Vitamin E intestinal absorption: Regulation of membrane transport across the enterocyte

Transporters in vitamin uptake and cellular metabolism: impacts on health and disease

Vitamins are vital nutrients essential for metabolism, functioning as coenzymes, antioxidants, and regulators of gene expression. Their absorption and metabolism rely on specialized transport proteins that ensure bioavailability and cellular utilization. Water-soluble vitamins, including B-complex and vitamin C, are transported by solute carrier (SLC) family proteins and ATP-binding cassette (ABC) transporters for efficient uptake and cellular distribution. Fat-soluble vitamins (A, D, E, and K) rely on lipid-mediated pathways through proteins like scavenger receptor class B type I (SR-BI), CD36, and Niemann-Pick C1-like 1 (NPC1L1), integrating their absorption with lipid metabolism. Defective vitamin transporters are associated with diverse metabolic disorders, including neurological, hematological, and mitochondrial diseases. Advances in structural and functional studies of vitamin transporters highlight their tissue-specific roles and regulatory mechanisms, shedding light on their impact on health and disease. This review emphasizes the significance of vitamin transporters and their potential as therapeutic targets for deficiencies and related chronic conditions.

Dual-modulation of nutrient-transporter axis and functionalized carriers: A paradigm shift for precision oral vitamin D delivery

The transintestinal epithelial absorption of vitamin D is intricately regulated by specific transport protein networks. Emerging evidence from molecular nutrition research reveals that certain dietary nutrients can enhance intestinal vitamin D absorption through targeted modulation of lipid transport pathways. Despite significant advancements in vitamin D delivery systems demonstrating excellent intestinal mucoadhesion and in vitro bioaccessibility, their clinical translation remains limited by suboptimal in vivo bioavailability. To address this critical challenge, we propose an innovative synergistic nutrient absorption strategy that establishes precise coordination among three key elements: dietary nutrient composition, transport protein regulation, and intestinal absorption optimization. This comprehensive review systematically examines: (1) The molecular mechanisms governing transintestinal vitamin D transport and physiological modulation of protein-mediated absorption pathways; (2) The regulatory effects of dietary components on vitamin D absorption efficiency through protein pathway modulation, proposing a novel "nutrient-transporter-vitamin D axis" strategy integrating cutting-edge carrier technologies; (3) Future perspectives for developing functionalized vitamin D delivery systems. The proposed paradigm shift, combining nutrient-mediated transport enhancement with advanced carrier engineering, represents a transformative approach to overcome current limitations in oral vitamin D delivery. This dual-modulation strategy synergistically improves intestinal absorption and systemic bioavailability through simultaneous optimization of biological transport mechanisms and pharmaceutical delivery parameters, offering new possibilities for precision nutrition interventions.

Role of Scavenger Receptor B1 (SR-B1) in Improving Food Benefits for Human Health

Scavenger receptor class B member 1 (SR-B1) is a multiligand receptor with a broad range of functions spanning from the uptake of cholesteryl esters from high-density lipoproteins (HDLs) and transport of micronutrients such as fat-soluble vitamins and carotenoids across cell membranes to roles in tumor progression, pathogen recognition, and inflammatory responses. As a target of exposome factors such as environmental stressors and unhealthy lifestyle choices, as well as aging, dysregulated expression and activity of SR-B1 can negatively impact human health. Intriguingly, not only is SR-B1 a major determinant of nutrient homeostasis and, hence, metabolic health status, but these same nutrients and some phytochemicals have also demonstrated their ability to modulate SR-B1. Therefore, an integrated approach that, taking into account human health, nutrition, and food technology sciences, aims to produce foods with health-promoting effects should take advantage of the multifaceted properties of SR-B1. Improved functional foods and novel nanoparticle-based delivery systems, rich in nutrients and phytochemicals, with precise targeting to SR-B1 in specific tissues or structures could represent a strategic advance to improve human health and promote well-being.

Effects of Olive Pomace and Spice Extracts on Performance and Antioxidant Function in Broiler Chickens

This research aimed to evaluate the effects of an olive pomace extract (OE) and a fat-encapsulated extract composed of a blend of oleoresins from Capsicum sp., black pepper, and ginger (SPICY) on broiler chicken performance and antioxidant function. In total, 640 1-day-old male chicks were randomly assigned to five experimental diets (eight replicates/treatment, 16 birds/replicate). Diets included a basal diet with no added vitamin E (NC), NC plus 100 ppm of vitamin E (PC), NC plus 1250 ppm of OE, NC plus 250 ppm of (SPICY), and NC plus 1250 ppm OE plus 250 ppm of SPICY (SPIOE). Phytogenic additives were supplied by Lucta S.A., Spain. Compared to the NC, the PC significantly (p < 0.05) increased ADG from 8 to 14 days of age, with both OE and SPICY showing intermediate values between both controls. At the end of this trial, at 35 days of age, a significant (p < 0.05) increase in plasma GPx activity was observed in PC-fed birds compared to the NC, with no effects of malonyl dialdehyde (MDA) and total antioxidant capacity. Birds fed the OE and SPICY displayed intermediate values of GPx activity compared to both controls. The expression of heat shock protein 70 (HSP70) and glutathione S-Transferase Alpha 4 (GSTA4) was significantly lower (p < 0.05) in the jejunal mucosa of birds fed the OE compared to the NC. Moreover, the expression of HSP70 was significantly lower (p < 0.05) in birds fed the OE compared to SPICY but was not significantly different compared to the blend of both extracts (SPIOE). In conclusion, OE and SPICY were useful in maintaining growth performance in no vit E-supplemented diets, particularly in the case of OE mediated by its antioxidant action through HSP70.

Effect of oral nutritional supplements on inflammation and oxidative stress in hemodialysis patients: a meta-analysis

OBJECTIVE

This study aims to elucidate the effects of oral nutritional supplements on inflammatory factors and antioxidant status in patients undergoing hemodialysis through a meta-analysis of previous research.

