Cocoa beans improve mitochondrial biogenesis via PPARγ/PGC1α dependent signalling pathway in MPP+ intoxicated human neuroblastoma cells (SH-SY5Y).

Polyphenols are shown to protect from or delay the progression of chronic neurodegenerative diseases. Mitochondrial dysfunction plays a key role in the pathogenesis of Parkinson's disease (PD). This study was aims to gain insight into the role of ahydroalcoholic extract of cocoa (standardised for epicatechin content) on mitochondrial biogenesis in MPP+ intoxicated human neuroblastoma cells (SHSY5Y). The effects of cocoa on PPARγ, PGC1α, Nrf2 and TFAM protein expression and mitochondrial membrane potential were evaluated. A pre-exposure to cocoa extract decreased reactive oxygen species formation and restored mitochondrial membrane potential. The cocoa extract was found to up-regulate the expression of PPARγ and the downstream signalling proteins PGC1α, Nrf2 and TFAM. It increased the expression of the anti-apoptotic protein BCl2 and increased superoxide dismutase activity. Further, the cocoa extract down-regulated the expression of mitochondria fission 1 (Fis1) and up-regulated the expression of mitochondria fusion 2 (Mfn2) proteins, suggesting an improvement in mitochondrial functions in MPP+ intoxicated cells upon treatment with cocoa. Interestingly, cocoa up-regulates the expression of tyrosine hydroxylase, the rate limiting enzyme in dopamine synthesis. No change in the expression of PPARγ on treatment with cocoa extract was observed when the cells were pre-treated with PPARγ antagonist GW9662. This data suggests that cocoa mediates mitochondrial biogenesis via a PPARγ/PGC1α dependent signalling pathway and also has the ability to improve dopaminergic functions by increasing tyrosine hydroxylase expression. Based on our data, we propose that a cocoa bean extract and products thereof could be used as potential nutritional supplements for neuroprotection in PD.

Neuroprotective attributes of L-theanine, a bioactive amino acid of tea, and its potential role in Parkinson's disease therapeutics.

Meta-analyses of tea consumption and reduced risk of Parkinson's disease have thrown light in the pathway of exploring beneficial properties of tea components. On the basis of dry mass, a typical black or green tea beverage contains approximately 6% of free amino acids, which impart high quality, taste and distinctive aroma to the tea infusion. L-theanine (chemically known as γ-glutamylethylamide) is a non-proteinogenic amino acid of tea that takes part in the biosynthesis of its polyphenols. Recently discovered neuroprotective effects of L-theanine can be attributed to its structural analogy with glutamate, the principal excitatory neurotransmitter in brain. This unique amino acid also bears a potential to ameliorate the pathophysiological changes associated with Parkinson's disease as it displays antioxidant and anti-inflammatory properties, improves motor behavioral abnormalities, increases dopamine availability and may cause a favorable downshift in neurodegeneration due to glutamate excitotoxicity. To gain an explicit understanding of the role of L-theanine, this review article is the first one to focus on its mechanism of neuromodulatory action and to critically evaluate the possibilities of employing this bioactive amide in the forage of anti-Parkinsonian medication. We also hypothesize the idea of L-theanine being a potent natural agent against L-DOPA induced dyskinesia, since long-term reliance on dopamine replacement therapy is linked with elevation in glutamate receptor activity.

Asiatic Acid Attenuated Aluminum Chloride-Induced Tau Pathology, Oxidative Stress and Apoptosis Via AKT/GSK-3ß Signaling Pathway in Wistar Rats.

Asiatic acid (AA), a triterpenoid present in Centella asiatica, possesses the ability to cross blood brain barrier and received considerable attention for its neuroprotective role. We have reported the benefit of AA against aluminum chloride (AlCl3)-induced amyloid pathology, enhanced acetylcholine esterase (AChE) activity, and inflammation in Alzheimer's disease (AD) like model rats. Based on that, to find the exact mechanism of action of AA, the present study was designed to evaluate the oxidative stress, tau pathology, apoptosis, and Akt/GSK3ß signaling pathway on AlCl3-induced neurotoxicity in Wistar rats. AD-like pathology was induced by oral administration of AlCl3 (100 mg/kg b.w.) for 6 weeks, which demonstrated a significant reduction in spatial memory performance, anxiety, and motor dysfunction and diminished the expression of cyclin-dependent kinase 5 (CDK 5-enzyme implicated in the phosphorylation of tau proteins), pTau, oxidative stress, and apoptosis, whereas oral ingestion of AA (75 mg/kg b.w.) for 7 weeks attenuated the above-said indices, which could be by activating Akt/GSK3ß pathway. Current results suggested that AA could be able to modulate various pathological features of AD and could hold promise in AD treatment.

