Effect of the Flavonoid Rutin on the Modulation of the Myenteric Plexuses in an Experimental Model of Parkinson's Disease.

Recent discoveries have shown that enteric glial cells play an important role in different neurodegenerative disorders, such as Parkinson's disease (PD), which is characterized by motor dysfunctions caused by the progressive loss of dopaminergic neurons in the substance nigra pars compacta and non-motor symptoms including gastrointestinal dysfunction. In this study, we investigated the modulatory effects of the flavonoid rutin on the behavior and myenteric plexuses in a PD animal model and the response of enteric glia. Adult male Wistar rats were submitted to stereotaxic injection with 6-hydroxydopamine or saline, and they were untreated or treated with rutin (10 mg/kg) for 14 days. The ileum was collected to analyze tissue reactivity and immunohistochemistry for neurons (HuC/HuD) and enteric glial cells (S100ß) in the myenteric plexuses. Behavioral tests demonstrated that treatment with rutin improved the motor capacity of parkinsonian animals and improved intestinal transit without interfering with the cell population; rutin treatment modulated the reactivity of the ileal musculature through muscarinic activation, reducing relaxation through the signaling pathway of nitric oxide donors, and increased the longitudinal contractility of the colon musculature in parkinsonian animals. Rutin revealed modulatory activities on the myenteric plexus, bringing relevant answers regarding the effect of the flavonoid in this system and the potential application of PD adjuvant treatment.

Aminochrome Induces Neuroinflammation and Dopaminergic Neuronal Loss: A New Preclinical Model to Find Anti-inflammatory and Neuroprotective Drugs for Parkinson's Disease.

Studies have suggested aminochrome as an endogenous neurotoxin responsible for the dopaminergic neuron degeneration in Parkinson's disease (PD). However, neuroinflammation, an important alteration in PD pathogenesis, has been strictly induced in vitro by aminochrome. The aim of this study was to characterize the neuroinflammation induced in vivo by aminochrome. Wistar rats (male, 250-270 g) received a unilateral single dose by stereotaxic injection of saline into three sites in the striatum in the negative control group, or 32 nmol 6-hydroxydopamine (6-OHDA) in the positive control, or 6 nmol aminochrome. After 14 days, histological and molecular analyses were performed. We observed by immunofluorescence that aminochrome, as well as 6-OHDA, induced an increase in the number of Iba-1+ cells and in the number of activated (Iba-1+/ CD68+) microglia. An increase in the number of S100b+ cells and in the GFAP expression were also evidenced in the striatum and the SNpc of animals from aminochrome and positive control group. Dopaminergic neuronal loss was marked by reduction of TH+ cells and confirmed with reduction in the number of Nissl-stained neurons in the SNpc of rats from aminochrome and positive control groups. In addition, we observed by qPCR that aminocrhome induced an increase in the levels of IL-1ß, TNF-α, NLRP3, CCL5 and CCR2 mRNA in the SNpc. This work provides the first evidence of microgliosis, astrogliosis and neuroinflammation induced by aminochrome in an in vivo model. Since aminochrome is an endogenous molecule derived from dopamine oxidation present in the targeted neurons in PD, these results reinforce the potential of aminochrome as a useful preclinical model to find anti-inflammatory and neuroprotective drugs for PD. Aminochrome induced dopaminergic neuronal loss, microglial activation, astroglial activation and neuroinflammation marked by an increase in NLRP3, IL1ß, TNF-α, CCL2, CCL5 and CCR2.

In vitro and in vivo anti-inflammatory and anticoagulant activities of Myrciaria plinioides D. Legrand ethanol leaf extract.

Myrciaria plinioides D. Legrand (Myrtaceae) is a native plant of Southern Brazil, which have potential in the food industry due to its edible fruits. Many plants belonging to this genus have been used for a variety of illnesses, including inflammatory disorders due to antioxidant properties. However, therapeutic uses of M. plinioides have been poorly studied. The aim of study was to assess the anti-inflammatory and anticoagulant activities of the ethanol leaf extract of M. plinioides. In M. plinioides extract-treated RAW 264.7 cells, assessments of cell viability, TNF-α release and p38 MAPK pathway-dependent protein expression were detected. In addition, rat paw edema models were used to analyze the anti-inflammatory effect of the extract. Macrophages cell line treated with M. plinioides extract showed a slight decrease in cell viability. In LPS-stimulated macrophages treated with different concentrations of the extract for 24 h, TNF-α release was inhibited, while modulation of p38 signaling pathway and inhibition of NF-κB p65 protein expression were dose-dependent. In rats, the extract inhibited the formation of paw edema, while an inhibitory effect on trypsin-like enzymes derived from mast cells was seen. Furthermore, the extract presented anticoagulant activity via extrinsic pathway, being able to block specifically factor Xa and thrombin. The study suggests that extract possess potent anti-inflammatory and anticoagulant effects. M. plinioides present great biological potential as a source for the development of anti-inflammatory and anticoagulant drugs. Additional studies can be proposed to better elucidate the mechanism by which M. plinioides exerts its effects.

