Lycopene is a non-provitamin A carotenoid that exhibits several health benefits. Epidemiological data support a correlation between lycopene intake and the attenuation of several chronic diseases, including certain types of cancers and cardiovascular diseases. It is currently unknown whether the beneficial effects are from the native structure of lycopene or its metabolic derivatives: lycopenals, lycopenols, and lycopenoic acids. This literature review focuses on the current research on lycopene digestion, absorption, metabolism, and excretion. This review primarily focuses on in vivo studies because of the labile nature and difficulty of studying carotenoids within in vitro experimental models. The studies presented address tissue accumulation of lycopene, the modification of bioavailability due to genetic and dietary factors, and lycopene cleavage by the enzymes ß-carotene oxygenase 1 (BCO1) and ß-carotene oxygenase 2 (BCO2). The current literature suggests that the majority of lycopene is cleaved eccentrically by BCO2, yet further research is needed to probe the enzymatic cleavage activity at the tissue level. Additionally, results indicate that single nucleotide polymorphisms and dietary fat influence lycopene absorption and thus modify its health effects. Further research exploring the metabolism of lycopene, the mechanisms related to its health benefits, and optimal diet composition to increase the bioavailability is required.

Alveolar macrophages (AM) are critical to defense against respiratory pathogens. This study evaluated cellular iron imbalance to immunometabolism in endotoxin-polarized porcine AMs (PAMs). PAMs collected from five 6-week-old pigs were treated with a basal media, iron chelator, or ferric ammonium citrate to maintain iron replete or induce iron deficiency or overload, respectively. After 24 h treatment, PAMs were challenged with saline or lipopolysaccharide (LPS) for 6 h. Cells were analyzed for gene, protein, and untargeted metabolome. Cytokines were determined in culture media. Data were assessed using two-way ANOVA. Treatments successfully induced iron deficiency and overload. The mRNA of DMT1 and ZIP14 was increased up to 300-fold by LPS, but unaffected by iron. Surprisingly, both iron deprivation and overload attenuated LPS-induced inflammation, showing less TNFα production and lower mRNA of pro- and anti-inflammatory cytokines than iron-replete PAMs. Forty-eight metabolites were altered by either or both main effects. LPS enhanced the glycolysis and polyol pathways. Iron deprivation disrupted the TCA cycle. Iron overload increased intracellular cholesterol. Interestingly, iron deprivation augmented, whereas iron overload diminished, LPS-induced itaconic acid production, which has anti-microbial and anti-inflammatory properties. Therefore, iron-deficient PAMs may be more resistant to intracellular pathogens which use PAMs as a conduit for infection.

Pregnant women and children are vulnerable to vitamin A deficiency (VAD), which is often compounded by concurrent deficiencies in other micronutrients, particularly iron and zinc, in developing countries. The study investigated the effects of early-life VAD on motor and cognitive development and trace mineral status in a mouse model. C57BL/6J dams were fed either a vitamin A-adequate (VR) or -deficient (VD) diet across two consecutive gestations and lactations. Offspring from both gestations (G1 and G2) continued the same diets until 6 or 9 weeks of age. Behavioral assays were conducted to evaluate motor coordination, grip strength, spatial cognition, and anxiety. Hepatic trace minerals were analyzed. A VD diet depleted hepatic retinoids and reduced plasma retinol across all ages and gestations. Retracted rear legs and abnormal gait were the most common clinical manifestations observed in VD offspring from both gestations at 9 weeks. Poor performance on the Rotarod test further confirmed their motor dysfunction. VAD didn’t affect hemoglobin levels and had no consistent effect on hepatic trace mineral concentrations. These findings highlight the critical role of vitamin A in motor development. There was no clear evidence that VAD alters the risk of iron deficiency anemia or trace minerals.

Background: Retinoid signaling is implicated in regulating membrane-bound polyunsaturated fatty acids (PUFAs), which serve as substrates for oxylipin biosynthesis. Dysregulated vitamin A status and altered oxylipin profiles have both been associated with the development of metabolic diseases. However, whether early-life vitamin A deficiency (VAD) causally influences oxylipin metabolism and liver health remains unclear. Methods: C57BL/6J mouse pups were exposed to either a vitamin A-deficient (VD) or vitamin A-replete (VR) AIN-93G-based diet during the fetal and suckling periods, and they weremaintained on the same diet from weaning (3 weeks of age) to 9 weeks of age. Oxylipin composition in plasma, liver and cerebral tissues was analyzed by liquid chromatography–mass spectrometry. Hepatic and cerebral expressions of genes involved in inflammation, phospholipid and PUFA catabolism, and oxylipin synthesis were analyzed using RT-qPCR. Results: Dietary deprivation induced severe VAD, which significantly altered 21 oxylipins in the liver and 34 oxylipins in the cerebrum, but did not affect the plasma oxylipin profile. In the liver, all altered oxylipins were elevated by VAD, the majority being ω-6-derived species with pro-inflammatory properties. In contrast, 27 altered oxylipins were lower in the VD cerebrum, including more ω-3-derived species. Multivariate analysis identified 11,12-EpETrE, 8,9-EpETrE, and 20-HETE as key hepatic oxylipins distinguishing VAD. VAD also altered hepatic expression of genes involved in membrane phospholipid remodeling (PNPLA8, PLA2G6, LPCAT3), and oxylipin metabolism (ALOX5, EPHX2), and it upregulated inflammatory signaling in the liver only, while fibrosis markers (TGFB1, COL1A1) remained unchanged. Conclusions: These findings demonstrate that early-life VAD is associated with tissue-specific alterations in oxylipin metabolism and hepatic inflammatory responses.