Narirutin mitigates dextrose sodium sulfate-induced colitis in mice by modulating intestinal flora.

BACKGROUND: Ulcerative colitis (UC) is a prolonged inflammatory disease of the gastrointestinal tract. Current therapeutic options remain limited, underscoring the imperative to explore novel therapeutic strategies. Narirutin (NR), a flavonoid naturally present in citrus fruits, exhibits excellent anti-inflammatory effects in vitro, yet its in vivo efficacy, especially in UC, remains underexplored. OBJECTIVE: This work examined the effect of NR on dextrose sodium sulfate (DSS)-induced UC in mice in vivo, with a specific focus on the role of gut flora in it. METHODS: The effects of NR (10, 20, and 40 mg/kg) on DSS-induced UC in mice were investigated by monitoring changes in body weight, disease activity index (DAI) scores, colon length, and histological damage. Colonic levels of pro-inflammatory mediators, tight junction (TJ) proteins, and inflammation-related signaling pathway proteins were analyzed via enzyme-linked immunosorbent assay, western blot, and immunofluorescence. The role of gut microbiota in NR against colitis was analyzed through 16S rRNA sequencing, flora clearance assays, and fecal microbiota transplantation (FMT) assays. RESULTS: NR administration suppressed DSS-induced colitis as reflected in a decrease in body weight loss, DAI score, colon length shortening, and histological score. Furthermore, NR administration preserved the integrity of the DSS-induced intestinal barrier by inhibiting the reduction of TJ proteins (claudin3, occludin, and zonula occludens-1). Moreover, NR administration markedly repressed the activation of the toll-like receptor 4-mitogen-activated protein kinase/nuclear factor-κB pathway and reduced the amount of pro-inflammatory mediators in the colon. Importantly, the results of 16S rRNA sequencing showed that the intestinal flora of mice with colitis exhibited richer microbial diversity following NR administration, with elevated abundance of Lactobacillaceae (Lactobacillus) and decreased abundance of Bacteroidaceae (Bacteroides) and Shigella. In addition, the anti-colitis effect of NR almost disappeared after gut flora clearance. Further FMT assay also validated this gut flora-dependent protective mechanism of NR. CONCLUSION: Our findings suggest that NR is a prospective natural compound for the management of UC by modulating intestinal flora.

Arbutin alleviates intestinal colitis by regulating neutrophil extracellular traps formation and microbiota composition.

BACKGROUND: Ulcerative colitis (UC) is a chronic recurrent intestinal disease lacking effective treatments. ß-arbutin, a glycoside extracted from the Arctostaphylos uva-ursi leaves, that can regulate many pathological processes. However, the effects of ß-arbutin on UC remain unknown. PURPOSE: In this study, we investigated the role of ß-arbutin in relieving colitis and explored its potential mechanisms in a mouse model of dextran sulfate sodium (DSS)-induced colitis. METHODS: In C75BL/6 J mice, DSS was used to induce colitis and concomitantly ß-arbutin (50 and 100 mg/kg) was taken orally to evaluate its curative effect by evaluating disease activity index (DAI) score, colon length and histopathology. Alcian blue periodic acid schiff (AB-PAS) staining, immunohistochemistry (IHC), immunofluorescence (IF) and TdT-mediated dUTP Nick-End Labeling (Tunel) staining were used to assess intestinal barrier function. Flow cytometry, double-IF and western blotting (WB) were performed to verify the regulatory mechanism of ß-arbutin on neutrophil extracellular traps (NETs) in vivo and in vitro. NETs depletion experiments were used to demonstrate the role of NETs in UC. Subsequently, the 16S rRNA gene sequencing was used to analyze the intestinal microflora of mouse. RESULTS: Our results showed that ß-arbutin can protect mice from DSS-induced colitis characterized by a lower DAI score and intestinal pathological damage. ß-arbutin reduced inflammatory factors secretion, notably regulated neutrophil functions, and inhibited NETs formation in an ErK-dependent pathway, contributing to the resistance to colitis as demonstrated by in vivo and in vitro experiments. Meanwhile, remodeled the intestinal flora structure and increased the diversity and richness of intestinal microbiota, especially the abundance of probiotics and butyric acid-producing bacteria. It further promoted the protective effect in the resistance of colitis. CONCLUSION: ß-arbutin promoted the maintenance of intestinal homeostasis by inhibiting NETs formation, maintaining mucosal-barrier integrity, and shaping gut-microbiota composition, thereby alleviating DSS-induced colitis. This study provided a scientific basis for the rational use of ß-arbutin in preventing colitis and other related diseases.

