Altered muscarinic receptor expression in the cerebral cortex of epileptic rats: restorative role of Withania somnifera.

Temporal lobe epilepsy involves a sequence of events that can lead to neurotransmitter signalling alterations. There are many herbal extracts considered to be alternative therapeutic methods to manage epilepsy. In this study, we investigated the effect of Withania somnifera (WS) root extract and withanolide A (WA) in the management of temporal lobe epilepsy. Confocal imaging of TOPRO-3-stained cortical sections showed severe damage in the epileptic brain. We also observed a reduced antioxidant potential and increased peroxide levels in the epileptic test group of rats. Oxidative stress resulted in the down-regulation of CREB, NF-κB, and TNF-α, and with up-regulation of the apoptotic factors caspases 8 and 3 and Bax in the epileptic group. Epileptic condition also resulted in increased muscarinic receptor binding and mRNA expression in the cerebral cortex. Withania somnifera and withanolide A significantly reversed the altered muscarinic receptor expression and reversed the oxidative stress and resultant derailment in cell signalling. Thus our studies suggest that Withania somnifera and withanolide A play important roles in central muscarinic receptor functional balance and activation of the antioxidant system in the cerebral cortex in temporal lobe epilepsy. These findings can be of immense therapeutic significance for managing epilepsy.

Cholinergic receptor alterations in the cerebral cortex of spinal cord injured rat.

Many areas of the cerebral cortex process sensory information or coordinate motor output necessary for control of movement. Disturbances in cortical cholinergic system can affect locomotor coordination. Spinal cord injury causes severe motor impairment and disturbances in cholinergic signalling can aggravate the situation. Considering the impact of cortical cholinergic firing in locomotion, we focussed the study in understanding the cholinergic alterations in cerebral cortex during spinal cord injury. The gene expression of key enzymes in cholinergic pathway - acetylcholine esterase and choline acetyl transferase showed significant upregulation in the cerebral cortex of spinal cord injured group compared to control with the fold increase in expression of acetylcholine esterase prominently higher than cholineacetyl transferase. The decreased muscarinic receptor density and reduced immunostaining of muscarinic receptor subtypes along with down regulated gene expression of muscarinic M1 and M3 receptor subtypes accounts for dysfunction of metabotropic acetylcholine receptors in spinal cord injury group. Ionotropic acetylcholine receptor alterations were evident from the decreased gene expression of alpha 7 nicotinic receptors and reduced immunostaining of alpha 7 nicotinic receptors in confocal imaging. Our data pin points the disturbances in cortical cholinergic function due to spinal cord injury; which can augment the locomotor deficits. This can be taken into account while devising a proper therapeutic approach to manage spinal cord injury.

Oxidative stress and cell death in the cerebral cortex as a long-term consequence of neonatal hypoglycemia.

Neonatal hypoglycemia limits glucose supply to cells leading to long-term consequences in brain function. The present study evaluated antioxidant and cell death factors' alterations in cerebral cortex of 1-month-old rats exposed to neonatal hypoglycemia. Gene expression studies by real-time PCR were carried out using gene-specific TaqMan probes. Fluorescent dyes were used for immunohistochemistry and nuclear staining and imaged by confocal microscope. Total antioxidant level and expression of antioxidant enzymes - superoxide dismutase (SOD) and gluthathione peroxide (GPx) - mRNA was significantly reduced along with high peroxide level in the cerebral cortex of 1-month-old rats exposed to neonatal hypoglycemia. Real-time PCR analysis showed an upregulation of Bax, caspase 3, and caspase 8 gene expression. Confocal imaging with TOPRO-3 staining and immunohistochemistry with caspase 3 antibody indicated cell death activation. The reduced free radical scavenging capability coupled with the expression of key factors involved in cell death pathway points to the possibility of oxidative stress in the cortex of 1-month-old rats exposed to neonatal hypoglycemia. The observed results indicate the effects of neonatal hypoglycemia in determining the antioxidant capability of cerebral cortex in a later stage of life.

Curcumin pretreatment mediates antidiabetogenesis via functional regulation of adrenergic receptor subtypes in the pancreas of multiple low-dose streptozotocin-induced diabetic rats.

