Effect of chronic treatment with Rosiglitazone on Leydig cell steroidogenesis in rats: In vivo and ex vivo studies

<p>Abstract</p> <p>Background</p> <p>The present study was designed to examine the effect of chronic treatment with rosiglitazone - thiazolidinedione used in the treatment of type 2 diabetes mellitus for its insulin sensitizing effects - on the Leydig cell steroidogenic capacity and expression of the steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc) in normal adult rats.</p> <p>Methods</p> <p>Twelve adult male Wistar rats were treated with rosiglitazone (5 mg/kg) administered by gavage for 15 days. Twelve control animals were treated with the vehicle. The ability of rosiglitazone to directly affect the production of testosterone by Leydig cells <it>ex vivo </it>was evaluated using isolated Leydig cells from rosiglitazone-treated rats. Testosterone production was induced either by activators of the cAMP/PKA pathway (hCG and dbcAMP) or substrates of steroidogenesis [22(R)-hydroxy-cholesterol (22(R)-OH-C), which is a substrate for the P450scc enzyme, and pregnenolone, which is the product of the P450scc-catalyzed step]. Testosterone in plasma and in incubation medium was measured by radioimmunoassay. The StAR and P450scc expression was detected by immunocytochemistry.</p> <p>Results</p> <p>The levels of total circulating testosterone were not altered by rosiglitazone treatment. A decrease in basal or induced testosterone production occurred in the Leydig cells of rosiglitazone-treated rats. The ultrastructural and immunocytochemical analysis of Leydig cells from rosiglitazone-treated rats revealed cells with characteristics of increased activity as well as increased StAR and P450scc expression, which are key proteins in androgen biosynthesis. However, a number of rosiglitazone-treated cells exhibited significant mitochondrial damage.</p> <p>Conclusion</p> <p>The results revealed that the Leydig cells from rosiglitazone-treated rats showed significant reduction in testosterone production under basal, hCG/dbcAMP- or 22 (R)-OH-C/pregnenolone-induced conditions, although increased labeling of StAR and P450scc was detected in these cells by immunocytochemistry. The ultrastructural study suggested that the lower levels of testosterone produced by these cells could be due to mitochondrial damage induced by rosiglitazone.</p

2-(2-Nitro­anilino)-4,5,6,7-tetra­hydro­benzo[b]thio­phene-3-carbonitrile

The title compound, C15H13N3O2S, was synthesized by the reaction of 2-amino-5,6,7,8-tetra­hydro-4H-cyclo­hepta­[b]thio­phene-3-carbonitrile and o-fluoro­nitro­benzene. The dihedral angle between the thio­phene and nitro­phenyl rings is 75.15 (2)°. In the crystal, inter­molecular N—H⋯N and C—H⋯O inter­actions lead to the formation of a supra­molecular chain extending along the c-axis direction

2-(2-Nitro­anilino)-5,6,7,8-tetra­hydro-4H-cyclo­hepta­[b]thio­phene-3-carbonitrile

The title compound, C16H15N3O2S, was synthesized by the reaction of 2-amino-5,6,7,8-tetra­hydro-4H-cyclo­hepta­[b]thio­phene-3-carbonitrile and o-fluoro­nitro­benzene. The thio­phene and nitro­phenyl rings and amino and carbonitrile groups are coplanar with a maximum deviation of 0.046 (2) Å and a dihedral angle of 0.92 (6)° between the rings. The cyclo­hepta ring adopts a chair conformation. Intra­molecular N—H⋯O and C—H⋯S inter­actions occur. In the crystal, the mol­ecules form layers that are linked by π–π stacking inter­actions between the thio­phene and benzene rings [centroid–centroid distances = 3.7089 (12) and 3.6170 (12) Å]

2-Amino-4,5,6,7-tetra­hydro­benzo[b]thio­phene-3-carbonitrile

The title compound, C9H10N2S, was synthesized according to Gewald procedures by the reaction of cyclo­hexa­none with malonitrile and sulfur in the presence morpholine. The cyclo­hexane ring adopts a half-chair conformation and the thio­phene ring is essentially planar (r.m.s. deviation = 0.05 Å). The crystal packing is stabilized by two inter­molecular N—H⋯N hydrogen bonds, which link the mol­ecules into centrosymmetric rings with graph-set motif R 2 2(12)

Lasers in Surgery and Medicine

Texto completo: acesso restrito. p. 850–855Background and Objective: Cutaneous and mucocutaneous leishmaniasis are diseases characterized by skin or mucosal manifestations. In the new world, Leishmania braziliensis is the main etiological agent of cutaneous leishmaniasis, condition that may evolve to the mucocutaneous form. The therapeutic arsenal routinely employed to treat infected patients is unsatisfactory, especially for pentavalent antimonials, treatment recommended by the WHO, as they are often highly toxic, poorly tolerated and of variable effectiveness. This work aimed to evaluate in vitro the effectiveness of photodynamic antimicrobial chemotherapy as a new approach for the treatment of leishmaniasis. Materials and Methods: A laser (λ = 660 nm, 40 mW, 4.2 J/cm2, and 8.4 J/cm2, CW) associated to phenothiazine's derivatives (5 and 10 µg/ml, toluidine blue O, methylene blue, or phenothiazine) on the promastigote forms of L. braziliensis in a single session. Samples were removed and analyzed in a hemocytometer 72 hours after PACT and viability of the parasites was assessed in quadruplicates. Results: An important decrease in the number of viable parasites on all treated groups in comparison to their controls was observed as all tested compounds lead to significant parasite lethality being the highest lethality achieved with 10 µg/ml of TBO. No lethality was observed on groups treated with laser or with any of the compounds separately. Conclusions: TBO presented higher parasite lethality in comparison to MB with impressive reduction from 1 hour to 5 minutes of pre-incubation time. Lasers Surg. Med. 44: 850–855, 2012. © 2012 Wiley Periodicals, Inc

