Excess iron intake induced liver injury: The role of gut-liver axis and therapeutic potential

Consuming probiotics protects against cadmium exposure from rice consumption while promotes gut health: An assessment based on a mouse model

Cadmium (Cd) in rice constitutes a global health risk. It is crucial to develop strategies that not only reduce the bioavailability of Cd in rice but also confer additional health benefits. One potential approach involves the consumption of probiotics, which can bind Cd in the intestines and enhance gut health. The effects of consuming Akkermansia muciniphila, Bifidobacterium pseudolongum, and Psychrobacter sp. on the bioavailability of Cd in rice and gut health were evaluated using in vivo mouse bioassays and in vitro Cd immobilization assays. In mice fed Cd-contaminated rice without dietary calcium (Ca) and iron (Fe) supplementation (i.e., under conditions of mineral deficiency), the intake of these probiotics insignificantly reduced Cd accumulation in the kidneys and livers, although it did promote Cd excretion via feces. This outcome was primarily due to the competition for Ca and Fe between the probiotics and the host, which led to increased intestinal expression of Ca and Fe transporters under mineral-deficient conditions, thereby mitigating the probiotics' ability to reduce Cd bioavailability. Conversely, in mice fed Cd-contaminated rice with adequate dietary Ca and Fe (i.e., under conditions of mineral adequacy), probiotic intake significantly decreased Cd concentrations in the kidneys by 60.0 %-72.0 % compared to the control group exposed to Cd. Additionally, probiotic consumption fostered the growth of beneficial gut bacteria and strengthened intestinal tight junctions, reducing the inflammatory response in the intestines. These findings suggest that combining probiotics with sufficient Ca and Fe intake can effectively reduce dietary Cd exposure and enhance gut health.

Recovery effects of sodium carboxymethylcellulose-xanthan gum hydrogels containing peptide‑iron complexes against iron deficient anemia in vivo

In this study, the sodium carboxymethylcellulose (CMC) and xanthan gum (XG) were used to prepare the CXM-Fe hydrogels (CMC: 20 mg/mL, XG: 10 mg/mL) with the addition of Mytilus edulis protein hydrolysate‑iron (MEPH-Fe) complexes. The incorporation of MEPH-Fe complexes formed a denser network structure and the CXM-Fe hydrogels had better pH stability as well as gastrointestinal retention ability. Compared with ferrous sulfate and MEPH-Fe complexes, the CXM-Fe hydrogels at moderate doses (Fe2+:2 mg/kg) showed impressive recovery effects on iron deficiency anemia (IDA) mice in terms of hematological indices, organ coefficients and iron content, antioxidant capacity, and remarkedly attenuated the infiltration of inflammatory cells as well as the levels of inflammatory factors in iron deficiency-induced colonic inflammation.

Diammonium glycyrrhizinate alleviates iron overload-induced liver injury in mice via regulating the gut-liver axis

BACKGROUND

Evidence indicates a close association between iron overload (IO) and the pathogenesis of chronic liver diseases, highlighting the potential for interventions targeted at IO to impede or decelerate the progression of chronic liver diseases. Diammonium glycyrrhizinate (DG), the medicinal form of glycyrrhizic acid, a principal constituent of licorice, has been clinically employed as a hepatoprotective agent; however, its protective effect against IO-induced liver injury and underlying molecular mechanisms remain elusive.

PURPOSE

The aim of the present study is to investigate the hepatoprotective effect of DG against IO-induced liver injury with a focus on the gut-liver axis.

STUDY DESIGN AND METHODS

Animal models of IO-induced liver injury and DG treatment have been established in vivo. Iron deposition, liver injury, intestinal barrier damage, and liver inflammation were assessed in mice treated with iron dextran or DG. The microbiome composition in feces was analyzed using 16S rRNA full-length sequencing. Bile acids (BAs) profiles in feces were detected by UPLC-Q-TOF-MS technique, and the expression levels of receptors, enzymes or transporters involved in BAs metabolism were also determined.

RESULTS

DG partially reduced the iron deposition and the levels of ferrous ion in the livers of mice with IO, thereby mitigating oxidative damage. DG also improved gut microbiota dysbiosis, repaired intestinal barrier damage, inhibited endotoxin translocation to the liver, and subsequently suppressed TLR4/NF-κB/NLRP3 pathway-mediated liver inflammation caused by IO. Moreover, DG modulated BAs metabolism disorder in IO mice, reducing the accumulation of BAs in the liver.

CONCLUSION

DG alleviates IO-induced liver injury in mice by regulating the gut-liver axis. This study provides novel insights into the underlying mechanisms through which DG ameliorates liver injury caused by IO.

