UHPLC-MS-based metabolomics and chemoinformatics study reveals the neuroprotective effect and chemical characteristic in Parkinson's disease mice after oral administration of Wen-Shen-Yang-Gan decoction.

Parkinson's disease (PD), the typical neurodegenerative disease, is characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN). However, no therapeutic agent used currently could slow down neuronal cell loss so as to decelerate or halt the progression of PD. Traditional Chinese medicine (TCM) has been utilized to treat the dysfunction of the autonomic nervous system. Wen-Shen-Yang-Gan decoction (WSYGD) has a good effect on the clinical treatment of PD with constipation. However, it is not clear which ingredients and what mechanism are responsible for the therapeutic effect. In this study, the pharmacodynamic study of WSYGD in PD mice was applied. Concurrently, a novel method for the identification of metabolic profiles of WSYGD has been developed. Finally, we found that WSYGD could protect the PD mice induced by rotenone. The underlying mechanism of the protective effect may be related to the reduction of the DA neurons apoptosis via reducing inflammatory reaction. By virtue of UPLC-MS and chemoinformatics method, 35 prototype compounds and 27 metabolites were filtered out and tentatively characterized. In conclusion, this study provides an insight into the metabolism of WSYGD in vivo to enable understanding of the metabolic process and therapeutic mechanism of PD.

Search for safer and potent natural inhibitors of Parkinson's disease.

After Alzheimer's disease, Parkinson's disease (PD) has taken second place in becoming one of the most commonly occurring neurological diseases being responsible for a number of disabling motor symptoms ranging from bradykinesia, akinesia, tremors to rigidity, that mostly targets the elderly population and severely disrupts their quality of life. The true underlying pathology of PD yet remains a mystery, however, recent advances in the field have pointed towards the production of α-synuclein aggregates, oxidative stress, and an imbalance between levels of acetylcholine and dopamine neurotransmitters in the brain that have been shown to result in loss of coordinated movement. Current treatments of PD include the gold standard dopamine precursor L-dopa, dopamine agonists pergolide and bromocriptine, catechol-o-methyl transferases inhibitors, entacapone and tolcapone and monoamine oxidase inhibitors such as Selegine and Rasagiline amongst several other drugs. While these drugs are successful in treating motor symptoms of the disease, they do so with a plethora of side effects that are especially debilitating to the elderly. In the recent years, a considerable amount of attention has been shifted towards phytocompounds such as flavonoids and green tea catechins due to promising experimental results. In this review, we have compiled phytocompounds that have shown potent activity against some of the most important targets for antiparkinsonian therapy. These compounds have exhibited activities that transcend the limits of simply attenuating mitochondrial oxidative stress and have opened doors to the discovery of novel lead compounds for newer, efficacious antiparkinsonian therapies with wider therapeutic windows.

Integrated network analysis identifying potential novel drug candidates and targets for Parkinson's disease.

This study aimed to identify potential novel drug candidates and targets for Parkinson's disease. First, 970 genes that have been reported to be related to PD were collected from five databases, and functional enrichment analysis of these genes was conducted to investigate their potential mechanisms. Then, we collected drugs and related targets from DrugBank, narrowed the list by proximity scores and Inverted Gene Set Enrichment analysis of drug targets, and identified potential drug candidates for PD treatment. Finally, we compared the expression distribution of the candidate drug-target genes between the PD group and the control group in the public dataset with the largest sample size (GSE99039) in Gene Expression Omnibus. Ten drugs with an FDR < 0.1 and their corresponding targets were identified. Some target genes of the ten drugs significantly overlapped with PD-related genes or already known therapeutic targets for PD. Nine differentially expressed drug-target genes with p < 0.05 were screened. This work will facilitate further research into the possible efficacy of new drugs for PD and will provide valuable clues for drug design.

Neuroprotective potential of Ayahuasca and untargeted metabolomics analyses: applicability to Parkinson's disease.

