Crack cocaine inhalation increases seizure susceptibility by reducing acetylcholinesterase activity.

Crack cocaine is a highly addictive and potent stimulant drug. Animal studies have shown that the cholinergic system plays a role in neurotoxicity induced by cocaine or its active metabolites inhalation. Behavioral alterations associated with crack cocaine use include hyperactivity, depressed mood, and decreased seizure threshold. Here we evaluate the acetylcholinesterase (AChE) and reactive oxygen species (ROS) activity, behavioral profile, and the threshold for epileptic seizures in rats that received intrahippocampal pilocarpine (H-PILO) followed by exposure to crack cocaine (H-PILO + CRACK). Animals exposed to H-PILO + CRACK demonstrated increased severity and frequency of limbic seizures. The AChE activity was reduced in the groups exposed to crack cocaine alone (CRACK) and H-PILO + CRACK, whereas levels of ROS remained unchanged. In addition, crack cocaine exposure increased vertical locomotor activity, without changing water and sucrose intake. Short-term memory consolidation remained unchanged after H-PILO, H-PILO + CRACK, and CRACK administration. Overall, our data suggest that crack cocaine inhalation reduced the threshold for epileptic seizures in rats submitted to low doses of pilocarpine through the inhibition of AChE. Taken together, our findings can be useful in the development of effective strategies for preventing and treating the harmful effects of cocaine and crack cocaine on the central nervous system.

Maternal, fetal and neonatal consequences associated with the use of crack cocaine during the gestational period: a systematic review and meta-analysis.

OBJECTIVE: Crack cocaine consumption is one of the main public health challenges with a growing number of children intoxicated by crack cocaine during the gestational period. The primary goal is to evaluate the accumulating findings and to provide an updated perspective on this field of research. METHODS: Meta-analyses were performed using the random effects model, odds ratio (OR) for categorical variables and mean difference for continuous variables. Statistical heterogeneity was assessed using the I-squared statistic and risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. Ten studies met eligibility criteria and were used for data extraction. RESULTS: The crack cocaine use during pregnancy was associated with significantly higher odds of preterm delivery [odds ratio (OR), 2.22; 95% confidence interval (CI), 1.59-3.10], placental displacement (OR, 2.03; 95% CI 1.66-2.48), reduced head circumference (- 1.65 cm; 95% CI - 3.12 to - 0.19), small for gestational age (SGA) (OR, 4.00; 95% CI 1.74-9.18) and low birth weight (LBW) (OR, 2.80; 95% CI 2.39-3.27). CONCLUSION: This analysis provides clear evidence that crack cocaine contributes to adverse perinatal outcomes. The exposure of maternal or prenatal crack cocaine is pointedly linked to LBW, preterm delivery, placental displacement and smaller head circumference.

Moderate-Intensity Physical Exercise Protects Against Experimental 6-Hydroxydopamine-Induced Hemiparkinsonism Through Nrf2-Antioxidant Response Element Pathway.

INTRODUCTION: Exercise improves the motor symptoms of patients with Parkinson disease in a palliative manner. Existing evidence demonstrates that exercise induces neuroprotection based on the neurotrophic properties. We investigated the effect of exercise on mitochondrial physiology and oxidative stress in an animal model of hemiparkinsonism. METHODS: C57BL/6 mice completed a 6-week exercise program on a treadmill. We injected 6-hydroxydopamine (6-OHDA; 4 µg/2 µl) into the midstriatum. The animals progressively developed bradykinesia and R(-)-apomorphine-induced rotations that were attenuated by exercise. Transcriptional activation of protective genes is mediated by the antioxidant response element (ARE). Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) binds to ARE. We investigated the Nrf2-ARE pathway in the striatum of animals. RESULTS: Exercise protected 6-OHDA-induced loss of tyrosine hydroxylase immunolabeling and activated the Nrf2-ARE pathway in the nigrostriatal pathway. Exercise stimulated mitochondrial biogenesis in the striatum of animals that was more resistant to oxidant 6-OHDA and nitric oxide donor (±)-S-nitroso-N-acetylpenicillamine. CONCLUSIONS: In mice, exercise activated Nrf2-ARE signaling in the nigrostriatal pathway that was protective against the development of hemiparkinsonism.