Management of Iron Deficiency in Heart Failure: Practical Considerations and Implementation of Evidence-Based Iron Supplementation

Iron deficiency (ID) is present in approximately 50% of patients with heart failure (HF) and even higher prevalence rate up to 80% in post-acute HF setting. The current guidelines for HF recommend intravenous (IV) iron replacement in HF with reduced or mildly reduced ejection fraction and ID based on clinical trials showing improvements in quality of life and exercise capacity, and an overall treatment benefit for recurrent HF hospitalization. However, several barriers cause challenges in implementing IV iron supplementation in practice due, in part, to clinician knowledge gaps and limited resource availability to protocolize routine utilization in appropriate patients. Thus, the current review will discuss practical considerations in ID treatment, implementation of evidence-based ID treatment to improve regional health disparities with toolkits, inclusion/exclusion criteria of IV iron supplementation, and clinical controversies in ID treatment, as well as gaps in evidence and questions to be answered.

The Association Between Dietary Iron, the SNP of the JAZF1 rs864745, and Glucose Metabolism in a Chinese Population

OBJECTIVES

Dysglycemia is prevalent in China; previous studies had shown that dietary iron was associated with glucose metabolism, and rs864745 was also related to it. The objective of this study is to investigate the association between dietary iron, the SNP of the JAZF1 rs864745, and glucose metabolism among Chinese adults.

METHODS

3298 participants (1584 males and 1714 females) were recruited and underwent physical measurements, laboratory tests, and genotyping. All surveys were conducted by qualified public health professionals. Dietary iron was assessed using the 3-day 24 h dietary recall method and condiment weight records. Genotyping for rs864745 was performed using the SNaPshot Multiplex System.

RESULTS

After adjusting for covariates, a significant trend was found between the dietary iron and elevated fasting glucose (p = 0.012), whereas no such trend was observed for the rs864745 (p = 0.932). Among the male participants, the risk of elevated fasting glucose was associated with both dietary iron (compared to the lowest quartile, the ORs with 95% CIs for elevated fasting glucose in Q2,Q3, and Q4 were 1.52 (1.01, 2.45), 1.73 (1.05, 3.00), and 2.49 (1.33, 4.74), respectively) and the rs864745 (OR = 2.15 (1.02, 4.51)), and an interaction effect between them was observed (p = 0.041), which was absent in females (p = 0.999 and p = 0.131, respectively). Stratified by the SNP rs864745, the males without the C allele had a linear risk increase with iron (p = 0.018), while the C allele carriers did not. Additionally, ferritin and the rs864745 were associated with the AST-to-ALT ratio (p = 0.005 and p = 0.048, respectively).

CONCLUSIONS

Our study found that dietary iron and the SNP rs864745 interacted and were associated with elevated fasting glucose in Chinese males and absent in females. In addition, the presence of a C allele on rs864745 showed higher risks of elevated fasting glucose regardless of the consumption of dietary iron among the males.

Epidemiological and transcriptome data identify association between iron overload and metabolic dysfunction-associated steatotic liver disease and hepatic fibrosis

The primary objective of this study was to examine the association between iron overload (IO), metabolic dysfunction-associated steatotic liver disease (MASLD), and hepatic fibrosis. We hypothesized that there is a significant association. Data from the NHANES (2017-2020) were analyzed to explore IO's impact on MASLD and hepatic fibrosis in U.S. adults. We assessed serum ferritin, controlled attenuation parameter (CAP), liver stiffness measurement (LSM), and various covariates. Gene expression data were sourced from the FerrDb V2 and GEO databases. Differential gene expression analysis, Protein-Protein Interaction (PPI) Network construction, and Gene Ontology (GO) and KEGG pathway enrichment analyses were performed. The study verified the link between MASLD, hepatic fibrosis, and iron overload hub genes. This study of 5927 participants, averaging 46.78 years of age, revealed significant correlations between serum ferritin and CAP, LSM, after adjusting for covariates. Threshold effect analysis indicated nonlinear associations between serum ferritin and CAP, LSM, with distinct patterns observed by age and gender. Moreover, the area under the ROC curve for serum ferritin with MASLD and hepatic fibrosis was 0.8272 and 0.8376, respectively, demonstrating its performance in assessing these conditions. Additionally, molecular analyses identified potential hub genes associated with iron overload and MASLD, and hepatic fibrosis, revealing the underlying mechanisms. Our study findings reveal an association between iron overload, MASLD, and hepatic fibrosis. Additionally, the hub genes may be implicated in iron overload and subsequently contribute to the progression of MASLD and hepatic fibrosis. These findings support precision nutrition strategies.

