Ameliorative Effect of Palm Oil in Aluminum Lactate Induced Biochemical and Histological Implications in Rat Brain.

α-Tocotrienol is one of the major constituents of palm oil. It is a well-known antioxidant and cholesterol-lowering neuroprotectant. To prevent the initiation of Alzheimer's like symptoms, much attention has been shifted to the major role played by antioxidants. Previous epidemiological reports correlate the increasing incidence of developing Alzheimer's disease (AD), to the aluminum (Al) content in drinking water. Al, being a ubiquitous element, has a long history of being particularly reactive towards multiple aspects of neurobiology. So, the current study examines the effect of Al-induced behavioral, biochemical, and histopathological changes in rat brain; and the ameliorative effect of palm oil in reducing the resulting neurotoxicity. The experimental design consisted of 4 groups: control group which received rodent chow diet and water ad libitum; Al group received aluminum lactate (50 mg/kg bw); Al + palm oil group was administered with Al (50 mg/kg bw) and palm oil (60 mg/kg bw); and palm oil group received palm oil (60 mg/kg bw). Al was given by oral gavage once daily for 6 weeks and palm oil was administered intraperitoneally. After 6 weeks of supplementation, Al + palm oil group showed significantly lower malondialdehyde (MDA) content, but higher superoxide dismutase (SOD), catalase (CAT), GST, and GPx activity as compared to Al group. Al group has significantly higher level of MDA content, but lower SOD, CAT, GST, and GPx activity as compared to control group. In conclusion, this study suggested that palm oil was effective in preventing the Al-induced brain damage in rats.

N-Acetylcysteine Ameliorates Neurotoxic Effects of Manganese Intoxication in Rats: A Biochemical and Behavioral Study.

Clinical and experimental evidences reveal that excess exposure to manganese is neurotoxic and leads to cellular damage. However, the mechanism underlying manganese neurotoxicity remains poorly understood but oxidative stress has been implicated to be one of the key pathophysiological features related to it. The present study investigates the effects associated with manganese induced toxicity in rats and further to combat these alterations with a well-known antioxidant N-acetylcysteine which is being used in mitigating the damage by its radical scavenging activity. The study was designed to note the sequential changes along with the motor and memory dysfunction associated with biochemical and histo-pathological alterations following exposure and treatment for 2 weeks. The results so obtained showed decrease in the body weights, behavioral deficits with increased stress markers and also neuronal degeneration in histo-pathological examination after manganese intoxication in rats. To overcome the neurotoxic effects of manganese, N-acetylcysteine was used in the current study due to its pleiotropic potential in several pathological ailments. Taken together, N-acetylcysteine helped in ameliorating manganese induced neurotoxic effects by diminishing the behavioral deficits, normalizing acetylcholinesterase activity, and augmentation of redox status.

Neuroprotective effects of carbenoxolone against amyloid-beta 1-42 oligomer-induced neuroinflammation and cognitive decline in rats.

The aggregation of Aß plays a major role in the progression of Alzheimer's disease (AD) and induces neuroinflammation, neurodegeneration and cognitive decline. Recent studies have shown that the soluble aggregates of Aß are the major culprits in the development of these aberrations inside the brain. In this study, we investigated the neuroprotective potential of carbenoxolone (Cbx), which has been found to possess anti-inflammatory and nootropic properties. Male SD rats (250-300 g) were divided into the four groups (n = 8 per group): (1) sham control rats injected with vehicles, (2) Aß 1-42 group rats injected i.c.v. with Aß 42 oligomers (10 µl/rat), (3) Aß 1-42+Cbx group rats injected i.c.v. with Aß 42 oligomers (10 µl/rat) and i.p. with carbenoxolone disodium (20 mg/kg body weight) for six-weeks and (4) Cbx group rats injected i.p. with carbenoxolone disodium (20 mg/kg body weight) for six-weeks. Progressive learning and memory deficits were seen through a battery of behavioral tests and a significant increase in the expressions of GFAP and Iba-1 was observed which resulted in the release of pro-inflammatory cytokines post Aß oligomer injection. The levels of BDNF, Bcl-2 and pCREB were decreased while Bax, caspase-3, caspase-9 and cytochrome c levels were induced. Also, neurotransmitter levels were altered and neuronal damage was observed through histopathological studies. After Cbx supplementation, the expressions of GFAP, IBA-1, pro-inflammatory cytokines, iNOS, nNOS and nitric oxide levels were normalized. The expression levels of pro-apoptotic markers were decreased and neurotrophin levels were restored. Also, neurotransmitter levels and neuronal profile were improved and progressive improvements in behavioural performance were observed. Our results demonstrated that Cbx might have prevented the Aß induced neurodegeneration and cognitive decline by inhibiting the neuroinflammation and inducing BDNF/CREB signalling. These findings suggest that Cbx can be explored as a potential therapeutic agent against the progression of AD.