Lifestyle modification pivoting on nutritional management holds tremendous potential to meet the challenge of management of diabetes. The current study hypothesizes that regular uptake of curcumin lowers the incidence of diabetes by functional regulation of pancreatic adrenergic receptor subtypes. The specific objective of the study was to identify the regulatory pathways implicated in the antidiabetogenesis effect of curcumin in multiple low-dose streptozotocin (MLD-STZ)-induced diabetic Wistar rats. Administration of MLD-STZ to curcumin-pretreated rats induced a prediabetic condition. Scatchard analysis, real-time polymerase chain reaction, and confocal microscopic studies confirmed a significant increase in α2-adrenergic receptor expression in the pancreas of diabetic rats. Pretreatment with curcumin significantly decreased α2-adrenergic receptor expression. The diabetic group showed a significant decrease in the expression of ß-adrenergic receptors when compared with control. Pretreatment significantly increased ß-adrenergic receptor expression to near control. When compared with the diabetic rats, a significant up-regulation of CREB, phospholipase C, insulin receptor, and glucose transporter 2 were observed in the pretreated group. Curcumin pretreatment was also able to maintain near control levels of cyclic adenosine monophosphate, cyclic guanosine monophosphate, and inositol triphosphate. These results indicate that a marked decline in α2-adrenergic receptor function relents sympathetic inhibition of insulin release. It also follows that escalated signaling through ß-adrenergic receptors mediates neuronal stimulation of hyperglycemia-induced ß-cell compensatory response. Curcumin-mediated functional regulation of adrenergic receptors and modulation of key cell signaling molecules improve pancreatic glucose sensing, insulin gene expression, and insulin secretion.

Alteration in 5-HT2C, NMDA receptor and IP3 in cerebral cortex of epileptic rats: restorative role of Bacopa monnieri.

Bacopa monnieri is effective in stress management, brain function and a balanced mood. 5-HT2C receptors have been implicated in stress whereas NMDA receptors and mGlu5 play crucial role in memory and cognition. In the present study, we investigated the role of B. monnieri extract in ameliorating pilocarpine induced temporal lobe epilepsy through regulation of 5-HT2C and NMDA receptors in cerebral cortex. Our studies confirmed an increased 5-HT2C receptor function during epilepsy thereby facilitating IP3 release. We also observed an decreased NMDA receptor function with an elevated mGlu5 and GLAST gene expression in epileptic condition indicating the possibility for glutamate mediated excitotoxicity. These alterations lead to impaired behavioural functions as indicated by the Elevated Plus maze test. Carbamazepine and B. monnieri treatments to epileptic rats reversed the alterations in 5-HT2C, NMDA receptor functions and IP3 content thereby effectively managing the neurotransmitter balance in the cerebral cortex.

Cortical cholinergic dysregulation as a long-term consequence of neonatal hypoglycemia.

Neonatal hypoglycemia limits the glucose supply to cells, affecting the function of brain due to its high energy demand. This can cause long-term consequences in brain function, leading to memory and cognitive deficits. The present study evaluated the cholinergic functional regulation in cerebral cortex of one month old rats exposed to neonatal hypoglycemia to understand the long-term effects of early life stress. Receptor binding and gene expression studies were done in the cerebral cortex to analyze the changes in total muscarinicreceptors, muscarinic M1, M2, M3 receptors, and the enzymes involved in acetylcholine metabolism, cholineacetyl transferase and acetylcholine esterase. Neonatal hypoglycemia decreased total muscarinic receptors (p < 0.001) with reduced muscarinic M1, M2, and M3 receptor genes (p < 0.001) in one month old rats. The reduction in acetylcholine metabolism is indicated by the downregulated cholineacetyl transferase, upregulated acetylcholine esterase, and decreased vesicular acetylcholine transporter expression. These alterations in cholinergic function in one month old rat brain indicates the longterm consequences of neonatal hypoglycemia in cortical function, which can contribute to the onset of many disease conditions in later stages of life.

Long term effects of neonatal hypoglycaemia on pancreatic function.

OBJECTIVES: Low blood glucose in neonates predisposes to long term pancreatic damage. We focused on evaluating long term consequences of neonatal hypoglycaemia in pancreatic functions. METHODS: Pancreatic function was analysed by measuring DNA/protein synthesis, glucose/ATP uptake in vitro. Gene expression of Pdx1, NeuroD1, Pax4, Bax, caspase 3, Beclin1 were done. Muscarinic receptors were analysed by radio receptor assay. RESULT: Overall pancreatic efficiency was reduced in one-month-old rats exposed to neonatal hypoglycaemia as indicated by decreased DNA/protein synthesis and glucose/ATP uptake in vitro. Both Pdx1 and Neuro D1 expression were significantly down-regulated whereas Pax4 was up-regulated. Up-regulated Bax, caspase 3 and beclin1 along with reduced muscarinic receptors accounts for activation of cell death pathways. CONCLUSION: The study revealed a drastic reduction in pancreatic functions along with activation of apoptotic factors in one month old rats exposed to neonatal hypoglycaemia.