METHODS

This study conducted literature databases from inception to November 2024, including PubMed, Embase, Cochrane, Wanfang, and China National Knowledge Infrastructure (CNKI), to identify all published randomized controlled trials assessing the impact of oral nutritional supplementation on inflammation and oxidative stress in patients on maintenance hemodialysis. Heterogeneity was assessed using the Chi-square test. Subgroup analyses and sensitivity analyses were performed to explore the sources of heterogeneity. Publication bias was evaluated using funnel plots and the Egger test.

RESULTS

Supplementation with unsaturated fatty acids did not significantly affect serum CRP levels in patients undergoing hemodialysis (MD = - 0.93, 95% CI [- 2.53, 0.68], Z = 1.13, P = 0.26). The total antioxidant capacity in the antioxidant group was higher than that in the control group (MD = 0.09, 95% CI [0.05, 0.14], Z = 4.41, P < 0.0001). The MDA levels in the antioxidant group were lower than those in the control group (MD = - 2.28, 95% CI [- 2.75, - 1.80], Z = 9.42, P < 0.0001), while the difference in IL-6 levels between the antioxidant group and the control group was not statistically significant (MD = - 0.10, 95% CI [- 0.56, 0.36], Z = 0.41, P = 0.68).

CONCLUSION

Unsaturated fatty acids do not have a significant effect on serum CRP levels in patients undergoing hemodialysis. The antioxidants (vitamin E and polyphenols) can enhance the antioxidant capacity and reduce MDA levels in these patients; however, their impact on IL-6 levels is not significant. Further high-quality randomized controlled trials are needed to validate these conclusions.

Physiological potential of different Sorghum bicolor varieties depending on their bioactive characteristics and antioxidant potential as well as different extraction methods

A comprehensive study of sorghum bran and flour was performed to explore the secondary metabolite profiles of differently coloured genotypes and to evaluate the variability in the antioxidant properties based on differences in polarity and solubility. This research included one red variety and one white variety. Among the samples, the red variety contained significantly greater amounts of secondary metabolites than did the white variety, with total polyphenol contents of 808.04 ± 63.89 mg.100 g-1 and 81.56 ± 3.87 mg.100 g-1, respectively. High-molecular-weight condensed tannin-type flavonoid extracts with high antioxidant activity were obtained by using relatively low-polarity acetone-water solvents, which was reflected by the measured antioxidant values. Among the methods used, the electron-donating Trolox equivalent antioxidant assay provided the highest antioxidant capacity, with values ranging from 118.5 to 182.6 μmol g-1 in the case of the red variety, in accordance with the electron donor properties of condensed tannins. Key secondary metabolites were identified using MS techniques and quantified using HPLC. Catechin and procyanidin B1 were found in the red variety at concentrations of 3.20 and 96.11 mg.100 g-1, respectively, while the concentrations in the white variety were under the limit of detection. All four tocopherols were found in sorghum, with the red variety containing a higher amount than the white variety, but the vitamin B complex concentrations were higher in the white variety. Overall, the red sorghum variety proved to be a better source of secondary metabolites with potential health benefits and could be used as a nutrient-rich food source.

Fatty acid/monoglyceride type and amount modulate fat-soluble vitamin absorption from mixed assemblies in mice

We investigated the effects of fatty acid/ monoglyceride type and amount on the absorption of fat-soluble vitamins. Micelles or vesicles made with either caprylic acid (CA) + monocaprylin (MC) or oleic acid (OA) + monoolein (MO) at low or high concentrations were infused in bile duct-ligated mice. Retinol + retinyl ester and γ-tocopherol intestinal mucosa contents were higher in mice infused with CA + MC than with OA + MO (up to + 350 % for vitamin A and up to + 62 %, for vitamin E; p < 0.05). Cholecalciferol intestinal mucosa content was the highest in mice infused with micelles with CA + MC at 5 mg/mL (up to + 105 %, p < 0.05). Retinyl ester plasma response was higher with mixed assemblies formed at low concentration of FA + MG compared to high concentration (up to + 1212 %, p < 0.05), while no difference in cholecalciferol and γ-tocopherol plasma responses were measured. No correlation between size or zeta potential and vitamin absorption was found. The impact of FA and MG on fat-soluble vitamin absorption thus differs from one vitamin to another and should be considered to formulate adequate vitamin oral or enteral supplements.

Integrated meta-omics reveals the regulatory landscape involved in lipid metabolism between pig breeds

BACKGROUND

Domesticated pigs serve as an ideal animal model for biomedical research and also provide the majority of meat for human consumption in China. Porcine intramuscular fat content associates with human health and diseases and is essential in pork quality. The molecular mechanisms controlling lipid metabolism and intramuscular fat accretion across tissues in pigs, and how these changes in response to pig breeds, remain largely unknown.

RESULTS

We surveyed the tissue-resident cell types of the porcine jejunum, colon, liver, and longissimus dorsi muscle between Lantang and Landrace breeds by single-cell RNA sequencing. Combining lipidomics and metagenomics approaches, we also characterized gene signatures and determined key discriminating markers of lipid digestibility, absorption, conversion, and deposition across tissues in two pig breeds. In Landrace, lean-meat swine mainly exhibited breed-specific advantages in lipid absorption and oxidation for energy supply in small and large intestinal epitheliums, nascent high-density lipoprotein synthesis for reverse cholesterol transport in enterocytes and hepatocytes, bile acid formation, and secretion for fat emulsification in hepatocytes, as well as intestinal-microbiota gene expression involved in lipid accumulation product. In Lantang, obese-meat swine showed a higher synthesis capacity of chylomicrons responsible for high serum triacylglycerol levels in small intestinal epitheliums, the predominant characteristics of lipid absorption in muscle tissue, and greater intramuscular adipcytogenesis potentials from muscular fibro-adipogenic progenitor subpopulation.

CONCLUSIONS

The findings enhanced our understanding of the cellular biology of lipid metabolism and opened new avenues to improve animal production and human diseases. Video Abstract.

