Oxidative stress in Alzheimer's and Parkinson's diseases: insights from the yeast Saccharomyces cerevisiae

Beneficial effects of asiaticoside on cognitive deficits in senescence-accelerated mice

The effect of asiaticoside isolated from Hydrocotyle sibthorpioides (AHS) on the promotion of cognition in senescence-accelerated mice (SAMP) was evaluated. Six-month old male SAMP8 mice were orally administered 20, 40 or 80 mg/kg AHS daily for three months. SAMR1 mice were used as a "normal aging" control. The results showed that treatment with AHS significantly improved learning and memory abilities in behavioral tests. AHS-treated mice showed higher antioxidant enzyme activity and lower lipid oxidation in serum compared with untreated SAMP8 mice. Mechanistically, studies showed that AHS markedly reduced the content and deposition of β-amyloid peptide (Aβ) by inhibiting the expression of mRNA for amyloid protein precursor, β-site amyloid cleaving enzyme-1 and cathepsin B and promoting the expression of mRNA for neprilysin and insulin degrading enzyme. In addition, AHS significantly increased the expression of plasticity-related proteins including postsynaptic density-95, phosphor-N-methyl-D-aspartate receptor 1, phospho-calcium-calmodulin dependent kinase II, phospho-protein kinase A Catalyticβ subunit, protein kinase Cγ subunit, phospho-CREB and brain derived neurotrophic factor. Furthermore, AHS increased the levels of acetylcholine (Ach), but decreased cholinesterase (AchE) activity. These results demonstrated that AHS administration may prevent spatial learning and memory decline by scavenging free radicals, up-regulating the activity of antioxidant enzymes, decreasing the level of Aβ, ameliorating dysfunction in synaptic plasticity, and reversing abnormal changes in Ach level and AchE activity. Thus, AHS should be developed as a new drug to prevent age-related cognitive deficits.

The evolution of molecular hydrogen: a noteworthy potential therapy with clinical significance

Studies on molecular hydrogen have evolved tremendously from its humble beginnings and have continued to change throughout the years. Hydrogen is extremely unique since it has the capability to act at the cellular level. Hydrogen is qualified to cross the blood brain barrier, to enter the mitochondria, and even has the ability to translocate to the nucleus under certain conditions. Once in these ideal locations of the cell, previous studies have shown that hydrogen exerts antioxidant, anti-apoptotic, anti-inflammatory, and cytoprotective properties that are beneficial to the cell. Hydrogen is most commonly applied as a gas, water, saline, and can be applied in a variety of other mediums. There are also few side effects involving hydrogen, thus making hydrogen a perfect medical gas candidate for the convention of novel therapeutic strategies against cardiovascular, cerebrovascular, cancer, metabolic, and respiratory diseases and disorders. Although hydrogen appears to be faultless at times, there still are several deficiencies or snares that need to be investigated by future studies. This review article seeks to delve and comprehensively analyze the research and experiments that alludes to molecular hydrogen being a novel therapeutic treatment that medicine desperately needs.

Potential links between neurological disease and Tako-Tsubo cardiomyopathy: a literature review

Tako-Tsubo cardiomyopathy (TTC), is defined as a fully reversible acute deterioration of left-ventricular (LV) function, which is mainly found in women after an episode of emotional or physical stress (e.g. psychosocial stress, sepsis, surgery). The underlying mechanisms remain unclear. There is evidence suggesting a possible link between neurological disease and TTC. The pathophysiology of the several neurologic diseases has been reviewed searching for possible mechanisms that could lead to TTC in these patients.

NMR Metabolomics Analysis of Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disease, which is characterized by progressive death of dopaminergic neurons in the substantia nigra pars compacta. Although mitochondrial dysfunction and oxidative stress are linked to PD pathogenesis, its etiology and pathology remain to be elucidated. Metabolomics investigates metabolite changes in biofluids, cell lysates, tissues and tumors in order to correlate these metabolomic changes to a disease state. Thus, the application of metabolomics to investigate PD provides a systematic approach to understand the pathology of PD, to identify disease biomarkers, and to complement genomics, transcriptomics and proteomics studies. This review will examine current research into PD mechanisms with a focus on mitochondrial dysfunction and oxidative stress. Neurotoxin-based PD animal models and the rationale for metabolomics studies in PD will also be discussed. The review will also explore the potential of NMR metabolomics to address important issues related to PD treatment and diagnosis.

The role of oxidative stress in Parkinson's disease

Oxidative stress plays an important role in the degeneration of dopaminergic neurons in Parkinson's disease (PD). Disruptions in the physiologic maintenance of the redox potential in neurons interfere with several biological processes, ultimately leading to cell death. Evidence has been developed for oxidative and nitrative damage to key cellular components in the PD substantia nigra. A number of sources and mechanisms for the generation of reactive oxygen species (ROS) are recognized including the metabolism of dopamine itself, mitochondrial dysfunction, iron, neuroinflammatory cells, calcium, and aging. PD causing gene products including DJ-1, PINK1, parkin, alpha-synuclein and LRRK2 also impact in complex ways mitochondrial function leading to exacerbation of ROS generation and susceptibility to oxidative stress. Additionally, cellular homeostatic processes including the ubiquitin-proteasome system and mitophagy are impacted by oxidative stress. It is apparent that the interplay between these various mechanisms contributes to neurodegeneration in PD as a feed forward scenario where primary insults lead to oxidative stress, which damages key cellular pathogenetic proteins that in turn cause more ROS production. Animal models of PD have yielded some insights into the molecular pathways of neuronal degeneration and highlighted previously unknown mechanisms by which oxidative stress contributes to PD. However, therapeutic attempts to target the general state of oxidative stress in clinical trials have failed to demonstrate an impact on disease progression. Recent knowledge gained about the specific mechanisms related to PD gene products that modulate ROS production and the response of neurons to stress may provide targeted new approaches towards neuroprotection.