Inhibition of sodium glucose cotransporters following status epilepticus induced by intrahippocampal pilocarpine affects neurodegeneration process in hippocampus.

Temporal lobe epilepsy (TLE) is characterized by spontaneous recurrent seizures, starting from secondary functional disorders due to several insults, including self-sustaining continuous seizures identified as status epilepticus (SE). Although hypoglycemia has been associated with SE, the effect of inhibition of the Na(+)/glucose cotransporters (SGLTs) on hippocampus during SE is still unknown. Here we evaluated the functional role of SGLT in the pattern of limbic seizures and neurodegeneration process after pilocarpine (PILO)-induced SE. Vehicle (VEH, 1µL) or phlorizin, a specific SGLT inhibitor (PZN, 1µL, 50µg/µL), was administered in the hippocampus of rats 30min before PILO (VEH+PILO or PZN+PILO, respectively). The limbic seizures were classified using the Racine's scale, and the amount of wet dog shakes (WDS) was quantified before and during SE. Neurodegeneration process was evaluated by Fluoro-Jade C (FJ-C), and FJ-C-positive neurons (FJ-C+) were counted 24h and 15days after SE. The PZN-treated rats showed higher (p<0.05) number of WDS when compared with VEH+PILO. There was no difference in seizure severity between PZN+PILO and VEH+PILO groups. However, the pattern of limbic seizures significantly changed in PZN+PILO. Indeed, the class 5 seizures repeated themselves more times (p<0.05) than the other classes in the PZN group at 50min after SE induction. The PZN+PILO animals had a higher (p<0.05) number of FJ-C+ cells in the dentate gyrus (DG), hilus, and CA3 and CA1 of hippocampus, when compared with VEH+PILO. The PZN+PILO animals had a decreased number (p<0.05) of FJ-C+ cells in CA1 compared with VEH+PILO 15days after SE induction. Taken together, our data suggest that SGLT inhibition with PZN increased the severity of limbic seizures during SE and increased neurodegeneration in hippocampus 24h after SE, suggesting that SGLT1 and SGLT2 could participate in the modulation of earlier stages of epileptogenic processes.

Effects of cocaine, nicotine, and marijuana exposure in Drosophila Melanogaster development: A systematic review and meta-analysis.

Abuse-related drug usage is a public health issue. Drosophila melanogaster has been used as an animal model to study the biological effects of these psychoactive substances in preclinical studies. Our objective in this review is to evaluate the adverse effects produced by cocaine, nicotine, and marijuana during the development of D. melanogaster. We searched experimental studies in which D. melanogaster was exposed to these three psychoactive drugs in seven online databases up to January 2023. Two reviewers independently extracted the data. Fifty-one studies met eligibility criteria and were included in the data extraction: nicotine (n = 26), cocaine (n = 20), and marijuana (n = 5). Fifteen studies were eligible for meta-analysis. Low doses (∼0.6 mM) of nicotine increased locomotor activity in fruit flies, while high doses (≥3 mM) led to a decrease. Similarly, exposure to cocaine increased locomotor activity, resulting in decreased climbing response in D. melanogaster. Studies with exposure to marijuana did not present a profile for our meta-analysis. However, this drug has been less associated with locomotor changes, but alterations in body weight and fat content and changes in cardiac function. Our analyses have shown that fruit flies exposed to drugs of abuse during different developmental stages, such as larvae and adults, exhibit molecular, morphological, behavioral, and survival changes that are dependent on the dosage. These phenotypes resemble the adverse effects of psychoactive substances in clinical medicine.

Systematic review and meta-analysis of dysregulated microRNAs derived from liquid biopsies as biomarkers for amyotrophic lateral sclerosis.

