Anti-inflammation of isoliquiritigenin via the inhibition of NF-κB and MAPK in LPS-stimulated MAC-T cells.

BACKGROUND: The application of plant extracts has received great interest for the treatment of bovine mastitis. Isoliquiritigenin (ISL) is a rich dietary flavonoid that has significant antioxidative, anti-inflammatory and anticancer activities. This study was conducted to explore the protective efficacy and related mechanism of ISL against lipopolysaccharide (LPS)-stimulated oxidation and inflammation in bovine mammary epithelial cells (MAC-T) by in vitro experiments. RESULTS: Real-time PCR and ELISA assays indicated that ISL treatment at 2.5, 5 and 10 µg/mL significantly reduced the mRNA and protein expression of the oxidative indicators cyclooxygenase-2 and inducible nitric oxide synthase (P < 0.01), and of the inflammatory cytokines interleukin-6 (P < 0.05), interleukin-1ß (P < 0.01) and tumor necrosis factor-α (P < 0.01) in LPS-stimulated MAC-T cells. Moreover, Western blotting and immunofluorescence tests indicated that the phosphorylation levels of nuclear factor kappa (NF-κB) p65 and the inhibitor of NF-κB were significantly decreased by ISL treatment, thus blocking the nuclear transfer of NF-κB p65. In addition, ISL attenuated the phosphorylation levels of p38, extracellular signal-regulated kinase and c-jun NH2 terminal kinase. CONCLUSIONS: Our data demonstrated that ISL downregulated the LPS-induced inflammatory response in MAC-T cells. The anti-inflammatory and antioxidative activity of ISL involves the NF-κB and MAPK cascades.

Inhibitory effect of oil and fat on denitrification using food waste fermentation liquid as carbon source.

Food waste fermentation liquid (FWFL) can be used as carbon source to enhance nitrogen removal in wastewater treatment. However, the influence of lipid, a common component of food waste, on denitrification remains unclear. In this study, the effect of oil and fat on denitrification process and the underlying mechanisms were investigated using synthetic oil- and fat-bearing carbon source and verified with real FWFL. In the batch experiment, oil and fat had no obvious influence on denitrification, but in the semi-continuous experiment, the denitrification rate in the oil- and fat-added assays decreased to 44% and 38% of that in the control, respectively, after 45 batches. Oil and fat caused sludge floatation, and the floating sludge thickness increased with the continuous operation. Oil/fat-sludge aggregates were observed in the floating sludge and limited gas release. Microbial community analysis indicated that oil and fat did not affect denitrifying bacteria abundance. Limitation of mass transfer might be the main reason for the inhibition of oil and fat on denitrification. In the real FWFL experiment, the denitrification rate in the original and emulsified oil-bearing FWFL decreased to 24% and 56% of that in the demulsifying FWFL, respectively, after 45 batches. These findings indicate the necessity of removing lipids when FWFL is used as denitrification carbon source.

Functionalizing nanowires with catalytic nanoparticles for gas sensing application.

Metal oxide semiconducting nanowires are among the most promising materials systems for use as conductometric gas sensors. These systems function by converting surface chemical processes, often catalytic processes, into observable conductance variations in the nanowire. The surface properties, and hence the sensing properties of these devices can be altered dramatically improving the sensitivity and selectivity, by the deposition of catalytic metal nanoparticles on the nanowire's surface. This leads not only to promising sensor strategies but to a route for understanding some of the fundamental science occurring on these nanoparticles and at the metal/nanowire junction. In particular studying these systems can lead to a better understanding of the influence of the catalyst particle on the electronic structure of the nanowire and its electron transport. This report surveys results obtained so far in this area. In particular, the comparative sensing performance of single quasi-1D chemiresistors (i.e., nanowires or nanobelts) before and after surface decoration with noble metal catalyst particles show significant improvement in sensitivity toward oxidizing and reducing gases. Moreover, one finds that the sensing mechanism can depend dramatically on the degree of metal coverage of the nanowire.