Search

Aspidosperma macrocarpon Mart., popularly known as ‘guatambu’ or ‘peroba’, is found from North American (Mexico) to South American (Argentina) continents and in Brazil. Two indole alkaloids were isolated from leaves of A. macrocarpon, kopsanone (1) and unreported N(4)-oxide-kopsanone (2).

Ubiquitin conjugation to histone lysines regulates diverse processes such as gene silencing, transcriptional elongation, and DNA repair. Combining an avidity-based design strategy with molecular dynamics simulations, dos Santos Passos et al. develop genetically encoded sensors for H2AK13/15 or H2BK120 ubiquitinated nucleosomes and use them in live cells to monitor ubiquitin-dependent signaling., Histone posttranslational modifications (PTMs) are dynamic, context-dependent signals that modulate chromatin structure and function. Ubiquitin (Ub) conjugation to different lysines of histones H2A and H2B is used to regulate diverse processes such as gene silencing, transcriptional elongation, and DNA repair. Despite considerable progress made to elucidate the players and mechanisms involved in histone ubiquitination, there remains a lack of tools to monitor these PTMs, especially in live cells. To address this, we combined an avidity-based strategy with in silico approaches to design sensors for specifically ubiquitinated nucleosomes. By linking Ub-binding domains to nucleosome-binding peptides, we engineered proteins that target H2AK13/15Ub and H2BK120Ub with Kd values from 10−8 to 10−6 M; when fused to fluorescent proteins, they work as PTM sensors in cells. The H2AK13/15Ub-specific sensor, employed to monitor signaling from endogenous DNA damage through the cell cycle, identified and differentiated roles for 53BP1 and BARD1 as mediators of this histone PTM.

The essential oils (EOs) obtained from Peperomia tetraphylla (PT), P. pereskiifolia (PP), and P. glabella (PG), were evaluated in MAO-A and -B in vitro inhibitory assays. The oils demonstrated IC50...

In recent years, the role of HDAC6 in neurodegeneration has been partially elucidated, which led some authors to propose HDAC6 inhibitors as a therapeutic strategy to treat neurodegenerative diseases. In an effort to develop a selective HDAC6 inhibitor which can cross the blood brain barrier (BBB), a modified hydroxamate derivative (compound 3) was designed and synthetized. This compound was predicted to have potential for BBB penetration based on in silico and in vitro evaluation of passive permeability. When tested for its HDAC inhibitory activity, the IC50 value of compound 3 towards HDAC6 was in the nM range in both enzymatic and cell-based assays. Compound 3 showed a cell-based selectivity profile close to that of tubastatin A in SH-SY5Y human neuroblastoma cells, and a good BBB permeability profile.

Sirtuins (SIRTs) are a family of enzymes able to catalyze the deacetylation of the N-acetyl lysines of both histone and non-histone substrates. Inhibition of SIRTs catalytic activity was recently reported in the literature as being beneficial in human diseases, with very promising applications in cancer therapy and enzymatic neurodegeneration. By combining a structure-based virtual screening of the Specs database with cell-based assays, we identified the 5-benzylidene-hydantoin as new scaffold for the inhibition of SIRT2 catalytic activity. Compound 97 (Specs ID AH-487/41657829), active in the low μM range against SIRT2, showed the optimal physicochemical properties for passive absorption as well as relatively low cytotoxicity in vitro. Further studies revealed non-competitive and mixed-type kinetics toward acetyl-lysine substrates and NAD(+), respectively, and a non-selective profile for SIRT inhibition. A binding mode consistent with the experimental evidence was proposed by molecular modeling. Additionally, the levels of acetyl-p53 were shown to be increased in HeLa cells treated with 97. Taken together, these results encourage further investigation of 5-benzylidene-hydantoin derivatives for their SIRT-related therapeutic effects.

