A comparative study of the effects of phosphatidylserine rich in DHA and EPA on Aß-induced Alzheimer's disease using cell models.

Alzheimer's disease (AD) is an age-dependent, irreversible neurodegenerative disease, and one of the pathological features is amyloid-ß (Aß) deposition. Previous studies have shown that phosphatidylserine (PS) enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exhibited significant effects in preventing and alleviating the progress of AD. However, no studies have focused on the differences in the preventive effects on AD between EPA-PS and DHA-PS. Here, the effects of EPA-PS and DHA-PS on Aß production, Aß-induced neurotoxicity and Aß clearance have been studied. The results show that DHA-PS significantly reduced Aß production in CHO-APP/PS1 cells compared to EPA-PS. Moreover, both EPA-PS and DHA-PS significantly protected the primary hippocampal neurons against Aß-induced toxicity by inhibiting the mitochondrial-dependent apoptotic pathway and phosphorylation of JNK and p38. Compared to DHA-PS, EPA-PS administration significantly improved the Aß phagocytic capacity of BV2 cells. In addition, EPA-PS and DHA-PS significantly promoted the neurite outgrowth of primary hippocampal neurons. These findings might provide dietary guidance for the prevention of AD as well as a reference for the development of related functional foods.

Sterol sulfate alleviates atherosclerosis via mediating hepatic cholesterol metabolism in ApoE-/- mice.

Compared with terrestrial organisms, the sterols in sea cucumber exhibit a sulfate group at the C-3 position. Our previous study demonstrated that dietary sterol sulfate was superior to phytosterol in alleviating metabolic syndrome by ameliorating inflammation and mediating cholesterol metabolism in high-fat-high-fructose diet mice, which indicated its potential anti-atherosclerosis bioactivity. In the present study, administration with sea cucumber-derived sterol sulfate (SCS) significantly decreased the cholesterol level in oleic acid/palmitic acid-treated HepG2 cells, while no significant changes were observed in the triacylglycerol level. RNA-seq analysis showed that the metabolic changes were mostly attributed to the steroid biosynthesis pathway. ApoE-/- mice were used as an atherosclerosis model to further investigate the regulation of SCS on cholesterol metabolism. The results showed that SCS supplementation dramatically reduced atherosclerotic lesions by 45% and serum low-density lipoprotein cholesterol levels by 59% compared with the model group. Dietary SCS inhibited hepatic cholesterol synthesis via downregulating SREBP-2 and HMGCR. Meanwhile, SCS administration increased cholesterol uptake via enhancing the expression of Vldlr and Ldlr. Noticeably, SCS supplementation altered bile acid profiles in the liver, serum, gallbladder and feces, which might cause the activation of FXR in the liver. These findings provided new evidence about the high bioactivity of sterols with the sulfate group on atherosclerosis.