Puerarin Delays Mammary Gland Aging by Regulating Gut Microbiota and Inhibiting the p38MAPK Signaling Pathway.

Mammary gland aging is one of the most important problems faced by humans and animals. How to delay mammary gland aging is particularly important. Puerarin is a kind of isoflavone substance extracted from Pueraria lobata, which has anti-inflammatory, antioxidant, and other pharmacological effects. However, the role of puerarin in delaying lipopolysaccharide (LPS)-induced mammary gland aging and its underlying mechanism remains unclear. On the one hand, we found that puerarin could significantly downregulate the expression of senescence-associated secretory phenotype (SASP) and age-related indicators (SA-ß-gal, p53, p21, p16) in mammary glands of mice. In addition, puerarin mainly inhibited the p38MAPK signaling pathway to repair mitochondrial damage and delay mammary gland aging. On the other hand, puerarin could also delay the cellular senescence of mice mammary epithelial cells (mMECs) by targeting gut microbiota and promoting the secretion of gut microbiota metabolites. In conclusion, puerarin could not only directly act on the mMECs but also regulate the gut microbiota, thus, playing a role in delaying the aging of the mammary gland. Based on the above findings, we have discovered a new pathway for puerarin to delay mammary gland aging.

Hesperetin regulates the intestinal flora and inhibits the TLR4/NF-κB signaling axis to protect the blood-milk barrier and prevent mastitis.

The World Health Organization recommends breastfeeding for 6 months, but mastitis, a common disease during lactation, presents a major obstacle to fulfilling this recommendation. Maternal nutrient intake during lactation has been shown to be related to mastitis. Therefore, this study aimed to explore the effect of hesperetin, a phytonutrient, on mastitis. The oral administration of hesperetin to lipopolysaccharide (LPS)-induced mastitis mice alleviated their pathological damage, reduced the secretion of pro-inflammatory cytokines, and maintained the integrity of their blood-milk barrier. Moreover, our results showed that oral administration of hesperetin regulates the composition of the intestinal flora of mice. Fecal microbial transplantation (FMT) from the mice of hesperetin group alleviated LPS-induced mastitis in recipient mice. In additional, hesperetin attenuated the inflammatory response and increased the expression of tight junction proteins (TJs) in LPS-stimulated mouse mammary epithelial cells (mMECs). Through network pharmacological analysis and further research, we demonstrated hesperetin inhibits the expression of TLR4 and the activation of NF-κB signaling. In conclusion, hesperetin protects the blood-milk barrier and improve mastitis by regulating intestinal flora and inhibiting the activation of TLR4/NF-κB signaling axis. This study provides a theoretical basis for lactating females to consume hesperetin as a supplement to prevent mastitis and maintain mammary health.

Amygdalin Alleviates DSS-Induced Colitis by Restricting Cell Death and Inflammatory Response, Maintaining the Intestinal Barrier, and Modulating Intestinal Flora.

Inflammatory bowel disease (IBD) refers to a cluster of intractable gastrointestinal disorders with an undetermined etiology and a lack of effective therapeutic agents. Amygdalin (Amy) is a glycoside extracted from the seeds of apricot and other Rosaceae plants and it exhibits a wide range of pharmacological properties. Here, the effects and mechanisms of Amy on colitis were examined via 16S rRNA sequencing, ELISA, transmission electron microscopy, Western blot, and immunofluorescence. The results showed that Amy administration remarkably attenuated the signs of colitis (reduced body weight, increased disease activity index, and shortened colon length) and histopathological damage in dextran sodium sulfate (DSS)-challenged mice. Further studies revealed that Amy administration significantly diminished DSS-triggered gut barrier dysfunction by lowering pro-inflammatory mediator levels, inhibiting oxidative stress, and reducing intestinal epithelial apoptosis and ferroptosis. Notably, Amy administration remarkably lowered DSS-triggered TLR4 expression and the phosphorylation of proteins related to the NF-κB and MAPK pathways. Furthermore, Amy administration modulated the balance of intestinal flora, including a selective rise in the abundance of S24-7 and a decline in the abundance of Allobaculum, Oscillospira, Bacteroides, Sutterella, and Shigella. In conclusion, Amy can alleviate colitis, which provides data to support the utility of Amy in combating IBD.