In the present study, the effects were evaluated of alkaloid fractions (AFs) from Psychotria species and correlated genera, Palicourea and Rudgea, on monoamine oxidases (MAOs) and cholinesterases (ChEs). By HPLC-DAD and UPLC-DAD-MS analyses, indole alkaloids (IA) were detected in all AFs. For the Psychotria and Palicourea species, these IA corresponded to tetrahydro-β-carboline alkaloids (THβCA). On the other hand, pyrrolidinoindoline core compounds were observed for Rudgea species. Regarding their pharmacological activities, none of the AFs was able to inhibit AChE. However, the BChE activity was impaired by the Psychotria and Palicourea AFs. In addition, MAO-A was inhibited by both AFs, but only Psychotria nemorosa AF was able to inhibit significantly MAO-B. Rudgea AFs demonstrated a poor inhibitory profile on MAO-A. Taken together, our results highlighted the Psychotria and Palicourea genera as important sources of scaffolds for the development of MAO-A and BChE inhibitors aiming at the treatment of neurodegenerative and neuropsychiatric diseases.

Monoamine oxidase (MAO) inhibitors are used in the treatment of depression, anxiety disorders, and the symptomatic treatment of Parkinson's disease. Eryngium, the most representative of the Apiaceae family, is well known for the presence of essential oils (EOs), which have already demonstrated MAO inhibitory potential.The objective of this study is to evaluate the MAO inhibitory capacity of the EOs obtained from Eryngium floribundum Cham.Schlecht. (EF), E. eriophorum Cham.Schlecht. (EE), E. nudicaule Lam. (EN), E. horridum Malme (EH), and E. pandanifolium Cham.Schlecht. (EP).EOs were obtained from fresh whole plants by hydrodistillation (3 h). Chemical analyses were performed by GC/MS using apolar and polar columns, with oven temperature from 60 to 300 °C at 3 °C/min. The MAO-A and -B activities were evaluated in vitro by an end-point method using kynuramine as the substrate and mitochondrial suspension or human recombinant enzymes as the enzymatic source. DMSO 2%, clorgyline 10(-7) M, and pargyline 10(-6) M were used as controls.EFEO, EEEO, ENEO, EHEO, and EPEO GC/MS analysis showed (E)-caryophyllene (4.9-10.8%), germacrene D (0.6-35.1%), bicyclogermacrene (10.4-17.2), spathulenol (0.4-36.0%), and globulol (1.4-18.6%) as main constituents. None of the EOs inhibited MAO-A activity (4 and 40 μg/mL). However, EHEO inhibited MAO-B activity with an IC50 value of 5.65 μg/mL (1-200 μg/mL). Pentadecane (10 μM), its major constituent (53.5%), did not display significant MAO-B inhibition.The study demonstrates the promising application of Eryngium species as a source of potential central nervous system bioactive secondary metabolites, specially related to neurodegenerative disorders.

Hemp seed is known for its content of fatty acids, proteins, and fiber, which contribute to its nutritional value. Here we studied the secondary metabolites of hemp seed aiming at identifying bioactive compounds that could contribute to its health benefits. This investigation led to the isolation of 4 new lignanamides, cannabisin M (2), cannabisin N (5), cannabisin O (8), and 3,3'-demethyl-heliotropamide (10), together with 10 known lignanamides, among which 4 was identified for the first time from hemp seed. Structures were established on the basis of NMR, HR-MS, UV, and IR as well as by comparison with the literature data. Lignanamides 2, 7, and 9-14 showed good antioxidant activity, among which 7, 10, and 13 also inhibited acetylcholinesterase in vitro. The newly identified compounds in this study add to the diversity of hemp seed composition, and the bioassays implied that hemp seed, with lignanamides as nutrients, may be a good source of bioactive and protective compounds.