Antioxidant therapies in attention deficit hyperactivity disorder.

Attention Deficit Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder among children and adults. Impulsivity, inattention, and hyperactivity are hallmark of ADHD. While ADHD is not on the autism spectrum, they are related in several ways as they have some overlapping symptoms. The pathogenesis of ADHD has so far remained enigmatic, however, there is some evidence suggesting critical association among ADHD and the level of oxidative stress which trigger cell membrane damage, changes in inner structure and function of proteins, as well as structural damage to DNA which eventually culminate into development of ADHD. Although stimulants as well as some classes of non-stimulants are used to ameliorate symptom of ADHD, various adverse effects have been associated with such compounds. To date, treatment of ADHD is done with a combination of medications, behavior modifications, psycho-education, family therapy and life-style changes. The American Academy of Pediatrics officially promote stimulant medications and/or behavior therapy as 'first line of therapy'. In addition to the presently therapeutic armamentarium, evidences are emerging on relevancy of natural products. There has been an interest on the therapeutic role of antioxidants in the treatment of ADHD. The present review aims to highlight the beneficiary role played by different antioxidants in mitigating the symptoms of ADHD.

Amelioration of Aluminum Maltolate-Induced Inflammation and Endoplasmic Reticulum Stress-Mediated Apoptosis by Tannoid Principles of Emblica officinalis in Neuronal Cellular Model.

The neuroprotective role of tannoid principles of Emblica officinalis (EoT), an Indian and Chinese traditional medicinal plant against memory loss in aluminum chloride-induced in vivo model of Alzheimer's disease through attenuating AChE activity, oxidative stress, amyloid and tau toxicity, and apoptosis, was recently reported in our lab. However, to further elucidate the mechanism of neuroprotective effect of EoT, the current study was designed to evaluate endoplasmic reticulum stress-suppressing and anti-inflammatory role of EoT in PC 12 and SH-SY 5Y cells. These cells were divided into four groups: control (aluminum maltolate (Al(mal)3), EoT + Al(mal)3, and EoT alone based on 3-(4, 5-dimethyl 2-yl)-2, and 5-diphenyltetrazolium bromide (MTT) assay. EoT significantly reduced Al(mal)3-induced cell death and attenuated ROS, mitochondrial membrane dysfunction, and apoptosis (protein expressions of Bax; Bcl-2; cleaved caspases 3, 6, 9, 12; and cytochrome c) by regulating endoplasmic reticulum stress (PKR-like ER kinase (PERK), α subunit of eukaryotic initiation factor 2 (EIF2-α), C/EBP-homologous protein (CHOP), and high-mobility group box 1 protein (HMGB1)). Moreover, inflammatory response (NF-κB, IL-1ß, IL-6, and TNF-α) and Aß toxicity (Aß1-42) triggered by Al(mal)3 was significantly normalized by EoT. Our results suggested that EoT could be a possible/promising and novel therapeutic lead against Al-induced neurotoxicity. However, further extensive research is needed to prove its efficacy in clinical studies.

Attenuation of Aluminum Chloride-Induced Neuroinflammation and Caspase Activation Through the AKT/GSK-3ß Pathway by Hesperidin in Wistar Rats.