Orally administered neohesperidin attenuates MPTP-induced neurodegeneration by inhibiting inflammatory responses and regulating intestinal flora in mice.

Parkinson's disease (PD), a neurodegenerative disease, is the leading cause of movement disorders. Neuroinflammation plays a critical role in PD pathogenesis. Neohesperidin (Neo), a natural flavonoid extracted from citric fruits exhibits anti-inflammatory effects. However, the effect of Neo on PD progression is unclear. This study aimed to investigate the effects of Neo on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD in mice and its underlying mechanism. Our results indicated that Neo administration ameliorated motor impairment and neural damage in MPTP-injected mice, by inhibiting neuroinflammation and regulating gut microbial imbalance. Additionally, Neo administration reduced colonic inflammation and tissue damage. Mechanistic studies revealed that Neo suppressed the MPTP-induced inflammatory response by inhibiting excessive activation of NF-κB and MAPK pathways. In summary, the present study demonstrated that Neo administration attenuates neurodegeneration in MPTP-injected mice by inhibiting inflammatory responses and regulating the gut microbial composition. This study may provide the scientific basis for the use of Neo in the treatment of PD and other related diseases.

Valine promotes milk synthesis by regulating PKM2 nuclear accumulation and histone H3 acetylation through the TAS1R1-mTOR-DDX39B signaling pathway.

Valine, a branched-chain amino acid found in dairy cows, has been recognized for its critical role in milk synthesis. However, the precise effect of valine on lactation in dairy cows remains an area of investigation. In our study, bovine mammary epithelial cells (BMECs) were isolated to explore the mechanism through which valine enhances milk synthesis. The results showed that 100 µM valine significantly boosted the milk synthesis via TAS1R1-mTOR-DDX39B signaling pathway in BMECs. Subsequent investigations revealed that DDX39B governs the accumulation of PKM2 in the nuclei of BMECs. This nuclear buildup of PKM2 weakened the interaction between HDAC3 and histone H3, leading to an increase in the acetylation levels of histone H3. In an vivo context, the 0.25 % valine-enriched drinking water notably elevated in the expression of milk protein and fat in these mice. Further examination showed that 0.25 % valine drinking water considerably augmented the protein expression levels of DDX39B, PKM2, and p-mTOR in the mice mammary glands. In summary, our results suggest that valine, by modulating the TAS1R1-mTOR-DDX39B signaling pathway, directs the accumulation of PKM2 in the nucleus. This, in turn, escalates the acetylation levels of histone H3, promoting the synthesis of both milk protein and fat.

Acylated Ghrelin Activates PI3K/mTOR Signaling Pathway by Promoting ThPOK Acetylation to Promote Milk Fat Synthesis in Bovine Mammary Epithelial Cells.

Ghrelin regulates diverse physiological activities. However, the effects of this hormone on the milk fat synthesis remain unknown. This study aimed to investigate the effect of acylated ghrelin (AG) on milk fat synthesis by modifying the expression (knockdown or overexpression) of growth hormone secretagogue receptor 1a (GHSR1a) and Th-inducing POK (ThPOK) in primary bovine mammary epithelial cells (BMECs). The results showed that AG significantly increased the triglyceride relative content from 260.83 ± 9.87 to 541.67 ± 8.38 in BMECs via GHSR1a. ThPOK functions as a key regulatory target downstream of AG, activating the PI3K and mTOR signaling pathways to promote milk fat synthesis in BMECs. Moreover, AG-regulated ThPOK by increasing the EP300 activity, which promoted ThPOK acetylation to protect it from proteasomal degradation. In conclusion, AG increases ThPOK acetylation and stabilizes ThPOK through GHSR1a, thereby activating the PI3K/mTOR signaling pathway and ultimately promoting the milk fat synthesis in BMECs.