Neuroprotective effects of hydro-alcoholic extract of Eclipta alba against 1-methyl-4-phenylpyridinium-induced in vitro and in vivo models of Parkinson's disease.

Pathogenesis of Parkinson's disease (PD) specifically involves the degeneration of dopaminergic neurons in the substantia nigra region, which mainly begun with the overwhelmed oxidative stress and neuroinflammation. Considering the antioxidant and other pharmacological properties, Eclipta alba needs to be exploited for its possible neuroprotective efficacy against PD and other neurological disorders. Therefore, the current study was conducted to exemplify the remedial effects of hydro-alcoholic extract of E. alba (EA-MEx) against MPP+-elicited in vitro and in vivo PD models. SH-SY5Y, a neuroblastoma cell culture and male Wistar rats were used to impersonate the hallmarks of PD. Qualitative and quantitative analyses of EA-MEx revealed the presence of quercetin, ellagic acid, catechin, kaempferol, and epicatechin at varying concentrations. EA-MEx was found to deliver considerable protection against MPP+-induced oxidative damages in SH-SY5Y cells. Furthermore, in vivo study also supported the neuroprotective efficacy of EA-MEx, with significant mitigation of behavioral deficits induced by intrastriatal injection of MPP+. Furthermore, the disturbed levels of cellular antioxidant machinery have been significantly improved with the pre-treatment of EA-MEx. Mechanistically, the expression of α-synuclein, tyrosine hydroxylase, and mortalin were also found to be improved with the prior treatment of EA-MEx. Hence, the study suggests Eclipta alba as a suitable candidate for the development of better neuropathological therapeutics.

Studies on the Neuromodulatory Effects of Ginkgo biloba on Alterations in Lipid Composition and Membrane Integrity of Rat Brain Following Aluminium Neurotoxicity.

Brain contains the highest lipid content involved in various structural and physiological activities such as structural development, neurogenesis, synaptogenesis, signal transduction and myelin sheath formation. Lipids bilayer is essential to maintain the structural integrity for the physiological functions of protein. Impairments in lipid metabolism and its composition can lead to the progression of various brain ailments such as neurodegenerative and neuropsychiatric disorders. Aluminium (Al), the potent neurotoxin has been linked to Alzheimer's disease (AD) like pathology. Al can bind to biomembrane and influence oligomerization and conformational changes of proteins by acting as cross-linkers. The present study evaluated the influence of Ginkgo biloba (GBE) on the lipid profile alterations induced by Al lactate in hippocampal and cortical regions using FTIR spectroscopy. Rats were exposed with 10 mg/kg b.w. (intraperitoneal) of Al lactate for 6 weeks. This was followed by a treatment protocol of GBE (100 mg/kg b.w.) both preexposure (2 weeks) and conjunctive (6 weeks) exposure. A self recovery group was also included, where Al withdrawal was done for 2 weeks post Al exposure. A significant decrease in peak areas of cholesterol, sphingolipids and phospholipids was observed in Al treated groups. Further, polyunsaturated fatty acids and membrane fluidity has also decreased, as revealed by olefinic and methyl asymmetric stretching bands. Al treatment significantly increased the fluorescence polarization, anisotropy and order parameter, which however were normalized following GBE supplementation. Results also showed that pretreatment with GBE provided more beneficial effects on the adverse changes following Al in membrane composition and behavioral outcome.

