Liver Antioxidant Capacity and Steatosis in Laying Hens Exposed to Various Quantities of Lupin (Lupinus angustifolius) Seeds in the Diet

Despite the many beneficial properties of legume plants, their use in diets for poultry is limited by the presence of antinutritional factors. The aim of the study was to determine the activity of DT-diaphorase, ethoxycoumarin O-deethylase, and catalase, and the concentration of malondialdehyde in liver tissue, as well as the activity of SOD and CAT in the serum of Hy-line Brown hens fed a diet supplemented with various doses of Lupinus angustifolius seeds. The results indicate that the use of large amounts of lupin in the diet resulted in an increase in MDA concentration in the liver and the lipid vacuolization of hepatocytes. A significant increase in DTD activity was observed in chickens receiving 15% lupin. Regardless of lupin dose, no increase in SOD activity was observed in chicken serum after 33 days of the experiment. From the 66th day of the experiment, an increase in catalase activity in the serum of laying hens was observed, while low activity of this enzyme was found in the liver. It can be concluded that the short-term use of lupin in the diet of laying hens does not affect the activity of antioxidant enzymes and, therefore, does not affect the oxidative-antioxidant balance of their body.

Comparison of Various Aryl-Dithiolethiones and Aryl-Dithiolones As Hydrogen Sulfide Donors in the Presence of Rat Liver Microsomes

It has been reported that microsomal metabolism of ADT (5-(p-methoxyphenyl)-3H-1,2-dithiole-3-thione, anetholedithiolethione, Sulfarlem) and ADO (5-(p-methoxyphenyl)-3H-1,2-dithiole-3-one, anetholedithiolone) led to formation of H₂S mainly derived from oxidations catalyzed by cytochrome P450-dependent monooxygenases and that ADO was a better H₂S donor than ADT under these conditions. This article compares the H₂S donor abilities of 18 dithiolethione and dithiolone analogs of ADT and ADO upon incubation with rat liver microsomes. It shows that, for all the studied compounds, maximal H₂S formation was obtained after incubation with microsomes and NADPH and that this formation greatly decreased in the presence of N-benzylimidazole, a known inhibitor of cytochrome P450. This indicates that H₂S formation from all the studied compounds requires, as previously observed in the case of ADT and ADO, oxidations catalyzed by cytochrome P450-dependent monooxygenases. Under these conditions, the studied dithiolones were almost always better H₂S donors than the corresponding dithiolethiones. Interestingly, the best H₂S yields (up to 75%) were observed in microsomal oxidation of ADO and its close analogs, pCl-Ph-DO and Ph-DO, in the presence of glutathione (GSH), whereas only small amounts of H₂S were formed in microsomal incubations of those compounds with GSH but in the absence of NADPH. A possible mechanism for this effect of GSH is proposed on the basis of results obtained from reactions of GSH with 5-(p-methoxyphenyl)-3H-1,2-dithiole-3-one-1-sulfoxide, the ADO metabolite involved in H₂S formation in microsomal oxidation of ADO. SIGNIFICANCE STATEMENT: A series of 18 dithiolethiones and dithiolones were compared for their ability to form hydrogen sulfide (H₂S) in oxidations catalyzed by microsomal monooxygenases. The studied dithiolones were better H₂S donors than the corresponding dithiolethiones, and the addition of glutathione to the incubations strongly increased H₂S formation. A possible mechanism for this effect of GSH is proposed on the basis of results obtained from reactions of GSH with 5-(p-methoxyphenyl)-3H-1,2-dithiole-3-one-1-sulfoxide, a metabolite of the choleretic and sialologic drug Sulfarlem.