Increased cortical neuronal survival during liver injury: effect of gamma aminobutyric acid and 5-HT chitosan nanoparticles.

Use of nanoparticulate drug delivery system for an effective therapeutic outcome against diseases gains immense hope in the study of drug delivery to partially hepatectomised rats. In the present study, partially hepatectomised rats treated with Gamma aminobutyric acid (GABA) and serotonin (5-HT) chitosan nanoparticles, individually and in combination, were evaluated to analyse their role in GABAB, and 5-HT2A receptors functional regulation, interrelated neuronal survival mechanisms by nuclear factor kappa B (NF-kappaB), tumour necrosis factor-a (TNF-alpha), Akt-1 and the antioxidant enzyme superoxide dismutase (SOD) in the cerebral cortex. A significant decrease in GABA, and 5-HT2A receptor numbers and gene expressions denoted a homeostatic adjustment by the cerebral cortex to trigger the sympathetic innervations during elevated DNA synthesis in the liver. GABAB, and 5-HT2A signalling directly influenced the cyclic AMP response element binding protein (CREB) expression, neuronal survival and ROS mediated cell damage which was confirmed from the gene expression of NF-kappaB, TNF-alpha, Akt-1 and SOD. In addition to enhanced hepatocyte proliferation, GABA and 5-HT chitosan nanoparticle treatment protected the neurons from ROS mediated cell damage and promoted their survival in the cerebral cortex. This has application in liver based diseases and treatments with nanosized active compounds.

GABA and 5-HT chitosan nanoparticles decrease striatal neuronal degeneration and motor deficits during liver injury.

The metabolic alterations resulted from hepatic injury and cell loss lead to synaptic defects and neurodegeneration that undoubtedly contribute motor deficits. In the present study, GABA and 5-HT chitosan nanoparticles mediated liver cell proliferation influenced by growth factor and cytokines and neuronal survival in corpus striatum of partially hepatectomised rats was evaluated. Liver cell proliferation was initiated and progressed by the combined effect of increased expression of growth factor, insulin like growth factor-1 and decreased expressions of cytokines, tumor necrosis factor-α and Akt-1. This was confirmed by the extent of incorporation of thymidine analogue, BrdU, in the DNA of rapidly dividing cells. Inappropriate influx of compounds to corpus striatum resulting from incomplete metabolism elevated GABAB and 5-HT2A neurotransmissions compared to those treated with nanoparticles. This directly influenced cyclic AMP response element binding protein, glial cell derived neurotrophic factor and brain derived neurotrophic factor in the corpus striatum that facilitate neurogenesis, neuronal survival, development, differentiation and neuroprotection. Motor deficits due to liver injury followed striatal neuronal damage were scored by grid walk and rotarod studies, which confirmed the regain of motor activity by GABA and 5-HT chitosan nanoparticle treatment. The present study revealed the therapeutic significance of GABA and 5-HT chitosan nanoparticles in liver based diseases and related striatal neuronal damage that influenced by GABA and 5-HT.

Striatal cholinergic functional alterations in hypoxic neonatal rats: role of glucose, oxygen, and epinephrine resuscitation.

Molecular processes regulating cholinergic functions play an important role in the control of respiration under hypoxia. Cholinergic alterations and its further complications in respiration due to hypoxic insult in neonatal rats and the effect of glucose, oxygen, and epinephrine resuscitation was evaluated in the present study. Receptor binding and gene expression studies were done in the corpus striatum to analyse the changes in total muscarinic receptors, muscarinic M1, M2, M3 receptors, and the enzymes involved in acetylcholine metabolism, choline acetyltransferase and acetylcholinesterase. Neonatal hypoxia decreased total muscarinic receptors with reduced expression of muscarinic M1, M2, and M3 receptor genes. The reduction in acetylcholine metabolism is indicated by the downregulated choline acetyltransferase and upregulated acetyl cholinesterase expression. These cholinergic disturbances were reversed to near control in glucose-resuscitated hypoxic neonates. The adverse effects of immediate oxygenation and epinephrine administration are also reported. The present findings points to the cholinergic alterations due to neonatal hypoxic shock and suggests a proper resuscitation method to ameliorate these striatal changes.