Maintenance of Amyloid-beta Homeostasis by Carbenoxolone Post Aß-42 Oligomer Injection in Rat Brain.

The equilibrium between cerebral production and clearance of Aß is maintained either by the active removal through blood-brain barrier or by the uptake and degradation through ubiquitin-proteasome system (UPS) and autophagy. The dysfunction of UPS and dysregulation of molecular chaperones such as heat shock proteins (HSPs) is well correlated with the progression of Alzheimer's disease (AD). Therefore, the restoration of heat shock system and UPS appears to be an effective approach to maintain the Aß homeostasis. The alteration in the Aß homeostasis was induced by a single bilateral intrahippocampal injection of Aß 42 oligomers (10 µl/rat) into the dorsal hippocampus of the rat brain. Cbx (carbenoxolone), a HSP inducer and Aß 42 aggregation inhibitor, was tested (20 mg/kg body weight, i.p. for six-weeks) against the altered Aß homeostasis in the rat brain. Aß 42 oligomers downregulated the expression of HSPs and co-treatment with Cbx prevented this decline. Cbx was able to restore the UPS function post Aß 42 oligomer injection. Aß 42 oligomers induced upregulation of the expression levels of APP, BACE-1 and Tau was also normalized after the co-treatment with Cbx. A significant decrease in the thioflavin-T and Aß positive deposits in different regions of the rat brain was observed after Cbx co-treatment. Thus, the present study projects Cbx as a potential candidate for the maintenance of Aß homeostasis through inhibition of amyloid aggregation and restoration of the functioning of molecular chaperones and UPS system in the progression of AD.

Modulatory Effects of Ginkgo biloba Against Amyloid Aggregation Through Induction of Heat Shock Proteins in Aluminium Induced Neurotoxicity.

Protein misfolding and aggregation of amyloid beta (Aß) peptide, as well as formation of neurofibrillary tangles (NFTs) are the signature hallmarks of Alzheimer's disease (AD) pathology. To prevent this, molecular chaperones come into play as they facilitate the refolding of the misfolded proteins and cell protection under stress. Here, we have evaluated the possible effects of Ginkgo biloba (GBE) against aggregation of the Aß through activation of heat shock proteins (HSPs) in the Aluminium (Al) induced AD based model. GBE (100 mg/kg body weight) was administered per oral to the female SD rats in conjunction with intraperitoneal (i.p.) injection of Al lactate (10 mg/kg body weight) for six weeks. Pretreated animals were administered GBE for additional two weeks prior to any exposure of Al. GBE administration resulted in decrease in Aß aggregation, ubiquitin deposition, accompanying a significant decline in APP & Tau protein hyperphosphorylation which can be attributed to activation of Heat shock factor (HSF-1) and upregulation in the protein expression of HSPs. Histopathological investigation studies have also shown the decrease in aggregation of Aß peptide by GBE administration. Additionally, the decrease in ROS levels and Aß aggregation by GBE administration prohibited the decline in the neurotransmitter levels and monoamine oxidase levels in hippocampus and cortex. This further caused improvement in learning and memory of the animals. In conclusion, our results indicate that GBE prevents the symptoms of Al induced AD like pathophysiology by upregulating the HSPs levels and decreasing the aggregation load.

Temporal changes in physiological and molecular markers in various brain regions following transient global ischemia in rats.