ETHNOPHARMACOLOGY RELEVANCE: Ayahuasca is a tea produced through decoction of Amazonian plants. It has been used for centuries by indigenous people of South America. The beverage is considered to be an ethnomedicine, and it is traditionally used for the treatment of a wide range of diseases, including neurological illness. Besides, some scientific evidence suggests it may be applicable to Parkinson's disease (PD) treatment. Thus, Ayahuasca deserves in depth studies to clarify its potential role in this disease. AIM OF THE STUDY: This study aimed to use an untargeted metabolomics approach to evaluate the neuroprotective potential of the Ayahuasca beverage, the extracts from its matrix plants (Banisteriopsis caapi and Psychotria viridis), its fractions and its main alkaloids on the viability of SH-SY5Y neuroblastoma cells in an in vitro PD model. MATERIAL AND METHODS: The cytotoxicity of Ayahuasca, crude extracts, and fractions of B. caapi and P. viridis, as well as neuroprotection promoted by these samples in a 6-hydroxydopamine (6-OHDA)-induced neurodegeneration model, were evaluated by the MTT assay at two time-points: 48 h (T1) and 72 h (T2). The main alkaloids from Ayahuasca matrix plants, harmine (HRE) and N,N-dimethyltryptamine (DMT), were also isolated and evaluated. An untargeted metabolomics approach was developed to explore the chemical composition of samples with neuroprotective activity. Ultra-Performance Liquid Chromatography coupled to Electrospray Ionisation and Time-of-Flight (UPLC-ESI-TOF) metabolome data was treated and further analysed using multivariate statistical analyses (MSA): principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The metabolites were dereplicated using the Dictionary of Natural Products and an in house database. The main alkaloids were also quantified by UPLC-MS/MS. RESULTS: The samples did not cause cytotoxicity in vitro and three of samples intensely increased cell viability at T1. The crude extracts, alkaloid fractions and HRE demonstrated remarkable neuroprotective effect at T2 while the hydroalcoholic fractions demonstrated this neuroprotective effect at T1 and T2. Several compounds from different classes, such as ß-carbolines and monoterpene indole alkaloids (MIAs) were revealed correlated with this property by MSA. Additionally, a total of 2419 compounds were detected in both ionisation modes. HRE showed potent neuroprotective action at 72 h, but it was not among the metabolites positively correlated with the most efficacious neuroprotective profile at either time (T1 and T2). Furthermore, DMT was statistically important to differentiate the dataset (VIP value > 1), although it did not exhibit sufficient neuroprotective activity by in vitro assay, neither a positive correlation with T1 and T2 neuroprotective profile, which corroborated the MSA results. CONCLUSION: The lower doses of the active samples stimulated neuronal cell proliferation and/or displayed the most efficacious neuroprotection profile, namely by preventing neuronal damage and improving cell viability against 6-OHDA-induced toxicity. Intriguingly, the hydroalcoholic fractions exhibited enhanced neuroprotective effects when compared to other samples and isolated alkaloids. This finding corroborates the significance of a holistic approach. The results demonstrate that Ayahuasca and its base plants have potential applicability for PD treatment and to prevent its progression differently from current drugs to treat PD.

Effect of M. chamomilla L. tea on chlorpromazine induced catalepsy: A neuroprotective study.

We determined anti-Parkinson's activity of M. chamomilla L. tea in chlorpromazine (CPZ) developed investigational animal model. In this research, effects of M. chamomilla L. tea 2.14ml/ kg P.O were studied on cataleptic behavior and its effect on brain histopathological changes and immunohistochemistry (IHC) in rats. The experimental design was developed by administering CPZ (3mg/kg, I/P) for twenty-one days to produce Parkinson's disease-like symptoms to 4 animal groups. We observed that chlorpromazine significantly produced motor dysfunctions (catalepsy) in a time period of twenty-one days. The M. chamomilla L. significantly (P<0.005) minimized/shorten/taper down catalepsy in rats just like standard group (Levodopa/carbidopa treated group). The maximum reduction was observed from both treated and standard groups on the 21st day. M. chamomilla L. treated rats mid brain sections showed presence of proliferative blood vessels, increase cellularity with reactive glial cells as compared to CPZ group. Furthermore, immunostaining CD68 & CD21 of M. chamomilla L. treated rats mid brain region showed few CD68 cells & no polymorphs neutrophils after CD21 staining. Thus, this research work disclosed the neuroprotective effect of M. chamomilla L. tea against Parkinson's disease-like symptoms or anti-Parkinson's activity induced by CPZ.

