Oxidized Milk Induces Spatial Learning and Memory Impairment by Altering Gut Microbiota in Offspring Mice during Pregnancy and Lactation

Pongamol Alleviates Neuroinflammation and Promotes Autophagy in Alzheimer's Disease by Regulating the Akt/mTOR Signaling Pathway

Alzheimer's disease (AD), one of the neurodegenerative disorders, is highly correlated with the abnormal hyperphosphorylation of Tau and aggregation of β-amyloid (Aβ). Oxidative stress, neuroinflammation, and abnormal autophagy are key drivers of AD and how they contribute to neuropathology remains largely unknown. The flavonoid compound pongamol is reported to possess a variety of pharmacological activities, such as antioxidant, antibacterial, and anti-inflammatory. This study investigated the neuroprotective effect and its mechanisms of pongamol in lipopolysaccharide (LPS)-induced BV2 cells, d-galactose/sodium nitrite/aluminum chloride (d-gal/NaNO2/AlCl3)-induced AD mice, and Caenorhabditis elegans models. Our research revealed that pongamol reduced the release of inflammatory factors IL-1β, TNF-α, COX-2, and iNOS in LPS-induced BV2 cells. Pongamol also protected neurons and significantly restored memory function, inhibited Tau phosphorylation, downregulated Aβ aggregation, and increased oxidoreductase activity in the hippocampus of AD mice. In addition, pongamol reversed the nuclear transfer of NF-κB and increased the levels of Beclin 1 and LC3 II/LC3 I. Most importantly, the anti-inflammatory and promoter autophagy effects of pongamol may be related to the regulation of the Akt/mTOR signaling pathway. In summary, these results showed that pongamol has a potential neuroprotective effect, which greatly enriched the research on the pharmacological activity of pongamol for improving AD.

Dityrosine in food: A review of its occurrence, health effects, detection methods, and mitigation strategies

Protein and amino acid oxidation in food products produce many new compounds, of which the reactive and toxic compound dityrosine, derived from oxidized tyrosine, is the most widely studied. The high reactivity of dityrosine enables this compound to induce oxidative stress and disrupt thyroid hormone function, contributing to the pathological processes of several diseases, such as obesity, diabetes, cognitive dysfunction, aging, and age-related diseases. From the perspective of food safety and human health, protein-oxidation products in food are the main concern of consumers, health management departments, and the food industry. This review highlights the latest research on the formation pathways, toxicity, detection methods, occurrence in food, and mitigation strategies for dityrosine. Furthermore, the control of dityrosine in family cooking and food-processing industry has been discussed. Food-derived dityrosine primarily originates from high-protein foods, such as meat and dairy products. Considering its toxicity, combining rapid high sensitivity dityrosine detection techniques with feasible control methods could be an effective strategy to ensure food safety and maintain human health. However, the current dityrosine detection and mitigation strategies exhibit some inherent characteristics and limitations. Therefore, developing technologies for rapid and effective dityrosine detection and control at the industrial level is necessary.

Dietary oxidized beef protein alters gut microbiota and induces colonic inflammatory damage in C57BL/6 mice

This study aimed to investigate the effect of oxidized beef protein on colon health. C57BL/6 mice were fed diets containing in vitro oxidized beef protein (carbonyl content 5.83/9.02 nmol/mg protein) or normal beef protein (control group, carbonyl content 2.27 nmol/mg protein) for 10 weeks. Histological observations showed that oxidized beef protein diet induced notable inflammatory cell infiltrations in colon. The analysis of high-throughput sequencing indicated oxidized beef protein largely altered the composition of gut microbiota (GM) by increasing proinflammatory bacteria (Desulfovibrio, Bacteroides, Enterorhabdus) while reducing beneficial bacteria (Lactobacillus, Akkermansia). In addition, oxidized beef protein remarkably increased protein fermentation in the colon, which was evidenced by the elevated i-butyrate, i-valerate, and ammonia levels in feces. Furthermore, consuming oxidized beef protein destroyed colon barrier functions by decreasing tight junction proteins expression. These changes in colonic ecosystem activated the proinflammatory pathway of lipopolysaccharide/toll-like receptor-4/nuclear factor kappa B (LPS/TLR-4/NF-κB), eventually leading to colonic inflammatory damage in mice. Taken together, these results imply that consuming oxidized beef protein detrimentally regulates GM and impairs colon health.

Health Effects of Dietary Oxidized Milk Administration in Offspring Mice during Pregnancy and Lactation with Metabolomic Strategies

Milk is an important source of nutrients during pregnancy. Previous studies have consistently shown that oxidation in milk and dairy products can induce oxidative stress, inflammation, and fibrosis in the liver and kidney. However, the mechanism underlying these effects remains largely unexplored. This study aimed to investigate the effects of oxidized milk on fecal metabolism and liver and kidney function of offspring mice. Oxidative modification of milk was performed using H₂O₂-Cu or heating, causing varying degrees of oxidative damage. Kunming female mice were fed with a H₂O₂-Cu, heat, or normal control diet until their offspring were 3 weeks old. Feces were collected for the metabolomics study based on mass spectrometry. Forty-two potentially significant metabolic biomarkers were screened, and each group's relative intensity was compared. The results showed that oxidized milk mainly regulated isoleucine metabolism, proline metabolism, and tricarboxylic acid cycle. In addition, the histopathological analysis showed accumulation of protein and lipid oxidation products in the liver and kidney tissues after intake of oxidized milk, which induced oxidative stress, increased the levels of inflammatory factors, and significantly increased the expression of genes and proteins involved in inflammatory pathways. The above results suggest that intake of oxidized milk during gestation may increase the risk of liver and kidney injury in male offspring by interfering with amino acid and energy metabolism, highlighting the potential health risks of oxidized milk in humans.