Hesperidin, a flavanoglycone abundantly present in citrus fruits, is reported to have antioxidant, anti-inflammatory, and neuroprotective properties. Previous reports from our laboratory indicated the neuroprotective effect of hesperidin against aluminum chloride (AlCl3)-induced memory loss, acetylcholine esterase hyperactivity, oxidative stress, and enhanced expression of amyloid ß protein biosynthesis-related markers. However, their role on AlCl3-induced inflammation, caspase activation, Tau pathology, altered Akt/GSK 3ß signaling pathway, and Aß clearance marker has not yet been fully elucidated. Intraperitonial injection of AlCl3 (100 mg/kg body weight) for 60 days significantly elevated the expressions of insulin-degrading enzyme (IDE), cyclin-dependent kinase 5 (CDK 5), and phosphoTau (pTau); inflammatory markers such as glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), NF-kB, cyclooxygenase-2 (COX-2), interleukin (IL)-1ß, IL-4, IL-6, tumor necrosis factor-alpha (TNF-α), inducible nitric oxide synthase (iNOS); and apoptotic markers including cytosolic cytochrome c (cyto c), caspase-3, caspase-8, and caspase-9, and lowered expressions of mitochondrial cyto c, phospho-Akt (pAkt) and phospho-glycogen synthase kinase-3ß (pGSK-3ß) in the hippocampus and cortex. Co-administration of hesperidin to AlCl3 rats for 60 days significantly ameliorated the aluminum-induced pathological changes. The behavioral studies also supported the above findings. Our results imply that treatment with hesperidin might be a potent option for treating the symptoms of cognitive impairment in Alzheimer's disease by targeting its most prominent hallmarks.

Protective effect of Zizyphus spinachristi on MPP+-induced oxidative stress.

Oxidative stress and mitochondrial dysfunction mediated neuro apoptosis is reported to play a major role in the pathology of Parkinson's disease. Zizyphus spina-christi fruits (ZSCF) are used as traditional medicines that are well-known for their high antioxidant properties. In the present study, we investigated the protective effects of ZSCF extract against 1-methyl-4-phenylpyridinium (MPP+) induced neurotoxicity in SH-SY5Y cell lines. The effect of ZCSF on MPP+ induced cell viability (MTT - 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay), membrane damage - (lactate dehydrogenase (LDH),  oxidative stress  (levels of ROS, nitric oxide and GSH and activities of SOD and catalase),  mitochondrial membrane potential and apoptosis (activity of caspase 3 and protein expressions of cyto c, Bax and Bcl-2) were measured. Our results showed that ZSCF could be able to reduce the neurotoxicity of MPP+ and offer neuroprotection in vitro. This protective effect of ZCF might be mediated by its potent antioxidant properties. However, further research is necessary to isolate active compounds and performing preclinical and clinical studies to confirm the neuro-protective effects of ZSCF in PD.

Agaricus blazei extract abrogates rotenone-induced dopamine depletion and motor deficits by its anti-oxidative and anti-inflammatory properties in Parkinsonic mice.

Neuroinflammation and oxidative damage are the two main malfactors that play an important role in the pathogenesis of experimental and clinical Parkinson's disease (PD). The current study was aimed to study the possible anti-oxidant and anti-inflammatory effects of the methanolic extract of Agaricus blazei (A. blazei) against rotenone-induced PD in mice. Male Albino mice were randomized and divided into the following groups: control, treated with rotenone (1 mg/kg/day), co-treated with rotenone and A. blazei (50, 100, and 200 mg/kg b.w.), and treated with A. blazei alone (200 mg/kg b.w.). After the end of the experimental period, behavioral studies, biochemical estimations, and protein expression patterns of inflammatory markers were studied. Rotenone treatment exhibited enhanced motor impairments, neurochemical deficits, oxidative stress, and inflammation, whereas oral administration of A. blazei extract attenuated the above-said indices. Even though further research is needed to prove its efficacy in clinical studies, the results of our study concluded that A. blazei extract offers a promising and new therapeutic lead for treatment of PD.

Agaricus blazei extract attenuates rotenone-induced apoptosis through its mitochondrial protective and antioxidant properties in SH-SY5Y neuroblastoma cells.