Hypericum perforatum in the treatment of psychiatric and neurodegenerative disorders: Current evidence and potential mechanisms of action.

BACKGROUND: Psychiatric disorders are substantially associated with reduced quality of life and increased mortality. Depression and anxiety are two of the most common psychiatric disorders that often co-occur with each other as well as with other mental health conditions. Because of the limitations of currently available antidepressant therapies, there is a need for agents with improved efficacy and less adverse effects. Hypericum perforatum, widely known as St. John's wort, is a perennial herbaceous plant most well known for its antidepressant properties. METHODS: We reviewed the available in vitro, in vivo, and clinical evidence on the efficacy, safety, and mechanisms of action of St. John's wort and its active constituents in the treatment of psychiatric and neurodegenerative disorders. RESULTS: Several interesting data have been reported about the antidepressant properties of H. perforatum in clinical trials with different designs. In particular, a number of antidepressant-controlled trials demonstrated that H. perforatum and its active ingredients, hypericin and hyperforin, possess antidepressant properties similar to those of tricyclic antidepressants and selective serotonin reuptake inhibitors but with fewer and milder side effects. CONCLUSION: St. John's wort may exert potent antidepressant effects and represents an efficacious and safe treatment. However, the current clinical evidence regarding the efficacy of H. perforatum in other psychiatric and neurodegenerative disorders is not sufficient to draw a robust conclusion.

Supplementation of Blackcurrant Anthocyanins Increased Cyclic Glycine-Proline in the Cerebrospinal Fluid of Parkinson Patients: Potential Treatment to Improve Insulin-Like Growth Factor-1 Function.

BACKGROUND: Insulin-like growth factor-1 (IGF-1) function is impaired in Parkinson disease. Cyclic glycine-proline (cGP), a metabolite of IGF-1, is neuroprotective through improving IGF-1 function. Parkinson disease patients score lower on Hospital-associated Anxiety and Depression Scale after supplementing blackcurrant anthocyanins (BCA), which may be associated with IGF-1 function. We evaluated the changes of cGP and IGF-1 before and after the supplementation. METHODS: Plasma and cerebrospinal fluid (CSF) were collected from 11 male patients before and after 28 day supplementation of BCA. The concentrations of IGF-1, IGF binding protein (IGFBP)-3, and cGP were measured using ELISA and HPLC-MS assays. The presence of cGP in the BCA was evaluated. RESULTS: cGP presented in the BCA. BCA supplementation increased the concentration of cGP (p < 0.01), but not IGF-1 and IGFBP-3 in the CSF. CSF concentration of cGP was correlated with plasma concentration of cGP (R = 0.68, p = 0.01) and cGP/IGF-1 molar ratio (R = 0.66, p = 0.01). The CSF/plasma ratio was high in cGP and low in IGF-1 and IGFBP-3. CONCLUSION: cGP is a natural nutrient to the BCA. The increased CSF cGP in Parkinson disease patients may result from the central uptake of plasma cGP. Given neurotrophic function, oral availability, and effective central uptake of cGP, the BCA has the potential to be developed to treat neurological conditions with IGF-1 deficiency.

Interaction of α-synuclein with Rhus typhina tannin - Implication for Parkinson's disease.

The etiology of Parkinson's disease (PD) relates to α-synuclein, a small protein with the ability to aggregate and form Lewy bodies. One of its prevention strategies is inhibition of α-synuclein oligomerization. We have investigated the interaction of α-synuclein and human serum albumin with 3,6-bis-О-di-О-galloyl-1,2,4-tri-О-galloyl-ß-d-glucose (a tannin isolated from the plant Rhus typhina). Using fluorescence spectroscopy method we found that this tannin interacts strongly with α-synuclein forming complexes. Circular dichroism analysis showed a time-dependent inhibition of α-synuclein aggregation in the presence of the tannin. On the other hand, 3,6-bis-О-di-О-galloyl-1,2,4-tri-О-galloyl-ß-d-glucose had a much stronger interaction with human serum albumin than α-synuclein. The calculated binding constant for tannin-protein interaction was considerably higher for albumin than α-synuclein. This tannin interacted with albumin through a "sphere of action" mechanism. The results lead to the conclusion that 3,6-bis-О-di-О-galloyl-1,2,4-tri-О-galloyl-ß-d-glucose is a potent preventive compound against Parkinson's disease. However, this tannin interacts very strongly with human serum albumin, significantly reducing the bioavailability of this compound.

