benzofurans and Parkinson-Disease--Secondary

Evidence suggests constipation precedes motor dysfunction and is the most common gastrointestinal symptom in Parkinson's disease (PD). 5-HT4 receptor (5-HT4R) agonist prucalopride has been approved to treat chronic constipation. Here, we reported intraperitoneal injection of prucalopride for 7 days increased dopamine and decreased dopamine turnover. Prucalopride administration improved motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrathydropyridine (MPTP)-induced PD mouse models. Prucalopride treatment also ameliorated intestinal barrier impairment and increased IL-6 release in PD model mice. However, prucalopride treatment exerted no impact on JAK2/STAT3 pathway, suggesting that prucalopride may stimulate IL-6 via JAK2/STAT3-independent pathway. In conclusion, prucalopride exerted beneficial effects in MPTP-induced Parkinson's disease mice by attenuating the loss of dopamine, improving motor dysfunction and intestinal barrier.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Benzofurans; Body Weight; Disease Models, Animal; Dopamine; Eating; Inflammation; Interleukin-6; Intestinal Mucosa; Janus Kinase 2; Male; Mice; Mice, Inbred C57BL; Motor Skills; MPTP Poisoning; Neostriatum; Parkinson Disease; Parkinson Disease, Secondary; STAT3 Transcription Factor

As microglial activation is a key factor in the pathogenesis of Parkinson's disease (PD), drugs that target this process may help to prevent or delay the development of PD. The present study investigated the effects of dl‑3‑n‑butylphthalide (NBP) on microglia in a lipopolysaccharide (LPS)-induced PD mouse model. The mice were randomly divided into a blank control group, LPS control group and NBP + LPS treatment group. Mice in the treatment group were given an intragastric infusion of 120 mg/kg NBP daily for 30 days during the establishment of the PD mouse model. At 4 and 28 weeks post‑treatment, the motor behaviours of the mice in each group were observed using the rotarod test and the open field test. In addition, immunohistochemical staining was performed to determine the levels of activated microglia, tumour necrosis factor‑α and α‑synuclein, and the number of tyrosine hydroxylase (TH)‑positive cells in the substantia nigra. NBP significantly improved dyskinesia, reduced microglial activation, decreased nuclear α‑synuclein deposition and increased the survival of TH‑positive cells in the substantia nigra of LPS‑induced PD model mice. These findings suggested that NBP may exert its therapeutic effect by reducing microglial activation in a mouse model of PD.

Topics: alpha-Synuclein; Animals; Benzofurans; Disease Models, Animal; Dyskinesias; Gene Expression Regulation; Immunohistochemistry; Lipopolysaccharides; Male; Maze Learning; Mice; Mice, Inbred C57BL; Microglia; Motor Activity; Neuroprotective Agents; Parkinson Disease, Secondary; Rotarod Performance Test; Substantia Nigra; Tumor Necrosis Factor-alpha; Tyrosine 3-Monooxygenase

The objective of the present study was to investigate the effects of 3-n-butylphthalide (NBP) on a 1-methyl-4-phenylpyridinium (MPP+)-induced cellular model of Parkinson's disease (PD) and to illustrate the potential mechanism of autophagy in this process. For this purpose, rat PC12 pheochromocytoma cells were treated with MPP+ (1 mM) for 24 h following pretreatment with NBP (0.1 mM). Cell metabolic viability was determined by the MTT assay and cell ultrastructure was examined by transmission electron microscopy. The intracellular distribution and expression of α-synuclein and microtubule-associated protein light chain 3 (LC3) were detected by immunocytochemistry and Western blotting. Our results demonstrated that: 1) NBP prevented MPP+-induced cytotoxicity in PC12 cells by promoting metabolic viability. 2) NBP induced the accumulation of autophagosomes in MPP+-treated PC12 cells. 3) Further study of the molecular mechanism demonstrated that NBP enhanced the colocalization of α-synuclein and LC3 and up-regulated the protein level of LC3-II. These results demonstrate that NBP protects PC12 cells against MPP+-induced neurotoxicity by activating autophagy-mediated α-synuclein degradation, implying that it may be a potential effective therapeutic agent for the treatment of PD.

