Evaluation of acetylcholinesterase and adenosine deaminase activities in brain and erythrocytes and proinflammatory cytokine levels in rats submitted to neonatal hypoxia-ischemia model

Inter-alpha Inhibitor Proteins Modulate Microvascular Endothelial Components and Cytokines After Exposure to Hypoxia-Ischemia in Neonatal Rats

Inter-alpha inhibitor proteins (IAIPs) are neuroprotective and attenuate lipopolysaccharide (LPS)-mediated blood-brain barrier (BBB) disruption in neonatal rodents. We investigated some mechanism(s) fundamental to neuroprotection by IAIPs including changes in cerebral endothelial components and inflammation. Postnatal day-7 rats exposed to sham surgery and placebo or carotid ligation plus 8% FiO2 (90 min) were given IAIPs (30 or 60 mg/kg) or placebo and were killed 6, 12, 24, or 36 h after hypoxia-ischemia (HI). Proteins regulating BBB permeability to leukocytes (vascular cell adhesion molecule 1, VCAM-1), lipid-soluble (P-glycoprotein, PGP), and lipid-insoluble molecules (zonula occludens-1, ZO-1) were measured by immunoblot, and cytokines were measured in serum and cortex. HI resulted in reductions in ZO-1 and increases in VCAM-1, PGP, interferon-γ (IFN-γ), interleukin-12 (IL-12), vascular endothelial growth factor (VEGF), IL-α, and macrophage colony-stimulating factor (M-CSF) in cortex and increases in IL-4, IL-5, IL-10, and granulocyte colony-stimulating factor (G-CSF) in serum. IAIPs attenuated the reductions in ZO-1 and delayed increases in VCAM-1 and PGP in cortex and attenuated increases in cytokines in serum (IL-4, IL-5, IL-10, IFN-γ, G-CSF) and cortex (IL-1α, IL-12, IFN-γ, VEGF, M-CSF) after HI. We conclude that vascular endothelial proteins and cytokines exhibit sequential changes after HI and IAIPs modulate some of these HI-related changes in neonatal rats.

Haloperidol-Induced Catalepsy and Its Correlations with Acetylcholinesterase Activity in Different Brain Structures of Mice

BACKGROUND/OBJECTIVES

Antipsychotic medicines are used to treat several psychological disorders and some symptoms caused by dementia and schizophrenia. Haloperidol (Hal) is a typical antipsychotic usually used to treat psychosis; however, its use causes motor or extrapyramidal symptoms (EPS) such as catalepsy. Hal blocks the function of presynaptic D2 receptors on cholinergic interneurons, leading to the release of acetylcholine (ACh), which is hydrolyzed by the enzyme acetylcholinesterase (AChE).

METHODS

This study was designed to investigate the Hal-inhibitory effects on AChE activity in regions representative of the cholinergic system of mice and potential associations between cataleptic effects generated by Hal using therapeutic doses and their inhibitory effects on AChE.

RESULTS

The distribution of the AChE activity in the different regions of the brain followed the order striatum > hippocampus > (prefrontal cortex/hypothalamus/ cerebellum) > brainstem > septo-hippocampal system. In ex vivo assays, Hal inhibited AChE activity obtained from homogenate tissue of the striatum, hippocampus, and septo-hippocampal system in a concentration-dependent manner. The inhibitory concentration of 50% of enzyme activity (IC50) indicated that the septo-hippocampal system required a higher concentration of Hal (IC50 = 202.5 µmol·L-1) to inhibit AChE activity compared to the striatum (IC50 = 162.5 µmol·L-1) and hippocampus (IC50 = 145 µmol·L-1). In in vivo assays, male Swiss mice treated with concentrations of Hal higher than 0.1 mg·kg-1 induced cataleptic effects. Positive correlations with Spearman's correlation were observed only between the lack of cataleptic effect and the decreased AChE activity of the hippocampus in the mice treated with 0.01 mg·kg-1 of Hal but not in the striatum and septo-hippocampal system.

CONCLUSIONS

Our results suggest that Hal could increase cholinergic effects via AChE inhibition, in addition to its dopamine antagonist effect, as an alternative approach to the treatment of behavioral disturbances associated with dementia.

Ganoderma lucidum polysaccharide peptide alleviates hyperuricemia by regulating adenosine deaminase and urate transporters

Hyperuricemia (HUA) affects human health and is involved in the pathogenesis of common chronic diseases. Previous studies showed that Ganoderma lucidum extract lowered HUA in animals. However, the active ingredient and pharmacological mechanism of Ganoderma lucidum extract in the improvement of HUA are unknown. The purpose of this study was to determine the anti-HUA efficacy and related mechanism of Ganoderma lucidum polysaccharide peptide (GLPP) using a potassium oxonate (PO)-induced mouse model and an adenosine-induced cell model. The experimental results showed that blood uric acid (UA) was decreased up to 40.6% by GLPP in HUA mice in a dose-dependent manner. Additionally, GLPP significantly reduced UA production by inhibiting the hepatic and blood adenosine deaminase (ADA) activity and increased UA excretion by decreasing the expression of glucose transporter 9 (GLUT9) and increasing the expression of organic anion transporter 1 (OAT1) in kidney. The adenosine-induced cell model showed that the inhibitory effect of GLPP on ADA activity may be the main reason for the alleviation of HUA by GLPP. Furthermore, PO-induced renal histopathological damage was also alleviated by GLPP in a dose-dependent manner. The experimental results in this study indicated that GLPP exerted anti-HUA effects via regulating the UA production and excretion, suggesting that GLPP could be developed into a therapeutic agent for HUA.

Role of Copper in the Onset of Alzheimer's Disease Compared to Other Metals

Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by amyloid plaques in patients' brain tissue. The plaques are mainly made of β-amyloid peptides and trace elements including Zn2+, Cu2+, and Fe2+. Some studies have shown that AD can be considered a type of metal dyshomeostasis. Among metal ions involved in plaques, numerous studies have focused on copper ions, which seem to be one of the main cationic elements in plaque formation. The involvement of copper in AD is controversial, as some studies show a copper deficiency in AD, and consequently a need to enhance copper levels, while other data point to copper overload and therefore a need to reduce copper levels. In this paper, the role of copper ions in AD and some contradictory reports are reviewed and discussed.

Clinical significance of interleukin-6, tumor necrosis factor-α and high-sensitivity C-reactive protein in neonates with hypoxic-ischemic encephalopathy

The present study aimed to investigate the potential roles of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and high-sensitivity C-reactive protein (Hs-CRP) in the progression and prognosis of neonatal hypoxic-ischemic encephalopathy (HIE). The observation group comprised 74 neonates with HIE and the control group comprised 74 healthy neonates. The serum levels of IL-6, TNF-α and Hs-CRP were measured in the patients with HIE and the normal control infants. The correlations between the variances in the levels of these inflammatory cytokines and the different clinical gradings and prognoses of the disease were analyzed. The data revealed significant upregulation of the serum levels of IL-6, TNF-α and Hs-CRP in patients with HIE. The increase in the levels of these inflammatory mediators correlated with the severity of the disease and also had a positive correlation with the prognosis of the disease. In conclusion, high levels of IL-6, TNF-α and Hs-CRP were observed in neonatal patients with HIE. Thus, these inflammatory mediators may play a role in the progression and prognosis of the disease.