The discovery of disease-specific biomarkers, such as microRNAs (miRNAs), holds the potential to transform the landscape of Amyotrophic Lateral Sclerosis (ALS) by facilitating timely diagnosis, monitoring treatment response, and accelerating drug discovery. Such advancement could ultimately improve the quality of life and survival rates for ALS patients. Despite more than a decade of research, no miRNA biomarker candidate has been translated into clinical practice. We conducted a systematic review and meta-analysis to quantitatively synthesize data from original studies that analyzed miRNA expression from liquid biopsies via PCR and compared them to healthy controls. Our analysis encompasses 807 miRNA observations from 31 studies, stratified according to their source tissue. We identified consistently dysregulated miRNAs in serum (hsa-miR-3665, -4530, -4745-5p, -206); blood (hsa-miR-338-3p, -183-5p); cerebrospinal fluid (hsa-miR-34a-3p); plasma (hsa-miR-206); and neural-enriched extracellular vesicles from plasma (hsa-miR-146a-5p, -151a-5p, -10b-5p, -29b-3p, and -4454). The meta-analyses provided further support for the upregulation of hsa-miR-206, hsa-miR-338-3p, hsa-miR-146a-5p and hsa-miR-151a-5p, and downregulation of hsa-miR-183-5p, hsa-miR-10b-5p, hsa-miR-29b-3p, and hsa-miR-4454 as consistent indicators of ALS across independent studies. Our findings provide valuable insights into the current understanding of miRNAs' dysregulated expression in ALS patients and on the researchers' choices of methodology. This work contributes to the ongoing efforts towards discovering disease-specific biomarkers.

Layered double hydroxides (LDHs) as efficient and safe carriers for miRNA inhibitors: In vitro and in vivo assessment of biocompatibility.

Layered double hydroxides (LDHs) have been employed as nano-sized carriers for therapeutic/bio-active molecules, including small interfering RNAs (siRNAs). However, the potential of LDHs nanoparticles for an efficient and safe antisense oligonucleotide (AMO) delivery still requires studies. In this research, we have tested the suitability of a Mg-Al-LDH-based nanocarrier loaded with a miRNA-196b-5p inhibitor. LDHs (and LDH-Oligo complex) were synthesized by the coprecipitation method followed by physicochemical characterization as hydrodynamic size, surface charge, crystallinity, and chemical groups. Thymic endothelial cell line (tEnd.1) were transfected with LDH-Oligo and were evaluated for i. cell viability by MTT, trypan blue, and propidium iodide assays; ii. transfection efficiency by flow cytometry, and iii. depletion of miRNA-196b-5p by RT-qPCR. In addition, Drosophila melanogaster larvae were fed LDHs and evaluated for: i. larval motility; ii. pupation rate; iii. larval-pupal transition; iv. lethality, and v. emergence rate. We demonstrated that LDHs nanoparticles are stable in aqueous solutions and exhibit a regular hexagonal shape. The LDH-AMO complex showed a transfection efficiency of 93.95 ± 2.15 % and induced a significant depletion of miRNA-196b-5p 48h after transfection. No cytotoxic effects were detected in tEnd.1 cells at concentrations up to 50 µg/ml, as well as in Drosophila exposed up to 500 µg of LDH. In conclusion, our data suggest that LDHs are biocompatible and efficient carriers for miRNA inhibitors and can be used as a viable and effective tool in functional miRNA inhibition assays.

Motor neuron-derived induced pluripotent stem cells as a drug screening platform for amyotrophic lateral sclerosis.

The development of cell culture models that recapitulate the etiology and features of nervous system diseases is central to the discovery of new drugs and their translation onto therapies. Neuronal tissues are inaccessible due to skeletal constraints and the invasiveness of the procedure to obtain them. Thus, the emergence of induced pluripotent stem cell (iPSC) technology offers the opportunity to model different neuronal pathologies. Our focus centers on iPSCs derived from amyotrophic lateral sclerosis (ALS) patients, whose pathology remains in urgent need of new drugs and treatment. In this sense, we aim to revise the process to obtain motor neurons derived iPSCs (iPSC-MNs) from patients with ALS as a drug screening model, review current 3D-models and offer a perspective on bioinformatics as a powerful tool that can aid in the progress of finding new pharmacological treatments.