Antioxidant interaction between α-tocopherol and γ-oryzanol in HepG2 cells

Minor constituents exhibit certain antioxidant interactions in vitro, and the effects in different media are different. However, it is not clear whether there are antioxidant interactions in cells after digestion and absorption. We utilized the cellular antioxidant evaluation model in HepG2 cells to study the antioxidant interaction between α-tocopherol and γ-oryzanol, and the interaction mechanism of a binary mixture was also illustrated. A cellular antioxidant assay (CAA) model and a combined index (CI) method were firstly used to explore the antioxidant activity and interaction of the binary mixture in HepG2 cells. The CAA value was positively correlated with the single addition concentration, while the results displayed a biphasic tendency with increasing concentrations of the binary mixture. The combination of TO11 (1 μg mL-1 α-tocopherol and 10 μg mL-1 γ-oryzanol) showed the greatest antioxidant activity and synergistic effect, and the maximum CAA value reached up to 94.84 ± 4.2. Then the mechanism of the synergistic antioxidant effect of the binary mixture was explained from three aspects including cellular uptake, intracellular reactive oxygen species (ROS) level and endogenous enzyme activity. The results demonstrated that the antioxidant interaction of the binary mixture in cells was related to cellular uptake of minor constituents, and the combination of TO11 exerted a synergistic effect by scavenging ROS and up-regulating glutathione peroxidase (GSH-Px) activity, resulting in the strongest cellular antioxidant activity. This study throws light on the nature of antioxidant interaction between minor constituents, which may contribute to the development of related functional foods and rational dietary collocation.

Exploring the relationship between metabolism and immune microenvironment in osteosarcoma based on metabolic pathways

BACKGROUND

Metabolic remodeling and changes in tumor immune microenvironment (TIME) in osteosarcoma are important factors affecting prognosis and treatment. However, the relationship between metabolism and TIME needs to be further explored.

METHODS

RNA-Seq data and clinical information of 84 patients with osteosarcoma from the TARGET database and an independent cohort from the GEO database were included in this study. The activity of seven metabolic super-pathways and immune infiltration levels were inferred in osteosarcoma patients. Metabolism-related genes (MRGs) were identified and different metabolic clusters and MRG-related gene clusters were identified using unsupervised clustering. Then the TIME differences between the different clusters were compared. In addition, an MRGs-based risk model was constructed and the role of a key risk gene, ST3GAL4, in osteosarcoma cells was explored using molecular biological experiments.

RESULTS

This study revealed four key metabolic pathways in osteosarcoma, with vitamin and cofactor metabolism being the most relevant to prognosis and to TIME. Two metabolic pathway-related clusters (C1 and C2) were identified, with some differences in immune activating cell infiltration between the two clusters, and C2 was more likely to respond to two chemotherapeutic agents than C1. Three MRG-related gene clusters (GC1-3) were also identified, with significant differences in prognosis among the three clusters. GC2 and GC3 had higher immune cell infiltration than GC1. GC3 is most likely to respond to immune checkpoint blockade and to three commonly used clinical drugs. A metabolism-related risk model was developed and validated. The risk model has strong prognostic predictive power and the low-risk group has a higher level of immune infiltration than the high-risk group. Knockdown of ST3GAL4 significantly inhibited proliferation, migration, invasion and glycolysis of osteosarcoma cells and inhibited the M2 polarization of macrophages.

CONCLUSION

The metabolism of vitamins and cofactors is an important prognostic regulator of TIME in osteosarcoma, MRG-related gene clusters can well reflect changes in osteosarcoma TIME and predict chemotherapy and immunotherapy response. The metabolism-related risk model may serve as a useful prognostic predictor. ST3GAL4 plays a critical role in the progression, glycolysis, and TIME of osteosarcoma cells.

Carotenoids in familial hypobetalipoproteinemia disorders: Malabsorption in Caco2 cell models and severe deficiency in patients

BACKGROUND

Familial hypobetalipoproteinemias (FHBL) are rare genetic diseases characterized by lipid malabsorption. We focused on abetalipoproteinemia (FHBL-SD1) and chylomicron retention disease (FHBL-SD3), caused by mutations in microsomal triglyceride transfer protein (MTTP) and SAR1B genes, respectively. Treatments include a low-fat diet and high-dose fat-soluble vitamin supplementations. However, patients are not supplemented in carotenoids, a group of lipid-soluble pigments essential for eye health.

OBJECTIVE

Our aim was to evaluate carotenoid absorption and status in the context of hypobetalipoproteinemia.

METHODS

We first used knock-out Caco-2/TC7 cell models of FHBL-SD1 and FHBL-SD3 to evaluate carotenoid absorption. We then characterized FHBL-SD1 and FHBL-SD3 patient status in the main dietary carotenoids and compared it to that of control subjects.

RESULTS

In vitro results showed a significant decrease in basolateral secretion of α- and β-carotene, lutein, and zeaxanthin (-88.8 ± 2.2 % to -95.3 ± 5.8 %, -79.2 ± 4.4 % to -96.1 ± 2.6 %, -91.0 ± 4.5 % to -96.7 ± 0.3 % and -65.4 ± 3.6 % to -96.6 ± 1.9 %, respectively). Carotenoids plasma levels in patients confirmed significant deficiencies, with decreases ranging from -89 % for zeaxanthin to -98 % for α-carotene, compared to control subjects.

CONCLUSION

Given the continuous loss in visual function despite fat-soluble vitamin treatment in some patients, carotenoid supplementation may be of clinical utility. Future studies should assess the correlation between carotenoid status and visual function in aging patients and investigate whether carotenoid supplementation could prevent their visual impairment.

Vitamin E Treatment Improves the Antioxidant Capacity of Patients Receiving Dialysis: A Systematic Review and Meta-Analysis

SCOPE

To summarize the effect of vitamin E-coated dialyzer membranes (VEMs) treatment or oral vitamin E intake on antioxidant molecules, such as superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), and total antioxidant level in patients receiving dialysis.

