Demystifying the Neuroprotective Role of Neuropeptides in Parkinson's Disease: A Newfangled and Eloquent Therapeutic Perspective

The role of NPY signaling pathway in diagnosis, prognosis and treatment of stroke

Neuropeptide Y (NPY), an extensively distributed neurotransmitter within the central nervous system (CNS), was initially detected and isolated from the brain of a pig in 1982. By binding to its G protein-coupled receptors, NPY regulates immune responses and contributes to the pathogenesis of numerous inflammatory diseases. The hippocampus contained the maximum concentration in the CNS, with the cerebral cortex, hypothalamus, thalamus, brainstem, and cerebellum following suit. This arrangement suggests that the substance has a specific function within the CNS. More and more studies have shown that NPY is involved in the physiological and pathological mechanism of stroke, and its serum concentration can be one of the specific biomarkers of stroke and related complications because of its high activity, broad and complex effects. By summarizing relevant literature, this article aims to gain a thorough understanding of the potential clinical applications of NPY in the treatment of stroke, identification of stroke and its related complications, and assessment of prognosis.

Metallic Nanocarriers for Therapeutic Peptides: Emerging Solutions Addressing the Delivery Challenges in Brain Ailments

Peptides and proteins have recently emerged as efficient therapeutic alternatives to conventional therapies. Although they emerged a few decades back, extensive exploration of various ailments or disorders began recently. The drawbacks of current chemotherapies and irradiation treatments, such as drug resistance and damage to healthy tissues, have enabled the rise of peptides in the quest for better prospects. The chemical tunability and smaller size make them easy to design selectively for target tissues. Other remarkable properties include antifungal, antiviral, anti-inflammatory, protection from hemorrhage stroke, and as therapeutic agents for gastric disorders and Alzheimer and Parkinson diseases. Despite these unmatched properties, their practical applicability is often hindered due to their weak susceptibility to enzymatic digestion, serum degradation, liver metabolism, kidney clearance, and immunogenic reactions. Several methods are adapted to increase the half-life of peptides, such as chemical modifications, fusing with Fc fragment, change in amino acid composition, and carrier-based delivery. Among these, nanocarrier-mediated encapsulation not only increases the half-life of the peptides in vivo but also aids in the targeted delivery. Despite its structural complexity, they also efficiently deliver therapeutic molecules across the blood-brain barrier. Here, in this review, we tried to emphasize the possible potentiality of metallic nanoparticles to be used as an efficient peptide delivery system against brain tumors and neurodegenerative disorders. SIGNIFICANCE STATEMENT: In this review, we have emphasized the various therapeutic applications of peptides/proteins, including antimicrobial, anticancer, anti-inflammatory, and neurodegenerative diseases. We also focused on these peptides' challenges under physiological conditions after administration. We highlighted the importance and potentiality of metallic nanocarriers in the ability to cross the blood-brain barrier, increasing the stability and half-life of peptides, their efficiency in targeting the delivery, and their diagnostic applications.

Several neuropeptides involved in parkinsonian neuroprotection modulate the firing properties of nigral dopaminergic neurons

Parkinson's disease is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta. The surviving nigral dopaminergic neurons display altered spontaneous firing activity in Parkinson's disease. The firing rate of nigral dopaminergic neurons decreases long before complete neuronal death and the appearance of parkinsonian symptoms. A mild stimulation could rescue dopaminergic neurons from death and in turn play neuroprotective effects. Several neuropeptides, including cholecystokinin (CCK), ghrelin, neurotensin, orexin, tachykinins and apelin, within the substantia nigra pars compacta play important roles in the modulation of spontaneous firing activity of dopaminergic neurons and therefore involve motor control and motor disorders. Here, we review neuropeptide-induced modulation of the firing properties of nigral dopaminergic neurons. This review may provide a background to guide further investigations into the involvement of neuropeptides in movement control by modulating firing activity of nigral dopaminergic neurons in Parkinson's disease.

Immunization with Neural-Derived Peptides in Neurodegenerative Diseases: A Narrative Review

Neurodegenerative diseases (NDDs) are a major health problem worldwide. Statistics suggest that in America in 2030 there will be more than 12 million people suffering from a neurodegenerative pathology. Furthermore, the increase in life expectancy enhances the importance of finding new and better therapies for these pathologies. NDDs could be classified into chronic or acute, depending on the time required for the development of clinical symptoms and brain degeneration. Nevertheless, both chronic and acute stages share a common immune and inflammatory pathway in their pathophysiology. Immunization with neural-derived peptides (INDP) is a novel therapy that has been studied during the last decade. By inoculating neural-derived peptides obtained from the central nervous system (CNS), this therapy aims to boost protective autoimmunity, an autoreactive response that leads to a protective phenotype that produces a healing environment and neuroregeneration instead of causing damage. INDP has shown promising findings in studies performed either in vitro, in vivo or even in some pre-clinical trials of different NDDs, standing as a potentially beneficial therapy. In this review, we will describe some of the studies in which the effect of INDP strategies have been explored in different (chronic and acute) neurodegenerative diseases.

Neuroprotection: Rescue from Neuronal Death in the Brain 2.0

The brain is vulnerable to endogenous or exogenous injuries [...]

The Role of Thymoquinone in Inflammatory Response in Chronic Diseases

Anti-inflammatory therapies have been shown to be effective in the prevention of various cardiovascular diseases, tumors, and cancer complications. Thymoquinone (TQ), the main active constituent of Nigella sativa, has shown promising therapeutic properties in many in vivo and in vitro models. However, TQ has poor bioavailability and is hydrophobic, prohibiting clinical trials with TQ alone. Studies have explored the combination of TQ with biological nanomaterials to improve its bioavailability. The TQ nanoparticle formulation shows better bioavailability than free TQ, and these formulations are ready for clinical trials to determine their potential as therapeutic agents. In this paper, we review current knowledge about the interaction between TQ and the inflammatory response and summarize the research prospects in Korea and abroad. We discuss the different biological activities of TQ and various combination therapies of TQ and nanomaterials in clinical trials.