Neuroprotective potential of Bacopa monnieri and Bacoside A against dopamine receptor dysfunction in the cerebral cortex of neonatal hypoglycaemic rats.

Neonatal hypoglycaemia initiates a series of events leading to neuronal death, even if glucose and glycogen stores return to normal. Disturbances in the cortical dopaminergic function affect memory and cognition. We recommend Bacopa monnieri extract or Bacoside A to treat neonatal hypoglycaemia. We investigated the alterations in dopaminergic functions by studying the Dopamine D1 and D2 receptor subtypes. Receptor-binding studies revealed a significant decrease (p < 0.001) in dopamine D1 receptor number in the hypoglycaemic condition, suggesting cognitive dysfunction. cAMP content was significantly (p < 0.001) downregulated in hypoglycaemic neonatal rats indicating the reduction in cell signalling of the dopamine D1 receptors. It is attributed to the deficits in spatial learning and memory. Hypoglycaemic neonatal rats treated with Bacopa extract alone and Bacoside A ameliorated the dopaminergic and cAMP imbalance as effectively as the glucose therapy. The upregulated Bax expression in the present study indicates the high cell death in hypoglycaemic neonatal rats. Enzyme assay of SOD confirmed cortical cell death due to free radical accumulation. The gene expression of SOD in the cortex was significantly downregulated (p < 0.001). Bacopa treatment showed a significant reversal in the altered gene expression parameters (p < 0.001) of Bax and SOD. Our results suggest that in the rat experimental model of neonatal hypoglycaemia, Bacopa extract improved alterations in D1, D2 receptor expression, cAMP signalling and cell death resulting from oxidative stress. This is an important area of study given the significant motor and cognitive impairment that may arise from neonatal hypoglycaemia if proper treatment is not implemented.

Increased neuronal survival in the brainstem during liver injury: role of γ-aminobutyric acid and serotonin chitosan nanoparticles.

γ-Aminobutyric acid (GABA)- and serotonin (5-HT)-mediated cell signaling, neuronal survival enhancement, and reduced neuronal death in brainstem during liver injury followed by active liver regeneration have a critical role in maintaining routine bodily functions. In the present study, GABAB and 5-HT2A receptor functional regulation, interrelated actions of neuronal survival factors, and expression of apoptotic factors in the brainstem during GABA and 5-HT chitosan nanoparticles-induced active liver regeneration in partially hepatectomized rats were evaluated. Partially hepatectomized rats were treated with the nanoparticles, and receptor assays and confocal microscopic studies of GABAB and 5-HT2A receptors, gene expression studies of GABAB and 5-HT2A receptors, nuclear factor-κB (NF-κB), tumor necrosis factor-α (TNF-α), Akt-1, phospholipase C, Bax, and caspase-8 were performed with the brainstems of experimental animals. A significant decrease in GABAB and 5-HT2A receptor numbers and gene expressions denoted a homeostatic adjustment by the brain to trigger the sympathetic innervations during elevated DNA synthesis in the liver. The neuronal apoptosis resulting from the loss of liver function after partial hepatectomy was minimized by nanoparticle treatment in rats compared with rats with no treatment during regeneration. This was confirmed from the gene expression patterns of NF-κB, TNF-α, Akt-1, phospholipase C, Bax, and caspase-8. The present study revealed the potential of GABA and 5-HT chitosan nanoparticles for increasing neuronal survival in the brainstem during liver injury following regeneration, which avoids many neuropsychiatric problems.

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 Parkinson's 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 Parkinson's disease.

Impaired motor learning attributed to altered AMPA receptor function in the cerebellum of rats with temporal lobe epilepsy: ameliorating effects of Withania somnifera and withanolide A.

The aim of this study was to investigate the effect of Withania somnifera (WS) extract, withanolide A (WA), and carbamazepine (CBZ) on cerebellar AMPA receptor function in pilocarpine-induced temporal lobe epilepsy (TLE). In the present study, motor learning deficit was studied by rotarod test, grid walk test, and narrow beam test. Motor learning was significantly impaired in rats with epilepsy. The treatment with WS and WA significantly reversed the motor learning deficit in rats with epilepsy when compared with control rats. There was an increase in glutamate content and IP3 content observed in rats with epilepsy which was reversed in WS- and WA-treated rats with epilepsy. alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor dysfunction was analyzed using radiolabeled AMPA receptor binding assay, AMPA receptor mRNA expression, and immunohistochemistry using anti-AMPA receptor antibody. Our results suggest that there was a decrease in Bmax, mRNA expression, and AMPA receptor expression indicating AMPA receptor dysfunction, which is suggested to have contributed to the motor learning deficit observed in rats with epilepsy. Moreover, treatment with WS and WA resulted in physiological expression of AMPA receptors. There was also alteration in GAD and GLAST expression which supplemented the increase in extracellular glutamate. The treatment with WS and WA reversed the GAD and GLAST expression. These findings suggest that WS and WA regulate AMPA receptor function in the cerebellum of rats with TLE, which has therapeutic application in epilepsy.