Medicinal Plants as Protective Strategies Against Parkinson's Disease.

Parkinson's disease is a neurodegenerative disease caused by the loss of dopaminergic neurons in the substantia nigra pars compacta region. An important mechanism contributing to its development is oxidative stress, induced by the imbalance between the endogenous antioxidant defenses and free radicals production. Naturally occurring bioactive compounds exhibit high antioxidant capacity that may help reducing oxidative stress and even reverse the damage induced by ROS. Fruits are particularly rich in phytochemicals with antioxidant effect, and their properties against the development of neurodegenerative diseases are of great interest. This review discusses how the fruits bioactive compounds and synthetic analogs have been assessed for their ability to regulate molecular pathways involved in neuronal survival such as MAPK, Nrf2, and NF-κB, thus elucidating the possible therapeutic and neuroprotective actions of these compounds.

Functional and Morphological Correlates in the Drosophila LRRK2 loss-of-function Model of Parkinson's Disease: Drug Effects of Withania somnifera (Dunal) Administration.

The common fruit fly Drosophila melanogaster (Dm) is a simple animal species that contributed significantly to the development of neurobiology whose leucine-rich repeat kinase 2 mutants (LRRK2) loss-of-function in the WD40 domain represent a very interesting tool to look into physiopathology of Parkinson's disease (PD). Accordingly, LRRK2 Dm have also the potential to contribute to reveal innovative therapeutic approaches to its treatment. Withania somnifera Dunal, a plant that grows spontaneously also in Mediterranean regions, is known in folk medicine for its anti-inflammatory and protective properties against neurodegeneration. The aim of this study was to evaluate the neuroprotective effects of its standardized root methanolic extract (Wse) on the LRRK2 loss-of-function Dm model of PD. To this end mutant and wild type (WT) flies were administered Wse, through diet, at different concentrations as larvae and adults (L+/A+) or as adults (L-/A+) only. LRRK2 mutants have a significantly reduced lifespan and compromised motor function and mitochondrial morphology compared to WT flies 1% Wse-enriched diet, administered to Dm LRRK2 as L-/A+and improved a) locomotor activity b) muscle electrophysiological response to stimuli and also c) protected against mitochondria degeneration. In contrast, the administration of Wse to Dm LRRK2 as L+/A+, no matter at which concentration, worsened lifespan and determined the appearance of increased endosomal activity in the thoracic ganglia. These results, while confirming that the LRRK2 loss-of-function in the WD40 domain represents a valid model of PD, reveal that under appropriate concentrations Wse can be usefully employed to counteract some deficits associated with the disease. However, a careful assessment of the risks, likely related to the impaired endosomal activity, is required.

