Flaxseed oil improves liver injury and inhibits necroptotic and inflammatory signaling pathways following lipopolysaccharide challenge in a piglet model

An Updated Review of Emerging Sources of Selenium in Weaned Piglet Nutrition

The antioxidant and immune systems of weaned piglets are not fully mature and are also subjected to serious stress challenges related to oxidative stress and inflammation. Selenium (Se) is an essential element for pigs, with documented roles encompassing antioxidative and anti-inflammatory properties via selenoproteins. Sodium selenite and Se-enriched yeast are commonly acknowledged as conventional sources of Se for piglets. In the past decade, several novel Se sources have emerged in the field of weaned piglet nutrition. In this review, we will initially outline the historical timeline of Se sources as reported in weaned piglet nutrition. Afterwards, our attention will turn towards the nutritional regulation of Se sources in relation to the antioxidant and anti-inflammatory aspects of healthy weaned piglets. Ultimately, we will provide a detailed review highlighting the potential of emerging Se sources in alleviating various adverse effects of stress challenges faced by weaned piglets. These challenges include oxidative stress, enterotoxigenic Escherichia coli infection, lipopolysaccharide-induced inflammation, heat stress, and exposure to feed mycotoxins. The output of this review will emphasize the fundamental importance of incorporating emerging Se sources in the diet of weaned piglets.

Selenium-Enriched Cardamine violifolia Alleviates LPS-Induced Hepatic Damage and Inflammation by Suppressing TLR4/NODs-Necroptosis Signal Axes in Piglets

Selenium-enriched Cardamine violifolia (SEC), a cruciferous plant, exerts excellent antioxidant and anti-inflammatory capacity, but its effect on hepatic function is unclear. This study investigated the effect and potential mechanism of SEC on hepatic injury induced by lipopolysaccharide (LPS). Twenty-four weaned piglets were randomly allotted to treatment with SEC (0.3 mg/kg Se) and/or LPS (100 μg/kg). After 28 days of the trial, pigs were injected with LPS to induce hepatic injury. These results indicated that SEC supplementation attenuated LPS-induced hepatic morphological injury and reduced aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities in plasma. SEC also inhibited the expression of pro-inflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) after the LPS challenge. In addition, SEC improved hepatic antioxidant capacity via enhancing glutathione peroxidase (GSH-Px) activity and decreasing malondialdehyde (MDA) concentration. Moreover, SEC downregulated the mRNA expression of hepatic myeloid differentiation factor 88 (MyD88) and nucleotide-binding oligomerization domain proteins 1 (NOD1) and its adaptor molecule receptor interacting protein kinase 2 (RIPK2). SEC also alleviated LPS-induced hepatic necroptosis by inhibiting RIPK1, RIPK3, and mixed-lineage kinase domain-like (MLKL) expression. These data suggest that SEC potentially mitigates LPS-induced hepatic injury via inhibiting Toll-like receptor 4 (TLR4)/NOD2 and necroptosis signaling pathways in weaned piglets.

Tryptophan alleviates lipopolysaccharide-induced liver injury and inflammation by modulating necroptosis and pyroptosis signaling pathways in piglets

The liver plays crucial roles in material metabolism and immune response. Bacterial endotoxin can cause various liver diseases, thereby causing significant economic losses to pig industry. Tryptophan is an essential amino acid in piglets. However, whether tryptophan can alleviate liver injury and inflammation by regulating necroptosis and pyroptosis has not been clarified. This study aimed to investigate whether dietary tryptophan can alleviate lipopolysaccharide (LPS)-induced liver injury in weaned piglets. 18 weaned piglets were randomly distributed to three treatments, each with 6 replicates: (1) control; (2) LPS-challenged control; (3) LPS + 0.2% tryptophan. After feeding with control or 0.2% tryptophan-supplemented diets for 35 d, pigs were intraperitoneally injected with saline or LPS (100 mg/kg body weight). At 4 h post-injection, blood samples and liver were collected. Results indicated that tryptophan reduced alanine aminotransferase, aspartate aminotransferase, decreased the mRNA expression and protein expression of 70-kDa heat shock proteins. Moreover, tryptophan increased the mRNA expression and protein expression of claudin-1, occludin and zonula occludens and decreased hydrogen peroxide and malondialdehyde contents, and increased catalase, glutathione peroxidase and total superoxide dismutase activities and proinflammatory cytokine levels in the liver. Meanwhile, tryptophan inhibited pyroptosis-related and necroptosis-related protein expression in liver. Collectively, tryptophan could relieve liver damage, increased the antioxidant capacity and reduced inflammation by inhibiting pyroptosis and necroptosis signaling pathways.

