13 research outputs found
Anti-inflammatory and antioxidant properties of Eriobotrya japonica leaves extracts
Background: In the present work we determined phenolic and flavonoids
content of Eriobotrya japonica leaves extracts and fractions and
their antioxidant and anti-inflammatory properties. Objectives: To
evaluate the inhibition of inflammatory PLA2 and antioxidant effects of
extracts and fractions from Eriobotrya japonica leaves Methods:
Antioxidant activity was evaluated with DPPH radical scavenging assay
and anti-inflammatory effect of fractions was measured by their
inhibition potency on the human pro-inflammatory phospholipase A2
(group IIA). Results: The EtOH/EtOAc 2:1 extract exhibited a potent
inhibition of the hG-IIA with an IC50 values of 8 \u3bcg/ml. It also
shows an antioxidant activity measured on DPPH with an IC50 of 42
\u3bcg/ml. Fractionation shows that CH2Cl2/MeOH 0:1 fraction was the
rich one on flavonoids compounds (4.3 mg/g dry weight) and demonstrates
a high antioxidant activity with an IC50 of 12 \u3bcg/ml. The
anti-inflammatory evaluation demonstrates that the same fraction was
the best one to inhibit the pro-inflammatory phospholipase A2 group IIA
with an IC50 of 4 \u3bcg/ml. Conclusion: Study conducted on Eriobotrya
japonica shows that CH2Cl2/MeOH 0:1 fraction inhibits efficiently the
hGIIA phospholipase.which is considered as pro-inflammatory enzyme
In vitro study of the PLA2 inhibition and antioxidant activities of Aloe vera leaf skin extracts
<p>Abstract</p> <p>Background</p> <p>In the present work we determined the total phenolic content of <it>Aloe vera </it>leaf skin (AVLS) extracts by using various solvents (hexane, chloroform-ethanol (1/1), ethyl acetate, butanol and water). We have also evaluated the antioxidant and the anti-PLA2 properties of these extracts by measuring their inhibition potency on the human pro-inflammatory phospholipase A2 (group IIA).</p> <p>Results</p> <p>The water extract exhibits the highest inhibitory effect with an IC<sub>50 </sub>= 0.22 mg/ml and interestingly no effect was observed on the digestive phospholipase A2 (group IB) even at a concentration of 5 mg/ml. Antioxidant activities were also analyzed and the most active extracts were observed when using chloroform ethanol (1/1) and ethyl acetate (IC<sub>50 </sub>= 0.274 and 0.326 mg/ml, respectively). Analysis of the total phenolic content reveals that the water extract, with the best anti-PLA2 effect, was poor in phenolic molecules (2 mg GAE/g). This latter value has to be compared with the chloroform-ethanol and the ethyl acetate extracts (40 and 23.8 mg GAE/g, respectively), mostly responsible for the antioxidant activity.</p> <p>Conclusion</p> <p>A significant correlation was established between the total phenolic content and the antioxidant capacity but not with the anti PLA2 activity. Results from phytochemical screening suggest that the anti PLA2 molecules were probably catechin tannins compounds.</p
Streptomyces flavogriseus HS1: Isolation and Characterization of Extracellular Proteases and Their Compatibility with Laundry Detergents
The present study describes the isolation of a new protease producing Streptomyces strain HS1 and the biochemical characterization of the secreted proteases. By sequencing of its noted 16S rDNA, HS1 strain was found to have a 100% identity with Streptomyces flavogriseus. The highest protease production was found using FermII media. In these conditions maximum protease production (99 U/mL) was obtained after 96 h incubation at 30°C and 150 rpm. HS1 strain produced at least five proteases as revealed by zymogram technique. The enzyme preparation exhibited activity over a broad range of pH (5–11) and temperature (25–70°C). Optimum activity was observed at a pH of 7.0 and a temperature of 50°C. Proteolytic activity was significantly unaffected by Ca2+ and Mg2+. EDTA and PMSF highly decreased the original activity. The crude extracellular proteases showed high stability when used as a detergent additive. These properties offer an interesting potential for enzymatic hydrolysis at the industrial level
Comparative study of physic-mechanical and antioxidant properties of edible gelatin film from the skin of cuttlefish.
International audiencePhysicochemical properties of edible films based on cuttlefish skin gelatin extracted without (G0) or with different concentrations of pepsins (5 (G5), 10 (G10) and 15 (G15) U/g of skin) were investigated. Edible films prepared with partially hydrolyzed gelatins had lower tensile strength (TS) and elongation at break (EAB), but higher water vapour permeability (WVP) and water solubility than the control film. FTIR spectra of obtained gelatin films revealed a significant loss of molecular order of the triple helix. In addition, differential scanning calorimetric (DSC) analysis indicated that partially hydrolyzed gelatine films exhibited lower transition temperature and enthalpy compared with those of control film. The properties of the films were related to their microstructure, which was observed by scanning electron microscopy. Films with G0 and G5 had a smooth surface and a more compact structure, while films prepared with G10 and G15 had coarser surface. Thus, the chain length of extracted gelatin directly affected the properties of corresponding films
Mechanisms of Liver Injury in Non-Alcoholic Steatohepatitis
Non-alcoholic steatohepatitis (NASH) is a disorder marked by alterations in hepatic lipid homeostasis as well as liver injury in the form of cell death, inflammation and fibrosis. Research into the pathophysiology of NASH is dynamic. New concepts from the fields of cell biology, microbiology, immunology and genetics are being tested for their applicability to NASH; discoveries in each of these areas are enriching our understanding of this complex disease. This review summarizes how recent developments from the bench and bedside are merging with more traditional concepts to reshape our view of NASH pathogenesis. Highlights include human studies that emphasize the role of de novo lipogenesis in NASH and experimental work uncovering a role for the inflammasome in NASH. Genetic predispositions to NASH are being clarified, and intestinal microbiome is emerging as a determinant of fatty liver. These unique ideas are now taking their place within an integrated picture of NASH pathogenesis