Oxidative Stress in Alzheimer's Disease: The Shortcomings of Antioxidant Therapies.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by gradual and progressive cognitive decline leading to dementia. At its core, the neuropathological features of AD include hallmark accumulations of amyloid-β and hyperphosphorylated tau proteins. Other harmful processes, such as oxidative stress and inflammation, contribute to the disease's neuropathological progression.

Restoration of the Ultrastructural Integrity of the Dermal Collagen Network by 12-Week Ingestion of Special Collagen Peptides.

Introduction: This pilot study investigated the effects of a 12-week administration of a nutritional supplement containing special collagen peptides on the structural and molecular properties of the collagen fiber network in the human skin. For the assessments, the suction blister method and electron microscopical comparisons were used.

Methods: Three suction blisters were generated on the inner forearm of each test subject before and after the 12-week administration of the nutritional supplement.

The Tryptophan Metabolite Indole-3-Propionic Acid Raises Kynurenic Acid Levels in the Rat Brain In Vivo.

Alterations in the composition of the gut microbiota may be causally associated with several brain diseases. Indole-3-propionic acid (IPrA) is a tryptophan-derived metabolite, which is produced by intestinal commensal microbes, rapidly enters the circulation, and crosses the blood-brain barrier. IPrA has neuroprotective properties, which have been attributed to its antioxidant and bioenergetic effects.

Nitric Oxide as a Determinant of Human Longevity and Health Span.

The master molecular regulators and mechanisms determining longevity and health span include nitric oxide (NO) and superoxide anion radicals (SOR). L-arginine, the NO synthase (NOS) substrate, can restore a healthy ratio between the dangerous SOR and the protective NO radical to promote healthy aging. Antioxidant supplementation orchestrates protection against oxidative stress and damage-L-arginine and antioxidants such as vitamin C increase NO production and bioavailability.

Tryptophan in Nutrition and Health 2.0.

This editorial summarizes the eight articles that have been collected for the Special Issue entitled "Tryptophan in Nutrition and Health 2 [...

Flavonoids as Promising Neuroprotectants and Their Therapeutic Potential against Alzheimer's Disease.

Alzheimer's disease (AD) is one of the serious and progressive neurodegenerative disorders in the elderly worldwide. Various genetic, environmental, and lifestyle factors are associated with its pathogenesis that affect neuronal cells to degenerate over the period of time. AD is characterized by cognitive dysfunctions, behavioural disability, and psychological impairments due to the accumulation of amyloid beta (A) peptides and neurofibrillary tangles (NFT).

Tryptophan in Nutrition and Health.

Tryptophan is a rate-limiting essential amino acid and a unique building block of peptides and proteins [...

Copper-mediated β-amyloid toxicity and its chelation therapy in Alzheimer's disease.

Unlabelled: The link between bio-metals, Alzheimer's disease (AD), and its associated protein, amyloid-β (Aβ), is very complex and one of the most studied aspects currently. Alzheimer's disease, a progressive neurodegenerative disease, is proposed to occurs due to the misfolding and aggregation of Aβ. Dyshomeostasis of metal ions and their interaction with Aβ has largely been implicated in AD.

Indoles as essential mediators in the gut-brain axis. Their role in Alzheimer's disease.

Sporadic late-onset Alzheimer's disease (AD) is the most frequent cause of dementia associated with aging. Due to the progressive aging of the population, AD is becoming a healthcare burden of unprecedented proportions. Twenty years ago, it was reported that some indole molecules produced by the gut microbiota possess essential biological activities, including neuroprotection and antioxidant properties.

Mobile Phone Chips Reduce Increases in EEG Brain Activity Induced by Mobile Phone-Emitted Electromagnetic Fields.

Recent neurophysiological studies indicate that exposure to electromagnetic fields (EMFs) generated by mobile phone radiation can exert effects on brain activity. One technical solution to reduce effects of EMFs in mobile phone use is provided in mobile phone chips that are applied to mobile phones or attached to their surfaces. To date, there are no systematical studies on the effects of mobile phone chip application on brain activity and the underlying neural mechanisms.

Melatonin Treatment Enhances Aβ Lymphatic Clearance in a Transgenic Mouse Model of Amyloidosis.

Background: It has been postulated that inadequate clearance of the amyloid β protein (Aβ) plays an important role in the accumulation of Aβ in sporadic late onset Alzheimer's disease (AD). While the blood brain barrier (BBB) has taken the center stage in processes involving Aβ clearance, little information is available about the role of the lymphatic system. We previously reported that Aβ is cleared through the lymphatic system.

