Synthesis and antitumoral activity of novel analogues monastrol-fatty acids against glioma cells.

Monastrol is a small cell-permeable heterocyclic molecule that is recognized as an inhibitor of mitotic kinesin Eg5. Heterocyclic-fatty acid derivatives are a new class of compounds with a broad range of biological activities. This work describes a comparative study of the in vitro antitumoral activity of a series of new long-chain monastrol analogues against rat glioblastoma cells. The novel analogues C6-substituted monastrol and oxo-monastrol were synthesized via Biginelli multicomponent condensation of fatty ß-ketoester in good yields using a simple approach catalyzed by nontoxic and free-metal sulfamic acid. Following synthesis, their in vitro antitumoral activities were investigated. Notably, all analogues tested were active against rat glioblastoma cells. Superior activity was observed by analogues derived from palmitic and stearic fatty acid chains; these compounds were the most potent molecules, showing 13-fold higher potency than monastrol with IC50 values of 5.11 and 6.85 µM, respectively. These compounds could provide promising new lead derivatives for more potent antitumor drugs.

Coumestrol/hydroxypropyl-ß-cyclodextrin association incorporated in hydroxypropyl methylcellulose hydrogel exhibits wound healing effect: in vitro and in vivo study.

Several beneficial effects on the skin have been reported for coumestrol (COU), such as protection against photoaging and improvement of skin elasticity and thickness in postmenopausal women. However no reports on the effect of COU on wound healing were found. Nevertheless, COU has low aqueous solubility, which is a crucial limitation for biological tests. The present study was designed as a two-step experiment to evaluate the wound healing effect of COU. First, we used fibroblasts and the experimental in vitro artificial wound model, scratch assay, to compare the effects of COU free, dissolved in dimethyl sulfoxide (DMSO) or Dulbecco's modified Eagle's medium (DMEM), or associated with hydroxypropyl-ß-cyclodextrin (HPßCD). The 50 µM (66.1%) and 10 µM (56.3%) COU/HPßCD association induced cell proliferation and migration in inflicted wounds. Subsequently, the in vivo wound healing experimental model (Wistar rats) revealed that COU/HPßCD incorporated into hypromellose (HPMC) hydrogel had similar efficacy in wound healing in comparison to the positive control (Dersani®), with the advantage that 50% wound healing was achieved within a shorter period. In summary, the results successfully demonstrated, for the first time, the wound healing effect of COU/HPßCD incorporated into HPMC hydrogel and describe the feasibility of the biological tests with the use of HPßCD instead DMSO.

Synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones exhibit selective in vitro antitumoral activity and inhibit cancer cell growth in a preclinical model of glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the worst form of primary brain tumor, which has a high rate of infiltration and resistance to radiation and chemotherapy, resulting in poor prognosis for patients. Recent studies show that thiazolidinones have a wide range of pharmacological properties including antimicrobial, anti-inflammatory, anti-oxidant and anti-tumor. Here, we investigate the effect antiglioma in vitro of a panel of sixteen synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones where 13 of these decreased the viability of glioma cells 30-65% (100 µM) compared with controls. The most promising compounds such as 4d, 4l, 4m and 4p promoted glioma reduction of viability greater than 50%, were further tested at lower concentrations (12.5, 25, 50 and 100 µM). Also, the data showed that the compounds 4d, 4l, 4m and 4p induced cell death primarily through necrosis and late apoptosis mechanisms. Interestingly, none of these 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones were cytotoxic for primary astrocytes, which were used as a non-transformed cell model, indicating selectivity. Our results also show that the treatment with sub-therapeutic doses of 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones (4d, 4l and 4p) reduced in vivo glioma growth as well as malignant characteristics of implanted tumors such as intratumoral hemorrhage and peripheral pseudopalisading. Importantly, 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones treatment did not induce mortality or peripheral damage to animals. Finally, 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones also changed the nitric oxide metabolism which may be associated with reduced growth and malignity characteristics of gliomas. These data indicates for the first time the therapeutic potential of synthetic 2-aryl-3-((piperidin-1-yl)ethyl)thiazolidin-4-ones to GBM treatment.

Stem cell therapy in intracerebral hemorrhage rat model.

Intracerebral hemorrhage (ICH) is a very complex pathology, with many different not fully elucidated etiologies and prognostics. It is the most severe subtype of stroke, with high mortality and morbidity rates. Unfortunately, despite the numerous promising preclinical assays including neuroprotective, anti-hypertensive, and anti-inflammatory drugs, to this moment only symptomatic treatments are available, motivating the search for new alternatives. In this context, stem cell therapy emerged as a promising tool. However, more than a decade has passed, and there is still much to be learned not only about stem cells, but also about ICH itself, and how these two pieces come together. To date, rats have been the most widely used animal model in this research field, and there is much more to be learned from and about them. In this review, we first summarize ICH epidemiology, risk factors, and pathophysiology. We then present different methods utilized to induce ICH in rats, and examine how accurately they represent the human disease. Next, we discuss the different types of stem cells used in previous ICH studies, also taking into account the tested transplantation sites. Finally, we summarize what has been achieved in assays with stem cells in rat models of ICH, and point out some relevant issues where attention must be given in future efforts.

