Antioxidant Properties and Cytoprotective Effect of Pistacia lentiscus L. Seed Oil against 7 beta-Hydroxycholesterol-Induced Toxicity in C2C12 Myoblasts: Reduction in Oxidative Stress, Mitochondrial and Peroxisomal Dysfunctions and Attenuation of Cell Death

Abstract

Aging is characterized by a progressive increase in oxidative stress, which favors lipid peroxidation and the formation of cholesterol oxide derivatives, including 7 beta-hydroxycholesterol (7 beta-OHC). This oxysterol, which is known to trigger oxidative stress, inflammation, and cell death, could contribute to the aging process and age-related diseases, such as sarcopenia. Identifying molecules or mixtures of molecules preventing the toxicity of 7 beta-OHC is therefore an important issue. This study consists of determining the chemical composition of Tunisian Pistacia lentiscus L. seed oil (PLSO) used in the Tunisian diet and evaluating its ability to counteract the cytotoxic effects induced by 7 beta-OHC in murine C2C12 myoblasts. The effects of 7 beta-OHC (50 mu M; 24 h), associated or not with PLSO, were studied on cell viability, oxidative stress, and on mitochondrial and peroxisomal damages induction. alpha-Tocopherol (400 mu M) was used as the positive control for cytoprotection. Our data show that PLSO is rich in bioactive compounds; it contains polyunsaturated fatty acids, and several nutrients with antioxidant properties: phytosterols, alpha-tocopherol, carotenoids, flavonoids, and phenolic compounds. When associated with PLSO (100 mu g/mL), the 7 beta-OHC-induced cytotoxic effects were strongly attenuated. The cytoprotection was in the range of those observed with alpha-tocopherol. This cytoprotective effect was characterized by prevention of cell death and organelle dysfunction (restoration of cell adhesion, cell viability, and plasma membrane integrity; prevention of mitochondrial and peroxisomal damage) and attenuation of oxidative stress (reduction in reactive oxygen species overproduction in whole cells and at the mitochondrial level; decrease in lipid and protein oxidation products formation; and normalization of antioxidant enzyme activities: glutathione peroxidase (GPx) and superoxide dismutase (SOD)). These results provide evidence that PLSO has similar antioxidant properties than alpha-tocopherol used at high concentration and contains a mixture of molecules capable to attenuate 7 beta-OHC-induced cytotoxic effects in C2C12 myoblasts. These data reinforce the interest in edible oils associated with the Mediterranean diet, such as PLSO, in the prevention of age-related diseases, such as sarcopenia.