STRUCTURAL BASES OF GASTROINTESTINAL MOTILITY CHANGES IN PARKINSON'S DISEASE: STUDY IN RATS.

BACKGROUND: Gastrointestinal disorders are frequently reported in patients with Parkinson's disease whose disorders reduce the absorption of nutrients and drugs, worsening the clinical condition of patients. However, the mechanisms involved in modifying gastrointestinal pathophysiology have not yet been fully explained. AIM: To evaluate its effects on gastrointestinal motility and the involvement of the vagal and splanchnic pathways. METHODS: Male Wistar rats (250-300 g, n = 84) were used and divided into two groups. Group I (6-OHDA) received an intrastriatal injection of 6-hydroxydopamine (21 µg/animal). Group II (control) received a saline solution (NaCl, 0.9%) under the same conditions. The study of gastric emptying, intestinal transit, gastric compliance and operations (vagotomy and splanchnotomy) were performed 14 days after inducing neurodegeneration. Test meal (phenol red 5% glucose) was used to assess the rate of gastric emptying and intestinal transit. RESULTS: Parkinson's disease delayed gastric emptying and intestinal transit at all time periods studied; however, changes in gastric compliance were not observed. The delay in gastric emptying was reversed by pretreatment with vagotomy and splanchnotomy+celiac gangliectomy, thus suggesting the involvement of such pathways in the observed motor disorders. CONCLUSION: Parkinson's disease compromises gastric emptying, as well as intestinal transit, but does not alter gastric compliance. The delay in gastric emptying was reversed by truncal vagotomy, splanchnotomy and celiac ganglionectomy, suggesting the involvement of such pathways in delaying gastric emptying.

In vitro activities of kappa-carrageenan isolated from red marine alga Hypnea musciformis: Antimicrobial, anticancer and neuroprotective potential.

This study assessed the antioxidant, antimicrobial, anticancer and neuroprotective activities of the kappa(k)-carrageenan isolated from the red alga Hypnea musciformis (Hm-SP). The chemical spectrum of the k-carrageenan from Hm-SP was confirmed by Fourier transform infrared (FT-IR) spectroscopy. Hm-SP revealed an antibacterial and antifungal action against Staphylococcus aureus and Candida albicans, respectively. Hm-SP did not promoted cytotoxic effects against Human breast cancer (MCF-7) and Human neuroblastoma (SH-SY5Y) cell-lines. However, it was observed a significant reduction of the cellular proliferation capacity in these cancer cells in presence of the Hm-SP. Furthermore, Hm-SP showed neuroprotective activity in 6-hydroxydopamine-induced neurotoxicity on SH-SY5Y cells by modulation of the mitochondria transmembrane potential and reducing Caspase 3 activity. In addition, Hm-SP demonstrates low antioxidant potential and did not induce significant cytotoxic effects or changes in the cell proliferation on Balb/c 3T3 mouse fibroblast cell-line. In summary, our data suggest that Hm-SP shows antimicrobial, anticancer and neuprotective activities.

Gastroprotective Effects of Sulphated Polysaccharides from the Alga Caulerpa mexicana Reducing Ethanol-Induced Gastric Damage.

The development of the gastric lesion is complex and the result of the imbalance between aggressive and protective factors, involving the generation of free radicals and disturbance in nitric oxide (NO) production. Sulphated polysaccharides (SP), from marine algae, are widely used in biotechnological and pharmaceutical areas. In this study, we evaluated the effects of SP from the green marine alga Caulerpa mexicana (Cm-SP) in ethanol-induced gastric damage models in mice. Cm-SP (2, 20, or 200 mg/kg), administered p.o., significantly reduced gastric damage, and these effects were inhibited through pretreatment with indomethacin. Cm-SP (200 mg/kg) prevented the ethanol-induced decline in glutathione and restored its normal level. Moreover, it was able to normalize the elevated thiobarbituric acid reactive substance levels. However, Cm-SP did not show any significant effects on NO2/NO3 level, when compared to the ethanol group. The pretreatment with L- NAME induced gastric mucosal damage and did not inhibit the gastroprotective effect of Cm-SP (200 mg/kg). In conclusion, the gastroprotective effects of Cm-SP in mice involve prostaglandins and reduction in the oxidative stress and are independent of NO.

