Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

HPLC/DAD-based chemical investigation of a coral-associated gliding bacterium of the genus Tenacibaculum yielded three desferrioxamine-class siderophores, designated tenacibactins K (1), L (2), and M (3). Their chemical structures, comprising repeated cadaverine–succinic acid motifs terminated by a hydroxamic acid functionality, were elucidated by NMR and negative MS/MS experiments. Compounds 1–3 were inactive against bacteria and a yeast but displayed cytotoxicity against 3Y1 rat embryonic fibroblasts and P388 murine leukemia cells at GI50 in submicromolar to micromolar ranges. Their iron-chelating activity was comparable to deferoxamine mesylate.

ANTIOXIDANT AND ANTIRADICAL ACTIVITY IN VITRO OF EXTRACTS FROM THE LEAVES OF RUBUS CHAMAEMORUS L. (ROSACEAE)

Cloudberry (Rubus chamaemorus L.) is the leader among northern berries in the content of phenolic compounds, which can cause a wide range of biological activity. Currently, there is an increased interest in the study of the antioxidant activity of plant extracts in order to search for promising sources of raw materials for the pharmaceutical and food industries. The article presents the results of a comparative analysis of interpopulation and gender differences in antioxidant and antiradical activities in vitro of cloudberry leaf extracts growing on the territory of the Republic of Belarus. Classical spectrophotometric methods were used for determination: phosphomolibdenic method, Fe + 2-chelating activity, NO-inhibiting activity, inhibition of hydroxyl radicals (OH), method of superoxide radical inhibition in an alkaline solution of dimethylsulfoxide, DPPH, ABTS. Differences in the content of phenolic compounds and flavonoids in the alcoholic extracts of leaf blades of Rubus chamaemorus L. It was found that the population of the Bolshoi Mokh preserve possesses the highest inhibition rates of hydroxyl radicals and superoxide radicals. The maximum iron-chelating activity was exhibited by the extracts of the male plant of the Bolshoy Moh preserve. The least inhibitory activity of Rubus chamaemorus L. leaf extracts was shown to the nitrogen-oxide radical. The established values of antioxidant and antiradical activities, as well as the content of phenolic compounds and flavonoids of the leaf blades of Rubus chamaemorus L. may be important for the development of measures to preserve the species and specific populations on the southern border of the habitat.

Silymarin Dehydroflavonolignans Chelate Zinc and Partially Inhibit Alcohol Dehydrogenase

Silymarin is known for its hepatoprotective effects. Although there is solid evidence for its protective effects against Amanita phalloides intoxication, only inconclusive data are available for alcoholic liver damage. Since silymarin flavonolignans have metal-chelating activity, we hypothesized that silymarin may influence alcoholic liver damage by inhibiting zinc-containing alcohol dehydrogenase (ADH). Therefore, we tested the zinc-chelating activity of pure silymarin flavonolignans and their effect on yeast and equine ADH. The most active compounds were also tested on bovine glutamate dehydrogenase, an enzyme blocked by zinc ions. Of the six flavonolignans tested, only 2,3-dehydroderivatives (2,3-dehydrosilybin and 2,3-dehydrosilychristin) significantly chelated zinc ions. Their effect on yeast ADH was modest but stronger than that of the clinically used ADH inhibitor fomepizole. In contrast, fomepizole strongly blocked mammalian (equine) ADH. 2,3-Dehydrosilybin at low micromolar concentrations also partially inhibited this enzyme. These results were confirmed by in silico docking of active dehydroflavonolignans with equine ADH. Glutamate dehydrogenase activity was decreased by zinc ions in a concentration-dependent manner, and this inhibition was abolished by a standard zinc chelating agent. In contrast, 2,3-dehydroflavonolignans blocked the enzyme both in the absence and presence of zinc ions. Therefore, 2,3-dehydrosilybin might have a biologically relevant inhibitory effect on ADH and glutamate dehydrogenase.

Protective effects of curcumin against iron-induced toxicity

: Iron is an essential element in cellular metabolism that participates in many biochemical reactions. Nevertheless, iron overload in the body is the cause of damage in some organs including liver, glands, brain, heart, gastrointestinal tract and lung. Iron chelation therapy could be considered as an effective approach for removing excess iron. Deferoxamine, deferiprone and deferasirox are three common iron chelators in clinical practice but cause several side effects. In this context, the use of curcumin, a dietary phytochemical derived from turmeric, as a natural and safe antioxidant with iron-chelating activity may be a useful strategy for the management of iron overload. This review focuses on the deleterious effect of iron accumulation in different organs of the body as well as the therapeutic potential of curcumin against iron-induced toxicity.

Evaluation of Functional, Nutritional and Bioactive Properties of Gluten Free Muffins Utilizing Industrial By-Products of Baby Corn

This study was planned to utilize by-products of baby corn, which was powdered upon drying. Different formulations containing baby corn: defatted soya: plantain: finger millet flours at 10:65:20:5, 15:55:20:10, 20:45:20:15 and 25:35:20:20 were prepared and analyzed for functional, nutritional and bioactive properties of the blended flours and muffins. The outcomes indicated that incorporation of baby corn flour had enhanced functional and pasting properties of the blended flours. The addition of baby corn flour increased the antioxidant properties and metal chelating activity of blended flours. The incorporation of baby corn flour had contributed better retention of antioxidant potential during baking as muffins with 25% baby corn showed more increase in antioxidant properties than 10% baby corn muffins. Hardness and specific volume of muffins increased, while total phenol content decreased significantly with increment in the level of baby corn flour. On the basis of sensory analysis muffins prepared with 20% level of baby corn flour was selected best. This study concluded that by-products of baby corn can be utilized for development of gluten free muffins with better nutrition and bioactive properties.