The present study was aimed to find out the effect of Agaricus blazei mushroom extract against rotenone-induced cellular model. SH-SY5Y neuroblastoma cells are divided into four experimental groups (control, rotenone (100 nM), A. blazei (5 µg/ml) + rotenone (100 nM), and A. blazei alone treated) based on MTT assay, cells were allowed to measure the ROS, TBARS levels, and antioxidants activities. Finally, mitochondrial transmembrane potential (MMP) and expressions of apoptotic proteins were also analyzed. Pre-treatment with A. blazei significantly enhanced cell viability, attenuated rotenone-induced ROS, MMP, and apoptosis. Our results indicated that anti-apoptotic properties of this natural compound due to its antioxidant and mitochondrial protective function protect rotenone-induced cytotoxicity. Therefore, it may be concluded that A. blazei can be further developed as a promising drug for the treatment of Parkinson's disease (PD).

Isolongifolene attenuates rotenone-induced mitochondrial dysfunction, oxidative stress and apoptosis.

The present study was carried out to investigate the neuroprotective effects of isolongifolene (ILF), a tricyclic sesquiterpene of Murraya koenigii, against rotenone-induced mitochondrial dysfunction, oxidative stress and apoptosis in a cellular model. SH-SY5Y human neuroblastoma cells were divided into four experimental groups (control, rotenone (100 nM), ILF (10 microM) + rotenone (100 nanoM), ILF 10 microM alone treated) based on 3-(4, 5-dimethyl 2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The results of the present study showed that the ILF treatment significantly alleviated rotenone-induced cytotoxicity, oxidative stress and mitochondrial dysfunction in SH-SY5Y cells. Moreover, ILF attenuated rotenone induced toxicity by down-regulating  Bax, caspases-3, 6, 8 and 9 expression and up-regulating of Bcl-2 expression. Furthermore regulation of p-P13K, p-AKT and p-GSK-3 beta expression by ILF, clearly confirmed its protective effects. Taken together, our results suggested that ILF attenuated rotenone-induced oxidative stress, mitochondrial dysfunction and apoptosis through the regulation of P13K/AKT/GSK-3 beta signaling pathways. However further pre-clinical studies are warranted in rodents to use ILF as a promising therapeutic agent for PD in future.

Neuroprotective role of Asiatic acid in aluminium chloride induced rat model of Alzheimer's disease.

Alzheimer's disease (AD) is the most common form of dementia, characterized by memory loss, cognitive impairment and personality disorders accompanied by diffuse structural abnormalities in the brain of elderly people. The current investigation explored the neuroprotective potential of asiatic acid (AA), a natural triterpene of Centella asiatica on aluminium chloride (AlCl3) induced rat model of AD. Oral administration of AlCl3 (100 mg/kg b.w.) for 42 days significantly elevated the levels of Al, activity of acetyl cholinesterase and expressions of amyloid precursor protein, amyloid beta1-42, beta and gamma secretases, glial fibrillary acidic protein, ionized calcium binding adaptor molecule 1, interleukins -1ß, 6, 4, 2, tumor necrosis factor alpha, inducible nitric oxide synthase, nuclear factor- k beta and cyclooxygenase-2 in the hippocampus and cortex  compared to the control group. Our observations suggested that AA treatment mitigated AlCl3 induced AD associated pathologies, which might be due to its multiple pharmacological actions. Further studies are necessary in order to explore the link between AlCl3-mediated oxidative stress and associated apoptosis to establish its neuroprotective role in AD.

Asiatic acid nullified aluminium toxicity in in vitro model of Alzheimer's disease.

Aluminium (Al) is a ubiquitously distributed environmental toxicant that lacks biological functions; however, its accumulation in the brain has been demonstrated to be linked to several neuropathological conditions particularly Alzheimer's disease (AD). Asiatic acid (AA), a triterpene extracted from Centella asiatica, has been reported to cross the blood brain barrier and also displayed antioxidant and neuroprotective activities. The present study was aimed to explore the neuroprotective effect of AA against aluminium maltolate (Al(mal)3) induced neurotoxicity by assessing cell viability, mitochondrial membrane potential, levels of reactive oxygen species (ROS), DNA damage and apoptosis (Hoechst and dual staining, comet assay; expressions of pro-apoptotic, anti-apoptotic and signaling indices) via AKT/GSK-3ß signaling pathway in SH-SY 5Y  neuroblastoma cells. Pre-treatment with AA significantly enhanced cell viability, attenuated rotenone-induced ROS, mitochondrial membrane dysfunction and apoptosis regulating AKT/GSK-3ß signaling pathway. Downregulation of Al induced neurodegeneration may be one of the approaches to control the impairment of metal ion homeostasis leading to neuronal injury in  early development of AD. However, more extensive work in animal model is desirable to confirm its neuroprotective action.