METHODS AND RESULTS

A literature search of PubMed, Embase, CNKI, and the Cochrane Library databases is performed from inception to July 1, 2023, with no language nor country restrictions. Twenty-four experimental studies involving 512 patients undergoing dialysis are selected for meta-analysis. The levels of antioxidant markers in the blood of patients receiving hemodialysis (HD) improve with long-term VEMs treatment (p = 0.016). According to the findings of each antioxidant index, there is a significant increase in the levels of erythrocyte-derived SOD (p = 0.047), CAT (p = 0.029), and plasma-derived total antioxidant level (p < 0.001). The antioxidant marker levels in patients receiving HD are significantly increased by oral vitamin E intake (p < 0.001). Erythrocyte-derived SOD (p = 0.003), GPX (p < 0.001), and CAT (p = 0.001) substantially improves after 2-6 months of intervention with oral vitamin E preparation. The antioxidant index of patients receiving peritoneal dialysis (PD) is unaffected by oral vitamin E treatment (p = 0.945).

CONCLUSION

Vitamin E therapy has a favorable effect on the retention of antioxidant compounds in patients undergoing dialysis.

Cluster-determinant 36 (CD36) mediates intestinal absorption of dietary astaxanthin and affects its secretion

The functional activity of dietary astaxanthin is closely related to its absorption, and the absorption of dietary carotenoids mainly mediated by transmembrane transport protein (TTP) has become the mainstream research direction in recent years. However, the main TTP mediating astaxanthin absorption and its potential mechanisms are still unclear. Hence, based on the preliminary screening results, this study aims to elucidate the role of cluster-determinant 36 (CD36) mediating astaxanthin absorption from the perspective of expression levels through in vitro cell model, in situ single-pass intestinal perfusion model and in vivo mice model. The results showed that astaxanthin uptake was significantly increased by 45.13% in CD36 overexpressing cells and decreased by 20.92% in the case of sulfo-N-succinimidyl oleate (SSO) inhibition. A similar trend also appeared in the duodenum and jejunum by in situ model. Moreover, astaxanthin uptake in the small intestine of CD36 knockout mice was significantly reduced by 88.22%. Furthermore, the inhibition or knockout of CD36 suppressed the expression of other transporters (SR-BI and NPC1L1). Interestingly, CD36 was also involved in the downstream secretion pathway, which is manifested by interfering with the expression of related proteins (ERK1/2, MTP, ApoB48, and ApoAI). Therefore, these results indicate the important role of CD36 in astaxanthin transmembrane transport for the first time, providing vital exploration way for the absorption of dietary fat-soluble substances.

Dietary inflammation index is associated with dyslipidemia: evidence from national health and nutrition examination survey, 1999-2019

BACKGROUND AND AIMS

This study aimed to investigate the association between the Dietary Inflammatory Index (DII) and dyslipidemia, as well as to evaluate the mortality risk associated with DII in participants with dyslipidemia.

METHODS

Data from the National Health and Nutrition Examination Survey database were divided into dyslipidemia and non-dyslipidemia groups. The association between DII and dyslipidemia was investigated using the weighted chi-square test, weighted t-test, and weighted logistic regression. Weighted Cox proportional hazards models were used to estimate the hazard ratios and 95% confidence intervals for all-cause and cardiovascular disease-related mortality within the dyslipidemia group.

RESULTS

A total of 17,820 participants, including 4,839 without and 12,981 with dyslipidemia were analyzed in this study. The results showed that DII was higher in the dyslipidemia group compared to the non-dyslipidemia group (1.42 ± 0.03 vs. 1.23 ± 0.04, P < 0.01). However, for energy, protein, carbohydrates, total fat, saturated fat, and iron, DII was lower in participants with dyslipidemia. Logistic regression analysis revealed a strong positive association between DII and dyslipidemia. The odds ratios for dyslipidemia from Q1 to Q4 were 1.00 (reference), 1.12 (0.96-1.31), 1.23 (1.04-1.44), and 1.33 (1.11-1.59), respectively. In participants with dyslipidemia, a high DII was associated with high all-cause and cardiovascular mortality.

CONCLUSION

DII was closely associated with dyslipidemia. A pro-inflammatory diet may play a role in unfavorable consequences and is linked to both all-cause mortality and cardiovascular death in patients with dyslipidemia. Participants with dyslipidemia should pay attention to their anti-inflammatory dietary patterns.

Effect of nano-delivery systems on the bioavailability and tissue biodistribution of vitamin E tocotrienols

Vitamin E is one of the most important essential vitamins to support the regulation of oxidative stress in human body. Tocotrienols are part of the vitamin E family. The potentials of tocotrienols as nutraceutical ingredient are largely understated due to low oral bioavailability, which is a common problem associated with fat-soluble bioactive compounds. Nanoencapsulation technology offers innovative solutions to enhance the delivery mechanisms of these compounds. In this study, the effect of nanoencapsulation on the oral bioavailability and tissue distribution of tocotrienols were investigated using two types of formulations, i.e. nanovesicles (NV-T3) and solid lipid nanoparticles (NP-T3). At least 5-fold increment in maximum plasma concentrations, evident with dual-peak pharmacokinetic profiles, were observed after oral administration of nano-encapsulated tocotrienols. Plasma tocotrienol composition showed a shift from α-tocotrienol dominant in control group (Control-T3) to γ-tocotrienol dominant after nanoencapsulation. Tissue distribution of tocotrienols was found to be strongly influenced by the type of nanoformulation. Both nanovesicles (NV-T3) and nanoparticles (NP-T3) showed elevated accumulation in the kidneys and liver (5-fold) compared to control group while selectivity for α-tocotrienol was evident for NP-T3. In brain and liver of rats given NP-T3, α-tocotrienol emerged as the dominant congener (>80%). Acute oral administration of nanoencapsulated tocotrienols did not show signs of toxicity. The study concluded enhanced bioavailability and selective tissue accumulation of tocotrienol congeners when delivered via nanoencapsulation.