Several mechanisms are involved in the loss of cellular integrity and tissue destructions in various brain regions during ischemic insult. The affected brain employs various self-repair mechanisms during the poststroke recovery. Therefore, the current study involves time course changes in different brain regions following ischemia in terms of inflammation, oxidative stress and apoptosis for which a bilateral common carotid arteries occlusion model was chosen. The development of oxidative stress was seen with a marked increase in ROS and NO levels with concomitant decrease in GSH levels and also the activities of anti-oxidant enzymes. These alterations were accompanied with decreased levels of neurotransmitters and motor and cognitive deficits at various time points. Increased expressions of various pro-inflammatory cytokines and a decline in BDNF levels in hippocampal regions on 7th day post ischemia, suggesting their role in its pathogenesis. The restoration of BDNF and neurotransmitter levels along with significant decline in inflammatory cytokine levels 14th day onwards following ischemia in hippocampus suggested poststroke recovery. The extent of neuronal damage was found to be increased significantly on 7th day post ischemia as indicated by TUNEL assay and hematoxylin and eosin staining depicting enhanced number of pyknotic neurons in cortical and hippocampal regions. Cortical regions of the ischemic brains were severely affected while hippocampal regions showed significant poststroke recovery, which might attributed to the normalization of BDNF and pro-inflammatory cytokine levels. In conclusion, the present study established the central role of BDNF and pro-inflammatory cytokines in the poststroke recovery. Also, the cortical and hippocampal regions were found to be more susceptible for ischemic injury. As our results indicated, full recovery after ischemic injury in different brain regions was not achieved, therefore further studies with long-term recovery time are required to be conducted.

Ginkgo biloba attenuates aluminum lactate-induced neurotoxicity in reproductive senescent female rats: behavioral, biochemical, and histopathological study.

Extensive use of aluminum (Al) in industry, cooking utensils, and wrapping or freezing the food items, due to its cheapness and abundance in the environment, has become a major concern. Growing evidence supports that environmental pollutant Al promotes the aggregation of amyloid beta (Aß) in the brain, which is the main pathological marker of Alzheimer's disease (AD). Further, AD- and Al-induced neurotoxic effects are more common among women following reproductive senescence due to decline in estrogen. Though clinically Ginkgo biloba extract (GBE) has been exploited as a memory enhancer, its role in Al-induced neurotoxicity in reproductive senescent female rats needs to be evaluated. Animals were exposed to intraperitoneal dose (10 mg/kg b.wt) of Al and oral dose (100 mg/kg b.wt.) of GBE daily for 6 weeks. A significant decline in the Al-induced Aß aggregates was observed in hippocampal and cortical regions of the brain with GBE supplementation, as confirmed by thioflavin (ThT) and Congo red staining. GBE administration significantly decreased the reactive oxygen species, lipid peroxidation, nitric oxide, and citrulline levels in comparison to Al-treated rats. On the contrary, a significant increase in the reduced glutathione, GSH/GSSG ratio as well as in the activities of antioxidant enzymes was observed with GBE administration. Based on the above results, GBE prevented the neuronal loss in the hippocampus and cortex, hence caused significant improvement in the learning and memory of the animals in terms of AChE activity, serotonin levels, Morris water maze, and active and passive avoidance tests. In conclusion, GBE has alleviated the behavioral, biochemical, and histopathological alterations due to Al toxicity in rats. However, molecular studies are going on to better understand the mechanism of GBE protection against the environmental toxicant Al exposure. Graphical abstract .

Carbenoxolone Reverses the Amyloid Beta 1-42 Oligomer-Induced Oxidative Damage and Anxiety-Related Behavior in Rats.