Neuroprotective Effect of Exogenous Galectin-1 in Status Epilepticus.

Intrahippocampal pilocarpine microinjection (H-PILO) induces status epilepticus (SE) that can lead to spontaneous recurrent seizures (SRS) and neurodegeneration in rodents. Studies using animal models have indicated that lectins mediate a variety of biological activities with neuronal benefits, especially galectin-1 (GAL-1), which has been identified as an effective neuroprotective compound. GAL-1 is associated with the regulation of cell adhesion, proliferation, programmed cell death, and immune responses, as well as attenuating neuroinflammation. Here, we administrated GAL-1 to Wistar rats and evaluated the severity of the SE, neurodegenerative and inflammatory patterns in the hippocampal formation. Administration of GAL-1 caused a reduction in the number of class 2 and 4 seizures, indicating a decrease in seizure severity. Furthermore, we observed a reduction in inflammation and neurodegeneration 24 h and 15 days after SE. Overall, these results suggest that GAL-1 has a neuroprotective effect in the early stage of epileptogenesis and provides new insights into the roles of exogenous lectins in temporal lobe epilepsy (TLE).

First evaluation of the anxiolytic-like effects of a bromazepam­palladium complex in mice.

A significant fraction of patients are affected by persistent fear and anxiety. Currently, there are several anxiolytic drug options, however their clinical outcomes do not fully manage the symptoms. Here, we evaluated the effects of a bromazepam­palladium derivative [2-{(7-bromo-2-oxo-1,3-dihydro-2H-1,4-benzodiazepin-5-il)pyridinyl-κ2-N,N}chloropalladium(II)], [(BMZ)PdCl2], on fear/anxiety and memory-related behavior in mice. For this, female Swiss mice were treated intraperitoneally (i.p.) with saline (NaCl 0.9%) or [(BMZ)PdCl2] (0.5, 5.0, or 50 µg/kg). After 30 min, different tests were performed to evaluate anxiety, locomotion, and memory. We also evaluated the acute toxicity of [(BMZ)PdCl2] using a cell viability assay (neutral red uptake assay), and whether the drugs mechanism of action involves the γ-aminobutyric acid type A (GABAA) receptor complex by pre-treating animals with flumazenil (1.0 mg/kg, i.p., a competitive antagonist of GABAA-binding site). Our results demonstrate that [(BMZ)PdCl2] induces an anxiolytic-like phenotype in the elevated plus-maze test and that this effect can be blocked by flumazenil. Furthermore, there were no behavioral alterations induced by [(BMZ)PdCl2], as evaluated in the light-dark box, open field, and step-down passive avoidance tests. In the acute toxicity assay, [(BMZ)PdCl2] presented IC50 and LD50 values of 218 ± 60 µg/mL and 780 ± 80 mg/kg, respectively, and GSH category 4. Taken together, our results show that the anxiolytic-like effect of acute treatment with [(BMZ)PdCl2] occurs through the modulation of the benzodiazepine site in the GABAA receptor complex. Moreover, we show indications that [(BMZ)PdCl2] does not promote sedation and amnesia and presents the same toxicity as the bromazepam prototype.

Modulation of Glucose Availability and Effects of Hypo- and Hyperglycemia on Status Epilepticus: What We Do Not Know Yet?

Status epilepticus (SE) can lead to serious neuronal damage and act as an initial trigger for epileptogenic processes that may lead to temporal lobe epilepsy (TLE). Besides promoting neurodegeneration, neuroinflammation, and abnormal neurogenesis, SE can generate an extensive hypometabolism in several brain areas and, consequently, reduce intracellular energy supply, such as adenosine triphosphate (ATP) molecules. Although some antiepileptic drugs show efficiency to terminate or reduce epileptic seizures, approximately 30% of TLE patients are refractory to regular antiepileptic drugs (AEDs). Modulation of glucose availability may provide a novel and robust alternative for treating seizures and neuronal damage that occurs during epileptogenesis; however, more detailed information remains unknown, especially under hypo- and hyperglycemic conditions. Here, we review several pathways of glucose metabolism activated during and after SE, as well as the effects of hypo- and hyperglycemia in the generation of self-sustained limbic seizures. Furthermore, this study suggests the control of glucose availability as a potential therapeutic tool for SE.