Topics: 1-Methyl-4-phenylpyridinium; Animals; Apium; Autophagy; Benzofurans; Blotting, Western; Cell Survival; Immunohistochemistry; Microscopy, Electron, Transmission; Neuroprotective Agents; Parkinson Disease, Secondary; PC12 Cells; Rats; Seeds

The aim of the present study was to explore the neuroprotective effects and mechanisms of action of dl-3-n-butylphthalide (NBP) in a 1-methyl-4-phenylpyridiniumion (MPP(+))-induced cellular model of Parkinson's disease (PD). NBP was extracted from seeds of Apium graveolens Linn. (Chinese celery). MPP(+) treatment of PC12 cells caused reduced viability, formation of reactive oxygen, and disruption of mitochondrial membrane potential. Our results indicated that NBP reduced the cytotoxicity of MPP(+) by suppressing the mitochondrial permeability transition, reducing oxidative stress, and increasing the cellular GSH content. NBP also reduced the accumulation of alpha-synuclein, the main component of Lewy bodies. Given that NBP is safe and currently used in clinical trials for stroke patients, NBP will likely be a promising chemical for the treatment of PD.

Topics: 1-Methyl-4-phenylpyridinium; alpha-Synuclein; Animals; Antioxidants; Apium; Benzofurans; Cell Survival; Cytoprotection; Glutathione; Membrane Potential, Mitochondrial; Mitochondria; Oxidative Stress; Parkinson Disease, Secondary; PC12 Cells; Rats; Reactive Oxygen Species

1. The treatment of Parkinson's disease relies predominantly upon dopamine replacement therapy, usually with l-dihydroxyphenylalanine (L-DOPA). However, side-effects of long-term treatment, such as L-DOPA-induced dyskinesias can be more debilitating than the disease itself. Non-dopaminergic treatment strategies might therefore be advantageous. 2. The aim of this study was to investigate the potential anti-parkinsonian efficacy of the kappa-opioid receptor agonist, enadoline, and the alpha-adrenoreceptor agonist, clonidine, both alone or in combination, in the reserpine-treated rat model of Parkinson's disease. 3. Rats were treated with reserpine (3 mg kg-1), and experiments carried out 18 h later, at which time they exhibited profound akinesia (normal animals 1251+/-228 mobile counts h-1, reserpine-treated animals 9+/-2 mobile counts h-1). Both enadoline and clonidine increased locomotion in reserpine-treated rats in a dose-dependent manner. The maximum locomotor-stimulating effect of enadoline alone was seen at a dose of 0.2 mg kg-1 (208+/-63 mobile counts h-1). The maximum effect of clonidine was seen at a dose of 2 mg kg-1 (536+/-184 mobile counts h-1). 4. Co-administration of enadoline (0.1 mg kg-1) and clonidine (0.01 - 0.1 mg kg-1) at sub-threshold doses, synergistically increased locomotion. 5. The synergistic stimulation of locomotion in the reserpine-treated rat involved activation of kappa-opioid receptors and a combination of both alpha1 and alpha2-adrenoreceptors. 6. The results presented suggest a need for further studies on the potential of stimulating kappa-opioid and/or alpha-adrenoreceptors as a therapy for Parkinson's disease. Furthermore, the studies may offer potential mechanistic explanations of the ability of alpha2-adrenergic receptor antagonist to reduce L-DOPA-induced dyskinesia in Parkinson's disease.

Topics: Adrenergic alpha-Agonists; Adrenergic alpha-Antagonists; Animals; Antiparkinson Agents; Benzofurans; Biogenic Monoamines; Clonidine; Disease Models, Animal; Drug Combinations; Drug Synergism; Locomotion; Male; Naltrexone; Narcotic Antagonists; Parkinson Disease, Secondary; Prazosin; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptors, Opioid, kappa; Reserpine; Yohimbine

Excessive glutamate transmission in the basal ganglia is a major factor in the neural mechanisms underlying parkinsonian akinesia. Activation of kappa opioid receptors causes a presynaptic reduction in glutamate release. Kappa opioid receptors are concentrated in those regions of the basal ganglia associated with increased glutamate transmission in parkinsonism. In this study, we use the alpha-methyl-p-tyrosine and reserpine-treated rat model of parkinsonism to investigate whether systemic administration of the kappa opioid agonists enadoline (CI-977) and U69,593 can alleviate the symptoms of parkinsonism either alone or in conjunction with dopamine replacement therapy. We report that, when administered alone, both enadoline and U69,593 can increase locomotion in monoamine-depleted rats. No increase in locomotor activity was seen after kappa opioid agonist administration in non-parkinsonian rats. The responses to kappa opioid agonists were blocked by co-administration of either the nonspecific opioid receptor antagonist naloxone or the selective kappa opioid receptor antagonist nor-binaltorphimine (nor-BNI). An important finding is that when enadoline and L-dopa are administered together, their anti-akinetic properties are synergistic. Thus, the doses of enadoline and L-dopa required to alleviate akinesia when administered together are lower than either administered alone. These data illustrate the importance of kappa opioid receptors in the neural mechanisms controlling voluntary movement and suggest that kappa opioid agonists may have a role as adjuncts to dopamine replacement in the management of Parkinson's disease.