Maslinic acid alleviates LPS-induced mice mastitis by inhibiting inflammatory response, maintaining the integrity of the blood-milk barrier and regulating intestinal flora.

Mastitis occurs frequently in breastfeeding women and not only affects the women's health but also hinders breastfeeding. Maslinic acid is a type of pentacyclic triterpenoid widely found in olives that has good anti-inflammatory activity. This study aims to discuss the protective function of maslinic acid against mastitis and its underlying mechanism. For this, mice models of mastitis were established using lipopolysaccharide (LPS). The results revealed that maslinic acid reduced the pathological lesions in the mammary gland. In addition, it reduced the generation of pro-inflammatory factors and enzymes (IL-6, IL-1ß, TNF-α, iNOS, and COX2) in both mice mammary tissue and mammary epithelial cells. The high-throughput 16S rDNA sequencing of intestinal flora showed that in mice with mastitis, maslinic acid treatment altered ß-diversity and regulated microbial structure by increasing the abundance of probiotics such as Enterobacteriaceae and downregulating harmful bacteria such as Streptococcaceae. In addition, maslinic acid protected the blood-milk barrier by maintaining tight-junction protein expression. Furthermore, maslinic acid downregulated mammary inflammation by inhibiting the activation of NLRP3 inflammasome, AKT/NF-κB, and MAPK signaling pathways. Thus, in a mice model of LPS-induced mastitis, maslinic acid can inhibit the inflammatory response, protect the blood-milk barrier, and regulate the constitution of intestinal flora.

Tartary buckwheat flavonoids alleviates high-fat diet induced kidney fibrosis in mice by inhibiting MAPK and TGF-ß1/Smad signaling pathway.

Tartary buckwheat flavonoids (TBF) are active components extracted from Tartary buckwheat, which have abundant biological effects. According to this study, we investigated the effect of TBF on high-fat diet (HFD)-induced kidney fibrosis and its related mechanisms. In vivo, we established an HFD-induced kidney fibrosis model in mice and administered TBF. The results showed that TBF was able to alleviate kidney injury and inflammatory response. Subsequently, the mRNA levels between the HFD group and the TBF + HFD group were detected using RNA-seq assay. According to the gene set enrichment analysis (GSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) results, the differential genes were enriched in lipid metabolism and mitogen-activated protein kinases(MAPK) signaling pathways. We examined the protein expression of lipid metabolism-related pathways and the level of lipid metabolism. The results showed that TBF significantly activated the adenosine monophosphate activated protein kinase/acetyl-CoA carboxylase (AMPK/ACC) pathway and effectively reduced kidney total cholesterol (TC), triglyceride (TG) and low-density lipoproteinc cholesterol (LDL-C) levels and increased high-density lipoprotein cholesterol (HDL-C) levels in mice. TBF also inhibited transforming growth factor-ß1/Smad (TGF-ß1/Smad) and MAPK signaling pathways, thus slowing down the kidney fibrosis process. In vitro, using palmitic acid (PA) to stimulate TCMK-1 cells, the in vivo results similarly demonstrated that TBF could alleviate kidney fibrosis in HFD mice by inhibiting TGF1/Smad signaling pathway and MAPK signaling pathway.

Staphylococcus aureus induces mitophagy to promote its survival within bovine mammary epithelial cells.

Mitophagy occurs in a variety of pathogenic infections. However, the role of mitophagy in the intracellular survival of Staphylococcus aureus (S.aureus) within bovine mammary epithelial cells (BMECs) and which molecules specifically mediate the induction of mitophagy remains unclear. Therefore, this study aims to investigate the role and mechanism of mitophagy in the intracellular survival of S.aureus. Here, we reported that S.aureus induced complete mitophagy to promote its survival within BMECs. The further mechanistic study showed that S. aureus induced mitophagy by activating the p38-PINK1-Parkin signaling pathway. These findings expand our knowledge of the intracellular survival mechanism of S.aureus in the host and provide a desirable therapeutic strategy against S.aureus and other intracellular infections.