Determination of Heavy Metals and Anti – Nutrients in Cow Meat Sold in Minna, Major Markets

Introduction: Meat is a major source of protein for the urban – population, but it could be susceptible to contamination by heavy metals, heavy metals and anti - nutrients pose a serious threat to human well being due to thier toxicity and chelating activity, this call for the need to determine thier level in meat which is one of our daily food. Objectives: This study is designed to determine the concentrations of heavy metals (Lead, Chromium, Cupper, Cadmium, and Zinc) and anti-nutrients (Phytate, Oxalate and cyanogenic glycoside) in cow meat sold in different locations in Minna, Niger State. Method: A total of 12 beef samples were bought from beef outlet in 4 major markets in Minna namely Bosso Market, Kure Market, Mobil Market, and Tunga Market. The level of the heavy metals were assayed using Atomic Absorbance Spectrophotometry (AAS) while that of anti – nutrients were determined using standard analytical methods. Results: Show that the concentration of Lead is highest across all locations while that of Zinc is the lowest across all locations. The order of the level of heavy metal concentration across the locations are Pb > Cd = Cu >Cr > Zn. Lead (Pb) concentrations across the four markets are 6.340±1.3562µg/g, 6.766±0.3684µg/g, 6.057±1.2097µg/g, 3.716±0.247µg/g respectively, while that of zinc are 0.310±0.0061µg/g, 0.304±0.0023µg/g, 0.298±0.0227µg/g, 0.299±0.0180µg/g respectively. Conclusion: Results from this study indicate that heavy metal toxicity could result from the consumption of cow meat from these study areas.

Identifying a Deferiprone–Resveratrol Hybrid as an Effective Lipophilic Anti-Plasmodial Agent

Malaria i a serious health problem caused by Plasmodium spp. that can be treated by an anti-folate pyrimethamine (PYR) drug. Deferiprone (DFP) is an oral iron chelator used for the treatment of iron overload and has been recognized for its potential anti-malarial activity. Deferiprone–resveratrol hybrids (DFP-RVT) have been synthesized to present therapeutic efficacy at a level which is superior to DFP. We have focused on determining the lipophilicity, toxicity and inhibitory effects on P. falciparum growth and the iron-chelating activity of labile iron pools (LIPs) by DFP-RVT. According to our findings, DFP-RVT was more lipophilic than DFP (p < 0.05) and nontoxic to blood mononuclear cells. Potency for the inhibition of P. falciparum was PYR > DFP-RVT > DFP in the 3D7 strain (IC50 = 0.05, 16.82 and 47.67 µM, respectively) and DFP-RVT > DFP > PYR in the K1 strain (IC50 = 13.38, 42.02 and 105.61 µM, respectively). The combined treatment of DFP-RVT with PYR additionally enhanced the PYR activity in both strains. DFP-RVT dose-dependently lowered LIP levels in PRBCs and was observed to be more effective than DFP at equal concentrations. Thus, the DFP-RVT hybrid should be considered a candidate as an adjuvant anti-malarial drug through the deprivation of cellular iron.

Evaluation of antioxidants activity of some tree barks grown in Libya (Al Jabal Al Akhdar) Pinus halepensis Mill, Pistacia lentiscus L, Juniperus phoenicea L

The aim of the present study investigated anti-oxidant activity of various methanol-water extracts from tree barks grown in Libya (Al Jabal AL Akhdar) by four anti-oxidant assays FRAP. DPPH. H2O2 and Metal chelating activity. Additionally, these antioxidant activities were compared with BHA, BHT as reference antioxidants. Tree bark has a large, diverse class of compounds, many with antioxidant properties. This study showed FRAP inhibitory activity of the Pinus halepensis bark extracts 56.8%, while Juniperus phoenicea L 57.6%, and Pistacia lentiscus L bark extracts was 69.2% The DPPH radical scavenging in the bark extracts exerted an inhibition of 66.8 %, 62.3% ,74.6% for Pinus halepensis, Juniperus phoenicea and Pistacia lentiscus L respectively. While H2O2 activity shows variation, ranging from 67. 8 to 81. 3%. The Metal chelating activity of the barks extract was 59% in Pinus halepensis and 57% in Juniperus phoenicea L bark extracts furthermore Pistacia lentiscus L was 67.8% in addition the Metal chelating activity of BHT and BHA 92%, 94% respectively. The high antioxidant activity of bark was founded in Pistacia lentiscus L bark extracts.

Rationally repurposed nitroxoline inhibits preclinical models of Epstein–Barr virus-associated lymphoproliferation

Repurposing of currently used drugs for new indications benefits from known experience with those agents. Rational repurposing can be achieved when newly uncovered molecular activities are leveraged against diseases that utilize those mechanisms. Nitroxoline is an antibiotic with metal-chelating activity used to treat urinary tract infections. This small molecule also inhibits the function of bromodomain and extraterminal (BET) proteins that regulate oncogene expression in cancer. Lymphoproliferation driven by the Epstein–Barr virus (EBV) depends on these same proteins. We therefore tested the efficacy of nitroxoline against cell culture and small animal models of EBV-associated lymphoproliferation. Nitroxoline indeed reduces cell and tumor growth. Nitroxoline also acts faster than the prototype BET inhibitor JQ1. We suggest that this rational repurposing may hold translational promise.