Neuroprotective effect of Demethoxycurcumin, a natural derivative of Curcumin on rotenone induced neurotoxicity in SH-SY 5Y Neuroblastoma cells.

BACKGROUND: Mitochondrial dysfunction and oxidative stress are the main toxic events leading to dopaminergic neuronal death in Parkinson's disease (PD) and identified as vital objective for therapeutic intercession. This study investigated the neuro-protective effects of the demethoxycurcumin (DMC), a derivative of curcumin against rotenone induced neurotoxicity. METHODS: SH-SY5Y neuroblastoma cells are divided into four experimental groups: untreated cells, cells incubated with rotenone (100 nM), cells treated with DMC (50 nM) + rotenone (100 nM) and DMC alone treated. 24 h after treatment with rotenone and 28 h after treatment with DMC, cell viability was assessed using the MTT assay, and levels of ROS and MMP, plus expression of apoptotic protein were analysed. RESULTS: Rotenone induced cell death in SH-SY5Y cells was significantly reduced by DMC pretreatment in a dose-dependent manner, indicating the potent neuroprotective effects of DMC. Rotenone treatment significantly increases the levels of ROS, loss of MMP, release of Cyt-c and expression of pro-apoptotic markers and decreases the expression of anti-apoptotic markers. CONCLUSIONS: Even though the results of the present study indicated that the DMC may serve as a potent therapeutic agent particularly for the treatment of neurodegenerative diseases like PD, further pre-clinical and clinical studies are required.

Fenugreek Seed Powder Attenuated Aluminum Chloride-Induced Tau Pathology, Oxidative Stress, and Inflammation in a Rat Model of Alzheimer's Disease.

Alzheimer's disease (AD) is a common neurodegenerative disorder that mainly affects the aged population and is characterized by the progressive loss of the hippocampal and cortical neurons, which results in memory and cognitive impairments. Trigonella foenum-graecum (fenugreek) has been reported to have hypoglycemic, hypocholesterolemic, hyperinsulinemic and anti-diabetic properties. Traditionally, it was used as a galactagogue and to treat anorexia, fever gastritis, gastric ulcers, and various nervous disorders. However, the neuroprotective effect of fenugreek seed powder against aluminum chloride (AlCl3) induced AD rats has not been analyzed. The result of the present study indicated that the chronic administration of AlCl3 induced significant learning and memory impairments, oxidative stress, and alterations in the protein immunocontent patterns of IDE and CDK5 (enzymes involved in the metabolism of tau and amyloid proteins), pTau, GFAP and Iba-1, IL-1ß, IL-6, TNF-α, iNOS, NF-κB, COX-2, CDK5, BDNF, and STAT3. Our behavioral, biochemical, and molecular studies revealed that the co-administration of fenugreek seed powder significantly attenuated the AlCl3 induced memory deficits, amyloid and tau pathology, oxidative stress, and inflammation in AD rats could be due to the synergistic action of its active components.

Neurotrophic Effect of Asiatic acid, a Triterpene of Centella asiatica Against Chronic 1-Methyl 4-Phenyl 1, 2, 3, 6-Tetrahydropyridine Hydrochloride/Probenecid Mouse Model of Parkinson's disease: The Role of MAPK, PI3K-Akt-GSK3ß and mTOR Signalling Pathways.