Role of Modulation of Hippocampal Glucose Following Pilocarpine-Induced Status Epilepticus.

Status epilepticus (SE) is defined as continuous and self-sustaining seizures, which trigger hippocampal neurodegeneration, mitochondrial dysfunction, oxidative stress, and energy failure. During SE, the neurons become overexcited, increasing energy consumption. Glucose uptake is increased via the sodium glucose cotransporter 1 (SGLT1) in the hippocampus under epileptic conditions. In addition, modulation of glucose can prevent neuronal damage caused by SE. Here, we evaluated the effect of increased glucose availability in behavior of limbic seizures, memory dysfunction, neurodegeneration process, neuronal activity, and SGLT1 expression. Vehicle (VEH, saline 0.9%, 1 µL) or glucose (GLU; 1, 2 or 3 mM, 1 µL) were administered into hippocampus of male Wistar rats (Rattus norvegicus) before or after pilocarpine to induce SE. Behavioral analysis of seizures was performed for 90 min during SE. The memory and learning processes were analyzed by the inhibitory avoidance test. After 24 h of SE, neurodegeneration process, neuronal activity, and SGLT1 expression were evaluated in hippocampal and extrahippocampal regions. Modulation of hippocampal glucose did not protect memory dysfunction followed by SE. Our results showed that the administration of glucose after pilocarpine reduced the severity of seizures, as well as the number of limbic seizures. Similarly, glucose after SE reduced cell death and neuronal activity in hippocampus, subiculum, thalamus, amygdala, and cortical areas. Finally, glucose infusion elevated the SGLT1 expression in hippocampus. Taken together our data suggest that possibly the administration of intrahippocampal glucose protects brain in the earlier stage of epileptogenic processes via an important support of SGLT1.

Maternal crack cocaine use in rats leads to depressive- and anxiety-like behavior, memory impairment, and increased seizure susceptibility in the offspring.

Crack users suffer the effects of cocaine present in the drug and the action of other active compounds from its pyrolysis. An emergent fact is an increase in the number of pregnant crack cocaine users. Studies suggest that crack cocaine and its metabolites cross the placenta, promoting premature birth, fever, irritability, sweating, and seizures in the early months of life. In children, the effects of crack cocaine have been associated with cognitive deficits, difficulty in verbalization, aggressiveness, and depression, besides enhancing the susceptibility to epileptic seizures, including status epilepticus (SE) in adulthood. Therefore, we investigated the effect of maternal exposure to smoke crack cocaine on several behavioral parameters in the offspring during adulthood. A series of behavioral tests and intrahippocampal pilocarpine (H-PILO) microinjection at sub-convulsive and convulsive doses in a rat model demonstrated that exposure to crack cocaine during the embryonic period leads to anxiogenic-like behavior and long-term memory impairment in both genders and promotes depressive-like behavior in the female. Besides, crack cocaine offspring exposed to a sub-convulsive H-PILO dose showed higher susceptibility to SE, increased seizure frequency, and neurodegeneration, while animals that received a convulsive dose of H-PILO displayed no alteration in SE severity. Taken together, our data suggest that crack cocaine exposure during the gestational period leads to an increased predilection for anxiety and depression, long-term memory deficits, and reduction in the threshold for developing epileptic seizures associated with neuronal death, which predispose crack cocaine babies to develop neuropsychological disorders.

Anticonvulsant and anxiolytic-like effects of compounds isolated from Polygala sabulosa (Polygalaceae) in rodents: in vitro and in vivo interactions with benzodiazepine binding sites.