Mechanisms involved in antinociception induced by a polysulfated fraction from seaweed Gracilaria cornea in the temporomandibular joint of rats.

Temporomandibular disorder is a common clinical condition involving pain in the temporomandibular joint (TMJ) region. This study assessed the antinociceptive effects of a polysulfated fraction from the red seaweed Gracilaria cornea (Gc-FI) on the formalin-induced TMJ hypernociception in rats and investigated the involvement of different mechanisms. Male Wistar rats were pretreated with injection (sc) of saline or Gc-FI 1h before intra- TMJ injection of formalin to evaluate the nociception. The results showed that pretreatment with Gc-FI significantly reduced formalin-induced nociceptive behavior. Moreover, the antinociceptive effect of the Gc-FI was blocked by naloxone (a non-selective opioid antagonist), suggesting the involvement of opioids selective receptors. Thus, the pretreatment with selective opioids receptors antagonists, reversed the antinociceptive effect of the Gc-FI in the TMJ. The Gc-FI antinociceptive effect depends on the nitric oxide/cyclic GMP/protein kinase G/ATP-sensitive potassium channel (NO/cGMP/PKG/K+ATP) pathway because it was prevented by pretreatment with inhibitors of nitric oxide synthase, guanylate cyclase enzyme, PKG and a K+ATP blocker. In addition, after inhibition with a specific heme oxygenase-1 (HO-1) inhibitor, the antinociceptive effect of the Gc-FI was not observed. Collectively, these data suggest that the antinociceptive effect induced by Gc-FI is mediated by µ/δ/κ-opioid receptors and by activation NO/cGMP/PKG/K+ATP channel pathway, besides of HO-1.

Neuroprotective Effects of Sulphated Agaran from Marine Alga Gracilaria cornea in Rat 6-Hydroxydopamine Parkinson's Disease Model: Behavioural, Neurochemical and Transcriptional Alterations.

Parkinson's disease (PD) is a multifactorial disease associated with the degeneration of dopaminergic neurons and behavioural alterations. Natural bioactive compounds may provide new therapeutic alternatives for neurodegenerative disorders, such as PD. The sulphated polysaccharides isolated from marine algae are heterogenic molecules that show different biological activities. The red marine alga Gracilaria cornea has a sulphated polysaccharide (SA-Gc) with structure and anti-inflammatory and antinociceptive activities reported in the literature. Therefore, this study aimed to evaluate the neuroprotective effects of SA-Gc in rat model PD induced by 6-hydroxydopamine (6-OHDA). Firstly, we established the PD model in rats, induced by an intrastriatal injection (int.) of 6-OHDA, followed by a single administration of SA-Gc (15, 30 or 60 µg; int.). On the 14th day, behavioural tests were performed. After killing, brain areas were dissected and used for neurochemical and/or transcriptional analyses. The results showed that SA-Gc (60 µg, int.) promoted neuroprotective effects in vivo through reducing the oxidative/nitroactive stress and through alterations in the monoamine contents induced by 6-OHDA. Furthermore, SA-Gc modulated the transcription of neuroprotective and inflammatory genes, as well as returning behavioural activities and weight gain to normal conditions. Thus, this study reports the neuroprotective effects of SA-Gc against 6-OHDA in rats.

Structural bases of gastrointestinal motility changes in parkinson's disease: study in rats / Bases estruturais das alterações da motilidade gastrintestinal na doença de parkinson: estudo em ratos