Lysine promotes proliferation and ß-casein synthesis through the SLC6A14-ERK1/2-CDK1-mTOR signaling pathway in bovine primary mammary epithelial cells.

Lysine, as the first limiting amino acid in dairy cows, has been shown to play an important role in milk synthesis and cell proliferation. However, the underlying mechanism remains unclear. In this study, we isolated bovine primary mammary epithelial cells (BMECs) and studied the mechanism in which lysine promotes cell proliferation and ß-casein synthesis through overexpression and knockdown of CDK1 and supplements BCH, U0126, and rapamycin in BMECs. Results show that 0.7 mM lysine can significantly promote cell proliferation and the synthesis of ß-casein in BMECs. In addition, lysine activates the ERK signaling pathway to promote the expression of CDK1. Further studies have shown that CDK1 can promote cell proliferation and the synthesis of ß-casein through the mTOR signaling pathway in BMECs. Lastly, lysine can promote cell proliferation and the synthesis of ß-casein through SLC6A14 in BMECs. The above results indicate that lysine promotes cell proliferation and the synthesis of ß-casein through the SLC6A14-ERK-CDK1-mTOR signaling pathway in BMECs.

Mammary Fibrosis Tendency and Mitochondrial Adaptability in Dairy Cows with Mastitis.

Dairy cow mammary gland fibrosis causes huge economic losses to livestock production, however, research on dairy cow mammary gland fibrosis is in its infancy and it lacks effective treatments. Therefore, the purpose of this experiment was to explore the correlation between mastitis and fibrosis and mitochondrial damage, and to further explore its pathogenesis. In vivo, mammary tissue and milk samples were collected from healthy cows (n = 10) and mastitis cows (n = 10). The results of the study showed that compared with the control group, the mastitis tissue showed tissue damage, accumulation of collagen fibers, and the content of TGF-ß1 in mammary tissue and milk was significantly increased; the level of inflammatory mediators was significantly increased; the fibrotic phenotype, collagen 1, α-SMA, vimentin gene, and protein levels were significantly increased, while the E-cadherin gene and protein levels were significantly decreased. In vitro, based on TGF-ß1-induced bMECs, the above experimental results were further confirmed, and TGF-ß1 significantly promoted the fibrotic phenotype of bMECs. On the other hand, in vivo results showed that fibrotic mammary tissue had a significantly stronger mitochondrial damage phenotype and significantly higher ROS than the control group. In vitro, the results also found that TGF-ß1 induced a significant increase in the mitochondrial damage phenotype of bMECs, accompanied by a large amount of ROS production. Furthermore, in a TGF-ß1-induced bMEC model, inhibiting the accumulation of ROS effectively alleviated the elevated fibrotic phenotype of TGF-ß1-induced bMECs. In conclusion, the fibrotic phenotype of mammary gland tissue in dairy cows with mastitis was significantly increased, and mastitis disease was positively correlated with mammary fibrotic lesions. In an in vitro and in vivo model of cow mammary fibrosis, bMECs have impaired mitochondrial structure and dysfunction. Inhibiting the accumulation of ROS effectively alleviates the elevated fibrotic phenotype, which may be a potential therapeutic approach to alleviate mammary fibrosis.

Orally Administered Ginkgolide C Attenuates DSS-Induced Colitis by Maintaining Gut Barrier Integrity, Inhibiting Inflammatory Responses, and Regulating Intestinal Flora.