RATIONALE: Polygala sabulosa, a folk medicine, presents dihydrostyryl-2-pyrones (DST) and styryl-2-pyrones (STY), compounds structurally similar to kavalactones. Our previous study showed that the ethyl acetate fraction (EA) and these constituents present anxiolytic-like, hypno-sedative, and anticonvulsant effects in mice. OBJECTIVES: This study investigated the role of benzodiazepine binding site (BDZ-bs) in the central effects of either EA or three DST (1, 2, and 3) and three STY (4, 5, and 7), using in vivo and in vitro assays. METHODS AND RESULTS: In the elevated plus-maze (EPM), flumazenil (FMZ), a BDZ antagonist, partially blocked the anxiolytic-like effect of DST-3 or STY-4 and STY-7, but not DST-1. Using electroencephalogram (EEG), EA protected against pentylenetetrazole (PTZ)-induced convulsion in rats, an effect partially blocked by FMZ, suggesting the participation of the BDZ-bs in this action. EA also protected against the maximal electroshock (MES)-induced convulsions in mice, a profile distinct from diazepam (DZP). DST and STY compounds inhibited the [(3)H]-flunitrazepam ([(3)H]-FNZ) binding to BDZ-bs in rat cortical synaptosomes with K (i) higher than 100 microM (DST-1), 41.7 microM (DST-2), 35.8 microM (DST-3), 90.3 microM (STY-4), 31.0 microM (STY-5) and 70.0 microM (STY-7). In the saturation assay, DST-3 and STY-7 competitively inhibited the binding of [(3)H]-FNZ to BDZ-bs with a significant decrease in apparent affinity (K (d)) and no change in maximal binding (B (max)). CONCLUSIONS: The present data support a partial BDZ-bs mediation of the anxiolytic-like and anticonvulsant effects of EA of P. sabulosa and its main isolated constituents, DST and STY.

Modulation of anxiety in rats evaluated in the elevated T-maze: evidence of the relationship between substance P and diazepam.

This study aimed to investigate the relationship between substance P (SP) and diazepam (DZP) in the modulation of anxiety and memory in rats as evaluated in the elevated T-maze (ETM). For this purpose, in the first experiment, rats were intraperitoneally (i.p.) pretreated with saline or DZP (1mg/kg) and 25min later they were intracerebroventricularly (i.c.v.) injected with PBS or SP (10 pmol). In the second experiment, rats were i.p. pretreated with saline or DZP (1mg/kg) and 25 min later were i.c.v. injected with FK888 (100 pmol, a NK1 antagonist). After 1 min, animals were i.c.v. injected with vehicle (PBS+ethanol 10%) or SP (10 pmol). Our results show that DZP significantly decreased the latency to leave the enclosed arm of the ETM in the test and re-test session, indicating an anxiolytic and an amnesic effect, respectively. Although the central administration of SP did not significantly alter 'per se' the latency to leave the enclosed arm of the ETM in the test and re-test sessions, there was a trend to increase this parameter in the test session (indicating an anxiogenic-like effect). Furthermore, SP was able to reverse, via NK1 receptors, the effect produced by DZP during the test session. Moreover, none of the treatments interfered in the one-way escape behavior recorded in the test or re-test session in the ETM. In conclusion, our results strengthen and extend previous experimental data showing an interaction between the tachykinergic and benzodiazepine-GABA systems in the modulation of anxiety.

Rhythms of Core Clock Genes and Spontaneous Locomotor Activity in Post-Status Epilepticus Model of Mesial Temporal Lobe Epilepsy.

