The protective effect of melatonin on chronic paradoxical sleep deprivation induced metabolic and memory deficit in rats.

BACKGROUNDS: Impaired sleep is independent risk factor of neurodegeneration and dementia. Chronic insomnia impairs melatonin (MEL) production that is directly proportionate to its duration. The underlying mechanisms linking sleep loss to dementia and the possible therapeutic effect of melatonin have not been fully elucidated. Previous research showed great controversy concerning the effects of paradoxical sleep deprivation (PSD) on body weight, serum lipoproteins, and inflammatory cytokines. GOALS: To examine the effect of chronic paradoxical sleep deprivation (PSD) with and without MEL supplementation on memory using RAWM, parameters of metabolic syndrome (MS), liver enzymes, serum cortisol, and inflammatory cytokines as well as liver, colon, and brain histopathology. METHODS: Forty rats were divided into four groups ten animals each; C: control, G: grid group, SD: sleep deprivation group, and SD+MEL sleep deprivation treated with melatonin. RESULTS: MEL supplementation reversed PSD-induced memory deficits (P<0.05), the elevation of serum cortisol (P<0.001), glucose (P<0.05), ALT (P<0.05), AST (P<0.001), TNF-alpha (P<0.001), IL-10 (P<0.01) and improved colon, liver, and brain architecture. Melatonin reduced body weight (P<0.05), total cholesterol, LDL-c, and triglycerides as well as increased HDL-c (P<0.001). CONCLUSION: MEL has a protective effect against chronic PSD-induced metabolic malfunction and cognitive deterioration by reducing stress, improving immunity, and maintaining colonic wall integrity.

Folic acid ameliorates neonatal isolation-induced autistic like behaviors in rats: epigenetic modifications of BDNF and GFAP promotors.

The current study investigated the role of epigenetic dysregulation of brain derived neurotrophic factor (BDNF) and glial fibrillary acidic protein (GFAP) genes and oxidative stress as possible mechanisms of autistic-like behaviors in neonatal isolation model in rats and the impact of folic acid administration on these parameters. Forty Wistar albino pups were used as follows: control, folic acid administered, isolated, and isolated folic acid treated groups. Isolated pups were separated from their mothers for 90 min daily from postnatal day (PND) 1 to 11. Pups (isolated or control) received either the vehicle or folic acid (4 mg/kg/day) orally from PND 1 to 29. Behavioral tests were done from PND 30 to 35. Oxidative stress markers and antioxidant defense in the frontal cortex homogenate were determined. DNA methylation of BDNF and GFAP genes was determined by qPCR. Histopathological examination was carried out. Neonatal isolation produced autistic-like behaviors that were associated with BDNF and GFAP hypomethylation, increased oxidative stress, increased inflammatory cell infiltration, and structural changes in the frontal cortex. Folic acid administration concurrently with isolation reduced neonatal isolation-induced autistic-like behaviors, decreased oxidative stress, regained BDNF and GFAP gene methylation, and ameliorated structural changes in the frontal cortices of isolated folic acid treated rats. Novelty: Neonatal isolation induces "autistic-like" behavior and these behaviors are reversed by folic acid supplementation. Neonatal isolation induces DNA hypomethylation of BDNF and GFAP, increased oxidative stress markers, and neuroinflammation. All of these changes were reversed by daily folic acid supplementation.

Forced exercise activates the NrF2 pathway in the striatum and ameliorates motor and behavioral manifestations of Parkinson's disease in rotenone-treated rats.