Disruption of cerebellar cholinergic system in hypoxic neonatal rats and its regulation with glucose, oxygen and epinephrine resuscitations.

Cholinergic system is important for respiratory control from the first days of life. Disturbances in cholinergic pathway due to early life stress like hypoxic shock can adversely affect the ventilatory response. The present study evaluates neonatal hypoxic insult mediated cholinergic disturbances and the role of glucose, oxygen and epinephrine resuscitation. The changes in total muscarinic, muscarinic M1, M2, M3 receptors and the enzymes involved in acetylcholine metabolism - cholineacetyl transferase and acetylcholine easterase in the cerebellum were analyzed. Hypoxic stress decreased cerebellar muscarinic receptor density with a decreased muscarinic M1, M2 and M3 receptor gene expression. The metabolic shift in the acetylcholine synthesis and release is indicated by the decreased cholineacetyl transferase mRNA expression and increased acetylcholine esterase gene expression. Glucose, acting as a precursor for acetyl choline synthesis and an immediate energy source, helps in reversing the cholinergic disturbances in hypoxic neonates. The limitation of immediate oxygenation and epinephrine administration in ameliorating cholinergic disturbances in hypoxic neonates was also reported. This will help in devising a better resuscitation program for the management of neonatal hypoxia.

Neonatal hypoxic insult-mediated cholinergic disturbances in the brain stem: effect of glucose, oxygen and epinephrine resuscitation.

Molecular processes regulating cholinergic functions play an important role in the control of respiration under neonatal hypoxia. The present study evaluates neonatal hypoxic insult-mediated cholinergic alterations and the protective role of glucose, oxygen and epinephrine resuscitation. The changes in total muscarinic, muscarinic M1, M2, M3 receptors and the enzymes involved in acetylcholine metabolism--cholineacetyl transferase and acetylcholine easterase in the brain stem were analyzed. Hypoxic stress decreased total muscarinic receptors along with a reduction in muscarinic M1, M2 and M3 receptor genes in the brain stem. The reduction in acetylcholine metabolism is indicated by the down regulated cholineacetyl transferase and up regulated acetylcholine easterase expression. These cholinergic disturbances in the brain stem were reversed by glucose resuscitation to hypoxic neonates. The adverse effects of immediate oxygenation and epinephrine administration were also reported. This has immense clinical significance in establishing a proper resuscitation for the management of neonatal hypoxia.

NMDA and AMPA receptor mediated excitotoxicity in cerebral cortex of streptozotocin induced diabetic rat: ameliorating effects of curcumin.

Functional activity of neurotransmitter receptor and their sensitivity to regulation are altered in DM. We evaluated the neuroprotective effect of curcumin in glutamate mediated excitotoxicity in cerebral cortex of streptozotocin induced diabetic rats. Gene expression studies in diabetic rats showed a down regulation of glutamate decarboxylase mRNA leading to accumulation of glutamate. Radioreceptor binding assays showed a significant increase in α-amino-3-hydroxy-5-methyl-4-isoxazole propionate and N-methyl-D-aspartate receptors density which was confirmed by immunohistochemical studies. Decreased glutathione peroxidases gene expression indicates enhanced oxidative stress in diabetic rats. This leads to decreased expression of glutamate aspartate transporter, which in turn reduces glutamate transport. All these events lead to excitotoxic neuronal death in the cerebral cortex, which was confirmed by the increased expression of caspase 3, caspase 8 and BCL2-associated X protein. Curcumin and insulin treatment reversed these altered parameters to near control. We establish, a novel therapeutic role of curcumin by reducing the glutamate mediated excitotoxicity in cerebral cortex of diabetes through modulating the altered neurochemical parameters.

Striatal dopamine receptors modulate the expression of insulin receptor, IGF-1 and GLUT-3 in diabetic rats: effect of pyridoxine treatment.