The characteristic feature of Alzheimer's disease (AD) is the deposition of amyloid beta inside the brain mainly consisting of Aß 40 and 42 aggregates. Soluble aggregates of Aß 42 are reported to be more toxic and exert their neurotoxicity by the induction of oxidative damage and cognitive deficits such as anxiety-like behavior. These alterations emerge due to the induction of gap junction communication through increased activity and expression of connexins such as connexin43 (Cx43) leading to the release of small neurotoxic molecules. In the present study, single intracerebroventricular (icv) injection of Aß 42 oligomers (10 µl/rat) was used to induce oxidative damage and anxiety-related behavior in rats. Carbenoxolone (Cbx), a gap junction blocker, was tested (20 mg/kg body weight, i.p., for 6 weeks) against these alterations. Cbx supplementation reversed the Aß 42 oligomer-induced alterations in the antioxidant defense system. The levels ROS, lipid peroxidation, and protein carbonyls were normalized with Cbx co-treatment leading to the decreased DNA fragmentation and pyknosis in different regions of the rat brain. Cbx induced the anxiolytic behavior and ameliorated the cognitive decline in rats post Aß 42 oligomer injection. The increased expression of Cx43 post Aß 42 oligomer injection was also reduced with Cbx supplementation, which might have inhibited the release of small neurotoxic molecules. Our results showed that Cbx prevents the Aß 42 oligomer-induced oxidative damage and anxiety-like behavior partly by blocking the gap junction communication, which suggests that the therapeutic potential of Cbx may be explored in the progression of AD.

CD34 and CD117 Stemness of Lineage-Negative Cells Reverses Memory Loss Induced by Amyloid Beta in Mouse Model.

A majority of the neurodegenerative disorders including Alzheimer's disease are untreatable and occur primarily due to aging and rapidly changing lifestyles. The rodent Alzheimer's disease models are critical for investigating the underlying disease pathology and screening of novel therapeutic targets in preclinical settings. We aimed to characterize the stemness properties of human umbilical cord blood (hUCB) derived lineage-negative (Lin-) stem cells based on CD34 and CD117 expression as well as surface morphology using flow cytometry and scanning electron microscopy, respectively. The efficacy of the stem cells was tested by its capacity to rescue the injury caused by intrahippocampal delivery of varying doses of amyloid beta. The hUCB Lin- stem cells reversed memory loss due to Aß42-induced injury more effectively at micromolar concentration, and not picomolar concentration. More studies are required to delineate the underlying molecular events associated with hUCB Lin- stem cells.

Anti-inflammatory effects of Ginkgo biloba extract against trimethyltin-induced hippocampal neuronal injury.

BACKGROUND: Despite the immense neuromodulatory potentials of Ginkgo biloba extract as a memory enhancer, its underlying mechanism seems inadequate particularly with regard to its anti-inflammatory properties. AIM: The objective of the present study is to investigate the protective potentials of Ginkgo biloba extract (GBE) against hippocampal neuronal injury induced by trimethyltin (TMT), a potent neurotoxicant. METHODS: Male SD rats were administered trimethyltin (8.5 mg kg-1 b.wt) single intraperitoneal (i.p.) injection, followed by Ginkgo biloba extract (100 mg kg-1 b.wt i.p) for 21 days. RESULTS: The co-administration of GBE with TMT showed marked improvement in cognitive functions. Concomitantly, there was a significant decrease in oxidative stress as evident by reduction in MDA and total ROS levels. In addition, there was a marked suppression of astrocyte activation (GFAP), transcription factor NFκB and proinflammatory cytokines (TNF-α, IL-1α, 1L-6), which were found to be elevated by TMT administration. Histopathological observations showed remarkable improvement in hippocampal neuronal injury in the conjunctive group. CONCLUSION: Therefore, it is suggested that Ginkgo biloba extract is an effective agent against trimethyltin-induced hippocampal neuronal loss owing to its antioxidative as well as anti-inflammatory properties.

Effect of the NADPH oxidase inhibitor apocynin on ischemia-reperfusion hippocampus injury in rat brain.