Nitrone Derivatives as Therapeutics: From Chemical Modification to Specific-targeting.

Nitrones have been extensively used for the detection of transient free radicals using electron paramagnetic resonance. Since the mid-80's, nitrones have also been widely used as protective agents against oxidative stress in several biological models. Due to the high potency of nitrones, there has been extensive research on the development of derivatives with improved biological and spin trapping properties as well as enhanced intra-cellular compartmentalization.

Evidence for lymphatic Aβ clearance in Alzheimer's transgenic mice.

Evidence has shown that lymphatic drainage contributes to removal of debris from the brain but its role in the accumulation of amyloid β peptides (Aβ) has not been demonstrated. We examined the levels of various forms of Aβ in the brain, plasma and lymph nodes in a transgenic model of Alzheimer's disease (AD) at different ages. Herein, we report on the novel finding that Aβ is present in the cervical and axillary lymph nodes of AD transgenic mice and that Aβ levels in lymph nodes increase over time, mirroring the increase of Aβ levels observed in the brain.

Hypothalamic-pituitary-thyroid axis hormones stimulate mitochondrial function and biogenesis in human hair follicles.

Thyroid hormones regulate mitochondrial function. As other hypothalamic-pituitary-thyroid (HPT) axis hormones, i.e.

Melatonin replacement therapy in preterm infants: the impact of pharmacokinetics.

The paper by Merchant et al. demonstrates that the pharmacokinetic profile of melatonin differs in preterm infants from that of adults. The findings of this study can guide the necessary future preventive and therapeutic clinical trials on melatonin in preterm infants.

Melatonin and synthetic melatonergic agonists: actions and metabolism in the central nervous system.

The CNS is both source and target of melatonin. This methoxyindole formed in the pineal gland is also produced in other CNS regions and additionally enters the brain by uptake from the circulation as well as via the pineal recess. The mammalian circadian pacemaker, the suprachiasmatic nucleus (SCN), not only controls the pineal, but also receives a feedback information on darkness.

Thyrotropin-releasing hormone controls mitochondrial biology in human epidermis.

Context: Mitochondrial capacity and metabolic potential are under the control of hormones, such as thyroid hormones. The most proximal regulator of the hypothalamic-pituitary-thyroid (HPT) axis, TRH, is the key hypothalamic integrator of energy metabolism via its impact on thyroid hormone secretion.

Objective: Here, we asked whether TRH directly modulates mitochondrial functions in normal, TRH-receptor-positive human epidermis.

Amphiphilic amide nitrones: a new class of protective agents acting as modifiers of mitochondrial metabolism.

Our group has demonstrated that the amphiphilic character of alpha-phenyl-N-tert-butyl nitrone based agents is a key feature in determining their bioactivity and protection against oxidative toxicity. In this work, we report the synthesis of a new class of amphiphilic amide nitrones. Their hydroxyl radical scavenging activity and radical reducing potency were shown using ABTS competition and ABTS(+) reduction assays, respectively.

A novel endogenous indole protects rodent mitochondria and extends rotifer lifespan.

Aging is a multi-factorial process, however, it is generally accepted that reactive oxygen species (ROS) are significant contributors. Mitochondria are important players in the aging process because they produce most of the cellular ROS. Despite the strength of the free-radical hypothesis, the use of free radical scavengers to delay aging has generated mixed results in vertebrate models, and clinical evidence of efficacy is lacking.

Thyrotropin-releasing hormone and oestrogen differentially regulate prolactin and prolactin receptor expression in female human skin and hair follicles in vitro.

Background: Human skin and scalp hair follicles are both a nonclassical target and an extrapituitary source of prolactin (PRL), which is a potent hair growth modulator. However, how the expression of PRL and PRL receptor (PRLR) is regulated in human skin is unknown.

Objectives: To investigate whether two key stimulators of pituitary PRL secretion, thyrotropin-releasing hormone (TRH) and oestrogen, also regulate cutaneous PRL and PRLR expression.

Thyroid-stimulating hormone, a novel, locally produced modulator of human epidermal functions, is regulated by thyrotropin-releasing hormone and thyroid hormones.

Several elements of the hypothalamic-pituitary-thyroid axis (HPT) reportedly are transcribed by human skin cell populations, and human hair follicles express functional receptors for TSH. Therefore, we asked whether the epidermis of normal human skin is yet another extrathyroidal target of TSH and whether epidermis even produces TSH. If so, we wanted to clarify whether intraepidermal TSH expression is regulated by TRH and/or thyroid hormones and whether TSH alters selected functions of normal human epidermis in situ.