Changes in the Mitochondria in the Aging Process-Can α-Tocopherol Affect Them?

Aerobic organisms use molecular oxygen in several reactions, including those in which the oxidation of substrate molecules is coupled to oxygen reduction to produce large amounts of metabolic energy. The utilization of oxygen is associated with the production of ROS, which can damage biological macromolecules but also act as signaling molecules, regulating numerous cellular processes. Mitochondria are the cellular sites where most of the metabolic energy is produced and perform numerous physiological functions by acting as regulatory hubs of cellular metabolism. They retain the remnants of their bacterial ancestors, including an independent genome that encodes part of their protein equipment; they have an accurate quality control system; and control of cellular functions also depends on communication with the nucleus. During aging, mitochondria can undergo dysfunctions, some of which are mediated by ROS. In this review, after a description of how aging affects the mitochondrial quality and quality control system and the involvement of mitochondria in inflammation, we report information on how vitamin E, the main fat-soluble antioxidant, can protect mitochondria from age-related changes. The information in this regard is scarce and limited to some tissues and some aspects of mitochondrial alterations in aging. Improving knowledge of the effects of vitamin E on aging is essential to defining an optimal strategy for healthy aging.

Natural Products as a Tool to Modulate the Activity and Expression of Multidrug Resistance Proteins of Intestinal Barrier

The role of intestinal barrier homeostasis in an individual’s general well-being has been widely addressed by the scientific community. Colorectal cancer is among the illnesses that most affect this biological barrier. While chemotherapy is the first choice to treat this type of cancer, multidrug resistance (MDR) is the major setback against the commonly used drugs, with the ATP-binding cassette transporters (ABC transporters) being the major players. The role of P-glycoprotein (P-gp), multidrug resistance protein 1 (MRP1), or breast cancer resistance protein (ABCG2) in the efflux of chemotherapeutic drugs is well described in cancer cells, highlighting these proteins as interesting druggable targets to reverse MDR, decrease drug dosage, and consequently undesired toxicity. Natural products, especially phytochemicals, have a wide diversity of chemical structures, and some particular classes, such as phenolic acids, flavonoids, or pentacyclic triterpenoids, have been reported as inhibitors of P-gp, MRP1, and ABCG2, being able to sensitize cancer cells to chemotherapy drugs. Nevertheless, ABC transporters play a vital role in the cell’s defense against xenobiotics, and some phytochemicals have also been shown to induce the transporters’ activity. A balance must be obtained between xenobiotic efflux in non-tumor cells and bioaccumulation of chemotherapy drugs in cancer cells, in which ABC transporters are essential and natural products play a pivotal role that must be further analyzed. This review summarizes the knowledge concerning the nomenclature and function of ABC-transporters, emphasizing their role in the intestinal barrier cells. In addition, it also focuses on the role of natural products commonly found in food products, e.g., phytochemicals, as modulators of ABC-transporter activity and expression, which are promising nutraceutical molecules to formulate new drug combinations to overcome multidrug resistance.

Proteins involved in fat-soluble vitamin and carotenoid transport across the intestinal cells: New insights from the past decade

It is now well established that vitamins D, E, and K and carotenoids are not absorbed solely through passive diffusion. Broad-specificity membrane transporters such as SR-BI (scavenger receptor class B type I), CD36 (CD36 molecule), NPC1L1 (Niemann Pick C1-like 1) or ABCA1 (ATP-binding cassette A1) are involved in the uptake of these micronutrients from the lumen to the enterocyte cytosol and in their secretion into the bloodstream. Recently, the existence of efflux pathways from the enterocyte back to the lumen or from the bloodstream to the lumen, involving ABCB1 (P-glycoprotein/MDR1) or the ABCG5/ABCG8 complex, has also been evidenced for vitamins D and K. Surprisingly, no membrane proteins have been involved in dietary vitamin A uptake so far. After an overview of the metabolism of fat-soluble vitamins and carotenoids along the gastrointestinal tract (from the mouth to the colon where interactions with microbiota may occur), a focus is placed on the identified and candidate proteins participating in the apical uptake, intracellular transport, basolateral secretion and efflux back to the lumen of fat-soluble vitamins and carotenoids in enterocytes. This review also highlights the mechanisms that remain to be identified to fully unravel the pathways involved in fat-soluble vitamin and carotenoid intestinal absorption.

Regulation of Cholesterol Metabolism by Phytochemicals Derived from Algae and Edible Mushrooms in Non-Alcoholic Fatty Liver Disease

Cholesterol synthesis occurs in almost all cells, but mainly in hepatocytes in the liver. Cholesterol is garnering increasing attention for its central role in various metabolic diseases. In addition, cholesterol is one of the most essential elements for cells as both a structural source and a player participating in various metabolic pathways. Accurate regulation of cholesterol is necessary for the proper metabolism of fats in the body. Disturbances in cholesterol homeostasis have been linked to various metabolic diseases, such as hyperlipidemia and non-alcoholic fatty liver disease (NAFLD). For many years, the use of synthetic chemical drugs has been effective against many health conditions. Furthermore, from ancient to modern times, various plant-based drugs have been considered local medicines, playing important roles in human health. Phytochemicals are bioactive natural compounds that are derived from medicinal plants, fruit, vegetables, roots, leaves, and flowers and are used to treat a variety of diseases. They include flavonoids, carotenoids, polyphenols, polysaccharides, vitamins, and more. Many of these compounds have been proven to have antioxidant, anti-inflammatory, antiobesity and antihypercholesteremic activity. The multifaceted role of phytochemicals may provide health benefits to humans with regard to the treatment and control of cholesterol metabolism and the diseases associated with this disorder, such as NAFLD. In recent years, global environmental climate change, the COVID-19 pandemic, the current war in Europe, and other conflicts have threatened food security and human nutrition worldwide. This further emphasizes the urgent need for sustainable sources of functional phytochemicals to be included in the food industry and dietary habits. This review summarizes the latest findings on selected phytochemicals from sustainable sources-algae and edible mushrooms-that affect the synthesis and metabolism of cholesterol and improve or prevent NAFLD.