Z-Vallesiachotamine is a monoterpene indole alkaloid that has a β-N-acrylate group in its structure. This class of compounds has already been described in different Psychotria species. Our research group observed that E/Z-vallesiachotamine exhibits a multifunctional feature, being able to inhibit targets related to neurodegeneration, such as monoamine oxidase A, sirtuins 1 and 2, and butyrylcholinesterase enzymes. Aiming at better characterizing the multifunctional profile of this compound, its effect on cathecol-O-methyltransferase activity was investigated. The cathecol-O-methyltransferase activity was evaluated in vitro by a fluorescence-based method, using S-(5′-adenosyl)-l-methionine as methyl donor and aesculetin as substrate. The assay optimization was performed varying the concentrations of methyl donor (S-(5′-adenosyl)-l-methionine) and enzyme. It was observed that the highest concentrations of both factors (2.25 U of the enzyme and 100 μM of S-(5′-adenosyl)-l-methionine) afforded the more reproducible results. The in vitro assay demonstrated that Z-vallesiachotamine was able to inhibit the cathecol-O-methyltransferase activity with an IC50 close to 200 μM. Molecular docking studies indicated that Z-vallesiachotamine can bind the catechol pocket of catechol-O-methyltransferase enzyme. The present work demonstrated for the first time the inhibitory properties of Z-vallesiachotamine on cathecol-O-methyltransferase enzyme, affording additional evidence regarding its multifunctional effects in targets related to neurodegenerative diseases. Keywords: Monoterpene indole alkaloids, Vallesiachotamine, Catechol-O-methyltransferase, Docking, Neurodegenerative diseases

Phytochemical investigation of the alkaloid extract of Palicourea sessilis by LC-HRMS/MS using molecular networking and an in silico MS/MS fragmentation approach suggested the presence of several new monoterpene indole alkaloids. These compounds were isolated by semipreparative HPLC, and their structures confirmed by means of HRMS, NMR, and ECD measurements as 4-N-methyllyaloside (3), 4-N-methyl-3,4-dehydrostrictosidine (4), 4β-hydroxyisodolichantoside (6), and 4α-hydroxyisodolichantoside (7), as well as the known alkaloids alline (1), N-methyltryptamine (2), isodolichantoside (5), and 5-oxodolichantoside (8). In addition, the acetylcholinesterase inhibitory activity of the compounds was evaluated up to 50 μM.

Histone deacetylase 6 (HDAC6) is a cytoplasmic HDAC isoform able to remove acetyl groups from cellular substrates such as α-tubulin. In addition to the two deacetylase domains, HDAC6 has a C-terminal zinc-finger ubiquitin (Ub)-binding domain (ZnF-UBP) able to recognize free Ub. HDAC6-Ub interaction is thought to function in regulating the elimination of misfolded proteins during stress response through the aggresome pathway. Small molecules inhibiting deacetylation by HDAC6 were shown to reduce aggresomes, but the interplay between HDAC6 catalytic activity and Ub-binding function is not fully understood. Here we describe two methods to measure the HDAC6-Ub interaction in vitro using full-length HDAC6. Both methods were effective for screening inhibitors of the HDAC6-Ub protein-protein interaction independently of the catalytic activity. Our results suggest a potential role for the HDAC6 deacetylase domains in modulating HDAC6-Ub interaction. This new aspect of HDAC6 regulation can be targeted to address the roles of HDAC6-Ub interaction in normal and disease conditions.

Indole alkaloids and synthetic indole derivatives are well known for their therapeutic importance. In fact, preclinical and clinical studies had already demonstrated several pharmacological activities for these compounds. Here, we overview the multifunctional potential of these molecules for the inhibition of enzymes related to neurodegenerative disease: acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidases A and B (MAO-A and MAO-B). A focus will be given on Psychotria L. genus, considering its reported central effects. Finally, three Psychotria alkaloids, namely desoxycordiofoline (61), bahienoside A (64) and bufotenine (65), along with the synthetic indole derivatives (5S)- 5-(1H-indol-3-ylmethyl)imidazolidine-2,4-dione (66), 5-(1H-indol-3-ylmethyl)-2-thioxoimidazolin-4-one (67), 5-(1Hindol- 3-ylmethyl)-3-methyl-2-thioxoimidazolidin-4-one (68), and methyl 2-(aminoN-(2-(4-methylcyclohex-3-enyl)propan- 2-yl)methanethioamino)-3-(1H-indol-3-yl)propanoate (69), were evaluated in vitro regarding their interactions with AChE, BChE, MAO-A and MAO-B. It was observed that 66 and 68 were able to inhibit MAO-A activity with IC 50 value of 8.23 and 0.07 μM. Molecular docking calculations were performed in order to understand the interactions between both ligands (66 and 68) and MAO-A. It was observed that the indole scaffold of both compounds bind into the MAO-A active site in the same orientation, establishing van der Waals contacts with lipophilic amino acids. Additionally, the hydantoin ring of 66 is able to interact by hydrogen bonds with two conserved water molecules in the MAO-A active site, while the methyl-thiohydantoin ring of 68 is within hydrogen bond distance from the hydrogen atom attached to the (N-5) of FAD cofactor. Taking together, our findings demonstrate that the indolyl-hydantoin and indolylmethyl-thiohydantoin rings might consists of good scaffolds for the development of new MAO-A inhibitors possessing neuroprotective properties.

