The antiepileptic activity of JSTX-3 is mediated by N-methyl-D-aspartate receptors in human hippocampal neurons

We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced by perfusion of human hippocampal slices with artificial cerebrospinal fluid lacking Mg2+ or N-methyl-D-aspartate. Hippocampi were surgically removed from patients with refractory medial temporal lobe epilepsy, sliced in the surgical room and taken to the laboratory immersed in normal artificial cerebrospinal fluid. Epileptiform activity was induced by perfusion with Mg2+-free artificial cerebrospinal fluid or by iontophoretically applied N-methyl-D-aspartate and intracellular and field recordings of CAI neurons were performed. The ictal-like discharges induced by Mg2+-free artificial cerebrospinal fluid and N-methyl-D-aspartate were blocked by incubation with JSTX-3. This effect was similar to that obtained with the N-methyl-D-aspartate receptor antagonist DL(-)2-amino-5 phosphonovaleric acid. Our findings suggest that in human hippocampal neurons, the antiepileptic effect of JSTX-3 is mediated by its action on N-methyl-D-aspartate receptor

Chemical constituents and pharmacological profile of Gunnera manicata L. extracts

Gunnera perpensa L. (Gunneraceae) is a native South African plant widely used in traditional medicine as an antibacterial and antifungal. In southern Brazil there is the native species called Gunnera manicata L. that also belongs to the Gunneraceae. Nevertheless, there is no information about chemical and pharmacological properties of South American Gunnera species. Therefore this study aimed at assessing the phytochemical and pharmacological profiles of aqueous and methanol Brazilian G. manicata extracts. The results showed that antimicrobial activity in an agar diffusion assay was effective against Staphylococcus aureus and Candida albicans . Phenolic compounds were investigated by liquid chromatography coupled with a tandem mass spectrometer (LC-MS/MS) and all extracts presented gallic acid and only the methanol extract obtained from the leaves exhibited hyperoside. Rutin, quercetin and chlorogenic acid were not found in the samples analysed. Total phenolic content was higher in methanol extract and total flavonoid content was low in all extracts. Antioxidant activity was evaluated by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical test, and all samples presented good to moderate antioxidant activity. These results encourage complementary studies on the chemical composition of the plant extracts focusing on isolation and structure elucidation of their active compounds

Relationship between insulin-like growth factor I, dehydroepiandrosterone sulfate and proresorptive cytokines and bone density in cystic fibrosis.

INTRODUCTION: Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA) and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1beta, tumor necrosis factor alpha, and interleukin-6. METHODS: We studied 32 outpatients (18 females; mean age: 26.2+/-7.9 years) at a tertiary care medical center. The subjects had venous samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse correlation between IL-1beta and BMD at all sites. RESULTS: In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD. CONCLUSIONS: These findings may have therapeutic implications for enhancing bone density in these patients