Assessment of spent hemp biomass as a potential ingredient in ruminant diet: nutritional quality and effect on performance, meat and carcass quality, and hematological parameters in finishing lambs

Spent hemp biomass (SHB), a byproduct of cannabinoid extraction from the production of industrial hemp has not been approved by FDA-CVM since its effects on animal health, performance, and product quality are unknown. Our objective was to investigate the effects of feeding two levels of SHB and a 4-wk withdrawal period on performance, carcass characteristic, meat quality, and hematological parameters in finishing lambs. A total of 35 weaned, Polypay male lambs kept in single pens were randomly assigned to five feeding treatments (n = 7) and fed diets containing either no SHB (CON) or SHB at 10% (LH1) or 20% (HH1) for 4 wk with 4 wk of clearing period from SHB, or SHB at 10% (LH2) or 20% (HH2) for 8 wk. Chemical analysis revealed SHB to have a nutritive quality similar to alfalfa with no mycotoxin, terpenes, or organic residuals as a result of the extraction process. Feed intake of lambs was negatively affected by 20% SHB in period 1 but not in period 2 where feed intake was the greatest in HH1 and LH2. In contrast, none of the performance data, including liveweight gains, were different across the groups and periods. In period 1, blood glucose, cholesterol, calcium, paraoxonase, and tocopherol were decreased by the level of SHB fed, while bilirubin and alkaline phosphatase (ALP) were increased. In period 2, the concentration in blood of urea, magnesium, bilirubin, ALP, and ferric reducing ability of the plasma (FRAP) were higher in LH2 and HH2 as compared with CON, while β-hydroxybutyrate was lower in HH2. Blood parameters related to liver health, kidney function, immune status, and inflammation were unaffected by feeding SHB. Most carcass and meat quality parameters did not differ across feeding groups either. Except carcass purge loss and meat cook loss were larger in lambs that were fed 20% SHB. Although lower feed intake of lambs that were fed 20% SHB initially in period 1 suggested SHB was not palatable to the lambs, increased feed intake at a lower level of inclusion at 10% in period 2 may point to a positive long-term effect of feeding SHB.

A review of recent progress in improving the bioavailability of nutraceutical-loaded emulsions after oral intake

Increasing awareness of the health benefits of specific constituents in fruits, vegetables, cereals, and other whole foods has sparked a broader interest in the potential health benefits of nutraceuticals. Many nutraceuticals are hydrophobic substances, which means they must be encapsulated in colloidal delivery systems. Oil-in-water emulsions are one of the most widely used delivery systems for improving the bioavailability and bioactivity of these nutraceuticals. The composition and structure of emulsions can be designed to improve the water dispersibility, physicochemical stability, and bioavailability of the encapsulated nutraceuticals. The nature of the emulsion used influences the interfacial area and properties of the nutraceutical-loaded oil droplets in the gastrointestinal tract, which influences their digestion, as well as the bioaccessibility, metabolism, and absorption of the nutraceuticals. In this article, we review recent in vitro and in vivo studies on the utilization of emulsions to improve the bioavailability of nutraceuticals. The findings from this review should facilitate the design of more efficacious nutraceutical-loaded emulsions with increased bioactivity.

The Effect of β-Carotene, Tocopherols and Ascorbic Acid as Anti-Oxidant Molecules on Human and Animal In Vitro/In Vivo Studies: A Review of Research Design and Analytical Techniques Used

Prolonged elevated oxidative stress (OS) possesses negative effect on cell structure and functioning, and is associated with the development of numerous disorders. Naturally occurred anti-oxidant compounds reduce the oxidative stress in living organisms. In this review, antioxidant properties of β-carotene, tocopherols and ascorbic acid are presented based on in vitro, in vivo and populational studies. Firstly, environmental factors contributing to the OS occurrence and intracellular sources of Reactive Oxygen Species (ROS) generation, as well as ROS-mediated cellular structure degradation, are introduced. Secondly, enzymatic and non-enzymatic mechanism of anti-oxidant defence against OS development, is presented. Furthermore, ROS-preventing mechanisms and effectiveness of β-carotene, tocopherols and ascorbic acid as anti-oxidants are summarized, based on studies where different ROS-generating (oxidizing) agents are used. Oxidative stress biomarkers, as indicators on OS level and prevention by anti-oxidant supplementation, are presented with a focus on the methods (spectrophotometric, fluorometric, chromatographic, immuno-enzymatic) of their detection. Finally, the application of Raman spectroscopy and imaging as a tool for monitoring the effect of anti-oxidant (β-carotene, ascorbic acid) on cell structure and metabolism, is proposed. Literature data gathered suggest that β-carotene, tocopherols and ascorbic acid possess potential to mitigate oxidative stress in various biological systems. Moreover, Raman spectroscopy and imaging can be a valuable technique to study the effect of oxidative stress and anti-oxidant molecules in cell studies.

Phytochemical and Nutritional Profile Composition in Fruits of Different Sweet Chestnut (Castanea sativa Mill.) Cultivars Grown in Romania

Chestnut (Castanea sativa Mill.), a valuable fruit crop, is cultivated in small areas in Romania, mostly in the west, where the moderate continental climate has a slight Mediterranean influence. This work aims to investigate the bioactive characteristics (total polyphenols, total flavonoids and antioxidant activity), individual polyphenolic composition, phytochemical and nutritional HRMS screening profiles, sugar and mineral composition of six sweet chestnut cultivars, namely ‘Marsol’, ‘Maraval’, ‘Bournette’, ‘Précoce Migoule’ and ‘Marissard’ grown at Fruit Growing Research—Extension Station (SCDP) Vâlcea, in Northern Oltenia, Romania. Fruit samples were collected in two consecutive years, in order to study the impact of genetic variability between cultivars and the influence of the different climatic conditions corresponding to different cultivation years. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) allow the discrimination between the sweet chestnut fruits harvested in different years and different sweet chestnut cultivars. Analytical investigations revealed that sweet chestnut cultivars grown in Romania show similar bioactive, phytochemical and nutritional composition to cultivars grown in the large European chestnut-producing countries, indicating the high adaptation potential of the chestnut in the temperate continental zone with small Mediterranean influences characteristic of the southwestern area of Romania.