Schisantherin A protects against 6-OHDA-induced dopaminergic neuron damage in zebrafish and cytotoxicity in SH-SY5Y cells through the ROS/NO and AKT/GSK3ß pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: The fruit of Schisandra chinensis (Turcz.) Baill, has been traditionally used in management of liver diseases and ageing associated neurodegeneration. The bioactive compound from this medicinal plant would be valuable for its potential use in prevention and treatment of Parkinson׳s disease. AIM OF THE STUDY: The overall objective of the present study was to understand the neuroprotective effect of schisantherin A, a dibenzocyclooctadiene lignan from the fruit of S. chinensis (Turcz.) Baill, and to elucidate its underlying mechanism of action. MATERIAL AND METHODS: This study investigated the protective effect of schisantherin A against selective dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA)-induced neural damage in human neuroblastoma SH-SY5Y cells and zebrafish models. Oxidative stress and related signaling pathways underlying the neuroprotective effect were determined by multiple biochemical assays and Western blot. RESULTS: Pretreatment with schisantherin A offered neuroprotection against 6-OHDA-induced SH-SY5Y cytotoxicity. Moreover, schisantherin A could prevent 6-OHDA-stimulated dopaminergic neuron loss in zebrafish. Our mechanistic study showed that schisantherin A can regulate intracellular ROS accumulation, and inhibit NO overproduction by down-regulating the over-expression of iNOS in 6-OHDA treated SH-SY5Y cells. Schisantherin A also protects against 6-OHDA-mediated activation of MAPKs, PI3K/Akt and GSK3ß. CONCLUSION: These findings demonstrate that schisantherin A may have potential therapeutic value for neurodegenerative diseases associated with abnormal oxidative stress such as Parkinson׳s disease.

Tissue distribution profiles of three antiparkinsonian alkaloids from Piper longum L. in rats determined by liquid chromatography-tandem mass spectrometry.

The alkaloids of Piper longum L. (PLA) improved motor dysfunction and dopamine depletion in a rat model of Parkinson's disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. A rapid, accurate, simple, and high-performance liquid chromatography-mass spectrometry method was developed and fully validated to simultaneously detect three P. longum L. antiparkinsonian alkaloids (piperine (PPR), piperlonguminine (PPL), and Δα,ß-dihydropiperlonguminine (DPPL)) in rat plasma, heart, liver, spleen, lung, kidney, and brain tissues. Rat plasma and tissue homogenates were pretreated with methanol/acetonitrile (1:1, v/v) using a simple protein precipitation method. Chromatographic separation was achieved on a Phenomenex Gemini C18 column (50mm×2.00mm, 5µm) with a gradient mobile phase containing 0.1% (v/v) formic acid in water or acetonitrile. The elution was pumped at a flow rate of 0.4ml/min, and the injection volume was 10µl with a total running time of 4min. The analysis was performed by selected reaction monitoring of the transitions m/z 285.9→201.1, m/z 274.3→209.9, and m/z 276.2→134.9 for PPR, PPL, and DPPL, respectively. All three analytes showed good linearity (R>0.995) in plasma and tissue homogenates, and the lower limit of quantification was 0.20ng/ml. The distribution of PPR, PPL and DPPL in all 7 tissues was examined. The highest concentrations for PPR and PPL were observed in the liver, while the highest DPPL concentration was observed in the kidney. Following oral administration, the highest levels of PPR, PPL and DPPL in different tissues were found at approximately 2h. PPR, PPL and DPPL could cross the blood-brain barrier. The present study provides evidences for that PPR, PPL and DPPL may play roles in improving motor dysfunction and dopamine depletion.

Neurobehavioral assessment of hydroalcoholic extract of Trigonella foenum-graecum seeds in rodent models of Parkinson's disease.

CONTEXT: Neuroprotective therapy to rescue dopaminergic neurons is an important trait in the management of Parkinson's disease (PD). OBJECTIVE: The present study identified and evaluated SFSE-T, a standardized hydroalcoholic extract of Trigonella foenum-graecum L. seeds (Fabaceae), in animal models of PD. MATERIALS AND METHODS: The identification of SFSE-T was carried out by high-performance liquid chromatography for the marker compound trigonelline (TGN). The effects of single dose oral treatment of SFSE-T (10, 30 or 100 mg/kg) were studied using animal models of PD, namely, 6-hydroxydopamine (6-OHDA)-induced unilateral lesions in rats, and 4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration in C57BL/6 mice. The effects of SFSE-T on monoamino oxidase (MAO) enzyme in vitro as well as possible side effects of SFSE-T in vivo were also evaluated. RESULTS: The concentration of TGN in a test sample of SFSE-T was found to be 82%. SFSE-T (30 mg/kg, oral) showed a significant increase in the number of ipsilateral rotations (45.67 rotations in 30-min period) as compared with vehicle control group (no rotations) when tested in 6-OHDA-induced unilateral lesioned rats. SFSE-T (30 mg/kg, oral) showed significant reversal of motor dysfunction (spontaneous motor activity scores, speed, distance traveled and number of square crossed) caused by MPTP induced lesions in C57BL/6 mice in pretreatment (1 h) schedule but not in post-treatment (1 h) schedule. SFSE-T neither showed anticholinergic effects nor showed selective MAO-B enzyme inhibition in vitro. DISCUSSION AND CONCLUSION: SFSE-T showed reversal of motor symptoms in an animal model of PD probably through neuroprotective properties.