The interaction of Mesial Temporal Lobe Epilepsy (mTLE) with the circadian system control is apparent from an oscillatory pattern of limbic seizures, daytime's effect on seizure onset and the efficacy of antiepileptic drugs. Moreover, seizures per se can interfere with the biological rhythm output, including circadian oscillation of body temperature, locomotor activity, EEG pattern as well as the transcriptome. However, the molecular mechanisms underlying this cross-talk remain unclear. In this study, we systematically evaluated the temporal expression of seven core circadian transcripts (Bmal1, Clock, Cry1, Cry2, Per1, Per2, and Per3) and the spontaneous locomotor activity (SLA) in post-status epilepticus (SE) model of mTLE. Twenty-four hour oscillating SLA remained intact in post-SE groups although the circadian phase and the amount and intensity of activity were changed in early post-SE and epileptic phases. The acrophase of the SLA rhythm was delayed during epileptogenesis, a fragmented 24 h rhythmicity and extended active phase length appeared in the epileptic phase. The temporal expression of circadian transcripts Bmal1, Cry1, Cry2, Per1, Per2, and Per3 was also substantially altered. The oscillatory expression of Bmal1 was maintained in rats imperiled to SE, but with lower amplitude (A = 0.2) and an advanced acrophase in the epileptic phase. The diurnal rhythm of Cry1 and Cry2 was absent in the early post-SE but was recovered in the epileptic phase. Per1 and Per2 rhythmic expression were disrupted in post-SE groups while Per3 presented an arrhythmic profile in the epileptic phase, only. The expression of Clock did not display rhythmic pattern in any condition. These oscillating patterns of core clock genes may contribute to hippocampal 24 h cycling and, consequently to seizure periodicity. Furthermore, by using a pool of samples collected at 6 different Zeitgeber Times (ZT), we found that all clock transcripts were significantly dysregulated after SE induction, except Per3 and Per2. Collectively, altered SLA rhythm in early post-SE and epileptic phases implies a possible role for seizure as a nonphotic cue, which is likely linked to activation of hippocampal-accumbens pathway. On the other hand, altered temporal expression of the clock genes after SE suggests their involvement in the MTLE.

Psychopharmacological effects and safety of styryl-2-pyrones and dihydrostyryl-2-pyrones-rich fraction from Polygala sabulosa: absence of withdrawal syndrome and tolerance to anxiolytic-like and anticonvulsant effects.

OBJECTIVES: To investigate whether mice develop tolerance to the anxiolytic-like and anticonvulsant effects of subchronic treatment with EA (the styryl-2-pyrones and dihydrostyryl-2-pyrones-rich fraction of Polygala sabulosa), as well as any withdrawal symptoms after abrupt discontinuation; to compare the effects of EA with those of diazepam (DZP) on withdrawal-induced anxiety; and to evaluate the toxicity of EA according to OECD guidelines. METHODS: Male or female mice were acutely or subchronically treated with EA or DZP, and their tolerance to anxiolytic (evaluated in the elevated plus maze, EPM) and anticonvulsant effects (measured against pentylenetetrazole (PTZ)-induced convulsions) were investigated. Other groups received EA or DZP for 28 days followed by withdrawal, being the anxiety-like behaviour evaluated in the EPM. KEY FINDINGS: Both acute and subchronic treatments with EA induced an anxiolytic effect in the EPM. The anticonvulsant activity of DZP, but not EA, was reduced by protracted treatment. EA withdrawal retained the anxiolytic profile, while DZP withdrawal induced anxiogenesis. EA counteracted the anxiogenic-like actions of DZP withdrawal. EA has low toxicity as it did not cause any changes in the biochemical, haematological and histopathological markers. CONCLUSIONS: EA avoids the development of tolerance to its anxiolytic-like and anticonvulsant actions, and does not promote withdrawal syndrome. EA does not cause relevant toxic effects in rodents.

Participation of dihydrostyryl-2-pyrones and styryl-2-pyrones in the central effects of Polygala sabulosa (Polygalaceae), a folk medicine topical anesthetic.

