Atrazine-induced apoptosis of splenocytes in BALB/C mice

<p>Abstract</p> <p>Background</p> <p>Atrazine (2-chloro-4-ethytlamino-6-isopropylamine-1,3,5-triazine; ATR), is the most commonly applied broad-spectrum herbicide in the world. Unintentional overspray of ATR poses an immune function health hazard. The biomolecular mechanisms responsible for ATR-induced immunotoxicity, however, are little understood. This study presents on our investigation into the apoptosis of splenocytes in mice exposed to ATR as we explore possible immunotoxic mechanisms.</p> <p>Methods</p> <p>Oral doses of ATR were administered to BALB/C mice for 21 days. The histopathology, lymphocyte apoptosis and the expression of apoptosis-related proteins from the Fas/Fas ligand (FasL) apoptotic pathway were examined from spleen samples.</p> <p>Results</p> <p>Mice administered ATR exhibited a significant decrease in spleen and thymus weight. Electron microscope histology of ultrathin sections of spleen revealed degenerative micromorphology indicative of apoptosis of splenocytes. Flow cytometry revealed that the percentage of apoptotic lymphocytes increased in a dose-dependent manner after ATR treatment. Western blots identified increased expression of Fas, FasL and active caspase-3 proteins in the treatment groups.</p> <p>Conclusions</p> <p>ATR is capable of inducing splenocytic apoptosis mediated by the Fas/FasL pathway in mice, which could be the potential mechanism underlying the immunotoxicity of ATR.</p

Synthesis of some potent immunomodulatory and anti-inflammatory metabolites by fungal transformation of anabolic steroid oxymetholone

<p>Abstract</p> <p>Background</p> <p>Biotransformation of organic compounds by using microbial whole cells provides an efficient approach to obtain novel analogues which are often difficult to synthesize chemically. In this manuscript, we report for the first time the microbial transformation of a synthetic anabolic steroidal drug, oxymetholone, by fungal cell cultures.</p> <p>Results</p> <p>Incubation of oxymetholone (<b>1</b>) with <it>Macrophomina phaseolina</it>, <it>Aspergillus niger</it>, <it>Rhizopus stolonifer</it>, and <it>Fusarium lini</it> produced 17β-hydroxy-2-(hydroxy-methyl)-17α-methyl-5α-androstan-1-en-3-one (<b>2</b>), 2α,17α-di(hydroxyl-methyl)-5α-androstan-3β,17β-diol (<b>3</b>), 17α-methyl-5α-androstan-2α,3β,17β-triol (<b>4</b>), 17β-hydroxy-2-(hydroxymethyl)-17α-methyl-androst-1,4-dien-3-one (<b>5</b>), 17β-hydroxy-2α-(hydroxy-methyl)-17α-methyl-5α-androstan-3-one (<b>6</b>), and 2α-(hydroxymethyl)-17α-methyl-5α-androstan-3β-17β-diol (<b>7</b>). Their structures were deduced by spectral analyses, as well as single-crystal X-ray diffraction studies. Compounds <b>2</b>–<b>5</b> were identified as the new metabolites of <b>1</b>. The immunomodulatory, and anti-inflammatory activities and cytotoxicity of compounds <b>1</b>–<b>7</b> were evaluated by observing their effects on T-cell proliferation, reactive oxygen species (ROS) production, and normal cell growth in MTT assays, respectively. These compounds showed immunosuppressant effect in the T-cell proliferation assay with IC₅₀ values between 31.2 to 2.7 μg/mL, while the IC₅₀ values for ROS inhibition, representing anti-inflammatory effect, were in the range of 25.6 to 2.0 μg/mL. All the compounds were found to be non-toxic in a cell-based cytotoxicity assay.</p> <p>Conclusion</p> <p>Microbial transformation of oxymetholone (<b>1</b>) provides an efficient method for structural transformation of <b>1</b>. The transformed products were obtained as a result of <it>de novo</it> stereoselective reduction of the enone system, isomerization of double bond, insertion of double bond and hydroxylation. The transformed products, which showed significant immunosuppressant and anti-inflammatory activities, can be further studied for their potential as novel drugs.</p

Prenatal stress causes alterations in the morphology of microglia and the inflammatory response of the hippocampus of adult female mice

<p>Abstract</p> <p>Background</p> <p>Stress during fetal life increases the risk of affective and immune disorders later in life. The altered peripheral immune response caused by prenatal stress may impact on brain function by the modification of local inflammation. In this study we have explored whether prenatal stress results in alterations in the immune response in the hippocampus of female mice during adult life.</p> <p>Methods</p> <p>Pregnant C57BL/6 mice were subjected three times/day during 45 minutes to restraint stress from gestational Day 12 to delivery. Control non-stressed pregnant mice remained undisturbed. At four months of age, non-stressed and prenatally stressed females were ovariectomized. Fifteen days after surgery, mice received an i.p. injection of vehicle or of 5 mg/kg of lipopolysaccharide (LPS). Mice were sacrificed 20 hours later by decapitation and the brains were removed. Levels of interleukin-1β (IL1β), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), interferon γ-inducible protein 10 (IP10), and toll-like receptor 4 mRNA were assessed in the hippocampus by quantitative real-time polymerase chain reaction. Iba1 immunoreactivity was assessed by immunocytochemistry. Statistical significance was determined by one-way or two-way analysis of variance.</p> <p>Results</p> <p>Prenatal stress, per se, increased IL1β mRNA levels in the hippocampus, increased the total number of Iba1-immunoreactive microglial cells and increased the proportion of microglial cells with large somas and retracted cellular processes. In addition, prenatally stressed and non-stressed animals showed different responses to peripheral inflammation induced by systemic administration of LPS. LPS induced a significant increase in mRNA levels of IL-6, TNF-α and IP10 in the hippocampus of prenatally stressed mice but not of non-stressed animals. In addition, after LPS treatment, prenatally stressed animals showed a higher proportion of Iba1-immunoreactive cells in the hippocampus with morphological characteristics of activated microglia compared to non-stressed animals. In contrast, LPS induced similar increases in expression of IL1β and toll-like receptor 4 in both prenatally stressed and non-stressed animals.</p> <p>Conclusion</p> <p>These findings indicate that prenatal stress induces long-lasting modifications in the inflammatory status of the hippocampus of female mice under basal conditions and alters the immune response of the hippocampus to peripheral inflammation.</p