Using human pluripotent stem cell-derived dopaminergic neurons to evaluate candidate Parkinson's disease therapeutic agents in MPP+ and rotenone models.

To begin to develop a high-throughput assay system to evaluate potential small-molecule therapy for Parkinson's disease (PD), we have performed a low-throughput assay with a small number of compounds using human pluripotent stem cell-derived dopaminergic neurons. We first evaluated the role of 44 compounds known to work in rodent systems in a 1-methyl-4-phenylpyridinium (MPP(+)) assay in a 96-well format using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay as a readout for neuroprotection. Glial cell-derived neurotrophic factor was used as a positive control because of its well-documented neuroprotective effect on dopaminergic neurons, and two concentrations of each drug were tested. Of 44 compounds screened, 16 showed a neuroprotective effect at one or both dosages tested. A dose-response curve of a subset of the 16 positives was established in the MPP(+) model. In addition, we validated neuroprotective effects of these compounds in a rotenone-induced dopaminergic neuronal cell death, another established model for PD. Our human primary dopaminergic neuron-based assays provide a platform for rapid screening and/or validation of potential neuroprotective agents in PD treatment using patient-specific cells and show the importance of using human cells for such assays.

Evaluation of sialic acid-analogs for the attenuation of amyloid-beta toxicity.

BACKGROUND: Amyloid-beta peptide (Aß) is the main constituent of senile plaques and is implicated in the pathogenesis of Alzheimer's disease (AD). To that end, agents which either sequester Aß or interfere with Aß interaction/binding to cells have been investigated as a means to reduce the pathological effects of Aß. METHODS: Different structural analogs of sialic acid (N-acetylneuramic acid) were used to decorate a chitosan backbone using EDC chemistry. FTIR and colorimetric assays were used to characterize the complexes. The ability of these complexes to attenuate Aß toxicity was investigated in vitro using a model neuroblastoma cell line SH-SY5Y. RESULTS: Oxygen substitution in ring structure is responsible for the increase in toxicity and increase in protective properties of the complexes. Also, the multi OH tail present in sialic acid is critical to attenuate toxicity. Analogs show no protective properties which reinforces the conclusion that clustering of sugars in cellular membranes play a significant role in Aß binding. CONCLUSIONS: Successfully produced compounds that showed varying degree of efficacy in attenuating Aß toxicity to cells in culture. This work elucidates the impact that certain structures of sialic acid and its analogs can have on Aß binding. It will allow for more specific and detailed improvements in the therapeutic polysaccharide structures that can be developed and modified to overcome other shortcomings of AD therapeutic development, particularly of penetrating the blood-brain barrier. GENERAL SIGNIFICANCE: Oxygen atom plays crucial role on therapeutic effectiveness. This work can help as a general guideline for further therapeutic development.

Propensity of Selaginella delicatula aqueous extract to offset rotenone-induced oxidative dysfunctions and neurotoxicity in Drosophila melanogaster: Implications for Parkinson's disease.

