Iron depletion in HCT116 cells diminishes the upregulatory effect of phenethyl isothiocyanate on heme oxygenase-1

Isothiocyanates in medicine: A comprehensive review on phenylethyl-, allyl-, and benzyl-isothiocyanates

In recent years, isothiocyanates (ITCs), bioactive compounds primarily derived from Brassicaceae vegetables and herbs, have gained significant attention within the biomedical field due to their versatile biological effects. This comprehensive review provides an in-depth exploration of the therapeutic potential and individual biological mechanisms of the three specific ITCs phenylethyl isothiocyanate (PEITC), allyl isothiocyanate (AITC), and benzyl isothiocyanate (BITC), as well as their collective impact within the formulation of ANGOCIN® Anti-Infekt N (Angocin). Angocin comprises horseradish root (Armoracia rusticanae radix, 80 mg) and nasturtium (Tropaeoli majoris herba, 200 mg) and is authorized for treating inflammatory diseases affecting the respiratory and urinary tract. The antimicrobial efficacy of this substance has been confirmed both in vitro and in various clinical trials, with its primary effectiveness attributed to ITCs. PEITC, AITC, and BITC exhibit a wide array of health benefits, including potent anti-inflammatory, antioxidant, and antimicrobial properties, along with noteworthy anticancer potentials. Moreover, we highlight their ability to modulate critical biochemical pathways, such as the nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and signal transducer and activator of transcription (STAT) pathways, shedding light on their involvement in cellular apoptosis and their intricate role to guide immune responses.

Dietary Iron Intake and HIV-Related Outcomes Among Adults Initiating Antiretroviral Therapy in Tanzania

OBJECTIVE

Anemia is highly prevalent among people living with HIV (PLWHIV) and is often due to iron deficiency. This study evaluated the relationship of dietary iron intake levels and sources with mortality and clinical outcomes among adults initiating HAART.

DESIGN

We conducted a secondary analysis of a multivitamin supplementation trial among 2293 PLWHIV initiating HAART in Dar es Salaam, Tanzania.

METHODS

Dietary iron intake was assessed with a food frequency questionnaire at HAART initiation, and participants followed until death or censoring. Total, animal-, and plant-sourced iron were categorized into quartiles. Intake of food groups was categorized into 0-1, 2-3, and ≥4 servings/wk. Cox proportional hazards models estimated hazard ratios for mortality and incident clinical outcomes.

RESULTS

There were 175 deaths (8%). Red meat intake was associated with a lower risk of all-cause mortality (HR: 0.54; 95% CI: 0.35 to 0.83), AIDS-related mortality (HR: 0.49; 95% CI: 0.28 to 0.85), and severe anemia (HR: 0.57; 95% CI: 0.35 to 0.91), when intake ≥4 servings/wk, compared with 0-1 servings/wk. Legume intake was a lower risk of associated with all-cause mortality (HR: 0.49; 95% CI: 0.31 to 0.77) and AIDS-related mortality (HR: 0.37; 95% CI: 0.23 to 0.61), when intake ≥4 servings/wk, compared with 0-1 servings/wk. Although total dietary iron and overall plant-sourced iron intake were not associated with the risk of mortality or HIV-related outcomes, the highest quartile of animal-sourced iron intake was associated with a lower risk of all-cause mortality (HR: 0.56; 95% CI: 0.35 to 0.90) and a lower risk of AIDS-related mortality (HR: 0.50; 95% CI: 0.30 to 0.90), compared with the lowest quartile.

CONCLUSION

Intake of iron-rich food groups may be associated with a lower risk of mortality and critical HIV-related outcomes among adults initiating HAART.

TRIAL REGISTRATION

The parent trial was registered at Clinicaltrials.gov . Identifier: NCT00383669.

Ferroptosis-modulating small molecules for targeting drug-resistant cancer: Challenges and opportunities in manipulating redox signaling

Ferroptosis is an iron-dependent cell death program that is characterized by excessive lipid peroxidation. Triggering ferroptosis has been proposed as a promising strategy to fight cancer and overcome drug resistance in antitumor therapy. Understanding the molecular interactions and structural features of ferroptosis-inducing compounds might therefore open the door to efficient pharmacological strategies against aggressive, metastatic, and therapy-resistant cancer. We here summarize the molecular mechanisms and structural requirements of ferroptosis-inducing small molecules that target central players in ferroptosis. Focus is placed on (i) glutathione peroxidase (GPX) 4, the only GPX isoenzyme that detoxifies complex membrane-bound lipid hydroperoxides, (ii) the cystine/glutamate antiporter system Xc - that is central for glutathione regeneration, (iii) the redox-protective transcription factor nuclear factor erythroid 2-related factor (NRF2), and (iv) GPX4 repression in combination with induced heme degradation via heme oxygenase-1. We deduce common features for efficient ferroptotic activity and highlight challenges in drug development. Moreover, we critically discuss the potential of natural products as ferroptosis-inducing lead structures and provide a comprehensive overview of structurally diverse biogenic and bioinspired small molecules that trigger ferroptosis via iron oxidation, inhibition of the thioredoxin/thioredoxin reductase system or less defined modes of action.

