Association between iron metabolism and SARS-COV-2 infection, determined by ferritin, hephaestin and hypoxia-induced factor-1 alpha levels in COVID-19 patients.

BACKGROUND: Due to the growing evidence of the importance of iron status in immune responses, the biomarkers of iron metabolism are of interest in novel Coronavirus Disease 2019 (COVID-19). The present prospective study was carried out to compare iron status indicated by levels of ferritin with the levels of two novel biomarkers related to iron homeostasis, hephaestin and hypoxia-inducible factors-1 (HIF-1α) in the serum of patients with COVID-19 in comparison with a control group. METHODS AND RESULTS: Blood samples from 34 COVID-19 patients and from 43 healthy volunteers were collected and the levels of HEPH and HIF-1α were measured by ELISA and compared with levels of serum ferritin. COVID-19 patients had higher serum levels of ferritin than those levels in control group (P < 0.0001). Conversely levels of HIF-1α and HEPH in the COVID-19 group were significantly lower than those of control group (P < 0.0001 for both). An inverse correlation between hephaestin and ferritin as well as between HIF-1α and ferritin was found among all subjects (P < 0.0001), and among COVID-19 patients, but not to statistical significance. CONCLUSION: Levels of hephaestin and HIF-1α were found to be inversely related levels of ferritin across all participants in the study, and to our knowledge this is the first report of hephaestin and HIF-1α as potential markers of iron status. Further studies are needed to corroborate the findings, utilizing a broader range of markers to monitor inflammatory as well as iron status.

The transfer of iron between ceruloplasmin and transferrins.

BACKGROUND: It is over 60years since the discovery and isolation of the serum ferroxidase ceruloplasmin. In that time much basic information about the protein has been elucidated including its catalytic and kinetic properties as an enzyme, expression, sequence and structure. The importance of its biological role is indicated in genetic diseases such as aceruloplasminemia where its function is lost through mutation. Despite this wealth of data, fundamental questions about its action remain unanswered and in this article we address the question of how ferric iron produced by the ferroxidase activity of ceruloplasmin could be taken up by transferrins or lactoferrins. METHODS: Overlapping peptide libraries for human ceruloplasmin have been probed with a number of different lactoferrins to identify putative lactoferrin-binding regions on human ceruloplasmin. Docking software, 3D-Garden, has been used to model the binding of human lactoferrin to human ceruloplasmin. RESULTS: Upon probing the human ceruloplasmin library with human lactoferrin, three predominantly acidic lactoferrin-binding peptides, located in domains 2, 5 and 6 of human ceruloplasmin, were identified. The docking software identified a complex such that the N-lobe of human apo-lactoferrin interacts with the catalytic ferroxidase centre on human ceruloplasmin. GENERAL SIGNIFICANCE: In vitro binding studies and molecular modelling indicate that lactoferrin can bind to ceruloplasmin such that a direct transfer of ferric iron between the two proteins is possible. A direct transfer of ferric iron from ceruloplasmin to lactoferrin would prevent both the formation of potentially toxic hydroxyl radicals and the utilization of iron by pathogenic bacteria.

The effect of fenugreek 4-hydroxyisoleucine on liver function biomarkers and glucose in diabetic and fructose-fed rats.

Fenugreek (Trigonella foenum graecum L) is a plant traditionally used for the treatment of diabetes. It contains an unusual amino acid, 4-hydroxyisoleucine, demonstrated to have insulinotropic and antidiabetic properties in animal models. Here we examine the effect of 4-hydroxyisoleucine on liver function and blood glucose in two rat models of insulin resistance, fructose-fed rats and streptozotocin-induced diabetes type 2. In fructose-fed rats, levels of glucose and liver damage marker aspartate transaminase were markedly (84% and 93%, respectively) and significantly elevated compared with controls (p < 0.001 for both). Alanine transaminase was elevated slightly (18%), and all markers were restored to near control values after treatment with 4-hydroxyisoleucine at 50 mg/kg per day for 8 weeks, the effect being significant (p < 0.01) for all markers. This prolonged exposure to 4-hydroxyisoleucine was well tolerated in control animals and did not alter levels of glucose or liver damage markers significantly. In diabetic rats, treatment with 4-hydroxyisoleucine did not affect glucose or liver damage markers, but did improve HDL-cholesterol levels (31% increase, p < 0.05). These findings indicate 4-hydroxyisoleucine as a useful and well-tolerated treatment for insulin resistance, both directly as a hypoglycaemic and also as a protective agent for the liver.

Pharmacokinetics and bioavailability of gentiopicroside from decoctions of Gentianae and Longdan Xiegan Tang after oral administration in rats--comparison with gentiopicroside alone.