Blockage along with sudden restoration of blood following ischemia, results in several cascading events, such as a massive ROS production which plays an important role in the pathophysiology of ischemia. NADPH oxidase complex in mitochondria complex is believed to be the major source for ROS production. The present study explores the therapeutic potential of apocynin, an NADPH oxidase inhibitor in attenuating the ROS production, and the resultant neuroinflammation and mitochondrial injury during cerebral ischemia in rats. Bilateral common carotid artery occlusion (BCCAO) model was chosen for the study where intracellular ROS and NO levels as well as the NADPH oxidase activity were found to be increased significantly post 7th day of ischemic injury. Enhanced glial activation was observed and an upregulated expression of GFAP and Iba-1 in hippocampus along with that of the transcription factor NFκB and inflammatory markers iNOS, IL-1α, IL-1ß and TNF-α.The activity of mitochondrial electron transport chain (ETC) complexes I, II, IV and V were significantly decreased following ischemia. Consequently, there was a decrease in mitochondrial membrane potential (MMP) while an increased release of cytochrome c and upregulated apoptotic markers Bax, caspase-3 and 9 initiated the programmed neuronal death which was also reflected by the marked increase in TUNEL positive cells in the hippocampal region. The physiological functional alterations have been observed following ischemic injury i.e memory and motor deficits. The apocynin supplementation significantly reduced the NADPH oxidase activity and resulted in declined ROS production which in-turn prevented the glial activation and downregulated the inflammatory and pro-apoptotic markers. Apocynin also restored the MMP (Δψm) and mitochondrial enzymes via inhibition of ROS vicious and relationship between NADPH oxidase and mitochondrial complexes. Apocynin treatment was also successfully reduced the behavioural deficits in ischemic animals. In conclusion, inhibiting the NADPH oxidase complex presumably attenuated the mitochondrial injury, neuroinflammation and apoptosis following ischemic injury in rat brain.

Curcumin affords neuroprotection and inhibits α-synuclein aggregation in lipopolysaccharide-induced Parkinson's disease model.

Parkinson's disease (PD) pathology is characterized by the abnormal accumulation and aggregation of the pre-synaptic protein α-synuclein in the dopaminergic neurons as Lewy bodies (LBs). Curcumin, which plays a neuroprotective role in various animal models of PD, was found to directly modulate the aggregation of α-synuclein in in vitro as well as in in vivo studies. While curcumin has been shown to exhibit strong anti-oxidant and anti-inflammatory properties, there are a number of other possible mechanisms by which curcumin may alter α-synuclein aggregation which still remains obscure. Therefore, the present study was designed to understand such concealed mechanisms behind neuroprotective effects of curcumin. An animal model of PD was established by injecting lipopolysaccharide (LPS, 5 µg/5 µl PBS) into the substantia nigra (SN) of rats which was followed by curcumin administration (40 mg/kg b.wt (i.p.)) daily for a period of 21 days. Modulatory functions of curcumin were evident from the inhibition of astrocytic activation (GFAP) by immunofluorescence and NADPH oxidase complex activation by RT-PCR. Curcumin supplementation prevented the LPS-induced upregulation in the protein activity of transcription factor NFκB, proinflammatory cytokines (TNF-α, IL-1ß, and IL-1α), inducible nitric oxide synthase (iNOS) as well as the regulating molecules of the intrinsic apoptotic pathway (Bax, Bcl-2, Caspase 3 and Caspase 9) by ELISA. Curcumin also resulted in significant improvement in the glutathione system (GSH, GSSG and redox ratio) and prevented iron deposition in the dopaminergic neurons as depicted from atomic absorption spectroscopy (AAS) and Prussian blue staining, respectively. Curcumin also prevented α-synuclein aggregates in the dopaminergic neurons as observed from gene as well as protein activity of α-synuclein using RT-PCR and IHC. Collectively, our results suggest that curcumin can be further pursued as a candidate drug in the molecules targeted therapy for PD and other related synucleopathies.

Inhibition of Alzheimer's amyloid-beta aggregation in-vitro by carbenoxolone: Insight into mechanism of action.

