Membrane-stabilizing and protective effects of curcumin in a rotenone-induced rat model of Parkinson disease.

Parkinson disease (PD) is a chronic progressive neurodegenerative disease characterized by both motor and non-motor features. Numerous risk factors (oxidative stress, free radical formation, and several environmental toxins) have been associated with PD. The experimental studies were carried out under in vivo conditions. Biochemical data analysis indicated that compared with the parameters of control (C) rats, rotenone-induced PD rats showed a significant decrease in the specific content of the total fraction of isoforms of O2--producing, heat-stable, NADPH-containing associates (NLP-Nox) from membrane formations of tissues (brain, liver, lung, and small intestine). Compared with the C group indices, in the PD and PD + curcumin (PD + CU) groups there is some change in the shape of the optical absorption spectra of isoforms associated with a change in the amount of Nox in the isoform composition of the total fraction of the NLP-Nox associate. Thus, daily administration of CU (200 mg/kg, i.p.) to PD rats for 63 days had a regulatory effect, bringing the specific content and O2--producing activity of the total fraction of NLP-Nox isoforms closer to the norm. CU has membrane-stabilizing effects in rotenone-induced PD.

The effects of vibration on the neuronal activity of lateral vestibular nuclei in unilaterally labyrinthectomized rats.

Unilateral labyrinthectomy causes distinct oculomotor and postural disorder syndromes that gradually deteriorate. Simultaneously, compensatory mechanisms for the suppression of pathological disorders were activated. The current study aimed to investigate the characteristics of impulse activity in the ipsilateral and contralateral neurons of the lateral vestibular nucleus of unilaterally labyrinthectomized rats during various periods of vibration exposure. A program analysis of the background impulse activity of the neurons in the right- and left-lateral vestibular nuclei of rats under normal condition and after right-sided labyrinthectomy was performed. The animals were subjected to different periods of vibration exposure 2 days after surgery (5-, 10-, and 15-day periods). A comparison of the characteristics of the background impulse activity of neurons in both nuclei of intact rats revealed an initial asymmetry in the values of the mean impulse frequency and coefficient of variation of interimpulse intervals. After 5 days of vibration exposure, the values of the mean impulse frequency of neurons in both Deiters' nuclei were almost equal in labyrinthectomized rats. The mean impulse frequency of neurons on the uninjured side was higher than that on the injured side on the days following vibration exposure. The characteristics and functional significance of the findings are discussed.

Pathology and prevention of brain microvascular and neuronal dysfunction induced by a high-fructose diet in rats.

A high-fructose diet causes metabolic abnormalities in rats, and the cluster of complications points to microvascular and neuronal disorders of the brain. The aim of this study was to evaluate i) the involvement of microvascular disorders and neuronal plasticity in the deleterious effects of a high-fructose diet on the rat brain and ii) a comparative assessment of the effectiveness of Phytocollection therapy (with antidiabetic, antioxidant, and acetylcholinesterase inhibitory activities) compared to Galantamine as first-line therapy for dementia and Diabeton as first-line therapy for hyperglycemia. The calcium adenosine triphosphate non-injection histoangiological method was used to assess capillary network diameter and density. A high-fructose diet resulted in a significant decrease in the diameter and density of the capillary bed, and pharmacological manipulations had a modulatory effect on microcirculatory adaptive mechanisms. In vivo single-unit extracellular recording was used to investigate short-term plasticity in the medial prefrontal cortex. Differences in the parameters of spike background activity and expression of excitatory and inhibitory responses of cortical neurons have been discovered, allowing for flexibility and neuronal function stabilization in pathology and pharmacological prevention. Integration of the coupling mechanism between microvascular function and neuronal spike activity could delay the progressive decline in cognitive function in rats fed a high fructose diet.

Superoxide-producing thermostable associate from the small intestines of control and alloxan-induced diabetic rats: quantitative and qualitative changes.