The Chemical Composition and Health-Promoting Benefits of Vegetable Oils-A Review

With population and economic development increasing worldwide, the public is increasingly concerned with the health benefits and nutritional properties of vegetable oils (VOs). In this review, the chemical composition and health-promoting benefits of 39 kinds of VOs were selected and summarized using Web of Science TM as the main bibliographic databases. The characteristic chemical compositions were analyzed from fatty acid composition, tocols, phytosterols, squalene, carotenoids, phenolics, and phospholipids. Health benefits including antioxidant activity, prevention of cardiovascular disease (CVD), anti-inflammatory, anti-obesity, anti-cancer, diabetes treatment, and kidney and liver protection were examined according to the key components in representative VOs. Every type of vegetable oil has shown its own unique chemical composition with significant variation in each key component and thereby illustrated their own specific advantages and health effects. Therefore, different types of VOs can be selected to meet individual needs accordingly. For example, to prevent CVD, more unsaturated fatty acids and phytosterols should be supplied by consuming pomegranate seed oil, flaxseed oil, or rice bran oil, while coconut oil or perilla seed oil have higher contents of total phenolics and might be better choices for diabetics. Several oils such as olive oil, corn oil, cress oil, and rice bran oil were recommended for their abundant nutritional ingredients, but the intake of only one type of vegetable oil might have drawbacks. This review increases the comprehensive understanding of the correlation between health effects and the characteristic composition of VOs, and provides future trends towards their utilization for the general public's nutrition, balanced diet, and as a reference for disease prevention. Nevertheless, some VOs are in the early stages of research and lack enough reliable data and long-term or large consumption information of the effect on the human body, therefore further investigations will be needed for their health benefits.

Necroptosis Contributes to LPS-Induced Activation of the Hypothalamic-Pituitary-Adrenal Axis in a Piglet Model

Stressors cause activation of the hypothalamic-pituitary-adrenal (HPA) axis and a systemic inflammatory response. As a newly proposed cell death manner in recent years, necroptosis occurs in a variety of tissue damage and inflammation. However, the role of necroptosis in HPA axis activation remains to be elucidated. The aim of this study was to investigate the occurrence of necroptosis and its role in HPA activation in a porcine stress model induced by Escherichia coli lipopolysaccharide (LPS). Several typical stress behaviors like fever, anorexia, shivering and vomiting were observed in piglets after LPS injection. HPA axis was activated as shown by increased plasma cortisol concentration and mRNA expression of pituitary corticotropin-releasing hormone receptor 1 (CRHR1) and adrenal steroidogenic acute regulatory protein (StAR). The mRNA expression of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and IL-6 in the hypothalamus, pituitary gland and adrenal gland was elevated by LPS, accompanied by the activation of necroptosis indicated by higher mRNA expression of necroptosis signals including receptor-interacting protein kinase (RIP) 1, RIP3, and phosphorylated mixed-lineage kinase domain-like protein (MLKL). Furthermore, necrostatin-1 (Nec-1), an inhibitor of necroptosis, inhibited necroptosis indicated by decreased mRNA levels of RIP1, RIP3, MLKL, and phosphoglycerate mutase family member 5 (PGAM5) in the hypothalamus, pituitary gland and adrenal gland. Nec-1 also decreased the mRNA expression of TNF-α and IL-β and inhibited the activation of the HPA axis indicated by lower plasma cortisol concentration and mRNA expression of adrenal type 2 melanocortin receptor (MC2R) and StAR. These findings suggest that necroptosis is present and contributes to HPA axis activation induced by LPS. These findings provide a potential possibility for necroptosis as an intervention target for alleviating HPA axis activation and stress responses.

Glycine alleviated diquat-induced hepatic injury via inhibiting ferroptosis in weaned piglets

Objective

The beneficial effects of glycine were tested in piglets with diquat-induced hepatic injury.

Methods

Thirty-two piglets were assigned by a 2 × 2 factorial experimental design including glycine supplementation and diquat challenge. After 3 weeks of feeding with a basic diet or a 1% glycine supplemented diet, piglets were challenged with diquat or saline. After 1 week later, the piglets were slaughtered and samples were collected.

Results

Our results indicated that glycine alleviated diquat induced morphological hepatic injury, decreased the activities of plasma alanine aminotransferase, aspartate aminotransferase and glutamyl transpeptidase in the piglets under diquat challenge, and increased total antioxidant capacity and antioxidative enzyme activity significantly. Adding glycine enhanced the concentrations of hepatic adenosine triphosphate and adenosine diphosphate. Transmission electron microscope observation showed that diquat induced clear hepatocytes ferroptosis and its effect could be alleviated by glycine to a certain degree. Moreover, glycine significantly affected mRNA and protein expression of ferroptosis-related signals in the liver.

Conclusion

These results demonstrated that glycine attenuated liver damage via inhibiting ferroptosis.