Ketoprofen-loaded polymeric nanocapsules selectively inhibit cancer cell growth in vitro and in preclinical model of glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the worst and most common brain tumor, characterized by high proliferation and invasion rates. Nanoparticles of biodegradable polymers for anticancer drug delivery have attracted interest in recent years since they provide targeted delivery and may overcame the obstacle imposed by blood-brain barrier. Here we investigated the antitumoral effect of ketoprofen-loaded nanocapsules (Keto-NC) treatment on in vitro and in vivo glioma progression. We observed that Keto-NC treatment decreased selectively the cell viability of a panel of glioma cell lines, while did not exhibited toxicity to astrocytes. We further demonstrate that the treatment with sub-therapeutic dose of Keto-NC reduced the in vivo glioma growth as well as reduced the malignity characteristics of implanted tumors. Keto-NC treatment improved the weight, the locomotion/exploration behavior of glioma-bearing rats. Importantly, Keto-NC treatment neither induced mortality or peripheral damage. Finally, Ketoprofen also altered the extracellular nucleotide metabolism of peripheral lymphocytes, suggesting that antiinflammatory effects of ketoprofen could also be associated with the modulation of the adenine nucleotide metabolism in lymphocytes. Data indicate at first time the potential of Keto-NC as a promising therapeutic alterative to GBM treatment.

Beta-amyloid peptide toxicity in organotypic hippocampal slice culture involves Akt/PKB, GSK-3beta, and PTEN.

In the present study we investigated the toxicity induced by exposing organotypic slice culture to beta-amyloid peptide 25-35 (25microM) for 1, 3, 6, 12, 24 and 48h. To elucidate a mechanism involved in its toxicity, we studied the PI3-K cell signaling pathway, particularly Akt/PKB, GSK-3beta, and PTEN proteins. Cell death was quantified by propidium iodide uptake and proteins were analyzed by immunoblotting. Our results showed a significant cell death after 48h of beta-amyloid 25-35 peptide exposition. The exposition of cultures to beta-amyloid peptide resulted in an increase in the phosphorylation state of Akt and GSK-3beta proteins after 6h, followed by a decrease of the phosphorylation state of these proteins after 12h of exposition. However, after 24h of peptide treatment, the phosphorylation of GSK-3beta presented a new increase while the phosphorylation of Akt remained down. The immunocontent of the PTEN protein, an indirect Akt phosphatase, increased after 24 and 48h of beta-amyloid exposition. These results suggest an involvement of Akt dephosphorylation/inactivation in the toxicity induced by the beta-amyloid 25-35 peptide in organotypic slice hippocampal culture, probably induced by increasing PTEN immunocontent. Taken together, our results provide more information about the molecular mechanisms involved on beta-amyloid peptide toxicity.

Extracellular inosine modulates ERK 1/2 and p38 phosphorylation in cultured Sertoli cells: possible participation in TNF-alpha modulation of ERK 1/2.

Extracellular ATP and adenosine modulation of MAPKs is well described in different cells types, but few studies have addressed the effects of extracellular inosine on these kinases. Previous results showed that hydrogen peroxide and TNF-alpha increase extracellular inosine concentration in cultured Sertoli cells and this nucleoside protects Sertoli cells against hydrogen peroxide induced damage and participates in TNF-alpha induced nitric oxide production. In view of the fact that MAPKs are key mediators of the cellular response to a large variety of stimuli, we investigated the effect of extracellular inosine on the phosphorylation of ERK 1/2 and p38 MAPKs in cultured Sertoli cells. The involvement of this nucleoside in the activation of ERK 1/2 by TNF-alpha was also investigated. Inosine and the selective A1 adenosine receptor agonist R-PIA increases the phosphorylation of ERK 1/2 and p38, and this was blocked by the selective A1 adenosine receptors antagonists, CPT and DPCPX. These antagonists also inhibited TNF-alpha increase in the phosphorylation of ERK 1/2. TNF-alpha also rapidly augmented extracellular inosine concentration in cultured Sertoli cells. These results show that extracellular inosine modulates ERK 1/2 and p38 in cultured Sertoli cells, possible trough A1 adenosine receptor activation. This nucleoside also participates in TNF-alpha modulation of ERK 1/2.

Extracellular nucleotides and nucleosides induce proliferation and increase nucleoside transport in human glioma cell lines.

Extracellular purines (adenosine triphosphate (ATP), adenosine 5'-diphosphate (ADP) and adenosine) and pyrimidines (uridine 5'-triphosphate (UTP) and UDP) are important signaling molecules that mediate diverse biological effects via P1 and P2 purinergic receptors. The human glioma cell lines U87 MG, U251 MG and U138 MG were treated with purines and pyrimidines for 24 or 48 h and proliferation was measured by [3H]-thymidine incorporation, flow cytometry and cell counting. The studies showed that extracellular nucleotides and nucleosides induce proliferation of the studied glioma cells. Incorporation of [3H]-thymidine followed the order of ATP approximately equal to guanosine approximately equal to inosine approximately equal to adenosine > UTP > ADP while ATPgammaS and 2MeSATP had no effect. The effect of ATP was partially inhibited by suramin and by reactive blue 2 (RB2). Co-treatment with the following antagonists of P1 purinoreceptors DPCPX, CPT or 8PT did not block the effect of adenosine while a specific antagonist of the A3 receptor, MRS1220, totally blocked the effect of adenosine. ATP and adenosine also increased the overall uptake of [3H]-thymidine into the cell, producing a positive effect on the [3H]-thymidine incorporation measurements. These data indicate that the uptake of thymidine and proliferation of gliomas can be induced by purines and pyrimidines via both P1 and P2 purinoceptors.