Regulation of various signalling (Ras-MAPK, PI3K and AKT) pathways by augmented activity of neurotrophic factors (NTFs) could prevent or halt the progress of dopaminergic loss in Parkinson's disease (PD). Various in vitro and in vivo experimental studies indicated anti-parkinsonic potential of asiatic acid (AA), a pentacyclic triterpene obtained from Centella asiatica. So the present study is designed to determine the neurotrophic effect of AA against 1-methyl 4-phenyl 1, 2, 3, 6-tetrahydropyridine hydrochloride/probenecid (MPTP/p) neurotoxicity in mice model of PD. AA treatment for 5 weeks significantly attenuated MPTP/p induced motor abnormalities, dopamine depletion and diminished expressions NTFs and tyrosine kinase receptors (TrKB). We further, revealed that AA treatment significantly inhibited the MPTP/p-induced phosphorylation of MAPK/P38 related proteins such as JNK and ERK. Moreover, AA treatment increased the phosphorylation of PI3K, Akt, GSK-3ß and mTOR, suggesting that AA activated PI3K/Akt/mTOR signalling pathway, which might be the cause of neuroprotection offered by AA. The present findings provided more elaborate in vivo evidences to support the neuroprotective effect of AA on dopaminergic neurons of chronic Parkinson's disease mouse model and the potential of AA to be developed as a possible new therapeutic target to treat PD.

Neuroprotective effect of asiatic acid on rotenone-induced mitochondrial dysfunction and oxidative stress-mediated apoptosis in differentiated SH-SYS5Y cells.

Parkinson's disease (PD) is a chronic neurodegenerative disease, manifested due to the loss of dopaminergic neurons, which ultimately leads to impaired movement in elderly populations. The pathogenesis of PD is associated with numerous factors including oxidative stress, mitochondrial dysfunction and apoptosis. There is no effective therapy available to cure or halt the progression of this disease still now. Asiatic acid (AA) is a triterpene extracted from Centella asiatica has been reported as an antioxidant and anti-inflammatory agent, that offers neuroprotection against glutamate toxicity. Therefore, in this study, we have investigated the effect of AA in a rotenone (an inhibitor of mitochondrial complex I) induced in vitro model of PD. Following the exposure of SH-SY5Y cells to rotenone, there was a marked overproduction of ROS, mitochondrial dysfunction (as indexed by the decrease in mitochondrial membrane potential) and apoptosis (Hoechst and dual staining, comet assay; expressions of pro-apoptotic and anti-apoptotic indices). Pre-treatment with AA reversed these changes might be due to its antioxidant, mitoprotective and anti-apoptotic properties. However further extensive studies on in vivo models of PD are warranted to prove AA neuroprotective effect before entering into the clinical trial.

Hesperidin ameliorates cognitive dysfunction, oxidative stress and apoptosis against aluminium chloride induced rat model of Alzheimer's disease.

BACKGROUND/AIMS: Deregulation of metal ion homeostasis has been assumed as one of the key factors in the progression of neurodegenerative diseases. Aluminium (Al) has been believed as a major risk factor for the cause and progression of Alzheimer's disease (AD). In our lab, we have previously reported that hesperidin, a citrus bioflavonoid reversed memory loss caused by aluminium intoxication through attenuating acetylcholine esterase activity and the expression of Amyloid ß biosynthesis related markers. Al has been reported to cause oxidative stress associated apoptotic neuronal loss in the brain. So in the present study, protective effect of hesperidin against aluminium chloride (AlCl3) induced cognitive impairment, oxidative stress and apoptosis was studied. METHODS: Male Wistar rats were divided into control, AlCl3 treated (100 mg/kg., b.w.), AlCl3 and hesperidin (100 mg/kg., b.w.) co-treated and hesperidin alone treated groups. In control and experimental rats, learning and memory impairment were measured by radial arm maze, elevated plus maze and passive avoidance tests. In addition, oxidative stress and expression of pro and anti-apoptotic markers were also evaluated. RESULTS: Intraperitoneal injection of AlCl3 (100 mg/kg., b.w.) for 60 days significantly enhanced the learning and memory deficits, levels of thiobarbituric acid reactive substances and the expression of Bax and diminished the levels of reduced glutathione, activities of enzymatic antioxidants and the expression of B-cell lymphoma-2 (Bcl-2) as compared to control group in the hippocampus, cortex, and cerebellum. Coadministration of hesperidin (100 mg/kg., b.w. oral) for 60 days prevented the cognitive deficits, biochemical anomalies and apoptosis induced by AlCl3 treatment. CONCLUSION: Results of the present study demonstrated that hesperidin could be a potential therapeutic agent in the treatment of oxidative stress and apoptosis associated neurodegenerative diseases including AD.