Flavonoids are compounds responsible for several organoleptic characteristics of plant-derived foods. They are also bioactive compounds with antiinflammatory role. Different mechanisms for this activity have been reported, but their effects on cell migration are not fully understood. In the present study, the role of flavonoids on leukocyte migration in vivo was investigated, using the carrageenan-induced pleurisy model and intravital microscopy in rats. It was found that quercetin (1), rutin (2), flavone (5), apigenin (6) and flavonol (7) reduced cell migration to the pleural cavity and inhibited rolling, adhesion and transmigration. Additionally, flow cytometry assays showed that the in vitro treatment with all compounds (15–60 µm) did not cause cell death and 1 inhibited the cleavage of L-selectin and the β2-integrin expression, whereas 2 and 7 only inhibited the β2-integrin expression. Together, data herein presented clearly show the ability of flavonoids to inhibit in vivo neutrophil influx into inflamed tissue, by acting in different mechanisms of neutrophil migration. Copyright © 2014 John Wiley & Sons, Ltd.

Objectives The inhibition of acetylcholinesterase (AChE), the key enzyme in the breakdown of acetylcholine, is currently the main pharmacological strategy available for Alzheimer's disease (AD). In this sense, many alkaloids isolated from natural sources, such as physostigmine, have been long recognized as acetyl- and butyrylcholinesterase (BChE) inhibitors. Since the approval of galantamine for the treatment of AD patients, the search for new anticholinesterase alkaloids has escalated, leading to promising candidates such as huperzine A. This review aims to summarize recent advances in current knowledge on alkaloids as AChE and BChE inhibitors, highlighting structure–activity relationship (SAR) and docking studies. Key findings Natural alkaloids belonging to the steroidal/triterpenoidal, quinolizidine, isoquinoline and indole classes, mainly distributed within Buxaceae, Amaryllidaceae and Lycopodiaceae, are considered important sources of alkaloids with anti-enzymatic properties. Investigations into the possible SARs for some active compounds are based on molecular modelling studies, predicting the mode of interaction of the molecules with amino acid residues in the active site of the enzymes. Following this view, an increasing interest in achieving more potent and effective analogues makes alkaloids good chemical templates for the development of new cholinesterase inhibitors. Summary The anticholinesterase activity of alkaloids, together with their structural diversity and physicochemical properties, makes them good candidate agents for the treatment of AD.

The human histone deacetylase isoform 6 (HDAC6) has been demonstrated to play a major role in cell motility and aggresome formation, being interesting for the treatment of multiple tumour types and neurodegenerative conditions. Currently, most HDAC inhibitors in preclinical or clinical evaluations are non-selective inhibitors, characterised by a hydroxamate zinc-binding group (ZBG) showing off-target effects and mutagenicity. The identification of selective HDAC6 inhibitors with novel chemical properties has not been successful yet, also because of the absence of crystallographic information that makes the rational design of HDAC6 selective inhibitors difficult. Using HDAC inhibitory data retrieved from the ChEMBL database and ligand-based computational strategies, we identified 8 original new non-hydroxamate HDAC6 inhibitors from the SPECS database, with activity in the low μM range. The most potent and selective compound, bearing a hydrazide ZBG, was shown to increase tubulin acetylation in human cells. No effects on histone H4 acetylation were observed. To the best of our knowledge, this is the first report of an HDAC6 selective inhibitor bearing a hydrazide ZBG. Its capability to passively cross the blood-brain barrier (BBB), as observed through PAMPA assays and its low cytotoxicity in vitro, suggested its potential for drug development.