Anemia, Iron Status, and HIV: A Systematic Review of the Evidence

People living with HIV (PLWHIV) are at high risk of anemia due to inadequate iron intake, HIV and opportunistic infections, and inflammation, and as a side effect of antiretroviral therapy. Though iron supplementation can reduce iron deficiency anemia (IDA) in the general population, its role in anemia and in the health of PLWHIV is unclear due to concerns that iron supplementation may increase HIV replication and risk of opportunistic infections. We systematically reviewed the evidence on indicators of iron status, iron intake, and clinical outcomes among adults and children with HIV. The evidence suggests that anemia is associated with an increased risk of all-cause mortality and incident tuberculosis among HIV-infected individuals, regardless of anemia type, and the magnitude of the risk is greater with more severe anemia. High serum ferritin is associated with adverse clinical outcomes, although it is unclear if this is due to high iron or inflammation from disease progression. One large observational study found an increased risk of all-cause mortality among HIV-infected adults if they received iron supplementation. Published randomized controlled trials of iron supplementation among PLWHIV tend to have small sample sizes and have been inconclusive in terms of effectiveness and safety. Large randomized trials exploring approaches to safely and effectively provide iron supplementation to PLWHIV are warranted.

MiR-20b Down-Regulates Intestinal Ferroportin Expression In Vitro and In Vivo

Ferroportin (FPN) is the only known cellular iron exporter in mammalian. However, post-transcriptional regulation of intestinal FPN has not yet been completely understood. In this study, bioinformatics algorithms (TargetScan, PicTar, PITA, and miRanda) were applied to predict, screen and obtain microRNA-17 family members (miR-17, miR-20a, miR-20b, and miR-106a) targeting FPN, ‘seed sequence’ and responding binding sites on the 3′untranslated region (3′UTR) region of FPN. Dual-luciferase reporter assays revealed miRNA-17 family members’ mimics decreased the luciferase activity, whereas their inhibitors increased the luciferase activity. Compared with the FPN 3′UTR wild type reporter, co-transfection of a miRNA-17 family members’ over-expression plasmids and FPN 3′UTR mutant reporters enhanced the luciferase activity in HCT116 cells. Transfection with miR-20b overexpression plasmid significantly enhanced its expression, and it inhibited endogenous FPN protein expression in Caco-2 cells. Additionally, tail-vein injection of miR-20b resulted in increasing duodenal miR-20b expression, decreasing duodenal FPN protein expression, which was closely related to lower plasma iron level in mice. Taken together, these data suggest that the miR-20b is identified to regulate intestinal FPN expression in vitro and in vivo, which will provide a potential target for intestinal iron exportation.

The role of oxidative stress in activity of anticancer thiosemicarbazones

Thiosemicarbazones are chelators of transition metals such as iron or copper whose anticancer potency is intensively investigated. Although two compounds from this class have entered clinical trials, their precise mechanism of action is still unknown. Recent studies have suggested the mobilization of the iron ions from a cell, as well as the inhibition of ribonucleotide reductase, and the formation of reactive oxygen species. The complexity and vague nature of this mechanism not only impedes a more rational design of novel compounds, but also the further development of those that are highly active that are already in the preclinical phase. In the current work, a series of highly active thiosemicarbazones was studied for their antiproliferative activity in vitro. Our experiments indicate that these complexes have ionophoric properties and redox activity. They appeared to be very effective generating reactive oxygen species and deregulating the antioxidative potential of a cell. Moreover, the genes that are responsible for antioxidant capacity were considerably deregulated, which led to the induction of apoptosis and cell cycle arrest. On the other hand, good intercalating properties of the studied compounds may explain their ability to cleave DNA strands and to also poison related enzymes through the formation of reactive oxygen species. These findings may help to explain the particularly high selectivity that they have over normal cells, which generally have a stronger redox equilibrium.