Photodynamic antimicrobial chemotherapy (PACT) using phenothiazine derivatives as photosensitizers against Leishmania braziliensis

Background and Objective Cutaneous and mucocutaneous leishmaniasis are diseases characterized by skin or mucosal manifestations. In the new world, Leishmania braziliensis is the main etiological agent of cutaneous leishmaniasis, condition that may evolve to the mucocutaneous form. The therapeutic arsenal routinely employed to treat infected patients is unsatisfactory, especially for pentavalent antimonials, treatment recommended by the WHO, as they are often highly toxic, poorly tolerated and of variable effectiveness. This work aimed to evaluate in vitro the effectiveness of photodynamic antimicrobial chemotherapy as a new approach for the treatment of leishmaniasis. Materials and Methods A laser (??=?660?nm, 40?mW, 4.2?J/cm2, and 8.4?J/cm2, CW) associated to phenothiazine's derivatives (5 and 10?mu g/ml, toluidine blue O, methylene blue, or phenothiazine) on the promastigote forms of L. braziliensis in a single session. Samples were removed and analyzed in a hemocytometer 72?hours after PACT and viability of the parasites was assessed in quadruplicates. Results An important decrease in the number of viable parasites on all treated groups in comparison to their controls was observed as all tested compounds lead to significant parasite lethality being the highest lethality achieved with 10?mu g/ml of TBO. No lethality was observed on groups treated with laser or with any of the compounds separately. Conclusions TBO presented higher parasite lethality in comparison to MB with impressive reduction from 1?hour to 5?minutes of pre-incubation time. Lasers Surg. Med. 44: 850855, 2012. (c) 2012 Wiley Periodicals, Inc

Development and application of LC-UV method for the quantification of the anti-inflammatory thiazolidinone PG15 in rat plasma

A simple and rapid liquid chromatography-ultraviolet detection (LC-UV) method has been developed and validated for quantifying (5Z,E)-3-[2-(4-chlorophenyl)-2-oxoethyl]-5-(1H-indol-3-ylmethylene)-thiazolidine-2,4-dione (PG15) in rat plasma. A C18 reversed phase column provided chromatographic separation of the analyte which was followed by UV detection at 385 nm. The method involves precipitation of PG15 from plasma and isocratic elution with methanol:water (90:10, v/v). Total elution time was 7.5 min. The proposed method was validated and showed linear correlation in the range of 62.5 to 4000 ng mL-1. The within- and between-day precision, expressed as the relative standard error, were found to be less than 15 and 10 %, respectively, for all the concentrations investigated. The accuracy, measured using the quality control samples, was in the range of 86.1-114.9 %. The applicability of the validated method was tested in a pre-clinical pharmacokinetic study of the thiazolidinone PG15

Síntese de um novo derivado tiazolidínico com potencial atividade anti-inflamatória

The presence of the thiazolidine ring in penicillins and related derivatives was the first recognition of thiazolidines in nature. As these heterocyclic compounds have important biological properties, such as potential anti-inflammatory and analgesic activity, according to previous works (Singh et al. - 1986; Boschelli et al. - 1992). This fact drove us to the synthesis of new derivatives with potential anti-inflammatory activity. We synthesized and identified the physicochemical characteristics of a new thiazolidine derivative (LPSF/SF-22). Initially we obtained the intermediate compound LPSF through the Knoevenagel condensation reaction between the thiazolidine-2 4-dione N-alkylated and a product resulting from the reaction between an aldehyde and an ester, using ethanol as solvent and piperidine as catalyst. Then the final product (LPSF/SF-22)was obtained by alkylation of N-substituted thiazolidine. The thiazolidine derivative was purified and analyzed by thin layer chromatography (TLC), resulting in a Rf system n-hexane/AcOEt 7:3 = 0,50, income equal to 78% and melting point 243-244°C. Through the methods employed in this work we obtained a product with greater profitability

IL-17 and related cytokines involved in systemic sclerosis: Perspectives

Systemic sclerosis (SSc) is a multisystemic, complex, and rare disease of connective tissue, with high morbidity and mortality, and without specific treatment. The disease is characterized by three main principles: vascular disease, autoantibody production and inflammation, and fibrosis. Since it is well defined that SSc is characterized by elevated production of TGF-β, IL-6, and IL-1, all of them cytokines related to Th17 differentiation, the hypothesis is that this disease may be strongly related to a polarization of the immune response towards the Th17 pathway. Considering the importance of a better understanding of the pathophysiology of Th17 pathway in SSc, this article aims to propose an update for a better understanding of current knowledge on main cytokines secreted by the Th17 cells (IL-17 A, IL-21, and IL-22) and the future prospects in the current disease