The primary objective of this investigation was to examine the neuroprotective efficacy of an aqueous extract of Selaginella delicatula (a pteridophyte) employing a rotenone (ROT) Drosophila model in vivo. Aqueous extract of S. delicatula (SDAE) exhibited multiple antioxidant activity in selected chemical systems. Initially, we examined the ability of SDAE-enriched diet to modulate the levels of endogenous oxidative markers and antioxidant defenses in Drosophila melanogaster. Further, employing a co-exposure paradigm, we investigated the propensity of SDAE to protect flies against ROT-induced lethality, locomotor dysfunction, oxidative stress, mitochondrial dysfunctions and neurotoxicity. Adult flies were fed SDAE-enriched diet (0.05, 0.1 and 0.2%) with or without ROT (500 µM) for seven consecutive days. SDAE offered concentration-dependent protection against ROT-induced lethality (30-95% protection), while the survivor flies performed better in the negative geotaxis assay suggesting attenuation of ROT-induced locomotor deficits. Biochemical analysis revealed that SDAE completely restored ROT-induced elevation in the levels of ROS, protein carbonyls and hydroperoxides in both head and body regions of flies. Elevations in the activities of antioxidant enzymes (superoxide dismutase, glutathione reductase) and glutathione-S-transferase caused by ROT were also restored to normal levels by SDAE. Further, SDAE improved the activity levels of membrane bound enzymes viz., NADH-cytochrome c reductase and succinate dehydrogenase suggesting its propensity to protect mitochondrial integrity. Interestingly, SDAE normalized the activity levels of acetylcholinesterase and ROT-induced dopamine depletion. Collectively, these findings suggest the neuromodulatory potential of SDAE and our further studies are directed toward characterization of the nature of biomolecule/s and their mechanism of action employing relevant cell models.

Identification of compounds that inhibit the kinase activity of leucine-rich repeat kinase 2.

Mutations in leucine-repeat rich kinase 2 (LRRK2) are the most common known cause of late-onset Parkinson's disease. In this study, a novel system to purify active recombinant LRRK2 expressed in mammalian cells was generated. This recombinant enzyme was used to characterize the specificity of LRRK2 and identify small compounds that can inhibit the kinase activity. Recombinant LRRK2 was shown to autophosphorylate and phosphorylate MBP and a peptide (LRRKtide) corresponding to the T558 [corrected] site in moesin. A series of well-characterized kinase peptide substrates was not modified by LRRK2 demonstrating remarkable specificity. G2019S, the most common disease-causing mutation in LRRK2, increased kinase activity more dramatically than previously appreciated ( approximately 10-fold). Several small molecules sharing a basic indolocarbazole structure (Gö6976, K-252a, and staurosporine) where identified as potent inhibitors of LRRK2 kinase activity. These findings provide important insights and tools to study the mechanisms of LRRK2 pathobiology, and could lead to therapeutic applications.

Estimation of L-dopa from Mucuna pruriens LINN and formulations containing M. pruriens by HPTLC method.

A selective, precise, and accurate high-performance thin-layer chromatographic (HPTLC) method has been developed for the analysis of L-dopa in Mucuna pruriens seed extract and its formulations. The method involves densitometric evaluation of L-dopa after resolving it by HPTLC on silica gel plates with n-butanol-acetic acid-water (4.0+1.0+1.0, v/v) as the mobile phase. Densitometric analysis of L-dopa was carried out in the absorbance mode at 280 nm. The relationship between the concentration of L-dopa and corresponding peak areas was found to be linear in the range of 100 to 1200 ng/spot. The method was validated for precision (inter and intraday), repeatability, and accuracy. Mean recovery was 100.30%. The relative standard deviation (RSD) values of the precision were found to be in the range 0.64-1.52%. In conclusion, the proposed TLC method was found to be precise, specific and accurate and can be used for identification and quantitative determination of L-dopa in herbal extract and its formulations.

Antiparkinsonian-like effects of Plumbago scandens on tremorine-induced tremors methodology.

Tremorine-induced tremors model is used to evaluate antiparkinsonian drugs because rest tremor is a sign that distinguishes Parkinson's disease (PD) from other diseases. The effects of crude ethanolic extract (CEE) and total acetate fraction (TAF) of Plumbago scandens were investigated at several doses. These extracts at doses of 125 and 250 mg/kg i.p. failed to reduce tremors in tremorine-treated mice. TAF showed significant effects only at a dose of 500 mg/kg. Both CEE and TAF at doses of 1000 and 2000 mg/kg i.p. suppressed the tremors in a dose-dependent fashion for 60 min. Biperiden, an anticholinergic drug, was used as standard at a dose of 3 mg/kg i.p. This study suggests that P. scandens is a plant with possible therapeutic value for PD.