Ulcerative colitis (UC), one of the foremost common forms of inflammatory bowel disease, poses a serious threat to human health. Currently, safe and effective treatments are not available. This study investigated the protective effect of ginkgolide C (GC), a terpene lactone extracted from Ginkgo biloba leaves, on UC and its underlying mechanism. The results showed that GC remarkably mitigated the severity of DSS-induced colitis in mice, as demonstrated by decreased body weight loss, reduced disease activity index, mitigated tissue damage, and increased colon length. Furthermore, GC inhibited DSS-induced hyperactivation of inflammation-related signaling pathways (NF-κB and MAPK) to reduce the production of inflammatory mediators, thereby mitigating the inflammatory response in mice. GC administration also restored gut barrier function by elevating the number of goblet cells and boosting the levels of tight junction-related proteins (claudin-3, occludin, and ZO-1). In addition, GC rebalanced the intestinal flora of DSS-treated mice by increasing the diversity of the flora, elevating the abundance of beneficial bacteria, such as Lactobacillus and Allobaculum, and decreasing the abundance of harmful bacteria, such as Bacteroides, Oscillospira, Ruminococcus, and Turicibacter. Taken together, these results suggest that GC administration effectively alleviates DSS-induced colitis by inhibiting the inflammatory response, maintaining mucosal barrier integrity, and regulating intestinal flora. This study may provide a scientific basis for the rational use of GC in preventing colitis and other related diseases.

Phytic Acid Improves Hepatic Steatosis, Inflammation, and Oxidative Stress in High-Fat Diet (HFD)-Fed Mice by Modulating the Gut-Liver Axis.

Nonalcoholic fatty liver disease (NAFLD) induced by obesity is a grave threat to human health. Phytic acid (PA) is a natural compound found in high-fiber diets, such as soybeans. This study investigated the effects and mechanisms of PA on obesity, hepatic lipid metabolism, and gut-liver axis homeostasis in high-fat diet (HFD)-fed mice. PA was observed to significantly inhibit obesity and alleviate liver steatosis in mice. PA improved HFD-induced liver inflammation, oxidative stress and fibrosis. Moreover, PA improved HFD-induced colonic inflammation, gut barrier damage and systemic inflammation in mice. Furthermore, PA effectively ameliorated the decreased diversity and gut microbiota composition in HFD-fed mice. Additionally, PA decreased the abundance of harmful bacteria Proteobacteria and Desulfovibrionaceae and increased the abundance of probiotic bacteria Muribaculaceae and Lachnospiraceae. Thus, PA is effective in restoring the homeostasis of the gut-liver axis. It further provides a theoretical basis for the prevention and treatment of NAFLD in patients with obesity by the rational intake of foods containing PA.

CIDEA Regulates De Novo Fatty Acid Synthesis in Bovine Mammary Epithelial Cells by Targeting the AMPK/PPARγ Axis and Regulating SREBP1.

Cell-death-inducing DNA fragmentation factor-α-like effector A (CIDEA) is a lipid-droplet-associated protein that helps to promote lipid metabolism in adipocytes of mice and humans. However, studies on the regulatory mechanism of CIDEA on lipid metabolism in the mammary glands of dairy cows are rare. Therefore, the role of CIDEA in bovine mammary epithelial cells (bMECs) was investigated in this study. The CIDEA expression levels in the mammary glands of high-fat-milk-producing cows were significantly higher compared to those in low-fat-milk-producing cows. Results of in vitro studies in bMECs showed that the inhibition of CIDEA inhibited the expression of fatty acid synthesis-related genes and triglyceride (TAG) synthesis-related genes. Conversely, the overexpression of CIDEA leads to an increase in the content of TAG and fatty acid. The results of mechanistic studies indicated that the overexpression of CIDEA inhibits AMP-activated protein kinase (AMPK) activity, which enhances the expression of peroxisome proliferator-activated receptor-γ (PPARγ) and consequently increases the TAG content. Furthermore, the overexpression of CIDEA promoted the nuclear translocation of sterol regulatory element-binding protein 1 (SREBP1). Therefore, a theoretical framework is provided by this study for the regulation of lipid metabolism in dairy cows by means of nutrition and the hormone targeting of CIDEA.

Lysine stimulates the development of the murine mammary gland at puberty via PI3K/AKT/mTOR signalling axis.