ABSTRACT Background: Gastrointestinal disorders are frequently reported in patients with Parkinson's disease whose disorders reduce the absorption of nutrients and drugs, worsening the clinical condition of patients. However, the mechanisms involved in modifying gastrointestinal pathophysiology have not yet been fully explained. Aim: To evaluate its effects on gastrointestinal motility and the involvement of the vagal and splanchnic pathways. Methods: Male Wistar rats (250-300 g, n = 84) were used and divided into two groups. Group I (6-OHDA) received an intrastriatal injection of 6-hydroxydopamine (21 µg/animal). Group II (control) received a saline solution (NaCl, 0.9%) under the same conditions. The study of gastric emptying, intestinal transit, gastric compliance and operations (vagotomy and splanchnotomy) were performed 14 days after inducing neurodegeneration. Test meal (phenol red 5% glucose) was used to assess the rate of gastric emptying and intestinal transit. Results: Parkinson's disease delayed gastric emptying and intestinal transit at all time periods studied; however, changes in gastric compliance were not observed. The delay in gastric emptying was reversed by pretreatment with vagotomy and splanchnotomy+celiac gangliectomy, thus suggesting the involvement of such pathways in the observed motor disorders. Conclusion: Parkinson's disease compromises gastric emptying, as well as intestinal transit, but does not alter gastric compliance. The delay in gastric emptying was reversed by truncal vagotomy, splanchnotomy and celiac ganglionectomy, suggesting the involvement of such pathways in delaying gastric emptying.

RESUMO Racional: Distúrbios gastrintestinais são frequentemente relatados em pacientes com doença de Parkinson cujos distúrbios reduzem a absorção de nutrientes e fármacos, agravando o quadro clínico dos pacientes. No entanto, os mecanismos envolvidos na alteração da fisiopatologia gastrintestinal ainda não foram totalmente elucidados. Objetivo: Avaliar os seus efeitos sobre a motilidade gastrintestinal e o envolvimento das vias vagal e esplâncnica. Métodos: Ratos Wistar machos (250-300 g, n=84) foram utilizados e divididos em dois grupos. O grupo I (6-OHDA) recebeu injeção intraestriatal de 6-hidroxidopamina (21 µg/animal). O grupo II (controle) recebeu solução salina (NaCl, 0,9%) nas mesmas condições. O estudo do esvaziamento gástrico, trânsito intestinal, complacência gástrica e operações (vagotomia e esplancnotomia) foram realizadas 14 dias após a indução da neurodegeneração. Refeição teste (vermelho de fenol+glicose 5%) foi utilizada para avaliar a taxa de esvaziamento gástrico e o trânsito intestinal. Resultados: A doença de Parkinson retardou o esvaziamento gástrico e o trânsito intestinal em todos os tempos estudados; porém, alterações da complacência gástrica não foram observadas. O retardo do esvaziamento gástrico foi revertido por pré-tratamento com vagotomia e esplancnotomia+gangliectomia celíaca, sugerindo assim, o envolvimento de tais vias nos distúrbios motores observados. Conclusão: A doença de Parkinson compromete o esvaziamento gástrico, bem como o trânsito intestinal, mas não altera a complacência gástrica. O retardo do esvaziamento gástrico foi revertido pela vagotomia troncular, esplancnotomia e gangliectomia celíaca, sugerindo o envolvimento de tais vias no retardo do esvaziamento gástrico.

Mechanisms involved in the anti-inflammatory action of a polysulfated fraction from Gracilaria cornea in rats.

The anti-inflammatory mechanisms of the sulfated polysaccharidic fraction obtained from red marine alga Gracilaria cornea (Gc-FI) were investigated using a paw edema model induced in rats by different inflammatory agents (carrageenan, dextran, serotonin, bradykinin, compound 48/80 or L-arginine). Gc-FI at the doses of 3, 9 or 27 mg/kg, subcutaneously--s.c., significantly inhibited rat paw edema induced by carrageenan and dextran, as confirmed by myeloperoxidase and Evans' blue assessments, respectively. Gc-FI (9 mg/kg, s.c.) inhibited rat paw edema induced by histamine, compound 48/80 and L-arginine. Additionally, Gc-FI (9 mg/kg, s.c.) inhibited Cg-induced edema in animals with intact mast cells but did not inhibit that with degranulated mast cells by compound 48/80, revealing a protective role on mast cell membranes. Gc-FI down-regulated the IL-1ß, TNF-α and COX-2 mRNA and protein levels compared with those of the carrageenan group, based on qRT-PCR and immunohistochemistry analyses. After inhibition with ZnPP IX, a specific heme oxygenase-1 (HO-1) inhibitor, the anti-inflammatory effect of Gc-FI was not observed in Cg-induced paw edema, suggesting that the anti-inflammatory effect of Gc-FI is, in part, dependent on the integrity of the HO-1 pathway. Gc-FI can target a combination of multiple points involved in inflammatory phenomena.