Tannoid principles of Emblica officinalis attenuated aluminum chloride induced apoptosis by suppressing oxidative stress and tau pathology via Akt/GSK-3ßsignaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Fruits of Phyllanthus emblica Linn. or Emblica officinalis Gaertn. (Phyllanthaceae) are used in Ayurveda, Siddha, Unani, Arabic, Tibetan and various other folk medicinal systems to promote intelligence and memory. Recent study from our lab indicated the neuroprotective effect of tannoids principles of Emblica officinalis (EoT) against memory loss caused by aluminum chloride (AlCl3) intoxication through attenuating acetylcholine esterase activity and the expression of amyloid ß protein biosynthesis related markers. However the molecular mechanism of EoT has not yet been fully elucidated. AIM OF THE STUDY: The aim of the present study was to further investigate the neuroprotective mechanisms of EoT against AlCl3-induced cognitive deficits, tau hyperphosphorylation, oxidative stress and apoptosis. MATERIALS AND METHODS: Rats were treated with AlCl3 for 60 days to induce biochemical and physiological abnormalities similar to AD patients. AD rats were treated with EoT (100mg/kg., bw. oral) for 60 days. For the examination of neuroprotective effect of EoT, behavior analysis, biochemical estimations and western blot were performed in the hippocampus and cortex of control, EoT treated and untreated AD rats. RESULTS: Intraperitoneal injections of AlCl3 (100mg/kg., b.w.) for 60 days enhanced the learning and memory deficits, levels of TBARS and diminished the levels of reduced glutathione and activities of enzymatic antioxidants as compared to control group. Moreover toxicity of AlCl3 is accompanied by the enhanced expressions of Bax, caspases-3,-9, cytosolic cytochrome c (cyto c), and pTau along with diminished expressions of Bcl-2, mitochondrial cyto c, pGSK-3ß and pAkt. Coadministration of EoT nullified the cognitive deficits, biochemical abnormalities and apoptosis induced by AlCl3 treatment. Moreover EoT prevents tau hyperphosphorylation by targeting the GSK-3ß/Akt signaling pathway. CONCLUSIONS: This study confirms that EoT would be used as a potential drug candidate for AD and other tau pathology-related neuronal degenerative diseases.

Tannoid principles of Emblica officinalis renovate cognitive deficits and attenuate amyloid pathologies against aluminum chloride induced rat model of Alzheimer's disease.

BACKGROUND/AIMS: Emblica officinalis is mentioned as a maharasayana in many Ayurvedic texts and promotes intelligence, memory, freedom from disease, longevity, and strength of the senses. The present study has been designed to explore the memory-enhancing effect of the tannoid principles of E. officinalis (EoT) at the biochemical, anatomical, behavioral, and molecular levels against aluminum chloride (AlCl3) induced Alzheimer's disease (AD) in rats. Aluminum is reported to have an important role in the etiology, pathogenesis, and development of AD. METHODS: Male Wistar rats were divided into control, AlCl3 treated, AlCl3 and EoT (50, 100, and 200 mg/kg bw) co-treated, and EoT (200 mg/kg bw) alone treated groups. In control and experimental rats, behavior tests including water maze and open field test, estimation of aluminum, assay of acetylcholinesterase (AChE) activity, and expression of amyloidogenic proteins were performed. RESULTS: Intraperitonial injection of AlCl3 (100 mg/kg bw) for 60 days significantly elevated the concentration of aluminum (Al), activity of AChE and protein expressions of amyloid precursor protein, A-beta1-42, beta-, and gamma-secretases as compared to control group in hippocampus and cortex. Co-administration of EoT orally to AlCl3 rats for 60 days significantly revert back the Al concentration, AChE activity, and A-beta synthesis-related molecules in the studied brain regions. The spatial learning, memory, and locomotor impairments observed in AlCl3 treated rats were significantly attenuated by EoT. CONCLUSION: Therefore, EoT may be a promising therapy in ameliorating neurotoxicity of aluminum, however further studies are warranted to elucidate the exact mechanism of action of EoT.