Jes Paul

Bacopa monnieri and Bacoside-A for ameliorating epilepsy associated behavioral deficits.

Bacopa monnieri is an outstanding nervine tonic used for raising the mental performance. It helps in concentration, comprehension, recall and alertness, Brahmi is particularly beneficial as it aids in categorizing information in brain and its subsequent expression. Bacopa is also called as a natural antioxidant which may give details its neuroprotective role seen in the memory centers of the brain. Epilepsy is neuronal disorder characterized by learning, cognitive and memory impairments. The present review summarizes information concerning botany, chemistry and beneficial effect of Bacopa monnieri on epilepsy associated behavioral deficits.

Oxidative stress mediated neuronal damage in the corpus striatum of 6-hydroxydopamine lesioned Parkinson's rats: neuroprotection by serotonin, GABA and bone marrow cells supplementation.

Oxidative stress-induced neuronal cell death has been implicated in Parkinsons disease (PD). Oxidative stress initiated by 6-hydroxydopamine (6-OHDA) causes mitochondrial dysfunction leading to apoptosis and Parkinsonian neurodegeneration. We investigated the neuroprotective potential of serotonin (5-HT), gamma amino butyric acid (GABA) and autologous bone marrow cells (BMC) in combination against oxidative stress-induced cell death. PD was induced in adult male Wistar rats by intranigral infusion of 6-OHDA (8 μg/μl). The activities of antioxidant enzymes--superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were analysed. The extent of lipid peroxidation was quantified by measuring the formation of thiobarbituric acid reactive substances (TBARs). Real Time PCR gene expression of SOD, CAT and GPx were performed using specific Taqman probes. 6-OHDA induced decreased activity of SOD, CAT and GPx in corpus striatum was significantly reversed to near control (p<0.001) by treatment with 5-HT, GABA and bone marrow cells. Gene expression studies of SOD, CAT and GPx using Real Time PCR confirmed the above observation. TBAR levels were elevated (p<0.001) in 6-OHDA treated rats indicating lipid peroxidation. 5-HT and GABA along with autologous bone marrow cell supplementation significantly ameliorated 6-OHDA-induced lipid peroxidation (p<0.001). Our results suggest a new therapeutic strategy of neuroprotection against damage by oxidative stress in Parkinsons disease.

Down-regulation of cerebellar 5-HT2C receptors in pilocarpine-induced epilepsy in rats: Therapeutic role of Bacopa monnieri extract

Epilepsy is a syndrome of episodic brain dysfunction characterized by recurrent unpredictable, spontaneous seizures. Cerebellar dysfunction is a recognized complication of temporal lobe epilepsy and it is associated with seizure generation, motor deficits and memory impairment. Serotonin is known to exert a modulatory action on cerebellar function through 5HT(2C) receptors. 5-HT(2C) receptors are novel targets for developing anti-convulsant drugs. In the present study, we investigated the changes in the 5-HT(2C) receptors binding and gene expression in the cerebellum of control, epileptic and Bacopa monnieri treated epileptic rats. There was a significant down regulation of the 5-HT content (p<0.001), 5-HT(2C) gene expression (p<0.001) and 5-HT(2C) receptor binding (p<0.001) with an increased affinity (p<0.001). Carbamazepine and B. monnieri treatments to epileptic rats reversed the down regulated 5-HT content (p<0.01), 5-HT(2C) receptor binding (p<0.001) and gene expression (p<0.01) to near control level. Also, the Rotarod test confirms the motor dysfunction and recovery by B. monnieri treatment. These data suggest the neuroprotective role of B. monnieri through the upregulation of 5-HT(2C) receptor in epileptic rats. This has clinical significance in the management of epilepsy.