The incidence of type 2 diabetes mellitus is rising at alarming proportions. Central nervous system plays an important part in orchestrating glucose metabolism, with accumulating evidence linking dysregulated central nervous system circuits to the failure of normal glucoregulatory mechanisms. Pyridoxine is a water soluble vitamin and it has important role in brain function. This study aims to evaluate the role of pyridoxine in striatal glucose regulation through dopaminergic receptor expressions in streptozotocin induced diabetic rats. Radio receptor binding assays for dopamine D(1), D(2) receptors were done using [(3)H] 7-chloro-3-methyl-1-phenyl-1,2,4,5-tetrahydro-3-benzazepin-8-ol and [(3)H] 5-chloro-2-methoxy-4-methylamino-N-[-2-methyl-1-(phenylmethyl)pyrrolidin-3-yl]benzamide. Gene expressions were done using fluorescently labeled Taqman probes of dopamine D(1), D(2) receptor, Insulin receptor, Insulin like growth factor-1(IGF-1) and Glucose transporter-3 (GLUT-3). Bmax of dopamine D(1) receptor is decreased and B(max) of dopamine D(2) was increased in diabetic rats compared to control. Gene expression of dopamine D(1) receptor was down regulated and dopamine D(2) receptor was up regulated in diabetic rats. Our results showed decreased gene expression of Insulin receptor, IGF-1 and increased gene expression of GLUT-3 in diabetic rats compared to control. Pyridoxine treatment restored diabetes induced alterations in dopamine D(1), D(2) receptors, Insulin receptor, IGF-1, GLUT-3 gene expressions in striatum compared to diabetic rats. Insulin treatment reversed dopamine D(1), D(2) receptor, GLUT-3 mRNA expression, D(2) receptor binding parameters in the striatum compared to diabetic group. Our results suggest the potential role of pyridoxine supplementation in ameliorating diabetes mediated dysfunctions in striatal dopaminergic receptor expressions and insulin signaling. Thus pyridoxine has therapeutic significance in diabetes management.

Role of GABA and serotonin coupled chitosan nanoparticles in enhanced hepatocyte proliferation.

The development of nanoparticles containing active molecules having improved stability, sustained release and maximum half life helps in cell proliferation result in enhanced tissue regeneration. Our study focuses on the use of Gamma amino butyric acid (GABA) and serotonin (5-HT) coupled chitosan nanoparticles for the active liver regeneration in male Wistar rats. The nanoparticles were prepared and the morphology was studied using SEM. The FT-IR spectra of the nanoparticles and the maximum encapsulation efficiency of GABA and 5-HT binding to chitosan nanoparticles were observed. The in vitro release studies provided the percentage release of GABA and 5-HT from the nanoparticles at different time intervals. The quantification of DNA and protein syntheses was done using [(3)H] thymidine and [(3)H] leucine uptake studies that determined the enhancement in hepatocyte proliferation. Our results project the role of GABA and 5-HT chitosan nanoparticles in the treatment of liver based diseases.

Evaluation of GABA-chitosan nanoparticle induced cell signaling activation during liver regeneration after partial hepatectomy.

Liver damage due to infection, cirrhosis, accidents and diseases lead to destruction of hepatocytes and their regeneration to its original form is important for the proper functioning of the body. Gamma aminobutyric acid (GABA), a neurotransmitter, was coupled with a biopolymer chitosan and the nanosized complexes were made. The morphology was studied by scanning electron microscope and the interaction of GABA with chitosan was analysed by FT-IR spectroscopy. The interaction of GABA-chitosan nanoparticles with hepatocytes were observed by FITC labeled nanoparticles. After partial hepatectomy in male Wistar rats, DNA synthesis was estimated by tritiated thymidine uptake and the activity of thymidine kinase and protein synthesis by tritiated leucine uptake in hepatocytes. There was an increase in tritiated thymidine uptake in partially hepatectomised groups with nanoparticle treatment (GCNP) when compared to partially hepatectomised groups without nanoparticle treatment (PHNT) and with pure GABA treatment (G). Inositol 1,4,5 trisphosphate (IP3) content and gene expression of phospholipase C mRNA and nuclear factor kappa-light-chain-enhancer of activated B (NF-KB) mRNA was decreased for groups G and GCNP with respect to PHNT. Thus our results showed increased hepatocyte regeneration with decreased cell death in group G and more better with GCNP when compared to PHNT.