Novel Hybrid Acetylcholinesterase Inhibitors Induce Differentiation and Neuritogenesis in Neuronal Cells in vitro Through Activation of the AKT Pathway.

BACKGROUND: Alzheimer's disease (AD) is characterized by a progressive loss of episodic memory associated with amyloid-ß peptide aggregation and the abnormal phosphorylation of the tau protein, leading to the loss of cholinergic function. Acetylcholinesterase (AChE) inhibitors are the main class of drugs used in AD therapy. OBJECTIVE: The aim of the current study was to evaluate the potential of two tacrine-donepezil hybrid molecules (TA8Amino and TAHB3), which are AChE inhibitors, to induce neurodifferentiation and neuritogenesis in SH-SY5Y cells. METHODS: The experiments were carried out to characterize neurodifferentiation, cellular changes related to responses to oxidative stress and pathways of cell survival in response to drug treatments. RESULTS: The results indicated that the compounds did not present cytotoxic effects in SH-SY5Y or HepG2 cells. TA8Amino and TAHB3 induced neurodifferentiation and neuritogenesis in SH-SY5Y cells. These cells showed increased levels of intracellular and mitochondrial reactive oxygen species; the induction of oxidative stress was also demonstrated by an increase in SOD1 expression in TA8Amino and TAHB3-treated cells. Cells treated with the compounds showed an increase in PTEN(Ser380/Thr382/383) and AKT(Ser473) expression, suggesting the involvement of the AKT pathway. CONCLUSION: Our results demonstrated that TA8Amino and TAHB3 present advantages as potential drugs for AD therapy and that they are capable of inducing neurodifferentiation and neuritogenesis.

Potential Triazole-based Molecules for the Treatment of Neglected Diseases.

Neglected Diseases (NDs) affect million of people, especially the poorest population around the world. Several efforts to an effective treatment have proved insufficient at the moment. In this context, triazole derivatives have shown great relevance in medicinal chemistry due to a wide range of biological activities. This review aims to describe some of the most relevant and recent research focused on 1,2,3- and 1,2,4-triazolebased molecules targeting four expressive NDs: Chagas disease, Malaria, Tuberculosis and Leishmaniasis.

Evaluation of limonoid production in suspension cell culture of Citrus sinensis

ABSTRACTThe use of cell and plant tissue culture techniques to produce economically important active metabolites has been growing. Among these substances are total limonoid aglycones, which are produced by "pera" orange (Citrus sinensis (L.) Osbeck, Rutaceae) and have received considerable attention because of their anticancer actions. The main objective of the present study was to analyze and compare the levels of limonoid aglycones in seeds, callus cultures (originating from seeds), callus cultures (originating from hypocotyls), cell suspensions from hypocotyls cells, and cell suspensions from cotyledons. The cell cultures or C. sinensis were obtained by inoculating two strains of callus in MS medium supplemented with 2.0 µM 2,4-dichlorophenoxyacetic acid, 7.0 µM benzyl aminopurine, and 3% (w/v) sucrose in the dark. The highest concentrations of limonoid aglycone that were obtained were observed in cotyledon cell lines (240 mg/100 g dry weight) that were produced on day 21 of culture and hypocotyl cell lines on day 7 (210 mg/100 g dry weight). Explants of different origins under the same culture conditions had different limonoid aglycone content. The present results may suggest strategies for enhancing the productivity of biologically important limonoid aglycones and investigating the complex pathways of these secondary metabolites in plant tissue cultures.

Anti-leishmanial activity of alkaloidal extracts obtained from different organs of Aspidosperma ramiflorum.

The present study was designated to evaluate semi-quantitative antileishmanial activity of alkaloidal extracts that were obtained from 1g of different parts of Aspidosperma ramiflorum (leaves, roots, seeds, and stem barks). Alkaloidal extracts of barks and leaves presented a good activity against the extracellular form (promastigotes) of Leishmania (L.) amazonensis. It is known that compounds responsible for the antileishmanial activity in the alkaloidal extracts from A. ramiflorum are the monoterpenoid indole alkaloids ramiflorine A and ramiflorine B, therefore extracts obtained from different plant parts were analyzed by electrospray ionization mass spectrometry (ESI-MS) in order to evidence the presence of these bioactive alkaloids. Based on these findings, alkaloidal extract from leaves was fractionated on preparative thin-layer chromatography in a bioassay-guided fractionation affording individual purified ramiflorines A and B. Both ramiflorines A and B showed significant activity against Leishmania (L.) amazonensis (LD(50) values of 18.5±6.5µg/ml and 12.63±5.52µg/ml, respectively). Our results are showing that alkaloidal extract from leaves is a promising alternative to the use of stem barks from A. ramiflorum.

Structure and degree of polymerisation of fructooligosaccharides present in roots and leaves of Stevia rebaudiana (Bert.) Bertoni.

Fructooligosaccharides have been isolated from roots and leaves of Stevia rebaudiana, by hot aqueous extraction, followed by precipitation with ethanol. Their structure has been determined using methylation and NMR analysis, MALDI-TOF, and ESI-MS. Fructooligosaccharides contained almost exclusively (2→1)-linked ß-fructofuranosyl, with terminal α-glucopyranosyl and ß-fructofuranosyl units. MALDI-TOF and ESI-MS analyses showed the wide range of degree of polymerisation (DP) present in various extracts. From roots and leaves, three different fractions gave profiles of homologous series, with DPs ranging up to 17 with MALDI-TOF and 19 using ESI-MS. These inulin-type fructooligosaccharides were the major component of extracts from S. rebaudiana roots and significant components from the leaves.