Enhanced glutamate, IP3 and cAMP activity in the cerebral cortex of Unilateral 6-hydroxydopamine induced Parkinson's rats: Effect of 5-HT, GABA and bone marrow cell supplementation

Parkinsons disease is characterized by progressive cell death in the substantia nigra pars compacta, which leads to dopamine depletion in the striatum and indirectly to cortical dysfunction. Increased glutamatergic transmission in the basal ganglia is implicated in the pathophysiology of Parkinsons disease and glutamate receptor mediated excitotoxicity has been suggested to be one of the possible causes of the neuronal degeneration. In the present study, the effects of serotonin, gamma-aminobutyric acid and bone marrow cells infused intranigrally to substantia nigra individually and in combination on unilateral 6-hydroxydopamine induced Parkinsons rat model was analyzed. Scatchard analysis of total glutamate and NMDA receptor binding parameters showed a significant increase in Bmax (P < 0.001) in the cerebral cortex of 6-hydroxydopamine infused rat compared to control. Real Time PCR amplification of NMDA2B, mGluR5, bax, and ubiquitin carboxy-terminal hydrolase were up regulated in cerebral cortex of 6-hydroxydopamine infused rats compared to control. Gene expression studies of GLAST, ά-Synuclien and Cyclic AMP response element-binding protein showed a significant (P < 0.001) down regulation in 6-OHDA infused rats compared to control. Behavioural studies were carried out to confirm the biochemical and molecular studies. Serotonin and GABA along with bone marrow cells in combination showed reversal of glutamate receptors and behaviour abnormality shown in the Parkinsons rat model. The therapeutic significance in Parkinsons disease is of prominence.

Down regulation of cerebellar serotonergic receptors in streptozotocin induced diabetic rats: Effect of pyridoxine and Aegle marmelose.

Oxidative stress plays an important role in cerebellar damage caused by diabetes, leading to deterioration in glucose homeostasis causing metabolic disorders. The present study was carried out to find the effects of Aegle marmelose leaf extract and insulin alone and in combination with pyridoxine on the cerebellar 5-HT through 5-HT(2A) receptor subtype, gene expression studies on the status of antioxidants-superoxide dismutase (SOD), glutathione peroxidase (GPx), 5-HT(2A) and 5-HT transporter (5-HTT) and immunohistochemical studies in streptozotocin induced diabetic rats. 5-HT and 5-HT(2A) receptor binding parameters, B(max) and K(d), showed a significant decrease (p<0.001) in the cerebellum of diabetic rats compared to control. Gene expression studies of SOD, GPx, 5-HT(2A) and 5-HTT in cerebellum showed a significant down regulation (p<0.001) in diabetic rats compared to control. Pyridoxine treated alone and in combination with insulin, A. marmelose to diabetic rats reversed the B(max), K(d) of 5-HT, 5-HT(2A) and the gene expression of SOD, GPx, 5-HT(2A) and 5-HTT in cerebellum to near control. The gene expression of 5-HT(2A) and 5-HTT were confirmed by immunohistochemical studies. Also, the Rotarod test confirms the motor dysfunction and recovery by treatment. These data suggest the antioxidant and neuroprotective role of pyridoxine and A. marmelose through the up regulation of 5-HT through 5-HT(2A) receptor in diabetic rats. Our results suggest that pyridoxine treated alone and in combination with insulin and A. marmelose has a role in the regulation of insulin synthesis and release, normalizing diabetic related oxidative stress and neurodegeneration affecting the motor ability of an individual by serotonergic receptors through 5-HT(2A) function. This has clinical significance in the management of diabetes.

Increased excitability and metabolism in pilocarpine induced epileptic rats: Effect of Bacopa monnieri

We have evaluated the acetylcholine esterase and malate dehydrogenase activity in the muscle, epinephrine, norepinephrine, insulin and T3 content in the serum of epileptic rats. Acetylcholine esterase and malate dehydrogenase activity increased in the muscle and decreased in the heart of the epileptic rats compared to control. Insulin and T3 content were increased significantly in the serum of the epileptic rats. Our results suggest that repetitive seizures resulted in increased metabolism and excitability in epileptic rats. Bacopa monnieri and Bacoside-A treatment prevents the occurrence of seizures there by reducing the impairment on peripheral nervous system.

Decreased cerebral cortex and liver 5-HT2A receptor gene expression and enhanced ALDH activity in ethanol-treated rats and hepatocyte cultures.