BACKGROUND: NADPH oxidase 1 (Nox1), which is highly expressed in the colon, is thought to play a potential role in host defense as a physical and innate immune barrier against commensal or pathogenic microbes in the gastrointestinal epithelium. Diabetes can be caused by several biological factors, including insulin resistance is one of them. Alloxan is widely used to induce insulin-dependent diabetes in experimental animals. Alloxan increases the generation of reactive oxygen species as a result of metabolic reactions in the body, along with a massive increase in cytosolic calcium concentration. METHODS: Using a universal method, a superoxide radical (О2-)-thermostable associate between NADPH-containing lipoprotein (NLP) and NADPH oxidase (Nox)- NLP-Nox was isolated and purified from the small intestine (SI) of control (C) and alloxan-induced diabetic (AD) albino rats. RESULTS: In comparison to the C indices, in AD in the SI, an increase in the specific content of NLP-Nox associate and a decrease in the stationary concentration of produced О2- in liquid phase (in solution) and gas phase (during blowing by oxygen of the NLP-Nox solution) were observed. The NLP-Nox of SI associate in C and AD rats produced О2- by an immediate mechanism, using NLP as a substrate. The phenomenon of the hiding of the optical absorption maxima of the Nox in oxidized states at pH10,5 was observed in the composition of these SI associates of the C and AD rat groups. The characteristic absorption maxima of the «hidden¼ Nox were observed under these conditions after reduction by potassium dithionite. CONCLUSION: Thus, at AD, the decrease in the stationary concentration of produced О2- in the solution and gas phase was compensated for by an increase in the specific amount of associate. In addition,  the decrease in the stationary concentration of produced О2- by NLP-Nox associates at AD can be linked to a decrease in the level of NADPH in NLP-Nox composition. This could be used as a new mechanism of AD pathogenesis.

Protective effect of curcumin against rotenone-induced substantia nigra pars compacta neuronal dysfunction.

Rotenone is involved in the degeneration of dopaminergic neurons, and curcumin may prevent or effectively slow the progression of Parkinson's disease (PD). Previous research has shown that the naturally occurring phenolic compound curcumin can reduce inflammation and oxidation, making it a potential therapeutic agent for neurodegenerative diseases. The present study involves investigation of rotenone-induced histological changes in the brain area, hippocampus using Nissl staining after 35 day of subcutaneous injection of rotenone in adult male rats. We sought to determine whether curcumin could protect against rotenone-induced dopaminergic neurotoxicity in a rat model by in vivo electrical recording from Substantia nigra pars compacta (SNc). Curcumin treatment significantly improved electrical activity of neurons in the SNc of rotenone-induced PD model rats. The pattern of histological alterations corresponds with electrophysiological manifestations.

Protective effects of curcumin against rotenone-induced rat model of Parkinson's disease: in vivo electrophysiological and behavioral study.

Curcumin is a naturally occurring phenolic yellow chemical isolated from the rhizomes of the plant Curcuma longa (turmeric), and is a major component of the spice turmeric. Curcumin has protective effects against rotenone-induced neural damage in Parkinson's disease (PD). The present study aims at providing new evidence for the validity of the rotenone rat model of PD by examining whether neuronal activity in the hippocampus is altered. Male albino rats were treated with rotenone injections (2.5 mg/ml intraperitoneally) for 21 days. We examined the effects of curcumin (200 mg/kg) on behavior and electrophysiology in a rat model of PD induced by rotenone. Motor activity was assessed by cylinder test. The electrical activity of neurons was measured in hippocampus. Rotenone causes significant reduction of neuronal activity. The results show that curcumin can improve the motor impairments and electrophysiological parameters and may be beneficial in the treatment of PD.

Rotenone impairs hippocampal neuronal activity in a rat model of Parkinson's disease.

Parkinson's disease (PD) is the most common neurodegenerative disease of unknown etiology and characterized by motor symptoms of tremor, rigidity, bradykinesia, and postural instability. Interactions between the dopaminergic systems and the hippocampus in synaptic plasticity and behavior are found. The rotenone-induced animal model is commonly used in research studies involved in PD. Administration of rotenone causes alterations of electrical neuronal activity. Rotenone (2.5 mg/kg/day) was administered intraperitoneally for 21 days to adult rats, and rotenone effects on rearing activity and electrophysiology were examined. Dose-dependent reduction of evoked neural activity and a reduction in firing strength were found in the hippocampus. Behaviorally, Rotenone rats showed a more consistent decrease in rearing across the 3 weeks, compared with animals in the control group. Thus, rotenone causes changes in hippocampal electrical activity and behavioral changes.