The pharmacokinetics and bioavailability of gentiopicroside (GPS), an active component of the Gentian plant species, from orally administered decoctions of Gentianae (DG), or in combination with other plants in the prescription of Longdan Xiegan Tang (LXT), was compared in rats with oral administration of GPS alone, using doses adjusted to deliver equivalent amounts of GPS (150 mg/kg). Changes in plasma levels of GPS following oral administration of GPS or DG could be fitted to a one compartment open model with elimination half times (T(1/2)Ke) of 3.35+/-0.76 h and 6.21+/-3.07 h, respectively. Kinetics of plasma GPS following oral administration of LXT could be fitted to a two compartments open model with an elimination half time (T((1/2)beta)) of 3.83+/-1.54 h. The bioavailability of GPS from DG was markedly better, and that from LXT markedly worse, compared with GPS alone, as judged by the area under concentration-time curve (AUC) values of 70.0+/-13.9 microgh/ml (DG), 32.7+/-12.9 microgh/ml (GPS) and 19.1+/-5.9 microgh/ml (LXT). The study demonstrates the marked variability in pharmacokinetics and bioavailability of an active component from different herbal preparations.

Pharmacokinetic behavior of gentiopicroside from decoction of Radix Gentianae, Gentiana macrophylla after oral administration in rats: a pharmacokinetic comaprison with gentiopicroside after oral and intravenous administration alone.

The pharmacokinetics in rats of gentiopicroside (GPS) from orally administered decoctions of Radix Gentianae (DRG) and Gentiana macrophlla (DGM) were compared with that of GPS alone administered at 150 mg/kg orally and 30 mg/kg intravenously. The metabolic profile of GPS after intravenous injection could be fitted to two-compartment model whereas oral administration decoctions DRG or DGM, or GPS alone, could all be fitted to a one-compartment model. After oral administration of GPS alone, GPS was absorbed quickly and reached a maximum plasma concentration (Cmax) value, 5.78 +/- 2.24 microg/mL within 0.75 +/- 0.62 h. The plasma level of GPS declined with a T1/2ke, 3.35 +/- 0.76 h. After oral administration of decoctions DRG and DGM, GPS was absorbed and reached significantly higher maximum concentrations of 10.53 +/- 3.20 microg/mL (p < 0.01) and 7.43 +/- 1.64 microg/mL (p < 0.05) at later time points 1.60 +/- 0.76 (p < 0.01) and 2.08 +/- 0.74 h (p < 0.05), for DRG and DGM respectively, compared with oral GPS alone. Significantly larger AUC values were found for decoctions of GPS (83.49 +/- 20.8 microgxh/mL for DRG and 59.43 +/- 12.9 microgxh/mL for DGM) compared with oral GPS alone (32.67 +/- 12.9 microgxh/mL). The results demonstrate that the bioavailability of GPS was markedly improved when administered as a decoction than as purified GPS. The decoction from Radix Gentianae provided 2.5 times better bioavailability and that from Gentiana macrophlla 1.8 times higher. The study confirms the importance of careful pharmacokinetic analysis in the characterization of herbal medicines when applied for future clinical applications.

Structure-tunable Janus fibers fabricated using spinnerets with varying port angles.

The preparation of Janus fibers using a new side-by-side electrospinning process is reported. By manipulating the angle between the two ports of the spinneret emitting the working fluids, Janus nanofibers with tunable structures in terms of width, interfacial area and also volume of each side can be easily fabricated.

Pharmacokinetics and tissue distribution of gentiopicroside following oral and intravenous administration in mice.

The pharmacokinetics and tissue distribution of Gentiopicroside (GPS), one of the major active components of the Gentiana species of medicinal plants, was studied following oral and intravenous administration in mice. The distribution of GPS in mice after oral and intravenous doses could be fitted to a two-compartments open model. The serum half-life of GPS was 6.1 h and 2.8 h for intravenous and oral administration, respectively. The Tmax of GPS after oral administration was 0.50 h, and the bioavailability was 39.6%. The AUC gradient in individual tissues following intravenous administration was kidney >serum >liver >spleen >lung >thymus >fat >heart >muscle >stomach >intestinal >brain. The MRT gradient was muscle >serum >lung >spleen >lung >intestinal>heart >stomach >brain >liver >thymus >kidney >fat. Overall the data show that GPS could be absorbed rapidly in mice, but with a low bioavailability, and could distribute to tissues extensively, but was generally cleared quickly with short MRTs. The study demonstrates the need for repeated dosage, or better, a slow release formulation as an ideal means of administering GPS.

Non-insulin dependent anti-diabetic activity of (2S, 3R, 4S) 4-hydroxyisoleucine of fenugreek (Trigonella foenum graecum) in streptozotocin-induced type I diabetic rats.