Abstract Objective: In this work, we evaluated the differential binding of serotonin 2A (5-HT2A) receptor antagonist [3H](±)2,3-dimethoxyphenyl-1-[2-(4-piperidine)-methanol] ([3H] MDL 100907) to 5-HT2A receptors in cerebral cortex and liver. Methods: Wistar adult male rats of 180–200 g body weight were given free access to 15% (v/v; ∼ 7·5 g/kg body weight per day) ethanol for 15 days. Brain 5-HT and its metabolites were assayed by a high-performance liquid chromatography. 5-HT2A receptor binding assay was done with different concentrations of [3H] MDL 100907. Hepatocyte culture was done with 10−9–10−3M of 5-HT and ketanserin. The hepatocytes were incubated for 24 hours at 37°C in 5% CO2. Results: Decreased 5-HT content (p<0·05 and p<0·001) and decreased (p<0·001) 5-HT2A receptor binding in cerebral cortex and liver of ethanol-treated rats were observed when compared with control. 5-HT2A receptor mRNA in the cerebral cortex and liver showed an increase in crossing threshold value showing decrease in gene expression in ethanol-treated rats when compared with control. In 24-hour culture works, hepatocytes with 10% ethanol showed an increase in aldehyde dehydrogenase (ALDH) activity (p<0·001), and it decreased (p<0·001) to a near-control level in the case of hepatocytes in a medium with 10% ethanol + 10−5M 5-HT and 10% ethanol + 10−7M 5-HT when compared with the hepatocytes in the medium with 10% ethanol. Conclusion: Our results suggest that the decreased serotonin function mediated through 5-HT2A receptors have a regulatory role on ALDH activity. This will have clinical significance to correct alcoholics from addiction due to allergic aldehyde accumulation.

Dopamine D1 and D2 receptor subtypes functional regulation in cerebral cortex of unilateral rotenone lesioned Parkinson’s rat model: Effect of serotonin, dopamine and norepinephrine

Parkinsons disease is a progressive neurodegenerative disorder characterized by selective degeneration of dopaminergic neurons in substantia nigra pars compacta leading to marked reduction of dopamine levels in the cerebral cortex. The present study analysed the effect of serotonin, dopamine and norepinephrine as treatment on rotenone induced Hemi-Parkinsons disease in rats and its role in the regulation of dopamine receptor subtypes in the cerebral cortex of the experimental rats. Unilateral stereotaxic single dose infusions of rotenone were administered to the substantia nigra of adult male Wistar rats. Neurotransmitters--serotonin, dopamine and norepinephrine treatments--were given to rotenone induced Hemi-Parkinsons rats. Scatchard analysis of Dopamine D₁ and D₂ receptor showed a significant increase (p < 0.001) in the cerebral cortex of the Parkinsons rats compared to control. These altered parameters were reversed to near control in the serotonin and norepinephrine treated Parkinsons disease rats and no change was observed in dopamine treated Parkinsons rats. Real-time PCR results confirmed the receptor data. Our results showed serotonin and norepinephrine functionally reversed the dopamine receptors significantly in rotenone induced Hemi-Parkinsons rat. This has clinical significance in the therapeutic management of Parkinsons disease.

Dopamine D1 and D2 receptor subtypes functional regulation in corpus striatum of unilateral rotenone lesioned Parkinson's rat model: effect of serotonin, dopamine and norepinephrine

Abstract Parkinsons disease (PD) is due to widespread degeneration in the central and peripheral nervous systems. The hallmark pathology remains in the dopaminergic striatal insufficiency and degeneration of dopaminergic neurons in the substantia nigra. Objectives: The present study analysed the effect of serotonin (5-HT), dopamine, and norepinephrine as treatment on rotenone induced hemi-Parkinsons disease in rats and its role in the regulation of dopamine receptor subtypes in the corpus striatum of the experimental rats. Methods: Unilateral stereotaxic single-dose infusions of rotenone were administered to the substantia nigra of adult male Wistar rats. Neurotransmitters serotonin (5-HT), dopamine, and norepinephrine treatments were given to rotenone induced hemi-Parkinsons rats. Dopamine receptor and its subtypes (D1 and D2) binding assay were carried out. Gene expression studies of dopamine D1 and D2 were carried out using real-time PCR. Results: Scatchard analysis of dopamine and dopamine D2 receptor showed a significant increase (P<0.001) and dopamine D1 receptor showed a significant decrease (P<0.001) in the Bmax in corpus striatum of the PD rats compared to control. These altered parameters were reversed to near control in the serotonin- and norepinephrine-treated PD rats and no change was observed in dopamine-treated PD rats. Real-time PCR results confirmed the receptor data. Conclusion: Our results showed that serotonin and norepinephrine functionally reversed in dopamine receptors in rotenone-induced hemi-Parkinsons rat. This has clinical significance in the therapeutic management of PD.