N-3 PUFA Prevent Oxidative Stress in a Rat Model of Beta-Amyloid-Induced Toxicity

Polyunsaturated fatty acids (PUFA) are involved in brain disorders associated to amyloid beta (Aβ) toxicity for which oxidative stress, neurochemical dysfunctions, and neuroinflammation are underlying mechanisms. Here, mechanisms through which lifelong exposure to n-3 PUFA-enriched or n-6/n-3 balanced diets could elicit a protective role in a rat model of Aβ-induced toxicity were investigated. To this aim, we quantified hippocampal reactive oxygen species (ROS) amount, 8-hydroxy-2′-deoxyguanosine and interleukin-10 levels, NADPH oxidase (NOX) 1, NOX2, superoxide dismutase 1, and glutathione contents, as well as plasmatic malondialdehyde. Moreover, in the same experimental groups, we assessed tryptophan, serotonin, and its turnover, kynurenine, and noradrenaline amounts. Results showed increased hippocampal ROS and NOX2 levels, serotonin turnover, kynurenine, and noradrenaline contents in Aβ-treated rats. Both n-6/n-3 balanced and n-3 PUFA enriched diets reduced ROS production, NOX1 and malondialdehyde levels, serotonin turnover, and kynurenine amount in Aβ-injected rats, while increasing NOX2, superoxide dismutase 1, and serotonin contents. No differences in plasmatic coenzyme Q10, reduced glutathione (GSH) and tryptophan levels were detected among different experimental groups, whereas GSH + oxidized glutathione (GSSG) levels were increased in sham animals fed with n-3 PUFA enriched diet and in Aβ-treated rats exposed to both n-6/n-3 balanced and n-3 enriched diets. In addition, Aβ-induced decrease of interleukin-10 levels was prevented by n-6/n-3 PUFA balanced diet. N-3 PUFA enriched diet further increased interleukin-10 and 8-hydroxy-2′-deoxyguanosine levels. In conclusion, our data highlight the possible neuroprotective role of n-3 PUFA in perturbation of oxidative equilibrium induced by Aβ-administration.

Oxidative Stress, Folate Receptor Autoimmunity, and CSF Findings in Severe Infantile Autism

Background. Biomarkers such as oxidative stress, folate receptor alpha (FRα) autoimmunity, and abnormal brain serotonin turnover are common in autism. Methods. Oxidative stress biomarkers with pro- and antioxidants were measured in the severe form of infantile autism (n = 38) and controls (n = 24). Children and parents had repeated testing for serum FR autoantibodies, spinal fluid dopamine and serotonin metabolites, pterins, and N5-methyltetrahydrofolate (MTHF). Statistical analysis assessed correlations between variables. Genetic analysis included the SLC6A4 and SLC29A4 genes encoding synaptic serotonin reuptake proteins. Results. Compared to controls, the autism group showed a significant increase in oxidative DNA damage in lymphocytes, plasma ceruloplasmin and copper levels with a high copper/zinc ratio, thiol proteins, and superoxide dismutase (SOD) activity. Vitamin C levels were significantly diminished. In most autistic patients, the vitamin A (64%) and D (70%) levels were low. Serum FR autoantibodies fluctuating over 5–7 week periods presented in 68% of all autistic children, 41% of parents vs. 3.3% of control children and their parents. CSF showed lowered serotonin 5-hydroxyindole acetic acid (5HIAA) metabolites in 13 (34%), a low 5HIAA to HVA (dopamine metabolite) ratio in 5 (13%), low 5HIAA and MTHF in 2 (5%), and low MTHF in 8 patients (21%). A known SLC6A4 mutation was identified only in 1 autistic child with low CSF 5HIAA and a novel SLC29A4 mutation was identified in identical twins. Low CSF MTHF levels among only 26% of subjects can be explained by the fluctuating FR antibody titers. Two or more aberrant pro-oxidant and/or antioxidant factors predisposed to low CSF serotonin metabolites. Three autistic children having low CSF 5HIAA and elevated oxidative stress received antioxidative supplements followed by CSF 5HIAA normalisation. Conclusion. In autism, we found diverse combinations for FR autoimmunity and/or oxidative stress, both amenable to treatment. Parental and postnatal FR autoantibodies tend to block folate passage to the brain affecting folate-dependent pathways restored by folinic acid treatment, while an abnormal redox status tends to induce reduced serotonin turnover, corrected by antioxidant therapy. Trial Registration. The case-controlled study was approved in 2008 by the IRB at Liège University (Belgian Number: B70720083916). Lay Summary. Children with severe infantile autism frequently have serum folate receptor autoantibodies that block the transport of the essential vitamin folate across the blood-brain barrier to the brain. Parents are often asymptomatic carriers of these serum folate receptor autoantibodies, which in mothers can block folate passage across the placenta to their unborn child. This folate deficiency during the child’s intrauterine development may predispose to neural tube defects and autism. Oxidative stress represents a condition with the presence of elevated toxic oxygen derivatives attributed to an imbalance between the formation and protection against these toxic reactive oxygen derivatives. Oxidative stress was found to be present in autistic children where these reactive oxygen derivatives can cause damage to DNA, which changes DNA function and regulation of gene expression. In addition, excessive amounts of these toxic oxygen derivatives are likely to damage the enzyme producing the neuromessenger serotonin in the brain, diminished in about 1/3 of the autistic children. Testing children with autism for oxidative stress and its origin, as well as testing for serum folate receptor autoantibodies, could open new approaches towards more effective treatments.