The seeds of fenugreek, Trigonella foenum graecum, commonly used as a spice in Middle Eastern countries and widely used in south Asia and Europe, are known to have anti-diabetic properties. They contain an unusual amino acid (2S, 3R, 4S) 4-hydroxyisoleucine (4HO-Ile), so far found only in fenugreek, which has anti-diabetic properties of enhancing insulin secretion under hyperglycaemic conditions, and increasing insulin sensitivity. Here we describe for the first time the anti-diabetic activity of 4HO-Ile in a model of type I diabetes, streptozotocin-treated rats, where levels of insulin are much reduced, by 65%, compared to normal animals. Treatment of diabetic rats with daily doses of 4HO-Ile at 50 mg/kg/day for four weeks could reduce plasma glucose in the diabetic group. Moreover the high levels of lipids (cholesterol, HDL, LDL and triglycerides) and uric acid in the diabetic rats, could be restored to levels found in non-diabetic controls by the treatment with 4HO-Ile. These results demonstrate that 4HO-Ile has significant anti-diabetic activities that are independent of insulin and suggest the potential of 4HO-Ile as an adjunct to diabetes treatment and for type 1 as well as type 2 diabetes.

Evodiamine, a dual catalytic inhibitor of type I and II topoisomerases, exhibits enhanced inhibition against camptothecin resistant cells.

DNA topoisomerases are nuclear enzymes that are the targets for several anticancer drugs. In this study we investigated the antiproliferative activity against human leukaemia cell lines and the effects on topoisomerase I and II of evodiamine, which is a quinazolinocarboline alkaloid isolated from the fruit of a traditional Chinese medicinal plant, Evodia rutaecarpa. We report here the anti-proliferative activity against human leukaemia cells K562, THP-1, CCRF-CEM and CCRF-CEM/C1 and the inhibitory mechanism on human topoisomerases I and II, important anti-cancer drugs targets, of evodiamine. Evodiamine failed to trap [Topo-DNA] complexes and induce any detectable DNA damage in cells, was unable to bind or intercalate DNA, and arrested cells in the G(2)/M phase. The results suggest evodiamine is a dual catalytic inhibitor of topoisomerases I and II, with IC(50) of 60.74 and 78.81 µM, respectively. The improved toxicity towards camptothecin resistant cells further supports its inhibitory mechanism which is different from camptothecin, and its therapeutic potential.

Coaxial electrospinning with organic solvent for controlling the size of self-assembled nanoparticles.

We show that coaxial electrospinning using organic solvent as the sheath fluid is a viable way to produce tailor-made nanofibers composed of polyvinylpyrrolidine, tristearic and naproxen. Self-assembled hybrid nanoparticles are generated from the composite nanofibers under aqueous conditions and particle size has a linear relationship with fiber diameter.

¹H NMR study of monocrotaline and its metabolites in human blood.

Monocrotaline (MCT) is a naturally occurring hepatotoxic pyrrolizidine alkaloid found in plants. This investigation is aimed at furthering the understanding of the role of blood in mediating the transport of MCT and its reactive metabolites in humans. Reactions of monocrotaline and its metabolites, dehydromonocrotaline (DHM), retronecine (RET) and dehydroretronecine (DHR) with human blood plasma, red blood cells (RBCs), and whole blood were studied in vitro by proton nuclear magnetic resonance spectroscopy. In plasma MCT remained intact and weakly associated with plasma proteins, and DHM was rapidly hydrolyzed releasing necic and lactone acids, and the reactive pyrrolic metabolite. MCT and its metabolite DHM were internalized in RBCs to the extent of 46.0% and 48.9% respectively in 30 min. No polymerization of DHR was observed when incubated with plasma and RBCs. The data clearly showed that both human plasma and RBCs could be the carriers for the transportation of MCT and its metabolites, DHM, RET and DHR between organs and could stabilise the reactive MCT metabolite DHR.

Treatment with Qing'E, a kidney-invigorating Chinese herbal formula, antagonizes the estrogen decline in ovariectomized mice.

A Chinese herbal preparation, Qing'E formula (QEF), has been used clinically for treating osteoporosis in postmenopausal women by virtue of its kidney-invigorating function; however, no evidence base links QEF to estrogen replacement therapy. In this study, we undertake a characterization of estrogenic activity of QEF using an in vivo model of ovariectomized (OVX) mice together with in vitro studies with the MCF-7 cells for further molecular characterization. OVX mice were treated intragastrically with QEF at doses of 0.85, 1.7, and 3.4 g/kg per day for 4 weeks. QEF treatments restored the estrus cycle and demonstrated significant estrogenic activity, as indicated by reversal of uterine atrophy (six-fold increase in uterine weight), reduction in rectal temperature, and increased expression (1.6-fold) of estrogen receptors (ERs) in the uterus. Notably, the largest changes in these three parameters were found at the lowest dose. At the highest dose of QEF, significant changes were found in adrenal gland weight (30% increase), serum estradiol (E(2)) (60% increase), and luteinizing hormone (LH) (17% decrease) compared with untreated OVX controls. The data suggest estrogenic responses induced by QEF show tissue variation that reflects different affinities of ERs for QEF components. QEF could significantly induce luciferase expression (2.7-fold compared with control) from an estrogen response element luciferase reporter and induced expression of ERalpha and ERbeta (1.2-fold and 1.7-fold respectively) in MCF-7 cells. Both activities were inhibited 80-90% by the estrogen antagonist ICI 182,780. This study demonstrates that QEF activity is mediated through estrogenic components and provides an evidence base for QEF treatment of postmenopausal symptoms.