BACKGROUND: Parkinson's disease (PD) is a common neurodegenerative disorder characterized by progressive loss of nigrostriatal dopaminergic neurons leading to dopamine depletion and problems of movement, emotions, and cognition. While the pathogenesis of PD is not clear, damage of dopaminergic neurons by oxygen-derived free radicals is considered an important contributing mechanism. This study aimed to evaluate the role of treadmill exercise in male Wister rats as a single treatment and as an aid-therapy with L-dopa for rotenone-induced PD. To study the role of the Nrf2- ARE pathway as a mechanism involved in exercise-associated improvement in rotenone-induced PD in rats. METHOD: Animals were divided into 5 groups, (Control, rotenone, rotenone\exercise, rotenone\L-dopa, and rotenone\exercise\L-dopa (combination)groups). After the PD induction, rats in the rotenone\exercise and combination groups were daily treadmill exercised for 4 weeks. RESULTS: Treadmill exercise significantly improved behavioral and motor aspects of rotenone-induced PD. When treadmill exercise was introduced as a single intervention, it amended most behavioral aspects of PD, gait fully corrected, short-term memory, and motor coordination. Where L-dopa corrected locomotor activity and motor coordination but failed to improve short-term memory and only partially corrected the gait of rotenone-treated rats. When treadmill exercise was combined with L-dopa, all features of PD were corrected. It was found that exercise upregulated some of its associative genes to Nrf2 pathways such as TFAM, Nrf2 and NQO.1 mRNA expression. CONCLUSION: This study suggests that forced exercise improved parkinsonian like features by activating the Nrf2 pathway.

Cognitive Impairment, P300, and Transforming Growth Factor ß1 in Different Forms of Dementia.

BACKGROUND: There are currently few biomarkers to assist in early diagnosis of dementias. OBJECTIVE: To distinguish between different dementias: Alzheimer's disease (AD), vascular dementia (VaD), and Parkinson's disease dementia (PDD) using simple neurophysiologic (P300) and laboratory markers (transforming growth factor ß1 "TGF-ß1"). METHODS: The study included 15 patients for each type of dementia and 25 age- and sex-matched control subjects. Dementia patients were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders 4th edition-revised (DSM-IV-R). Modified Mini-Mental State Examination (3MS), Memory Assessment Scale (MAS), P300, and TGF-ß1 were examined for each participant. RESULTS: There were no significant differences between groups as regard to age, sex, and education, social, and economic levels. Significant differences between groups were observed in registration and naming variables of the 3MS. Compared with the control group, P300 latency was prolonged in all groups, although to a greater extent in AD and PDD than in VaD. A serum level of TGF-ß1 was significantly elevated in all groups but was significantly higher in AD and VaD than in PDD. 3MS tended to correlate with P300 more than TGF-ß1, and to be stronger in AD than the other groups. CONCLUSION: Measurements of P300 latency and serum levels of TGF-ß1 can help distinguish AD, PDD, and VaD. P300 was more prolonged in AD and PDD than VaD whereas TGF-ß1 was significantly higher in AD and VaD than PDD. Thus P300 and TGF-ß1 may be useful biomarkers for detection and evaluation of the extent of cognitive dysfunction.

Electrophysiological differences in cortical excitability in different forms of dementia: A transcranial magnetic stimulation and laboratory biomarkers study.

BACKGROUND: The aim of the present study was to identify neurophysiologic markers to differentiate between Alzheimer dementia (AD), Vascular dementia (VaD), and Parkinson's disease dementia (PDD), and to examine their relationship to levels of transforming growth factor ß1 (TGFß1). METHODS: The study included 15 patients with each type of dementia (AD, VaD, PDD) and 25 control subjects. Dementia patients were diagnosed according to the DiagnosticandStatisticalManualofMentalDisorders4thedition-revised(DSM-IV-R). Modified Mini Mental State Examination (MMMSE), motor cortex excitability including resting and active motor thresholds (rMT, aMT), input-output (I/O) curve, contralateral and ipsilateral silent periods (cSP, iSP), short-interval intracortical inhibition (SICI) at 1,2 and 4ms, and serum levels of TGFß1 were examined. RESULTS: There were no significant differences between groups with regards to age, sex, education or socioeconomic level. There was significant neuronal hyperexcitability in the form of reduced rMT and aMT and a shallower I/O curve in all three groups of dementia compared with the control group. The durations of cSP and iSP were longer in AD and PDD groups compared with the control group, whereas there were no significant differences in VaD. SICI was less effective in the three dementia groups than in the control group at intervals of 4ms. Serum levels of TGFß1 were significantly elevated in all dementia groups in comparison with the control group. There was a significant negative correlation between serum level of TGFß1 and cSP, iSP, and SICI across all patients and a significant negative correlation between serum level of TGFß1 and iSP duration in AD. CONCLUSION: Although motor thresholds were reduced in all patients, measures of SICI, cSP and iSP could distinguish between dementia groups. Serum level of TGFß1 negatively correlated with iSP specifically in the AD group. This suggests that levels of TGFß1 may relate to GABAergic dysfunction in dementia.