Alkaloid fractions of Psychotria suterella (SAE) and Psychotria laciniata (LAE) as well as two monoterpene indole alkaloids (MIAs) isolated from these fractions were evaluated against monoamine oxidases (MAO-A and -B) obtained from rat brain mitochondria. SAE and LAE were analysed by HPLC-PDA and UHPLC/HR-TOF-MS leading to the identification of the compounds 1, 2, 3 and 4, whose identity was confirmed by NMR analyses. Furthermore, SAE and LAE were submitted to the enzymatic assays, showing a strong activity against MAO-A, characterized by IC(50) values of 1.37 ± 1.05 and 2.02 ± 1.08 μg/mL, respectively. Both extracts were also able to inhibit MAO-B, but in higher concentrations. In a next step, SAE and LAE were fractionated by RP-MPLC affording three and four major fractions, respectively. The RP-MPLC fractions were subsequently tested against MAO-A and -B. The RP-MPLC fractions SAE-F3 and LAE-F4 displayed a strong inhibition against MAO-A with IC(50) values of 0.57 ± 1.12 and 1.05 ± 1.15 μg/mL, respectively. The MIAs 1 and 2 also inhibited MAO-A (IC(50) of 50.04 ± 1.09 and 132.5 ± 1.33 μg/mL, respectively) and -B (IC(50) of 306.6 ± 1.40 and 162.8 ± 1.26 μg/mL, respectively), but in higher concentrations when compared with the fractions. This is the first work describing the effects of MIAs found in neotropical species of Psychotria on MAO activity. The results suggest that species belonging to this genus could consist of an interesting source in the search for new MAO inhibitors.

A monoterpene indole alkaloid, psychollatine ( 1), was isolated from Psychotria umbellata leaves. Its structure was characterized by interpretation of spectroscopic data and by comparison of its NMR data with those of croceaine A ( 2) from Palicourea crocea. The configuration of psychollatine ( 1) was established by NOE difference and circular dichroism (CD) techniques, while its conformation was evaluated through molecular modeling studies and NMR coupling constants.

HDAC6 is a unique cytoplasmic histone deacetylase characterized by two deacetylase domains, and by a zinc-finger ubiquitin binding domain (ZnF-UBP) able to recognize ubiquitin (Ub). The latter has recently been demonstrated to be involved in the progression of neurodegenerative diseases and in mediating infection by the influenza A virus. Nowadays, understanding the dynamic and energetic features of HDAC6 ZnF-UBP-Ub recognition is considered as a crucial step for the conception of HDAC6 potential modulators. In this study, the atomic, solvent-related, and thermodynamic features behind HDAC6 ZnF-UBP-Ub recognition have been analyzed through molecular dynamics simulations. The behavior was then compared to the prototypical ZnF-UBP from ubiquitin-specific protease 5 (USP5) in order to spot relevant differences useful for selective drug design. Principal component analysis highlighted flapping motions of the L2A loop which were lowered down upon Ub binding in both systems. While polar and nonpolar interactions involving Ub G75 and G76 residues were also common features stabilizing both complexes, salt bridges showed a different pattern, more significant in HDAC6 ZnF-UBP-Ub, whose energetic contribution in USP5 ZnF-UBP-Ub was compensated by the presence of a more stable bridging water molecule. Whereas molecular mechanics/Poisson-Boltzmann surface area (MM-PBSA) free energies of binding were comparable for both systems, in agreement with experiments, computational alanine scanning and free energy decomposition data revealed that HDAC6 E1141 and D1178 are potential hotspots for the design of selective HDAC6 modulators.

The multifactorial nature of Alzheimer's disease calls for the development of multitarget agents addressing key pathogenic processes. To this end, by following a docking-assisted hybridization strategy, a number of aminocoumarins were designed, prepared, and tested as monoamine oxidases (MAOs) and acetyl- and butyryl-cholinesterase (AChE and BChE) inhibitors. Highly flexible N-benzyl-N-alkyloxy coumarins 2-12 showed good inhibitory activities at MAO-B, AChE, and BChE but low selectivity. More rigid inhibitors, bearing meta- and para-xylyl linkers, displayed good inhibitory activities and high MAO-B selectivity. Compounds 21, 24, 37, and 39, the last two featuring an improved hydrophilic/lipophilic balance, exhibited excellent activity profiles with nanomolar inhibitory potency toward hMAO-B, high hMAO-B over hMAO-A selectivity and submicromolar potency at hAChE. Cell-based assays of BBB permeation, neurotoxicity, and neuroprotection supported the potential of compound 37 as a BBB-permeant neuroprotective agent against H2O2-induced oxidative stress with poor interaction as P-gp substrate and very low cytotoxicity.