BACKGROUND: The major hallmark of Alzheimer's disease (AD) is the formation of amyloid aggregates, which are formed due to improper folding of proteins leading to the aggregation of amyloid beta (Aß) 42 peptide. Inhibition of Aß 42 aggregation using a drug such as carbenoxolone (Cbx), which has already been stated as neuroprotective, appears to be an effective approach against AD. OBJECTIVE: The present study was designed to investigate the anti-fibrillation activity of Cbx against the Aß 42 aggregation. METHODS: The aggregation of Aß 42 peptide was observed by performing in-vitro studies and the propensity of aggregation of Aß 42 peptide was evaluated by the prediction of binding sites and amyloidogenic regions. The binding of Cbx in these binding sites was predicted by computational studies. RESULTS: Thioflavin-T (Th-T assay), congo red assay and circular dichroism (CD) analysis suggested significant inhibition of Aß 42 aggregation by Cbx. The propensity of aggregation of Aß 42 peptide was evaluated by the prediction of binding sites and amyloidogenic regions. The mechanism of anti-fibrillation activity of Cbx was elucidated by molecular docking and simulation studies and has been predicted to interact with amyloidogenic residues of Aß 42 peptides as well as fibrils. Cbx also interacts with residues involved in the stabilization of the oligomeric structure. CONCLUSION: These results project Cbx as a suitable candidate for the inhibition of Aß 42 aggregation and the therapeutic potential of Cbx against AD can further be studied using in-vivo experiments.

Curcumin protects dopaminergic neurons against inflammation-mediated damage and improves motor dysfunction induced by single intranigral lipopolysaccharide injection.

Various studies have indicated a lower incidence and prevalence of neurological conditions in people consuming curcumin. The ability of curcumin to target multiple cascades, simultaneously, could be held responsible for its neuroprotective effects. The present study was designed to investigate the potential of curcumin in minimizing microglia-mediated damage in lipopolysaccharide (LPS) induced model of PD. Altered microglial functions and increased inflammatory profile of the CNS have severe behavioral consequences. In the current investigation, a single injection of LPS (5 ug/5 µl PBS) was injected into the substantia nigra (SN) of rats, and curcumin [40 mg/kg b.wt (i.p.)] was administered daily for a period of 21 days. LPS triggered an inflammatory response characterized by glial activation [Iba-1 and glial fibrillary acidic protein (GFAP)] and pro-inflammatory cytokine production (TNF-α and IL-1ß) leading to extensive dopaminergic loss and behavioral abnormality in rats. The behavioral observations, biochemical markers, quantification of dopamine and its metabolites (DOPAC and HVA) using HPLC followed by IHC of tyrosine hydroxylase (TH) were evaluated after 21 days of LPS injection. Curcumin supplementation prevented dopaminergic degeneration in LPS-treated animals by normalizing the altered levels of biomarkers. Also, a significant improvement in TH levels as well as behavioral parameters (actophotometer, rotarod, beam walking and grid walking tests) were seen in LPS injected rats. Curcumin shielded the dopaminergic neurons against LPS-induced inflammatory response, which was associated with suppression of glial activation (microglia and astrocytes) and transcription factor NF-κB as depicted from RT-PCR and EMSA assay. Curcumin also suppressed microglial NADPH oxidase activation as observed from NADPH oxidase activity. The results suggested that one of the important mechanisms by which curcumin mediates its protective effects in the LPS-induced PD model is by inhibiting glial activation. Therefore, curcumin could be a potential therapeutic agent for inflammation-driven neurodegenerative disorders like PD, and its neuroprotective role should be explored further.

Potential for Stem Cells Therapy in Alzheimer's Disease: Do Neurotrophic Factors Play Critical Role?

Alzheimer's disease (AD) is one of the most common causes of dementia. Despite several decades of research in AD, there is no standard disease- modifying therapy available and currentlyapproved drugs provide only symptomatic relief. Stem cells hold immense potential to regenerate damaged tissues and are currently tested in some brain-related disorders, such as AD, amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD). We review stem cell transplantation studies using preclinical and clinical tools. We describe different sources of stem cells used in various animal models and explaining the putative molecular mechanisms that can rescue neurodegenerative disorders. The clinical studies suggest safety, efficacy and translational potential of stem cell therapy. The therapeutic outcome of stem cell transplantation has been promising in many studies, but no unifying hypothesis can convincingly explain the underlying mechanism. Some studies have reported paracrine effects exerted by these stem cells via the release of neurotrophic factors, while other studies describe the immunomodulatory effects exerted by the transplanted cells. There are also reports which indicate that stem cell transplantation might result in endogenous cell proliferation or replacement of diseased cells. In animal models of AD, stem cell transplantation is also believed to increase expression of synaptic proteins.