Metabolism of natural forms of vitamin E and biological actions of vitamin E metabolites

Natural forms of vitamin E comprise four tocopherols and four tocotrienols. During the last twenty years, there have been breakthroughs in our understanding of vitamin E metabolism and biological activities of vitamin E metabolites. Research has established that tocopherols and tocotrienols are metabolized via ω-hydroxylase (CYP4F2)-initiated side chain oxidation to form 13'-hydroxychromanol and 13'-carobyxychromanol (13'-COOH). 13'-COOHs are further metabolized via β-oxidation and sulfation to intermediate carboxychromanols, terminal metabolite carboxyethyl-hydroxychroman (CEHC), and sulfated analogs. Animal and human studies show that γ-, δ-tocopherol and tocotrienols are more extensively metabolized than α-tocopherol (αT), as indicated by higher formation of CEHCs and 13'-COOHs from non-αT forms than those from αT. 13'-COOHs are shown to be inhibitors of cyclooxygenase-1/-2 and 5-lipoxygenase and much stronger than CEHCs for these activities. 13'-COOHs inhibit cancer cell growth, modulate cellular lipids and activate peroxisome proliferator-activated receptor-γ and pregnane X receptor. Consistent with mechanistic findings, αT-13'-COOH or δTE-13'-COOH, respective metabolites of αT or δ-tocotrienol, show anti-inflammatory and cancer-preventive effects, modulates the gut microbiota and prevents β-amyloid formation in mice. Therefore, 13'-COOHs are a new class of bioactive compounds with anti-inflammatory and anti-cancer activities and potentially capable of modulating lipid and drug metabolism. Based on the existing evidence, this author proposes that metabolites may contribute to disease-preventing effects of γ-, δ-tocopherol and tocotrienols. The role of metabolites in αT's actions may be somewhat limited considering controlled metabolism of αT because of its association with tocopherol-transport protein and less catabolism by CYP4F2 than other vitamin E forms.

Vitamin E: How much is enough, too much and why!

α-Tocopherol (α-T) is a required dietary nutrient for humans and thus is a vitamin. This narrative review focuses on vitamin E structures, functions, biological determinants and its deficiency symptoms in humans. The mechanisms for the preferential α-T tissue enrichment in the human body include the α-T transfer protein (TTPA) and the preferential metabolism of non-α-T forms. Potential new α-T biomarkers, pharmacokinetic data, and whether there are better approaches to evaluate and set the α-T dietary requirement are discussed. Finally, the possible role of α-T supplements in delay of chronic diseases and the evaluation of vitamin E safety are considered.

The Physiological Roles of Vitamin E and Hypovitaminosis E in the Transition Period of High-Yielding Dairy Cows

Simple Summary

In high-yield cows, most production diseases occur during transition periods. Alpha-tocopherol, the most biologically active form of vitamin E, declines in blood and reaches the lowest levels (hypovitaminosis E) around calving. Hypovitaminosis E is associated with the incidence of peripartum diseases. Therefore, many studies which have been published for more than 30 years have investigated the effects of α-tocopherol supplementation. This α-tocopherol deficiency was thought to be caused by complex factors. However, until recently, the physiological factors or pathways underlying hypovitaminosis E in the transition period have been poorly understood. In the last 10 years, the α-tocopherol-related genes expression, which regulate the metabolism, transportation, and tissue distribution of α-tocopherol in humans and rodents, has been reported in ruminant tissues. In this paper, we discuss at least six physiological phenomena that occur during the transition period and may be candidate factors predisposing to a decreased blood α-tocopherol level and hypovitaminosis E with changes in α-tocopherol-related genes expression.

Abstract

Levels of alpha-tocopherol (α-Toc) decline gradually in blood throughout prepartum, reaching lowest levels (hypovitaminosis E) around calving. Despite numerous reports about the disease risk in hypovitaminosis E and the effect of α-Toc supplementation on the health of transition dairy cows, its risk and supplemental effects are controversial. Here, we present some novel data about the disease risk of hypovitaminosis E and the effects of α-Toc supplementation in transition dairy cows. These data strongly demonstrate that hypovitaminosis E is a risk factor for the occurrence of peripartum disease. Furthermore, a study on the effectiveness of using serum vitamin levels as biomarkers to predict disease in dairy cows was reported, and a rapid field test for measuring vitamin levels was developed. By contrast, evidence for how hypovitaminosis E occurred during the transition period was scarce until the 2010s. Pioneering studies conducted with humans and rodents have identified and characterised some α-Toc-related proteins, molecular players involved in α-Toc regulation followed by a study in ruminants from the 2010s. Based on recent literature, the six physiological factors: (1) the decline in α-Toc intake from the close-up period; (2) changes in the digestive and absorptive functions of α-Toc; (3) the decline in plasma high-density lipoprotein as an α-Toc carrier; (4) increasing oxidative stress and consumption of α-Toc; (5) decreasing hepatic α-Toc transfer to circulation; and (6) increasing mammary α-Toc transfer from blood to colostrum, may be involved in α-Toc deficiency during the transition period. However, the mechanisms and pathways are poorly understood, and further studies are needed to understand the physiological role of α-Toc-related molecules in cattle. Understanding the molecular mechanisms underlying hypovitaminosis E will contribute to the prevention of peripartum disease and high performance in dairy cows.

