N-3 polyunsaturated fatty acids prevent the D-galactose-induced cognitive impairment by up-regulating the levels of 5-hydroxymethylcytosine in the mouse brain

The consumption of lard oil during pregnancy and postpartum periods has negative effects on cognitive function by altering the fatty acid profile and activating neuroinflammation via calcium signaling pathway in the maternal mice brain

It has been suggested that dietary intake of lipids and fatty acids may influence cognitive function, however, the effect of lard intake during pregnancy and postpartum periods on cognitive function of mother remains to be elucidated. We investigated the effect and mechanism of consuming soybean oil (SO), the mixed oil of lard and soybean oil at the ratio of 1:1 (LS) and lard oil (LO) during the pregnancy and postpartum periods on cognitive function of the maternal mice. All pregnant C57BL/6JNifdc mice were fed with soybean oil diet during day 0-10 (the day when vaginal plugs appeared in female mice was recorded as day 0), and then randomly assigned to SO, LS and LO groups (n = 10) from day 11 to day 44. The time in center zone and the number of times to enter in center zone were significantly higher in the SO group than in the LO group detected by the open-field test. The levels of neuroglial cells, NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome complex and pyroptosis related proteins in brain of the LO group were significantly higher than those in the SO group. RNA-sequencing results showed that the calcium signaling pathway related genes in brain, including Adcy8, Ntsr1, Trhr, Oxtr, Htr5b and Camk2d levels significantly higher in the LO group than in the SO group. Lipidomic analysis indicated that PG 18:2_18:2, PG 20:5_22:6, and CL 12:0_16:0_22:3_22:5 of glycerophospholipid metabolism in brain significantly connected with Htr5b of calcium signaling pathway. In conclusion, the intake of lard during the pregnancy and postpartum periods is detrimental to the cognitive function of maternal mice, which probably due to changes in the composition of fatty acid in the brain, thereby activating neuroinflammation via calcium signaling pathway in brain.

Thinned young apple powder prevents obesity-induced neuronal apoptosis via improving mitochondrial function of cerebral cortex in mice

Mitochondrial dysfunction is one of the triggers for obesity-induced neuron apoptosis. Thinned young apple is getting more attention on account of the extensive biological activities because of rich polyphenols and polysaccharides. However, the neuroprotective effect of thinned young apple powder (YAP) is still unclear. The aim of the present study was to investigate the preventive effect of YAP on obesity-induced neuronal apoptosis. C57BL/6J male mice were divided into 5 groups, control (CON), high fat diet (HFD), HFD + orlistat (ORL), HFD + low-dose young apple powder (LYAP) and HFD + high-dose young apple powder (HYAP) groups and intervened for 12 weeks. It was found that the YAP effectively reduced body weight gain. Importantly, the levels of pro-apoptosis protein were lower in LYAP and HYAP groups than the HFD group, such as Bak/Bcl2 and cleaved caspase3/caspase3. Pathway analysis based on untargeted metabolomics suggested that YAP alleviated obesity-induced neuronal apoptosis by three main metabolic pathway including arginine metabolism, citrate cycle (TCA cycle) and glutathione metabolism. Meanwhile, YAP improved the protein expression of mitochondrial respiratory chain complex, maintained the homeostasis of TCA cycle intermediates, protected the balance of mitochondrial dynamics and alleviated lipid accumulation. In addition, the levels of several antioxidants in cerebral cortex were higher in HYAP group than the HFD group like superoxide dismutase (SOD) and catalase (CAT). In summary, YAP supplementation suppressed neuronal apoptosis in the cerebral cortex of HFD-induced obesity mice by improving mitochondrial function and inhibiting oxidative stress.

Gut microbiome and brain transcriptome analyses reveal the effect of walnut oil in preventing scopolamine-induced cognitive impairment

Walnut Oil (WO) is recognized for its potential to improve cognition, but the mechanisms of its action related to improving cognitive impairment are not yet clear. In this study, the components of walnut oil were measured, and it was found that WO supplementation for 8 weeks could significantly prevent cognitive behavioral deficits and synaptic dysfunction induced by intraperitoneal injection of scopolamine (SCOP) in mice. By comparing and analyzing the changes in the hippocampal synaptic structure, oxidative stress, neurotransmitter fluctuations, brain transcriptome, inflammatory factors and gut microbiota in mice from different treatment groups, we observed a significant correlation between synaptic transmission genes, gut microbiota and neurotransmission in the WO supplemented group. It was found that WO supplementation could influence the secretion of neurotransmitters Ach and 5-HT by modulating the gut microbiota in vivo, thereby improving cognitive impairment through the central nervous system and hypothalamic-pituitary-adrenal (HPA) axis regulation.

Dendrobium officinale polysaccharide prevents neuronal apoptosis via TET2-dependent DNA demethylation in high-fat diet-induced diabetic mice

Dendrobium officinale polysaccharide (DP) has the potential function to prevent diabetes-induced neuronal apoptosis, whereas the mechanism is not completely clear. Ten eleven translocation dioxygenase 2 (TET2) is one of the most important therapeutic target for repairing neuronal damage in diabetic mice. The aim of the present study was to investigate whether DP could prevent neuronal apoptosis by regulating TET2 in the brain of HFD-induced diabetic mice. C57BL/6J mice were randomly divided into four groups (n = 12), control group (CON), high-fat diet group (HFD, negative control), metformin group (MET, positive control), and DP group (DP). Compared with HFD group, the neuronal apoptosis of brain was significantly lower in the DP group. The levels of TET2 protein, 5-hydroxymethylcytosine (5hmC) and 5-formylcytosine (5fC) were significantly lower in the HFD group than in both the DP and CON groups in the cerebral cortex of mice. The ratio of p-AMPK/AMPK and α-KG/(fumaric acid + succinic acid) were significantly lower in the HFD group than in the other groups. The present study suggests that DP has a preventive effect on diabetes-induced neuronal apoptosis by regulating TET2 function through improving phosphorylate AMPK and mitochondrial function, thus remodeling DNA epigenetics profile of mice brain.