The neurological disorders affect millions of people worldwide, and are bracketed as the foremost basis of disability-adjusted life years (DALYs). The treatment options are symptomatic and often the movement of drugs is restricted by a specialized network of endothelial cell layers (adjoined by tight cell-to-cell junction proteins; occludin, claudins, and junctional adhesion molecules), pericytes and astroglial foot processes. In recent years, advances in nanomedicine have led to therapies that target central nervous system (CNS) pathobiology via altering signaling mechanisms such as activation of PI3K/Akt pathway in ischemic stroke arrests apoptosis, interruption of α-synuclein aggregation prevents neuronal degeneration in Parkinson’s. Often such interactions are limited by insufficient concentrations of drugs reaching neuronal tissues and/or insufficient residence time of drug/s with the receptor. Hence, lipid nanoformulations, SLNs (solid lipid nanoparticles) and NLCs (nanostructured lipid carriers) emerged to overcome these challenges by utilizing physiological transport mechanisms across blood–brain barrier, such as drug-loaded SLN/NLCs adsorb apolipoproteins from the systemic circulation and are taken up by endothelial cells via low-density lipoprotein (LDL)-receptor mediated endocytosis and subsequently unload drugs at target site (neuronal tissue), which imparts selectivity, target ability, and reduction in toxicity. This paper reviews the utilization of SLN/NLCs as carriers for targeted delivery of novel CNS drugs to improve the clinical course of neurological disorders, placing some additional discussion on the metabolism of lipid-based formulations.
1 November 2017 in International Journal of Biological Macromolecules
A burgeoning literature documents the confluence of ovarian steroids and central serotonergic systems in the injunction of epileptic seizures and epileptogenesis. Estrogen administration in animals reduces neuronal death from seizures by up-regulation of the prosurvival molecule i.e. Bcl-2, anti-oxidant potential and protection of NPY interneurons. Serotonin modulates epileptiform activity in either direction i.e administration of 5-HT agonists or reuptake inhibitors leads to the activation of 5-HT3 and 5-HT1A receptors tending to impede focal and generalized seizures, while depletion of brain 5-HT along with the destruction of serotonergic terminals leads to expanded neuronal excitability hence abatement of seizure threshold in experimental animal models. Serotonergic neurotransmission is influenced by the organizational activity of steroid hormones in the growing brain and the actuation effects of steroids which come in adulthood. It is further established that ovarian steroids bring induction of dendritic spine proliferation on serotonin neurons thus thawing a profound effect on serotonergic transmission. This review features 5-HT1A and 5-HT3 receptors as potential targets for ameliorating seizure-induced neurodegeneration and recurrent hypersynchronous neuronal activity. Indeed 5-HT3 receptors mediate cross-talk between estrogenic and serotonergic pathways, and could be well exploited for combinatorial drug therapy against epileptogenesis.