Antidepressant-Like Properties of Fish Oil on Postpartum Depression-Like Rats Model: Involvement of Serotonergic System

Pathophysiology of postpartum depression (PPD) has been associated with many factors, such as neuroendocrine, neuroinflammation and neurotransmitter changes. Fish oil (FO) improves PPD both in humans and animals. However, little is known with regards to its pharmacology on a PPD-like rat model. Hence, the current study aimed at investigating the effects of FO on a PPD-like rat model. Female rats were induced with PPD-like symptoms and then randomly divided into six groups (n = 6) for two experimental protocols. Protocol 1 consisted of PPD-like rats (2 mL distilled water), PPD-like + FO (9 g/kg/d) and PPD-like + Fluoxetine (FLX) (15 mg/kg/d) groups of rats, whereas Protocol 2 consisted of PPD-like rats (2 mL distilled water) + PCPA (p-chlorophenylalanine) 150 mg/kg, PPD-like + FO (9 g/kg/d) + PCPA 150 mg/kg and PPD-like + FLX (15 mg/d) + PCPA 150 mg/kg groups of rats, respectively. All treatments were administered orally for 10 days postpartum, except PCPA, which was given intraperitoneally. Prior to euthanasia, the antidepressant-like effect of the FO was evaluated using the forced swimming test (FST) and open field test (OFT) on day 10 postpartum. Biochemical analysis of serotonin, serotonin metabolite and serotonin turnover from their prefrontal cortex and hippocampus were also measured. The results showed that FO decreased immobility time and increased swimming time significantly, but not climbing time in FST. Further, it also decreased serotonin metabolite and turnover significantly in the hippocampus of the PPD-like rats. In contrast, administration with PCPA reversed all the outcomes. The antidepressant-like effects of FO were found to be similar with that of FLX. Thus, it can be concluded that FO exerts its antidepressant-like effects in PPD-like rats through modulation of serotonergic system.

Correlation Between Salivary, Platelet and Central Serotonin Levels in Children

ABSTRACT:Background:Serotonin (5-HT) is a neurotransmitter synthesized in both the central nervous system (CNS) and in enterochromaffin cells of the gut. 5-HT biosynthesis is separate between the periphery and the CNS. Any observed correlations between centrally and peripherally measured 5-HT remain to be elucidated. Previous efforts have looked for a noninvasive marker of central serotonin, including serotonin in whole blood, plasma, platelets, saliva, and urine; however, results are conflicting.Aim:Finding a noninvasive marker for central serotonin turnover that can be used for diagnosis and therapeutic monitoring in patients with primary neurotransmitter deficiencies.Methods:Inclusion criterion was all children presenting with neurological symptoms whose clinical investigations included lumbar puncture (LP) for cerebrospinal fluid (CSF) collection and neurotransmitter metabolite analysis, were recruited. For central serotonin turnover, the serotonin metabolite 5-hydroxyindoleacetic acid (5HIAA) was used. Bivariate correlation between the serotonin levels in CSF (5HIAA), platelets, and saliva was calculated.Results:Twenty-six patients (aged 6 months to 15 years) with various neurologic presentations had LP for CSF collection and neurotransmitter metabolite analysis as part of their clinical care. An additional salivary and blood sample was obtained at the same time. Eighteen patients had suitable samples for quantitative measure of serotonin. There was no correlation between platelet serotonin and CSF 5HIAA levels (Pearson’s coefficient of correlation – PCC: 0.010) or between salivary serotonin and CSF 5HIAA (PCC: 0.258). There was a strong negative correlation between salivary and platelet serotonin (PCC: −0.679).Conclusion:Our findings suggest that salivary serotonin measurement is not a suitable noninvasive marker for measuring central serotonin turnover.

