Effects of Carpobrotus edulis Extract on Oxidative Stress and 158N Oligodendrocyte Death

Age-related diseases, including neurodegenerative diseases, are associated with oxidative stress and lipid peroxidation, and increase the levels of cholesterol auto-oxidation products such as 7β-hydroxycholesterol (7β-OHC). Thus, it is imperative to identify agents that can prevent 7β-OHC-induced side-effects.

We evaluated the potential protective effects of Carpobrotus edulis ethanol-water extract (EWe) on murine oligodendrocytes (158N) cultured in the absence or presence of 7β-OHC (20 μg/mL, 24 h). The cells were incubated with EWe (20-200 µg/mL) 2 h before 7β-OHC treatment. Mitochondrial activity and cell growth were evaluated with the MTT assay. Photometric methods were used to analyze antioxidant enzyme [catalase (CAT) and glutathione peroxidase (GPx)] activities and the generation of lipid and protein oxidation products [malondialdehyde (MDA), conjugated diene (CD), and carbonylated proteins (CPs)].

Treatment with 7β-OHC induced cell death and oxidative stress (reflected by alteration in CAT and SOD activities). Overproduction of lipid peroxidation products (MDA and CDs) and CPs was also reported. The cytotoxic effects associated with 7β-OHC were attenuated by 160 μg/mL of EWe of C. edulis. Cell death induced by 7β-OHC treatment was ameliorated, GPx and CAT activities were restored to normal, and MDA, CD, and CP levels were reduced following C. edulis extract treatment.

These data demonstrate the protective activities of C. edulis EWe against 7β-OHC-induced disequilibrium in the redox status of 158N cells, indicative of the potential role of this plant extract in the prevention of neurodegenerative diseases.