Garcinia gardneriana is chemically characterized by the presence of biflavonoids. Taking into account that flavonoids are able to inhibit monoamine oxidase (MAO) activity, in the present study, the chemical composition of the branches’ extract of the plant is described for the first time and the MAO inhibitory activity of the isolated biflavonoids was evaluated. Based on spectroscopic and spectrometric data, it was possible to identify volkesiflavone, morelloflavone (1), Gb-2a (2) and Gb-2a-7- O-glucoside (3) in the ethyl acetate fraction from ethanol extract of the branches. Compounds 1-3 were evaluated in vitro and demonstrated the capacity to inhibit MAO-A activity with an IC50 ranging from 5.05 to 10.7 μM, and from 20.7 to 66.2 μM for MAO-B. These inhibitions corroborate with previous IC50 obtained for monomeric flavonoids, with a higher selectivity for MAO-A isoform. The obtained results indicate that biflavonoids might be promising structures for the identification of new MAO inhibitory compounds.

Epigenetic enzymes such as histone deacetylases play a crucial role in the development of ageing-related diseases. Among the 18 histone deacetylase isoforms found in humans, class III histone deacetylases, also known as sirtuins, seem to be promising targets for treating neurodegenerative conditions. Recently, Psychotria alkaloids, mainly monoterpene indoles, have been reported for their inhibitory properties against central nervous system cholinesterase and monoamine oxidase proteins. Given the multifunctional profile of these alkaloids in the central nervous system, and the fact that the indole scaffold has been previously associated with sirtuin inhibition, we hypothesized that these indole derivatives could also interact with sirtuins. In the present study, alkaloids previously isolated from Psychotria spp. were evaluated for their potential interaction with human sirtuin 1 and sirtuin 2 by molecular docking and molecular dynamics simulation approaches. The in silico results allowed for the selection of five potentially active compounds, namely, prunifoleine, 14-oxoprunifoleine, E-vallesiachotamine, Z-vallesiachotamine, and vallesiachotamine lactone. The sirtuin inhibition of these compounds was confirmed in vitro in a dose-response manner, with preliminary information on their pharmacokinetics properties.

Strictosidinic acid 10mg/kg, isolated from Psychotria myriantha leaves, were administered intraperitoneally to Wistar male rats (n=5-6). After 60 minutes, striatum was dissected, homogenized and injected onto HPLC-ED chromatographic system. It was observed a 28.7% reduction in the 5-HT levels followed up by an increase of 5-HIAA levels (29.4%). Furthermore there was a decrease of 8.0% in DA levels and an increase in the levels of metabolites DOPAC (21.5%) and HVA (52.5%). The results indicate that strictosidinic acid has a promising effect in the central nervous system, justifying more studies about the central actions of Psychotria compounds.

Alkaloids constitute a huge group of natural products, and some of them have been extensively studied for their activity on targets related to the central nervous system (CNS), especially neurodegenerative diseases and depression. In this context, the inhibition of monoamine oxidases (MAOs) was considered in the search for natural products with promising scaffolds for drug development. Among various classes, indole alkaloids possess biological and pharmacological properties in the CNS, mainly related to the serotonergic and glutamatergic transmission. Those containing a β-carboline moiety, such as harmane, are especially known for their inhibition of MAOs. Another class of alkaloids with a number of studies on the inhibition of MAOs is that of the isoquinoline alkaloids. Chelidonine, a representative of this group, shows specific and irreversible inhibition of MAO-A. The studies conducted so far on the selectivity between MAO-A and -B inhibitors contributed to a better understanding of structure–activity relationship (SAR) for the various classes of alkaloids. One example is desoxypeganine, a quinazoline alkaloid that presents selective inhibition on MAO-A. Due to its specific inhibition, this naturally occurring alkaloid has been clinically investigated for its potential application as an alcohol and smoking cessation aid. On the other hand, quinolone alkaloids presented specific in vitro MAO-B inhibition and are mainly considered for age-related neurodegenerative diseases. Several other examples are given in this chapter that consider selectivity on MAO isoforms and SAR issues of various classes of alkaloids.