The new diagnostic test for dystonia

Dystonia is the debilitating movement disorder of central nervous system, often inherited, appearing as involuntary movements that occur due to deficiency or excess of neurotransmitters. The penetrance of dystonia is 30%, which means, that inherited dystonia is manifested only in 30% of mutating gene carriers, while the rest suffer from latent forms, so called forms frustes of this disorder. Until now only few mutations responsible for dystonia, had been unveiled, but we expect to exist up to 100 such mutations. Unless we uncover all mutations responsible for dystonia, we require reliable test for diagnosing latent forms of dystonia; and this necessity explains the importance of present study. The purpose of this research was to elaborate discrimination of dystonia on the basis of biogenic amines exchange peculiarities. The study presents the observational case control study. The control group was randomly composed of those patients, who were checked for neuroglial tumors. We checked catecholamines and serotonin metabolites in plasma and urine of 12 dystonia patients main group by means of chromatography method and compared the results obtained from these two groups by means of the decision tree method, discriminant analysis, and factor analysis. We revealed increased serotonin turnover in dystonia, and on the base of those increased metabolites in plasma, such as 5-hydroxytryptophane and 5-hydroxiindolacetic acid, by means of advanced statistical methods we eleborated sensitive and specific test for diagnosis of dystonia. We recommend introducing into clinical practice of diagnostic tests for dystonia on the base of analysis of diagnosing level in plasma of 5-hydroxytryptophane and 5-hydroxiindolacetic acid by means of discriminant analysis and classification tree method due to high sensitivity and high specifity of those methods.

Dipeptidyl peptidase IV inhibitors diprotin A and sitagliptin administered in the first postnatal week change the level of monoamines and their metabolites in the brain of adult rats

В наших предыдущих исследованиях установлено, что у крысят, подвергнутых действию ингибиторов дипептидилпептидазы IV (ДП-IV) дипротина А и ситаглиптина в период с 5 по 18 постнатальные дни (ПНД) или с 1 по 7 ПНД, во взрослом возрасте развивается тревожно-депрессивное состояние c повышенной стресс-провоцируемой агрессией. Нарушения поведения, вызванные действием ингибиторов ДП-IV на второй - третьей неделях постнатального развития, сопровождаются изменениями функционирования моноаминергических систем мозга в структурах, опосредующих эмоционально-мотивационную деятельность. Целью настоящего исследования было изучение уровня моноаминов и их метаболитов в мозге взрослых крыс, подвергнутых действию дипротина А и ситаглиптина в ПНД 1-7. Методы. Крысятам опытных групп внутрибрюшинно вводили дипротин А (2 мг/кг) или ситаглиптин (4 мг/кг), животным контрольной группы - физиологический раствор. У крыс в возрасте 2,5 мес. методом ВЭЖХ/ЭД оценивали уровень моноаминов и их метаболитов во фронтальной коре, стриатуме, миндалине, гиппокампе и гипоталамусе. Результаты. У крыс обеих опытных групп обнаружено снижение уровня серотонина во фронтальной коре и норадреналина в стриатуме. Кроме того, у животных, которым неонатально вводили дипротин А, повышался оборот серотонина во фронтальной коре и миндалине. Заключение. Данные свидетельствуют о том, что действие ингибиторов ДП-IV в ПНД 1-7 вызывает длительную дисфункцию моноаминергических систем мозга крыс. In our previous studies, we have shown that rat pups exposed to dipeptidyl peptidase IV (DP-IV) inhibitors during postnatal days (PND) 5-18 or PND 1-7, in adulthood develops anxiety-depressive state with stress-induced aggression. Behavioral disorders in adult rats caused by the action of DP-IV inhibitors in the second - third postnatal weeks are accompanied by changes in monoamine metabolism in the striatum. The aim of this study was to estimate the levels of monoamines and their metabolites in brain structures of adult rats exposed to diprotin A and sitagliptin at PND 1-7. Methods. Diprotin A (2 mg/kg) or sitagliptin (4 mg/kg) was administered intraperitoneally to rats of the experimental group, and physiological saline - to the control animals. The levels of monoamines and their metabolites were measured by the HPLC/ED in the frontal cortex, striatum, amygdala, hippocampus and hypothalamus in 2,5-months-old animals. Results. We revealed a significant decrease in the level of serotonin in the frontal cortex and norepinephrine in the striatum. In addition, diprotin A increased serotonin turnover in the frontal cortex and amygdala. Conclusion The data suggest that the action of DP-IV inhibitors at PND 1-7 induces long-term dysfunction of monoaminergic systems of the rat’s brain.