This study was undertaken to evaluate the psychopharmacological effects in mice of the hydroethanolic extract (HE), aqueous, hexane and ethyl acetate (EA) fractions, and 6-methoxy-7-prenyloxycoumarin, three dihydrostyryl-2-pyrones and three styryl-2-pyrones isolated from Polygala sabulosa (Polygalaceae), a folk medicine used as a topical anesthetic. In the elevated plus-maze test (EPM), the HE of P. sabulosa and its EA induced an increase in the percentage of time spent on, and in the frequency of entries into the open arms, as well as in the number of unprotected head-dipping, besides a reduction in protected stretch-attend postures, thus indicating an anxiolytic-like profile of action for this plant species. In the hypnosis test, HE and EA enhanced the duration of pentobarbital-induced sleep, a hypnosedative effect confirmed in ethyl ether-induced hypnosis. Moreover, both preparations reduced the duration of the first convulsion induced by pentylenetetrazol, besides decreasing the severity of the seizures. The dihydrostyryl-2-pyrones (1) and (3) as well as styryl-2-pyrones (4) and (7), centrally administered, showed a similar anxiolytic-like effect in the EPM test, while the dihydrostyryl-2-pyrone (2) and styryl-2-pyrone (5) were inactive at the doses used here. These results suggest that P. sabulosa is a herbal medicine which possesses anxiolytic-like, hypnosedative and anticonvulsant effects, and these central effects can be attributed to the presence of the dihydrostyryl-2-pyrone and styryl-2-pyrone compounds.

Using Postmortem hippocampi tissue can interfere with differential gene expression analysis of the epileptogenic process.

Neuropathological studies often use autopsy brain tissue as controls to evaluate changes in protein or RNA levels in several diseases. In mesial temporal lobe epilepsy (MTLE), several genes are up or down regulated throughout the epileptogenic and chronic stages of the disease. Given that postmortem changes in several gene transcripts could impact the detection of changes in case-control studies, we evaluated the effect of using autopsy specimens with different postmortem intervals (PMI) on differential gene expression of the Pilocarpine (PILO)induced Status Epilepticus (SE) of MTLE. For this, we selected six genes (Gfap, Ppia, Gad65, Gad67, Npy, and Tnf-α) whose expression patterns in the hippocampus of PILO-injected rats are well known. Initially, we compared hippocampal expression of naïve rats whose hippocampi were harvested immediately after death (0h-PMI) with those harvested at 6h postmortem interval (6h-PMI): Npy and Ppia transcripts increased and Tnf-α transcripts decreased in the 6h-PMI group (p<0.05). We then investigated if these PMI-related changes in gene expression have the potential to adulterate or mask RT-qPCR results obtained with PILO-injected rats euthanized at acute or chronic phases. In the acute group, Npy transcript was significantly higher when compared with 0h-PMI rats, whereas Ppia transcript was lower than 6h-PMI group. When we used epileptic rats (chronic group), the RT-qPCR results showed higher Tnf-α only when compared to 6h-PMI group. In conclusion, our study demonstrates that PMI influences gene transcription and can mask changes in gene transcription seen during epileptogenesis in the PILO-SE model. Thus, to avoid erroneous conclusions, we strongly recommend that researchers account for changes in postmortem gene expression in their experimental design.

Genetic susceptibility in Juvenile Myoclonic Epilepsy: Systematic review of genetic association studies.

BACKGROUND: Several genetic association investigations have been performed over the last three decades to identify variants underlying Juvenile Myoclonic Epilepsy (JME). Here, we evaluate the accumulating findings and provide an updated perspective of these studies. METHODOLOGY: A systematic literature search was conducted using the PubMed, Embase, Scopus, Lilacs, epiGAD, Google Scholar and Sigle up to February 12, 2016. The quality of the included studies was assessed by a score and classified as low and high quality. Beyond outcome measures, information was extracted on the setting for each study, characteristics of population samples and polymorphisms. RESULTS: Fifty studies met eligibility criteria and were used for data extraction. With a single exception, all studies used a candidate gene approach, providing data on 229 polymorphisms in or near 55 different genes. Of variants investigating in independent data sets, only rs2029461 SNP in GRM4, rs3743123 in CX36 and rs3918149 in BRD2 showed a significant association with JME in at least two different background populations. The lack of consistent associations might be due to variations in experimental design and/or limitations of the approach. CONCLUSIONS: Thus, despite intense research evidence established, specific genetic variants in JME susceptibility remain inconclusive. We discussed several issues that may compromise the quality of the results, including methodological bias, endophenotype and potential involvement of epigenetic factors. PROSPERO REGISTRATION NUMBER: CRD42016036063.