Flavonoids are compounds responsible for several organoleptic characteristics of plant-derived foods. They are also bioactive compounds with antiinflammatory role. Different mechanisms for this activity have been reported, but their effects on cell migration are not fully understood. In the present study, the role of flavonoids on leukocyte migration in vivo was investigated, using the carrageenan-induced pleurisy model and intravital microscopy in rats. It was found that quercetin (1), rutin (2), flavone (5), apigenin (6) and flavonol (7) reduced cell migration to the pleural cavity and inhibited rolling, adhesion and transmigration. Additionally, flow cytometry assays showed that the in vitro treatment with all compounds (15-60 µM) did not cause cell death and 1 inhibited the cleavage of L-selectin and the β2-integrin expression, whereas 2 and 7 only inhibited the β2-integrin expression. Together, data herein presented clearly show the ability of flavonoids to inhibit in vivo neutrophil influx into inflamed tissue, by acting in different mechanisms of neutrophil migration.

In the present study, the effects were evaluated of alkaloid fractions (AFs) from Psychotria species and correlated genera, Palicourea and Rudgea, on monoamine oxidases (MAOs) and cholinesterases (ChEs). By HPLC-DAD and UPLC-DAD-MS analyses, indole alkaloids (IA) were detected in all AFs. For the Psychotria and Palicourea species, these IA corresponded to tetrahydro-β-carboline alkaloids (THβCA). On the other hand, pyrrolidinoindoline core compounds were observed for Rudgea species. Regarding their pharmacological activities, none of the AFs was able to inhibit AChE. However, the BChE activity was impaired by the Psychotria and Palicourea AFs. In addition, MAO-A was inhibited by both AFs, but only Psychotria nemorosa AF was able to inhibit significantly MAO-B. Rudgea AFs demonstrated a poor inhibitory profile on MAO-A. Taken together, our results highlighted the Psychotria and Palicourea genera as important sources of scaffolds for the development of MAO-A and BChE inhibitors aiming at the treatment of neurodegenerative and neuropsychiatric diseases.

Ethnopharmacological relevance The study was aimed at evaluating medicinal and therapeutic potentials of two Lycopodiaceae species, Lycopodium clavatum (L.) and Lycopodium thyoides (Humb. & Bonpl. ex Willd), both used in South American folk medicine for central nervous system conditions. Alkaloid extracts were evaluated for chemical characterization, acetylcholinesterase and antioxidant activities. Materials and methods The alkaloid extracts obtained by alkaline extraction were determined for each species by GC/MS examination. The evaluation of the anticholinesterase and the antioxidant activities of the extracts were tested by determining in vitro and ex vivo models. Effects on acetylcholinesterase (AChE) were tested in vitro using rat brain homogenates and ex vivo after a single administration (25, 10 and 1 mg/kg i.p.) of the alkaloid extracts in mice. The in vitro antioxidant effects were tested for the 2-deoxyribose degradation, nitric oxide (NO) interaction, 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity and total reactive antioxidant potential (TRAP). After an acute administration (25 and 10 mg/kg i.p.) of the extracts in middle-aged (12 months) mice, the antioxidant effects were estimated through the thiobarbituric acid reactive substances test (TBARS), and the antioxidant enzymes activities for catalase (CAT) and superoxide dismutase (SOD) were measured. Results AChE activity was inhibited in vitro by the alkaloid-enriched extracts of both Lycopodium species in a dose and time-dependent manner in rat cortex, striatum and hippocampus. A significant inhibition was also observed in areas of the brain after acute administration of extracts, as well as decreased lipid peroxidation and increased CAT activity in the cortex, hippocampus and cerebellum. A moderate antioxidant activity was observed in vitro for the extracts. Chemically, the main alkaloids found for the two species were lycopodine and acetyldihidrolycopodine. Conclusion This study showed that the biological properties of the folk medicinal plants Lycopodium clavatum and Lycopodium thyoides include AChE inhibitory activity and antioxidant effects, two possible mechanisms of action in Alzheimer's related processes. Fil: Konrath, Eduardo Luis. Universidade Federal do Rio Grande do Sul; Brasil Fil: Neves, Bruna Medeiros. Universidade Federal do Rio Grande do Sul. Departamento de Bioquímica; Brasil Fil: Lunardi, Paula Santana. Universidade Federal do Rio Grande do Sul. Departamento de Bioquímica; Brasil Fil: Passos, Carolina Dos Santos. Universidade Federal do Rio Grande do Sul; Brasil Fil: Simões Pires, André. Universidade Federal do Rio Grande do Sul. Departamento de Bioquímica; Brasil Fil: Ortega, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Gonçalves, Carlos Alberto. Universidade Federal do Rio Grande do Sul; Brasil Fil: Cabrera, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Fonseca Moreira, José Cláudio. Universidade Federal do Rio Grande do Sul. Departamento de Bioquímica; Brasil Fil: Henriques, Amélia T.. Universidad Federal do Rio Grande do Sul; Brasil

