Journal of Nutritional Biochemistry最新文献

There is limited data on the effect of UV light exposure versus orally ingested vitamin D₃ on vitamin D metabolism and health. A 4-week study with 16 pigs (as a model for human physiology) was conducted. The pigs were either supplemented with 20 µg/d vitamin D₃ or exposed to UV light for 19 min/d to standardize plasma 25-hydroxyvitamin D₃ levels. Important differences were higher levels of stored vitamin D₃ in skin and subcutaneous fat, higher plasma concentrations of 3-epi-25-hydroxyvitamin D₃ and increases of cutaneous lumisterol₃ in UV-exposed pigs compared to supplemented pigs. UV light exposure compared to vitamin D₃ supplementation resulted in lower hepatic cholesterol, higher circulating plasma nitrite, a marker of the blood pressure-lowering nitric oxide, and a reduction in the release of pro- and anti-inflammatory cytokines from stimulated peripheral blood mononuclear cells. However, plasma metabolome and stool microbiome analyses did not reveal any differences between the two groups. To conclude, the current data show important health relevant differences between oral vitamin D₃ supplementation and UV light exposure. The findings may also partly explain the different vitamin D effects on health parameters obtained from association and intervention studies.

Nonalcoholic fatty liver disease (NAFLD) has emerged as a major public health crisis with significant health threats and economic burdens worldwide in the past decades. Betaine, a naturally occurring alkaloid compound present in various dietary sources including spinach and beets, has been shown to ameliorate hepatic lipid metabolism and attenuate (NAFLD), while the underlying mechanism remains elusive. Here, we propose a novel mechanism through which betaine exerts its protective effects against hepatic lipid accumulation and (NAFLD) from an epigenetics perspective. Specifically, we discover that betaine upregulates betaine homocysteine S-methyltransferase (BHMT) expression, leading to increased nicotinamide adenine dinucleotide phosphate (NADPH) production and subsequent upregulation of fat mass and obesity-associated protein (FTO) expression. Increased abundance of FTO targets peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC1α) mRNA and reduces the N⁶-methyladenosine (m⁶A) level in the CDS of Ppargc1α transcript, which positively regulates PGC1α expression and subsequently inhibits hepatic lipid accumulation. Overall, our works demonstrate that betaine may be a promising therapeutic strategy for treating (NAFLD) and improving liver function through the regulation of (NADPH) and m⁶A-mediated pathways.

The objective of our study was to investigate the impact of neonatal overfeeding on cognitive functions and neurosteroidogenesis in male rats. Offspring were assigned to either small litters (SL; 4 pups/mother), resulting in increased milk intake and body weight gain, or normal litters (NL; 10 pups/mother). On postnatal day (PND) 21, half of the male rats were euthanized, while the remaining were kept under standard conditions (4 rats/cage) until PND70. At this stage, subjects underwent assessments for locomotor activity, anxiety levels via the elevated plus maze, and episodic-like memory (ELM) tests. By PND90, the rats were euthanized for brain dissection. Utilizing micropunch techniques, dentate gyrus (DG), CA1, and CA3 regions were extracted for analysis of mRNA expression and methylation patterns. At PND21, SL rats exhibited increased body and adipose tissue weights, alongside elevated cholesterol, glucose, and triglyceride levels compared to NL counterparts. By PND90, although metabolic disparities were no longer evident, SL rats demonstrated heightened anxiety-like behavior and diminished performance in ELM tests. Early life changes included a decreased expression of aromatase (P450arom) and 3α-HSD in CA1, with increased levels in CA3 and DG among SL rats. Additionally, PND90 rats from SL exhibited increased P450arom and decreased 5α-reductase 1 (5αR-1) expression in DG. Notably, some of these variations were correlated with changes in methylation patterns of their promoter regions. Our findings reveal that neonatal overfeeding exerts a long-term adverse effect on cognitive abilities and neurosteroidogenic pathways, underscoring the lasting impact of nutritional experiences during critical early postnatal development periods.

The objective of this study was to investigate the influence of α-lipoic acid (LA; R enantiomer) supplementation on maternal and fetal metabolic health in pregnancies complicated by maternal obesity. Forty female Sprague-Dawley rats were randomized to one of 4 treatment groups (n=10/group) throughout prepregnancy (3 weeks) and gestation (20 days): (1) a low calorie control (CON); (2) a high calorie obesity-inducing diet (HC); (3) the HC diet with 0.25% LA (HC+LA) or; (4) the HC diet pair-fed to match the caloric intake of the HC+LA group (HC+PF). On gestation day 20, pregnant rats were placed under anesthesia for collection of maternal/fetal blood and tissues. Compared with the HC group, LA-supplemented mothers demonstrated lower maternal prepregnancy and gestational weight gain (GWG), improved glycemic control (lower homeostatic model assessment for insulin resistance), and higher cholesterol concentrations in serum [high-density lipoprotein cholesterol (HDL-C) and low-and very-low density lipoprotein cholesterol (LDL/VLDL) fractions] and liver. Male and female fetuses from LA-supplemented mothers exhibited lower body weight, improved insulin sensitivity, and evidence of altered lipid metabolism including lower serum HDL-C, lower serum triglyceride (TG), and increased hepatic TG accumulation. Although maternal LA supplementation showed some benefit for both mothers and fetuses with respect to obesity and glycemic control, concern about the potential longer-term implications of liver cholesterol (mothers) and TG accumulation (fetuses) needs further investigation.