Comparison of α-Tocopherol, α-Tocopherol Acetate, and α-Tocopheryl Polyethylene Glycol Succinate 1000 Absorption by Caco-2 TC7 Intestinal Cells

(1) Background: vitamin E is often supplemented in the form of tocopherol acetate, but it has poor bioavailability and can fail to correct blood tocopherol concentrations in some patients with severe cholestasis. In this context, α-tocopheryl polyethylene glycol succinate 1000 (TPGS) has been of value, but very little is known about the mechanisms of its absorption. The aim of our work was to evaluate the mechanisms of absorption/secretion of TPGS compared to tocopherol acetate (TAC) and α-tocopherol by human enterocyte-like Caco-2 TC7 cells. (2) Methods: two weeks post-confluence Caco-2 cells were incubated with tocopherol- or TAC- or TPGS-rich mixed micelles up to 24 h and, following lipid extraction, TAC and tocopherol amounts were measured by high performance liquid chromatography (HPLC) in apical, cellular, and basolateral compartments. (3) Results: at equivalent concentrations of tocopherol in the apical side, the amounts of tocopherol secreted at the basolateral pole of Caco-2 cells are (i) significantly greater when the tocopherol is in the free form in the micelles; (ii) intermediate when it is in the TAC form in the micelles (p < 0.001); and (iii) significantly lower with the TPGS form (p < 0.0001). Interestingly, our results show, for the first time, that Caco-2 cells secrete one or more esterified forms of the vitamin contained in TPGS at the basolateral side.

Vitamin E for the management of major depressive disorder: possible role of the anti-inflammatory and antioxidant systems

OBJECTIVES

Vitamin E has various functions in humans, including antioxidant, anti-inflammatory, anti-cancer, and anti-atherogenic actions, as well as direct effects on enzymatic activities and modulation of gene transcription. In addition to these functions, vitamin E is also important for the central nervous system, and its role in the prevention and/or treatment of some neurological diseases has been suggested. In particular, the role of vitamin E in the modulation of major depressive disorder (MDD) is an issue that has emerged in recent studies. Many factors have been implicated in the pathophysiology of this disorder, including inflammation, oxidative, and nitrosative stress.

METHODS

This narrative review discusses the involvement of inflammation, oxidative, and nitrosative stress in the pathophysiology of MDD and presents clinical and preclinical studies that correlate vitamin E with this psychiatric disorder.

RESULTS

We gathered evidence from clinical studies that demonstrated the relationship between low vitamin E status and MDD symptoms. Vitamin E has been reported to exert a beneficial influence on the oxidative and inflammatory status of individuals, factors that may account for the attenuation of depressive symptoms. Preclinical studies have reinforced the antidepressant-like response of vitamin E, and the mechanisms underlying its effect seem to be related to the modulation of oxidative stress and neuroinflammation.

CONCLUSION

We suggest that vitamin E has potential to be used as an adjuvant for the management of MDD, but more studies are clearly needed to ascertain the efficacy of vitamin E for alleviating depressive symptoms.

Regulation of intestinal lipid metabolism: current concepts and relevance to disease

Lipids entering the gastrointestinal tract include dietary lipids (triacylglycerols, cholesteryl esters and phospholipids) and endogenous lipids from bile (phospholipids and cholesterol) and from shed intestinal epithelial cells (enterocytes). Here, we comprehensively review the digestion, uptake and intracellular re-synthesis of intestinal lipids as well as their packaging into pre-chylomicrons in the endoplasmic reticulum, their modification in the Golgi apparatus and the exocytosis of the chylomicrons into the lamina propria and subsequently to lymph. We also discuss other fates of intestinal lipids, including intestinal HDL and VLDL secretion, cytosolic lipid droplets and fatty acid oxidation. In addition, we highlight the applicability of these findings to human disease and the development of therapeutics targeting lipid metabolism. Finally, we explore the emerging role of the gut microbiota in modulating intestinal lipid metabolism and outline key questions for future research.

Vitamin E Supplementation and Mitochondria in Experimental and Functional Hyperthyroidism: A Mini-Review

Mitochondria are both the main sites of production and the main target of reactive oxygen species (ROS). This can lead to mitochondrial dysfunction with harmful consequences for the cells and the whole organism, resulting in metabolic and neurodegenerative disorders such as type 2 diabetes, obesity, dementia, and aging. To protect themselves from ROS, mitochondria are equipped with an efficient antioxidant system, which includes low-molecular-mass molecules and enzymes able to scavenge ROS or repair the oxidative damage. In the mitochondrial membranes, a major role is played by the lipid-soluble antioxidant vitamin E, which reacts with the peroxyl radicals faster than the molecules of polyunsaturated fatty acids, and in doing so, protects membranes from excessive oxidative damage. In the present review, we summarize the available data concerning the capacity of vitamin E supplementation to protect mitochondria from oxidative damage in hyperthyroidism, a condition that leads to increased mitochondrial ROS production and oxidative damage. Vitamin E supplementation to hyperthyroid animals limits the thyroid hormone-induced increases in mitochondrial ROS and oxidative damage. Moreover, it prevents the reduction of the high functionality components of the mitochondrial population induced by hyperthyroidism, thus preserving cell function.

Mechanisms of Carotenoid Intestinal Absorption: Where Do We Stand?

A growing literature is dedicated to the understanding of carotenoid beneficial health effects. However, the absorption process of this broad family of molecules is still poorly understood. These highly lipophilic plant metabolites are usually weakly absorbed. It was long believed that β-carotene absorption (the principal provitamin A carotenoid in the human diet), and thus all other carotenoid absorption, was driven by passive diffusion through the brush border of the enterocytes. The identification of transporters able to facilitate carotenoid uptake by the enterocytes has challenged established statements. After a brief overview of carotenoid metabolism in the human upper gastrointestinal tract, a focus will be put on the identified proteins participating in the transport and the metabolism of carotenoids in intestinal cells and the regulation of these processes. Further progress in the understanding of the molecular mechanisms regulating carotenoid intestinal absorption is still required to optimize their bioavailability and, thus, their health effects.