Topics: alpha-Methyltyrosine; Animals; Antiparkinson Agents; Benzeneacetamides; Benzofurans; Dose-Response Relationship, Drug; Drug Synergism; Levodopa; Male; Motor Activity; Parkinson Disease, Secondary; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptors, Opioid, kappa; Reserpine

Although neural transplantation holds promise as a treatment for Parkinson's disease, parkinsonian primates have generally exhibited inconsistent and incomplete recovery of motor functions following intrastriatal grafting of fetal ventral mesencephalon. One possible contributing factor to this variable response is lack of appropriate integration of donor neurons with host striatal circuitry with the result that there is insufficient dopamine release and postsynaptic dopamine receptor activation. This issue was examined by measuring the effect of transplanting fetal ventral mesencephalon to the striatum of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated (MPTP) monkeys on striatal D2 receptor binding. One year after receiving MPTP, D2 receptor binding was upregulated in the dorsal and ventral striatum of African green monkeys. Grafting of fetal ventral mesencephalon to the dorsal striatum of MPTP-treated monkeys 9 months before sacrifice, eliminated the D2 receptor upregulation in dorsal, but not ventral, region. Dopamine concentration in dorsal striatum of grafted MPTP-treated monkeys was significantly higher than in that region of MPTP-treated non-grafted monkeys. In addition, dopamine concentration was significantly higher in dorsal compared to ventral striatum of grafted MPTP-treated monkeys. These data, in addition to those from a previous autoradiographic study on dopamine uptake site density in these monkeys, strongly supports the hypothesis that ectopically placed ventral mesencephalon not only produces, but maintains the release of sufficient levels of dopamine to restore postsynaptic dopamine transmission in regions influenced by graft-derived dopamine.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Autoradiography; Benzofurans; Brain Tissue Transplantation; Chlorocebus aethiops; Corpus Striatum; Disease Models, Animal; Dopamine Agents; Fetal Tissue Transplantation; Image Processing, Computer-Assisted; Iodine Radioisotopes; Mesencephalon; Parkinson Disease, Secondary; Radioligand Assay; Receptors, Dopamine D2; Up-Regulation

Parkinson's disease is characterized by an increased excitatory amino acid transmission in the internal segment of the globus pallidus and the substantia nigra pars reticulata. The effects of the kappa receptor agonist enadoline (CI-977) on glutamate transmission were investigated in vitro. Enadoline reduced the K(+)-evoked release of glutamate from slices of substantia nigra in a concentration-dependent manner (maximum effect: 78% inhibition at 200 microM). This effect was blocked by the selective kappa receptor antagonist nor-binaltorphimine. The endogenous ligand for kappa receptors is thought to be dynorphin. Dynorphin released from terminals of striato-pallidal and striato-nigral pathways might thus act as an endogenous modulatory agent on glutamatergic transmission in the basal ganglia. In vivo experiments were carried out in rodent and primate models of Parkinson's disease to assess the potential of manipulating kappa receptors as a potential treatment for Parkinson's disease. Enadoline reduced reserpine-induced akinesia when injected in the entopeduncular nucleus of the rat. Similarly, injections of CI-977 in the internal segment of globus pallidus (GPi) of the MPTP-treated marmoset alleviated parkinsonian symptoms and allowed the animal to recover its locomotor activity. This suggest that reducing the overactive glutamatergic transmission in the output regions of the basal ganglia by activating kappa receptors might potentially form the basis of a novel anti-parkinsonian therapy.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Anti-Arrhythmia Agents; Basal Ganglia; Benzofurans; Callithrix; Female; Glutamic Acid; In Vitro Techniques; Male; Motor Activity; Naltrexone; Parkinson Disease, Secondary; Pyrrolidines; Rats; Rats, Sprague-Dawley; Receptors, Opioid, kappa; Reserpine; Synaptic Transmission

Topics: Aged; Amiodarone; Benzofurans; Humans; Male; Parkinson Disease, Secondary