Alzheimer's disease like pathology induced six weeks after aggregated amyloid-beta injection in rats: increased oxidative stress and impaired long-term memory with anxiety-like behavior.

OBJECTIVES: Amyloid-beta (Aß) peptide deposition into insoluble plaques is a pathological hallmark of Alzheimer's disease (AD), but soluble oligomeric Aß is considered to be more potent and has been hypothesized to directly impair learning and memory. Also, evidences from some clinical studies indicated that Aß oligomer formation is the major cause for early AD onset. However, the biochemical mechanism involved in the oligomer-induced toxicity is not very well addressed. So, thise present study was undertaken to study the effects of single intracerebroventricular (icv) injection of protofibrillar Aß 1-42 on the behavioral and biochemical profile in rats. METHODS: Rats were divided into two groups (n = 8 per group): (1) sham control group and (2) Aß 1-42 injected group. A single dose of protofibrillar Aß 1-42 (5 ul) through icv injection was bilaterally administered into the dorsal hippocampus, while sham control animals were administered with 5 µl of vehicle. RESULTS: The results demonstrated that the protofibrillar Aß significantly inhibited long-term memory retention and increased anxiety levels as shown by the behavioral studies. The amyloid deposits were present inside the brain even six weeks after injection as confirmed by thioflavin-T staining and the neurodegeneration induced by these deposits was confirmed by Nissl's staining in hippocampal and cortical regions. The amyloid aggregates induced reactive oxygen species (ROS) production, acetylcholinesterase activity, nitrite levels, lipid peroxidation, and inhibited antioxidant enzyme activity in hippocampus, cortex, and striatum regions of rat brain after six weeks. DISCUSSION: The present study indicated that protofibrillar Aß 1-42 injection altered long term memory, induced anxiety-like behavior and also developed Alzheimer's disease like pathology in rats.

Apocyanin, NADPH oxidase inhibitor prevents lipopolysaccharide induced α-synuclein aggregation and ameliorates motor function deficits in rats: Possible role of biochemical and inflammatory alterations.

Parkinson's disease (PD), is an age-related, progressive neurodegenerative disorder that affects movement and is characterized by the loss of dopaminergic neurons in the nigrostriatal region. Although the clinical and pathological features of PD are complex, recent studies have indicated that microglial NADPH oxidase play a key role in its pathology. A little information is available regarding the role of apocyanin, an NADPH oxidase inhibitor, in ameliorating α-synuclein aggregation and neurobehavioral consequences of PD. Therefore, the present study evaluated its therapeutic potentials for the treatment of neurobehavioral consequences in lipolysaccharide (LPS) induced PD model. For the establishment of PD model LPS (5 µg/5 µl PBS) was injected into the Substantia nigra (SN) of rats. Apocyanin (10mg/kgb.wt) was injected intraperitoneal. Statistical analysis revealed that apocynin significantly ameliorated LPS induced inflammatory response characterized by NFkB, TNF-α and IL-1ß upregulation as assessed by ELISA. It also prevented dopaminergic neurons from toxic insult of LPS as indicated by inhibition of apoptotic markers i.e., caspase 3 and caspase 9 as depicted from RT-PCR and ELISA studies. This was further supported by TUNEL assay for DNA fragmentation. Effectiveness of apocyanin in protecting dopaminergic neuronal degeneration was further confirmed by assessment of α-synuclein deposition as depicted by IHC analysis. Consequently, an improvement in the behavioral outcome was observed following apocyanin treatment as depicted from various behavioral tests performed. Hence the data suggests that specific NADPH oxidase inhibitors, such as apocynin, may provide a new therapeutic approach to the control of neurological disabilities induced by LPS induced PD.