Library of Seleno-Compounds as Novel Agents against Leishmania Species

The in vitro leishmanicidal activities of a series of 48 recently synthesized selenium derivatives against Leishmania infantum and Leishmania braziliensis parasites were tested using promastigotes and intracellular amastigote forms. The cytotoxicity of the tested compounds for J774.2 macrophage cells was also measured in order to establish their selectivity. Six of the tested compounds (compounds 8, 10, 11, 15, 45, and 48) showed selectivity indexes higher than those of the reference drug, meglumine antimonate (Glucantime), for both Leishmania species; in the case of L. braziliensis, compound 20 was also remarkably selective. Moreover, data on infection rates and amastigote numbers per macrophage showed that compounds 8, 10, 11, 15, 45, and 48 were the most active against both Leishmania species studied. The observed changes in the excretion product profile of parasites treated with these six compounds were also consistent with substantial cytoplasmic alterations. On the other hand, the most active compounds were potent inhibitors of Fe superoxide dismutase (Fe-SOD) in the two parasite species considered, whereas their impact on human CuZn-SOD was low. The high activity, low toxicity, stability, low cost of the starting materials, and straightforward synthesis make these compounds appropriate molecules for the development of affordable antileishmanicidal agents

In vitro antileishmanial activity and iron superoxide dismutase inhibition of arylamine Mannich base derivatives

Leishmaniasis is one of the world’s most neglected diseases, and it has a worldwide prevalence of 12 million. There are no effective human vaccines for its prevention, and treatment is hampered by outdated drugs. Therefore, research aiming at the development of new therapeutic tools to fight Leishmaniasis remains a crucial goal today. With this purpose in mind, we present twenty arylaminoketone derivatives with a very interesting in vitro and in vivo efficacy against Trypanosoma cruzi that have now been studied against promastigote and amastigote forms of L. infantum, L. donovani and L. braziliensis strains. Six out of the twenty Mannich base-type derivatives showed Selectivity Index between 39 and 2337 times higher in the amastigote form than the reference drug glucantime. These six derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at a IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing a greater alteration in glucose catabolism and leading to greater levels of Fe-SOD (iron superoxide dismutase) inhibition. These molecules could be potential candidates for Leishmaniasis chemotherapy

Behavioral and Cognitive Improvement Induced by Novel Imidazoline I2 Receptor Ligands in Female SAMP8 Mice

As populations increase their life expectancy, age-related neurodegenerative disorders such as Alzheimer's disease have become more common. I2-Imidazoline receptors (I2-IR) are widely distributed in the central nervous system, and dysregulation of I2-IR in patients with neurodegenerative diseases has been reported, suggesting their implication in cognitive impairment. This evidence indicates that high-affinity selective I2-IR ligands potentially contribute to the delay of neurodegeneration. In vivo studies in the female senescence accelerated mouse-prone 8 mice have shown that treatment with I2-IR ligands, MCR5 and MCR9, produce beneficial effects in behavior and cognition. Changes in molecular pathways implicated in oxidative stress, inflammation, synaptic plasticity, and apoptotic cell death were also studied. Furthermore, treatments with these I2-IR ligands diminished the amyloid precursor protein processing pathway and increased Aβ degrading enzymes in the hippocampus of SAMP8 mice. These results collectively demonstrate the neuroprotective role of these new I2-IR ligands in a mouse model of brain aging through specific pathways and suggest their potential as therapeutic agents in brain disorders and age-related neurodegenerative diseases. Keywords Imidazoline I2 receptors (2-imidazolin-4-yl)phosphonates Behavior Cognition Neurodegeneration Neuroprotection Agin

Functional analysis of the 5' genomic sequence of a bovine norovirus.

BACKGROUND: Jena Virus (JV), a bovine Norovirus, causes enteric disease in cattle and represents a potential model for the study of enteric norovirus infection and pathogenesis. The positive sense RNA genome of JV is organised into ORF1 (non-structural proteins), ORF2 (major capsid protein) and ORF3 (minor capsid protein). The lack of a cell culture system for studying JV replication has meant that work to date has relied upon in vitro systems to study non-structural protein synthesis and processing. PRINCIPAL FINDINGS: Only two of the three major ORF1 proteins were identified (p110 and 2C) following in vitro translation of JV RNA, the N-term protein was not detected. The N-term encoding genomic sequence (5'GS) was tested for IRES-like function in a bi-cistronic system and displayed no evidence of IRES-like activity. The site of translation initiation in JV was determined to be at the predicted nucleotide 22. Following the insertion of an epitope within the 5'GS the JV N-term protein was identified in vitro and within RNA transfected cells. CONCLUSIONS: The in vitro transcription/translation system is currently the best system for analysing protein synthesis and processing in JV. Unlike similarly studied human noroviruses JV initially did not appear to express the N-terminal protein, presenting the possibility that the encoding RNA sequence had a regulatory function, most likely involved in translation initiation in an IRES-like manner. This was not the case and, following determination of the site of translation initiation the N-term protein was detected using an epitope tag, both in vitro and in vivo. Although slightly larger than predicted the N-term protein was detected in a processed form in vivo, thus not only demonstrating initial translation of the ORF1 polyprotein but also activity of the viral protease. These findings indicate that the block to noroviral replication in cultured cells lies elsewhere

In vitro antileishmanial activity and iron superoxide dismutase inhibition of arylamine Mannich base derivatives

Leishmaniasis is one of the world’s most neglected diseases, and it has a worldwide prevalence of 12 million. There are no effective human vaccines for its prevention, and treatment is hampered by outdated drugs. Therefore, research aiming at the development of new therapeutic tools to fight Leishmaniasis remains a crucial goal today. With this purpose in mind, we present twenty arylaminoketone derivatives with a very interesting in vitro and in vivo efficacy against Trypanosoma cruzi that have now been studied against promastigote and amastigote forms of L. infantum, L. donovani and L. braziliensis strains. Six out of the twenty Mannich base-type derivatives showed Selectivity Index between 39 and 2337 times higher in the amastigote form than the reference drug glucantime. These six derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at a IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing a greater alteration in glucose catabolism and leading to greater levels of Fe-SOD (iron superoxide dismutase) inhibition. These molecules could be potential candidates for Leishmaniasis chemotherapy