6533b86efe1ef96bd12cc474

RESEARCH PRODUCT

Study of the natural cactus extracts protective effects on oxidative stress and inflammation related to peroxisomal β-oxidation deficiencies

subject

description

The objective of my thesis work was to better understand the role of microglial cells in neuroinflammation initiated in several neurovegetative peroxisomal leukodystrophies and to explore the protective effects of substances from the cactus Opuntia ficus indica. To this end, we used as an in vitro model microglial cells deficient in ATP Binding Cassette D transporters (ABCD 1 and ABCD 2) or acyl-CoA oxidase 1 (ACOX1). These are two BV-2 murine cell lines, deficient in Abcd1/Abcd2-/- or deficient in Acox1-/-, obtained elsewhere by gene editing using the CRISPR/Cas9 methodology. Our results made it possible to: (i) characterize, by differential centrifugation and isopycnic ultracentrifugation analysis, the impact of these deficiencies (Acox1- /- or Abcd1/d2-/-) on the size and/or the density of peroxisomes and other cellular organelles thanks to the activities of marker enzymes. We also revealed a change in the phagocytic capacity of these mutant microglial cells; (ii) to explore the protective effect of cactus seed oil (CSO), Opuntia ficus-indica, in vivo in mice, treated or not with lipopolysaccharides (LPS), thus showing anti-inflammatory activity of CSO by reducing both cerebral expression of iNos and at the hepatic level the expressions of Il-1β and Il-6. CSO was also able to restore peroxisomal activities, antioxidant of catalase and -oxidative of ACOX1, respectively affected by LPS treatment; (iii) to evaluate, in wild and deficient in Acox1 cells, the protective potential of two families of cactus substances (flavanols: isorhamnetin, isorhamnetin-rutinoside, quercetin; and polyphenols: ferulaldehyde, syringaldehyde, vanillin) against inflammation and oxidative stress generated by the absence of ACOX1 activity and/or LPS treatment. These cactus-derived substances can reduce the expression of pro-inflammatory mediators (TNFα, NLRP3, IL-1β) and the production of NO, increase the expression of peroxisomal antioxidant enzymes (Catalase and SOD1), and restore the lysosomal functions impacted by cellular stress induced by the absence of ACOX1 activity or by LPS treatment.