Effects of Bioflavonoids from Taxus Media var. Hicksii on Superoxide Generation, Phosphorylation of Proteins and Translocation of Cytosolic Compounds to the Cell Membrane in Human Neutrophils

In present work, the effects of bioflavonoids (ginkgetin and sciadopitysin) on stimulus-induced superoxide generation, tyrosyl and serine/threonine phosphorylation of proteins in human neutrophils, and the translocation of cytosolic compounds (p47phox, p67phox and Rac) to cell membrane were studied, which were isolated from the needles of Taxus media var. Hicksii. Meanwhile, three normal flavonoids (apigenin, quercetin and isoquercetin) were involved as contrasts. The results indicated that ginkgetin and sciadopitysin were capable of concentration-dependently inhibitory effects on the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP), arachidonic acid (AA) and phorbol-12-myristate 13-acetate (PMA). And they also suppressed fMLP- and AA- induced tyrosyl or PMA-induced serine/threonine phosphorylation and the translocation of cytosolic compounds (p47phox, p67phox and Rac) to cell membrane, which were in parallel with the suppression of the stimulus-induced superoxide generation. The effect of these compounds on the radical-scavenging was also investigated. Ginkgetin and sciadopitysin did not show remarkable effect on DPPH radical-scavenging activity, and they didn’t display the radical-scavenging activity on superoxide anion generated by phenagine methoxysulfate (PMS)-NADH system. Apparently, ginkgetin and sciadopitysin had great performance in pharmacological value and they are worthy of in-depth study.

Download Full-text

Studies on In-vitro Anti-inflammatory and Antioxidant Potentials of Annona muricata Leaf Extracts

Croatian Journal of Food Science and Technology ◽

10.17508/cjfst.2020.12.2.05 ◽

2020 ◽

Vol 12 (2) ◽

pp. 177-183

Author(s):

Idorenyin Nwaehujor ◽

Samuel Akande ◽

Olubunmi Atolani ◽

Gabriel Olatunji

Keyword(s):

Hydrogen Peroxide ◽

Cell Membrane ◽

Antioxidant Activities ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Ethanol Extract ◽

Scavenging Activity ◽

Membrane Stabilization ◽

Anti Inflammatory ◽

Proteinase Inhibition

Inflammation has stimulated significant worldwide scientific interest because of its implication in many human diseases. Most inflammations are caused by reactive oxygen species or free radicals. Annona muricataleaf extracts were investigated for their in-vitroantioxidant and anti-inflammatory potentials. Annona muricataleavesweredried at room temperature, blended using a mill.and extracted with solvents of varying degree of polarities. The solventsused were hexane, ethyl acetate,and ethanol. After sequential extraction, the crude extracts were examined for their in-vitroanti-inflammatory activities on lipoxygenase inhibition, proteinase inhibition, albumin denaturation inhibition,and red blood cell membrane stabilization assays,while the antioxidant activities were examined using DPPH, ABTS and hydrogen peroxide assays. The results showed that the ethanol extract had significantlyhigher albumin denaturation inhibition activity at 500 μg/mL (p < 0.01). The activity of all the extracts on proteinase inhibition decreased with the increase in concentration of the extracts. Indomethacin (standard), ethanol extract,and ethyl acetate extract exhibited a dose dependent increase in lipoxygenase activity. The ethanol extract showed highred blood cell membrane stabilization activity at 500 μg/mL and the activity was comparable with that of the standard (diclofenac). Hydrogen peroxide scavenging activity of the extracts and standard (Vitamin C) were comparable at 20 –100 μg/mL. The ethanol extract showed significantly higher(p < 0.01) DPPH radical scavenging activity compared with other extracts. A similar trend was also observed for ABTS radical scavenging activity. Generally,the ethanol extract exhibited higher anti-inflammatory and antioxidant activities in most of the assays, this could be attributed to the polar compounds present in the extract.

Download Full-text

Free radical-scavenging activity and DNA damaging potential of auxins IAA and 2-methyl-IAA evaluated in human neutrophils by the alkaline comet assay

Journal of Biochemical and Molecular Toxicology ◽

10.1002/jbt.20323 ◽

2010 ◽

Vol 24 (3) ◽

pp. 165-173 ◽

Cited By ~ 8

Author(s):

Branka Salopek-Sondi ◽

Jasenka Piljac-Žegarac ◽

Volker Magnus ◽

Nevenka Kopjar

Keyword(s):

Free Radical ◽

Comet Assay ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Free Radical Scavenging Activity ◽

Human Neutrophils ◽

Scavenging Activity ◽

Alkaline Comet Assay

Download Full-text

Meso-Dihydroguaiaretic Acid Ameliorates Acute Respiratory Distress Syndrome through Inhibiting Neutrophilic Inflammation and Scavenging Free Radical

Antioxidants ◽

10.3390/antiox11010123 ◽

2022 ◽

Vol 11 (1) ◽

pp. 123

Author(s):

Yen-Tung Lee ◽

Yu-Li Chen ◽

Yi-Hsuan Wu ◽

Ih-Sheng Chen ◽

Hsun-Shuo Chang ◽

...

Keyword(s):

Acute Respiratory Distress Syndrome ◽

Free Radical ◽

Superoxide Anion ◽

Distress Syndrome ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Human Neutrophils ◽

Scavenging Activity ◽

Superoxide Anion Generation

The pathogenesis of acute respiratory distress syndrome (ARDS) is very complex. Patients with ARDS still suffer high mortality rates. Infiltration and activation of neutrophils in lungs are critical pathogenic factors in ARDS. In this study, we demonstrate that meso-dihydroguaiaretic acid (MDGA), a natural lignan, inhibits inflammatory responses in human neutrophils and ameliorates ARDS in mice. MDGA inhibited superoxide anion generation and elastase release in various G-protein coupled receptor agonists-induced human neutrophils. However, MDGA did not alter superoxide anion generation and elastase activity in cell-free systems. These results suggest that the anti-inflammatory effects of MDGA are mediated by regulating cellular signals in human neutrophils. In consistent with this, MDGA suppressed phosphorylation of extracellular signal-regulated kinase and c-Jun N-terminal kinase in activated human neutrophils. Moreover, MDGA inhibited CD11b expression and adhesion in activated human neutrophils. Interestingly, MDGA reduced reactive oxygen species (ROS) generation but not superoxide anion generation in protein kinase C (PKC) activator-induced human neutrophils, suggesting that MDGA may also have ROS scavenging ability. Indeed, MDGA showed strong free radical scavenging activity in cell-free assays. Significantly, MDGA suppressed PKC-induced neutrophil extracellular trap formation. Additionally, treatment of MDGA attenuated neutrophil infiltration and lung damage on lipopolysaccharide-induced ARDS in mice. In conclusion, our results demonstrate that MDGA has anti-neutrophilic inflammatory effects and free-radical scavenging activity. We also suggest that MDGA has potential to serve as a lead for developing new therapeutics to treat ARDS.

Download Full-text