. Compared with the retention time of the reduced glutathione chromatomap, the relative molecular mass of F1 was higher than 307, F2 and F3 was lower than 307. The result revealed that the protein hydrolysate from squid by-products by papain had strongly antioxidant capacity in vitro and high nutrition, and this finding provided a new way of advanced exploitation of squid scrap resources.
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