Mechanism of H2S Formation from the Metabolism of Anetholedithiolethione and Anetholedithiolone by Rat Liver Microsomes

The drug anetholedithiolethione (ADT) and its analogs have been extensively used as H₂S donors. However, the mechanism of H₂S formation from ADT under biologic conditions remains almost completely unknown. This article shows that only small amounts of H₂S are formed during incubation of ADT and of its metabolite anetholedithiolone (ADO) with rat liver cytosol or with rat liver microsomes (RLM) in the absence of NADPH, indicating that H₂S formation under these conditions is of hydrolytic origin only to a minor extent. By contrast, much greater amounts of H₂S are formed upon incubation of ADT and ADO with RLM in the presence of NADPH and dioxygen, with a concomitant formation of H₂S and para-methoxy-acetophenone (pMA). Moreover, H₂S and pMA formation under those conditions are greatly inhibited in the presence of N-benzyl-imidazole indicating the involvement of cytochrome P450-dependent monooxygenases. Mechanistic studies show the intermediate formation of the ADT-derived 1,2-dithiolium cation and of the ADO sulfoxide during microsomal metabolism of ADT and ADO, respectively. This article proposes the first detailed mechanisms for the formation of H₂S from microsomal metabolism of ADT and ADO in agreement with those data and with previously published data on the metabolism of compounds involving a C=S bond. Finally, this article shows for the first time that ADO is a better H₂S donor than ADT under those conditions. SIGNIFICANCE STATEMENT: Incubation of anetholedithiolethione (ADT) or its metabolite anetholedithiolone (ADO) in the presence of rat liver microsomes, NADPH, and O₂ leads to H₂S. This article shows for the first time that this H₂S formation involves several steps catalyzed by microsomal monooxygenases and that ADO is a better H₂S donor than ADT. We propose the first detailed mechanisms for the formation of H₂S from the microsomal metabolism of ADT and ADO.

Synthesis and biological evaluation of alpha-bromoacryloylamido indolyl pyridinyl propenones as potent apoptotic inducers in human leukaemia cells

The combination of two pharmacophores into a single molecule represents one of the methods that can be adopted for the synthesis of new anticancer molecules. To investigate the influence of the position of the pyridine nitrogen on biological activity, two different series of α-bromoacryloylamido indolyl pyridinyl propenones 3a-h and 4a-d were designed and synthesized by a pharmacophore hybridization approach and evaluated for their antiproliferative activity against a panel of six human cancer cell lines. These hybrid molecules were prepared to combine the α-bromoacryloyl moiety with two series of indole-inspired chalcone analogues, possessing an indole derivative and a 3- or 4-pyridine ring, respectively, linked on either side of 2-propen-1-one system. The structure-activity relationship was also investigated by the insertion of alkyl or benzyl moieties at the N-1 position of the indole nucleus. We found that most of the newly synthesized displayed high antiproliferative activity against U-937, MOLT-3, K-562, and NALM-6 leukaemia cell lines, with one-digit to double-digit nanomolar IC50 values. The antiproliferative activities of 3-pyridinyl derivatives 3f-h revealed that N-benzyl indole analogues generally exhibited lower activity compared to N-H or N-alkyl derivatives 3a-b and 3c-e, respectively. Moreover, cellular mechanism studies elucidated that compound 4a induced apoptosis along with a decrease of mitochondrial membrane potential and activated caspase-3 in a concentration-dependent manner.

Dithiolethiones: a privileged pharmacophore for anticancer therapy and chemoprevention

Dithiolethiones are five-membered sulfur-containing cyclic scaffolds that exhibit antioxidative, anti-inflammatory, antithrombic and chemotherapeutic activities. Dithiolethiones display the chemopreventive and cytoprotective effects by activating the antioxidant response element and mounting the transcription of cytoprotective phase II enzymatic machinery. In addition, several classes of dithiolethiones efficiently modulate the activities of proteins that play crucial roles in normal and cancer cells, including glutathione S-transferase, cyclooxygenases and master regulator NF-κB. The present paper summarizes synthetic aspects, pharmacological potentials and biological attributes of dithiolethiones and its derivatives. Additionally, this review concludes with a discussion on how the current state-of-the-art technologies may help in defining a structure–activity relationship of dithiolethiones, thereby facilitating the design and synthesis of potent drug candidates.