Os terpenóides constituem um vasto grupo de metabólitos secundários com ações sobre o SNC, destacando-se suas atividades sedativa, ansiolítica, antinociceptiva, anticonvulsivante, pró-convulsivante e alucinógena. Neste trabalho foi realizada uma revisão bibliográfica sobre terpenóides com ações descritas no SNC, enfocando moléculas e sistemas neurotransmissores relacionados com sua atividade. As substâncias abordadas encontram-se divididas em mono, sesqui, di, tri e meroterpenóides e incluem compostos isolados e plantas que apresentam ação principalmente sobre os sistemas neurotransmissores GABAérgico, glutamatérgico, dopaminérgico e opióide. The terpenoids are a large group of secondary metabolites which display many activities in the CNS, such as sedative, ansiolytic, antinociceptive, anticonvulsant, pro-convulsant and hallucinogenic. In this work we performed a research on terpenoids that exert effects on the CNS, focusing molecules and neurotransmitter systems related to their actions. The substances approached were classified as mono, sesqui, di, tri and meroterpenoids and include isolated compounds and plants which exert activities mainly on GABAergic, glutamatergic, dopaminergic and opioid neurotransmitter systems.

Background: Ferns are a group of plants that have been little explored from a chemical and biological perspective but that have interesting potential, occurring in various parts of the world. Objective: This work investigates the chemical profile and the biological effects of ferns from Brazil. Materials and Methods: Analyses were performed using rapid performance liquid chromatography (RP-LC) with a diode array detector (DAD). Extracts were tested for their in vitro antioxidant activity, by the total reactive antioxidant potential method and for their antichemotactic potential, by the Boyden chamber method. Cytotoxic effects were assessed by lactate dehydrogenase levels, while the monoamine oxidase (MAO) assay was carried out using a fluorescence-based method. Results: Different chemical compositions were found for the studied ferns, such as Asplenium gastonis, in which hesperidin was identified in its extract, while A. serra showed the presence of xanthone mangiferin. The most samples with highest antioxidant activity were the Asplenium serra, Lastreopsis amplissima and Cyathea dichromatolepis extracts, at 10 μg/mL. High antichemotactic activity was found for A. serra (94.06%) and Didymochlaena truncatula (93.41%), at 10 μg/mL. The extracts showed no cytotoxicity at the highest concentration. Against MAO-A, D. truncatula (82.61%), Alsophila setosa (82.21%), Cyathea phalerata (74.07%) and C. delgadii (70.32%) were the most active extracts (100 μg/mL). Conclusion: The hypothesis was considered that phenolics and triterpenes are responsible for these pronounced activities.

Psychotria is a complex genus whose neotropical species are known by the presence of glucosidic monoterpene indole alkaloids. These compounds are able to display a large range of effects on the central nervous system, such as anxiolytic, antidepressant, analgesic, and impairment of learning and memory acquisition. The aims of this study were to investigate the effects displayed by strictosidinic acid, isolated from Psychotria myriantha Mull. Arg. (Rubiaceae) leaves, on monoamine levels in rat hippocampus and on monoamine oxidase activity. A significance (p