Metformin versus laparoscopic ovarian drilling in clomiphene- and insulin-resistant women with polycystic ovary syndrome.

OBJECTIVE: To compare the hormonal-metabolic profiles and reproductive outcomes in clomiphene-resistant patients with polycystic ovary syndrome and insulin resistance between women receiving metformin and those undergoing laparoscopic ovarian drilling. METHODS: A total of 110 eligible participants were randomly allocated to diagnostic laparoscopy plus metformin therapy (group 1, n=55) or laparoscopic ovarian drilling (group 2, n=55). The t test was used for mean comparisons of hormonal-metabolic parameters and OGTT values before and after treatment. The chi(2) test was used for comparisons of ovulation, pregnancy, and abortion rates. RESULTS: Groups 1 and 2 showed a significant decline in testosterone, insulin-like growth factor-1 (P<0.001 vs P<0.001), and luteinizing hormone (P<0.05 vs P<0.001), while the glucose to insulin ratio was significantly increased (P<0.001 vs P<0.05) compared with baseline. Group 2 patients had more regular cycles and higher rates of ovulation and pregnancy compared with group 1: 76.4% [42/55] vs 58.2% [32/55], P<0.04; 50.8% [131/258] vs 33.5% [94/281], P<0.001; and 38.2% [21/55] vs 20.0% [11/55], P<0.03, respectively. The difference in the early abortion rate between the groups was not statistically significant. CONCLUSION: Although metformin results in a better attenuation of insulin resistance, laparoscopic ovarian drilling is associated with higher rates of ovulation and pregnancy.

Intake of melatonin is associated with amelioration of physiological changes, both metabolic and morphological pathologies associated with obesity: an animal model.

Obesity and its associated metabolic pathologies are the most common and detrimental diseases, affecting over 50% of the adult population. Our knowledge about the protective effects of melatonin against high-fat diet (HFD)-induced obesity is still marginal. In this investigation, we hypothesized that melatonin can minimize the metabolic pathologies and morphological changes associated with obesity in animals receiving an HFD. To examine these effects, and to test our hypothesis, an animal model formed of male Boscat white rabbits was established. The animals were divided into three groups: (i) a control group fed regular diet; (ii) an obesity group fed an HFD for 12 weeks; and (iii) a treated group fed HFD for 12 weeks and then treated with melatonin for 4 weeks. The animals were killed and their serum and tissues were evaluated for: (i) lipid profile (cholesterol, triglycerides and low-density lipoprotein) and glucose; (ii) antioxidant enzyme (serum glutathione peroxidase, GSH-PX); and (iii) fatty changes (liver, kidney and blood vessels). Compared with the control group, intake of HFD (obesity group) was associated with: (i) a statistically significant increase in blood pressure, heart rate, sympathetic nerve activity, body weight, food consumption, serum lipids, blood glucose levels and atherogenic index; (ii) decreased level of GSH-PX and high-density lipoprotein (HDL); and (iii) fatty changes in the liver and kidney as well as atheromatous changes in the blood vessels. Compared with the obesity group, intake of melatonin (treated group) was associated with: (i) a statistically significant decrease in blood pressure, heart rate, sympathetic nerve activity, body weight, food consumption, serum lipids, blood glucose levels and atherogenic index; (ii) increased level of GSH-PX and HDL; and (iii) disappearance of fatty changes in the liver and kidney as well as atheromatous changes in the blood vessels. The administration of melatonin reduced the metabolic pathologies associated with the intake of HFD, suggesting a protective role. Although the underlying mechanisms are unclear, they may include its antioxidant and receptor-mediated effects. The clinical ramifications of these effects await further investigations.