Differential gut microbiota composition in β-Thalassemia patients and its correlation with iron overload

Recent research highlights the significant impact of the gut microbiota on health and disease. Thalassemia, a hereditary blood disorder, requires regular blood transfusions, leading to an accumulation of iron in the body. Such changes could potentially alter the intestinal microbiota, thereby increasing the susceptibility of thalassemic patients to infection. In this study, we analyzed the fecal microbiota of 70 non-transfusion-dependent (NTDT) β-thalassemia/HbE patients and 30 healthy controls. Our findings indicate that iron chelation intervention had no detectable effect on the microbiome profile of thalassemic patients. However, the cross-sectional analysis revealed that the bacterial diversity and community structure in patients were significantly less diverse and distinct compared to those of healthy subjects. Using reference frames, we were also able to demonstrate that bacterial taxa that are known to produce short chain fatty acids, from the genera Alistipes, Coprococcus, and Oscillospira, and those from the family Ruminococcaceae, were less prevalent in the patients. In contrast, bacterial taxa associated with an unhealthy gut, including the genus Clostridium and those from the families Fusobacteriaceae, Enterobacteriaceae, and Peptostrptococcaceae, were more prevalent in patients and found to be correlated with higher levels of ferritin. Collectively, these changes in the microbiota could be regarded as markers of raised ferritin levels, and therefore, awareness should be exercised as they could interfere, albeit indirectly, with the treatment of the co-morbidities of thalassemia.

Direct and macrophage stimulation mediated effects of active, inactive, and cell-free supernatant forms of Akkermansia muciniphila and Faecalibacterium duncaniae on hepcidin gene expression in HepG2 cells

Hepcidin is a crucial regulator of iron homeostasis with protective effects on liver fibrosis. Additionally, gut microbiota can also affect liver fibrosis and iron metabolism. Although the hepatoprotective potential of Akkermansia muciniphila and Faecalibacterium duncaniae, formerly known as F. prausnitzii, has been reported, however, their effects on hepcidin expression remain unknown. We investigated the direct and macrophage stimulation-mediated effects of active, heat-inactivated, and cell-free supernatant (CFS) forms of A. muciniphila and F. duncaniae on hepcidin expression in HepG2 cells by RT-qPCR analysis. Following stimulation of phorbol-12-myristate-13-acetate (PMA) -differentiated THP-1 cells with A. muciniphila and F. duncaniae, IL-6 concentration was assessed via ELISA. Additionally, the resulting supernatant was treated with HepG2 cells to evaluate the effect of macrophage stimulation on hepcidin gene expression. The expression of genes mediating iron absorption and export was also examined in HepG2 and Caco-2 cells via RT-qPCR. All forms of F. duncaniae increased hepcidin expression while active and heat-inactivated/CFS forms of A. muciniphila upregulated and downregulated its expression, respectively. Active, heat-inactivated, and CFS forms of A. muciniphila and F. duncaniae upregulated hepcidin expression, consistent with the elevation of IL-6 released from THP-1-stimulated cells as a macrophage stimulation effect in HepG2 cells. A. muciniphila and F. duncaniae in active, inactive, and CFS forms altered the expression of hepatocyte and intestinal iron-mediated absorption /exporter genes, namely dcytb and dmt1, and fpn in HepG2 and Caco-2 cells, respectively. In conclusion, A. muciniphila and F. duncaniae affect not only directly but also through macrophage stimulation the expression of hepcidin gene in HepG2 cells. These findings underscore the potential of A. muciniphila and F. duncaniae as a potential therapeutic target for liver fibrosis by modulating hepcidin and intestinal and hepatocyte iron metabolism mediated gene expression.

Targeting SIRT1, NLRP3 inflammasome, and Nrf2 signaling with chrysin alleviates the iron-triggered hepatotoxicity in rats

Blood transfusion-requiring diseases such as sickle cell anemia and thalassemia are characterized by an imbalance between iron intake and excretion, resulting in an iron overload (IOL) disorder. Hepatotoxicity is prevalent under the IOL disorder because of the associated hepatocellular redox and inflammatory perturbation. The current work was devoted to investigate the potential protection against the IOL-associated hepatotoxicity using chrysin, a naturally-occurring flavone. IOL model was created in male Wistar rats by intraperitoneal injection of 100 mg/kg elemental iron subdivided on five equal injections; one injection was applied every other day over ten days. Chrysin was administered in a daily dose of 50 mg/kg over the ten-day iron treatment period. On day eleven, blood and liver samples were collected and subjected to histopathological, biochemical, and molecular investigations. Chrysin suppressed the IOL-induced hepatocellular damage as revealed by decreased serum activity of the intracellular liver enzymes and improved liver histological picture. Oxidative damage biomarkers, and pro-inflammatory cytokines were significantly suppressed. Mechanistically, the levels of the redox and inflammation-controlling proteins SIRT1 and PPARγ were efficiently up-regulated. The liver iron load, NLRP3 inflammasome activation, and NF-κB acetylation and nuclear shift were significantly suppressed in the iron-intoxicated rats. Equally important, the level of the antioxidant protein Nrf2 and its target HO-1 were up-regulated. In addition, chrysin significantly ameliorated the IOL-induced apoptosis as indicated by reduction in caspase-3 activity and modulation of BAX and Bcl2 protein abundance. Together, these findings highlight the alleviating activity of chrysin against the IOL-associated hepatotoxicity and shed light on the role of SIRT1, NLRP3 inflammasome, and Nrf2 signaling as potential contributing molecular mechanisms.