Lysine is one of the essential amino acids. The effect of lysine on milk protein and milk fat anabolism has been reported, but the effect on mammary glands development has not been studied in detail. The normal development of the mammary glands at puberty is crucial to lactation of mammals. In this study, to explore the effect of lysine on mammary glands development, we fed different concentrations of lysine (0.025%, 0.05%, 0.1%) to pubertal mice and found that the addition of 0.1% lysine to drinking water significantly promoted mammary glands development. Furthermore, we treated mMECs (mouse mammary epithelial cells) with different concentrations of lysine (0, 0.2, 0.4, 0.6, 0.8 and 1 mM) to explore the underlying mechanism, and found that lysine promoted the proliferation of mMECs and development of mammary glands through PI3K/AKT/mTOR signalling pathway in pubertal mice. Overall, the results of this study revealed that lysine activated the PI3K/AKT/mTOR signal axis, elevated protein concentrations of cell proliferation markers, such as PCNA, Cyclin D1 and D3, and enhanced the proliferation of mMECs, finally promoted the murine mammary glands development at puberty.

Astaxanthin Alleviates Nonalcoholic Fatty Liver Disease by Regulating the Intestinal Flora and Targeting the AMPK/Nrf2 Signal Axis.

Nonalcoholic fatty liver disease (NAFLD) is among the most prevalent chronic liver diseases around the globe. The accumulation of lipids in the liver and oxidative stress are important pathological mechanisms of NAFLD. Astaxanthin (AT) is a carotenoid extracted from shrimps and crabs with beneficial biological activities, including anti-oxidative and anti-inflammatory activities. 16S microflora sequencing, H&E staining, and the western blot technique were employed to investigate the impacts of AT on a high-fat diet (HFD)-induced NAFLD. Significant mitigation in lipid metabolism-related disorders and decreased oxidative stress in HFD-induced mice were observed due to AT, and significant changes in the gut flora of the model mice were also observed. The in vitro study showed that AT considerably lowered the protein expression level of fatty acid synthetase (FAS), sterol regulatory element-binding protein-1c (SREBP-1c), and acetyl-COA carboxylase (ACC) and increased the protein expression of nuclear factor-E2 associated factor 2 (Nrf2) and AMP-activated protein kinase (AMPK) in oleic acid (OA) and palmitic acid (PA)-induced HepG2 cells. Additionally, mechanistic studies revealed that compound C (AMPK inhibitor, CC) inhibited the regulatory effect of AT on the SREBP-1c and Nrf2 signaling pathways. In conclusion, AT can inhibit the SREBP-1c, FAS, and ACC signaling pathways, activate the AMPK and Nrf2 signaling pathways, and improve the structure of intestinal flora.

Sodium butyrate attenuates bovine mammary epithelial cell injury by inhibiting the formation of neutrophil extracellular traps.

Neutrophil extracellular traps (NETs) are an important means by which the body fights against exogenous bacteria. However, studies have shown that excessive NETs release can damage other cells. Accumulating evidence has shown that butyric acid can alleviate the inflammatory response of cells. However, the effect of butyric acid on Staphylococcus aureus-induced NETs formation and its underlying mechanism are still unclear. In this study, western blotting, immunofluorescence and CCK-8 assays were used to examine the effect of NETs formation by sodium butyrate (NaB). The results showed that NaB suppressed the release of S. aureus-induced NETs formation, as indicated by decreases in the levels of DNA, histones, myeloperoxidase, and neutrophil elastase. S. aureus can induce autophagy, and autophagy plays a key role in the formation of NETs. Our data showed that NaB activated mammalian target of rapamycin (mTOR) and the kinases protein kinase B (AKT) and unc-51 like kinase 1 (ULK1) at Ser757 and inhibited AMP-activated protein kinase (AMPK). To explore whether NaB inhibited the formation of NETs by inhibiting autophagy, we added 3-methyladenine (autophagy inhibitor) (3-MA, 5 mM) to bovine neutrophils, and the results showed that 3-MA significantly inhibited NETs release. Furthermore, we found that NETs and their component histones exhibited significantly increased the cytotoxic effects on bovine mammary epithelial cells (BMECs), indicating that NETs and their component histones play a key role in BMEC damage. In conclusion, NaB can reduce the excessive formation of NETs by inhibiting autophagy, thus reducing the damaging effect of NETs on BMECs.