Discovery of Potent EGFR Inhibitors through the Incorporation of a 3D-Aromatic-Boron-Rich-Cluster into the 4-Anilinoquinazoline Scaffold: Potential Drugs for Glioma Treatment

New 1,7-closo-carboranylanilinoquinazoline hybrids have been identified as EGFR inhibitors, one of them with higher affinity than the parent compound erlotinib. The comparative docking analysis with compounds bearing bioisoster-substructures, demonstrated the relevance of the 3D aromatic-boron-rich moiety for interacting into the EGFR ATP binding region. The capability to accumulate in glioma cells, the ability to cross the blood-brain barrier and the stability on simulated biological conditions, render these molecules as lead compounds for further structural modifications to obtain dual action drugs to treat glioblastoma.

New hits as phase II enzymes inducers from a focused library with heteroatom-heteroatom and Michael-acceptor motives

The increased activity of phase-II-detoxification enzymes, such as quinone reductase (QR) and glutation S-transferase (GST), correlates with protection against chemically induced carcinogenesis. Herein we studied 11 different chemotypes, pyrazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiazole, 1,3,4-oxathiazole, thienyl hydrazone, α,β-unsaturated-oxime, α,β-unsaturated-N-oxide, coumarin and α,β-unsaturated-carbonyl, as phase-II enzymes inducers in order to identify new pharmacophores with chemopreventive activity. Fifty-four compounds were analyzed on wild-type mouse-hepatoma Hepa-1c1c7 and on the aryl-hydrocarbon-nuclear-translocator (Arnt)-defective mutant BpRc1 cells. New monofunctional inducers of QR and GST were identified, the 1,2,5-oxadiazol-2-oxide (3), the 1,2,4-triazine-4-oxides (23) and (32) and the tetrahydropyrimidinones (28) and (49). It was confirmed that Nrf2 nuclear translocation is the operative molecular mechanism that allows compound (3) to exert protective effects via expression of downstream phase-II enzymes.

Cancer chemoprevention is the prevention, delay or reversal of the carcinogenesis by administration of drugs. A group of chemopreventative agents includes quinone reductase and glutation S-transferase. Herein we have studied 11 chemotypes, trying to identify new pharmacophores for chemopreventives. We found new inducers of quinone reductase and glutation S-transferase, with excellent in vitro chemopreventive indexes, the 1,2,5-oxadiazol-2-oxide (3), the 1,2,4-triazine-4-oxides (23) and (32) and the tetrahydropyrimidinones (28) and (49), confirming that Nrf2 nuclear translocation is the operative molecular mechanism that allows compound (3) to exert protection. We have therefore highlighted good candidates for further in vivo studies of cancer chemopreventive activity.

New hybrid bromopyridine-chalcones as in vivo phase II enzyme inducers: potential chemopreventive agents

We report the synthesis of eighteen new potential cancer chemopreventive agents, structurally designed to combine (naphtho)chalcone and (bromo)pyridine skeletons.

3-H-[1,2]Dithiole as a New Anti-Trypanosoma cruzi Chemotype: Biological and Mechanism of Action Studies

The current pharmacological Chagas disease treatments, using Nifurtimox or Benznidazole, show limited therapeutic results and are associated with potential side effects, like mutagenicity. Using random screening we have identified new chemotypes that were able to inhibit relevant targets of the Trypanosoma cruzi. We found 3H-[1,2]dithioles with the ability to inhibit Trypanosoma cruzi triosephosphate isomerase (TcTIM). Herein, we studied the structural modifications of this chemotype to analyze the influence of volume, lipophilicity and electronic properties in the anti-T. cruzi activity. Their selectivity to parasites vs. mammalian cells was also examined. To get insights into a possible mechanism of action, the inhibition of the enzymatic activity of TcTIM and cruzipain, using the isolated enzymes, and the inhibition of membrane sterol biosynthesis and excreted metabolites, using the whole parasite, were achieved. We found that this structural framework is interesting for the generation of innovative drugs for the treatment of Chagas disease.