A comprehensive review on recent novel food and industrial applications of flaxseed: 2014 onwards

Flaxseed or linseed is an oilseed obtained from a plant, known as the flax (Linum usitatissimum). It is a valuable source of various bioactive components such as omega-3 polyunsaturated fatty acids, proteins, lignans, dietary fibres and phytochemicals. The in-vivo, in-vitro studies and research on human subjects and in animal models, conducted throughout the globe, on health benefits associated with the consumption of various forms of flaxseed are discussed in this review. It provides an insight into recent developments and potential applications of flaxseeds in the form of whole seeds, meals, flour or oil in an array of food and feed products and non-food industrial applications. The details about novel health benefits associated with flaxseeds and information related to commercially available flaxseed-based i.e. enriched products are also the salient feature of the review. Here, we have provided the state of the art of most recent comprehensive information post the first detailed review on flaxseed as a modern food released in 2014.

A comprehensive review on recent novel food and industrial applications of flaxseed: 2014 onwards

Flaxseed or linseed is an oilseed obtained from a plant, known as the flax (Linum usitatissimum). It is a valuable source of various bioactive components such as omega-3 polyunsaturated fatty acids, proteins, lignans, dietary fibres and phytochemicals. The in-vivo, in-vitro studies and research on human subjects and in animal models, conducted throughout the globe, on health benefits associated with the consumption of various forms of flaxseed are discussed in this review. It provides an insight into recent developments and potential applications of flaxseeds in the form of whole seeds, meals, flour or oil in an array of food and feed products and non-food industrial applications. The details about novel health benefits associated with flaxseeds and information related to commercially available flaxseed-based i.e. enriched products are also the salient feature of the review. Here, we have provided the state of the art of most recent comprehensive information post the first detailed review on flaxseed as a modern food released in 2014.

Necroptosis Underlies Hepatic Damage in a Piglet Model of Lipopolysaccharide-Induced Sepsis

Background

Necroptosis is a newly recognized form of programmed cell death with characteristics of both necrosis and apoptosis. The role of necroptosis in hepatic damage during sepsis is poorly understood. In this study, we investigated the occurrence of necroptosis in hepatic damage, and its contribution to hepatic damage in a piglet model of lipopolysaccharide (LPS)-induced sepsis.

Methods

Two animal experiments were conducted. In trial 1, piglets were challenged with LPS and sacrificed at different time points after LPS challenge. In trial 2, piglets were pretreated with necrostatin-1, a specific inhibitor of necroptosis, prior to LPS challenge. Alterations in the hepatic structure and function, pro-inflammatory cytokine expression, and the necroptosis signaling pathway were investigated. Typical ultrastructural characteristics of cell necrosis was observed in the liver of LPS-challenged piglets.

Results

Expressions of critical components of necroptosis including kinases (RIP1, RIP3, and MLKL), mitochondrial proteins (PGAM5 and DRP1), and an intracellular damage-associated molecular pattern (HMGB1) were increased in the liver in a time-dependent manner, followed by hepatic inflammation, morphological damage, and dysfunction as manifested by elevated hepatic expression of IL-1β, IL-6 and TNF-α as well as increased serum AST and AKP activities and the AST/ALT ratio. Pretreatment with necrostatin-1 significantly reduced the expression of RIP1, RIP3 and MLKL as well as PGAM5, DRP1 and HMGB1, which subsequently led to obvious attenuation of hepatic inflammation and damage.

Conclusions

Our study demonstrates that necroptosis occurs in the liver during sepsis and contributes to septic hepatic injury.

Current innovations in nutraceuticals and functional foods for intervention of non-alcoholic fatty liver disease

As innovations in global agricultural production and food trading systems lead to major dietary shifts, high morbidity rates from non-alcoholic fatty liver disease (NAFLD), accompanied by elevated risk of lipid metabolism-related complications, has emerged as a growing problem worldwide. Treatment and prevention of NAFLD and chronic liver disease depends on the availability of safe, effective, and diverse therapeutic agents, the development of which is urgently needed. Supported by a growing body of evidence, considerable attention is now focused on interventional approaches that combines nutraceuticals and functional foods. In this review, we summarize the pathological progression of NAFLD and discuss the beneficial effects of nutraceuticals and the active ingredients in functional foods. We also describe the underlying mechanisms of these compounds in the intervention of NAFLD, including their effects on regulation of lipid homeostasis, activation of signaling pathways, and their role in gut microbial community dynamics and the gut-liver axis. In order to identify novel targets for treatment of lipid metabolism-related diseases, this work broadly explores the molecular mechanism linking nutraceuticals and functional foods, host physiology, and gut microbiota. Additionally, the limitations in existing knowledge and promising research areas for development of active interventions and treatments against NAFLD are discussed.