Oral Administration of Ethanolic Extract of Shrimp Shells-Loaded Liposome Protects against Aβ-Induced Memory Impairment in Rats

Shrimp Lipid Bioactives with Anti-Inflammatory, Antithrombotic, and Antioxidant Health-Promoting Properties for Cardio-Protection

Marine animals, especially shrimp species, have gained interest in research, due to the fact that they contain a plethora of biomolecules, specifically lipids, which have been proven to possess many health benefits in various diseases linked to chronic inflammation or other exogenous factors. This review refers to the lipid composition of a large number of shrimp species, as well as the effects that can alternate the lipid content of these crustaceans. Emphasis is given to the potent anti-inflammatory, antioxidant, and antithrombotic properties of shrimp bioactives, as well as the effects that these bioactives hold in other diseases, such as cancer, diabetes, neurodegenerative disorders, and more. The various health-promoting effects deriving from the consumption of shrimp lipid bioactives and the usage of products containing shrimp lipid extracts are also addressed in this study, through the exploration of several mechanisms of action and the interference of shrimp lipids in these biochemical pathways. Nevertheless, further research on this cultivatable edible species is needed, due to their existing limitations and future prospects which are discussed in this paper.

Breaking Barriers in Alzheimer's Disease: the Role of Advanced Drug Delivery Systems

Alzheimer's disease (AD), characterized by cognitive impairment, brain plaques, and tangles, is a global health concern affecting millions. It involves the build-up of amyloid-β (Aβ) and tau proteins, the formation of neuritic plaques and neurofibrillary tangles, cholinergic system dysfunction, genetic variations, and mitochondrial dysfunction. Various signaling pathways and metabolic processes are implicated in AD, along with numerous biomarkers used for diagnosis, risk assessment, and research. Despite these, there is no cure or effective treatment for AD. It is critically important to address this immediately to develop novel drug delivery systems (NDDS) capable of targeting the brain and delivering therapeutic agents to modulate the pathological processes of AD. This review summarizes AD, its pathogenesis, related signaling pathways, biomarkers, conventional treatments, the need for NDDS, and their application in AD treatment. It also covers preclinical, clinical, and ongoing trials, patents, and marketed AD formulations.

Pretreatment with Liposome-Encapsulated Shrimp Shell Extract Attenuated Neuronal Damage and Death in Aβ1-42-Induced Memory Deficits in Rats

The accumulation of amyloid-beta (Aβ) peptides is a crucial factor in the neuronal degeneration of Alzheimer's disease (AD). The current study investigated the underlying neuroprotective mechanisms of shrimp shell extract (SSE) and liposome-encapsulated SSE (SSE/L) against Aβ1-42-induced neuronal damage and death in rats. Intracerebroventricular infusion of Aβ1-42 effectively induced memory decline, as observed in a reduction of the rat's discriminating ability in the novel object recognition and novel object location tasks. Oral pretreatment with 100 mg/kg of SSE demonstrated no preventive effect on the memory decline induced by Aβ1-42 infusion. However, treatment with SSE/L 100 mg/kg BW effectively attenuated memory deficits in both behavioral assessments following two and four weeks after Aβ1-42 infusion. Moreover, SSE/L exerted neuroprotective effects by reducing lipid peroxidation and increasing Nrf2/HO-1 expression. There was a significant decrease in Iba1 and GFAP (biomarkers of microglia and astrocyte activity, respectively), as well as a decrease in the levels of NF-κB expression and the inflammatory cytokines TNF-α and IL-6 in the cortical and hippocampal tissues. Treatment with SSE/L also reduced the pro-apoptotic proteins Bax and cleaved caspase-3 while raising the anti-apoptotic protein Bcl2. In addition, the beneficial effects of SSE/L were along with the effects of a positive control commercial astaxanthin (AST). The findings of this study indicated that SSE/L provided neuroprotective effects on Aβ1-42-induced AD rats by ameliorating oxidative stress, neuroinflammation and apoptotic cell death. Therefore, SSE/L might be employed to prevent and mitigate Aβ accumulation-induced neurotoxicity in AD.

PEGylated-liposomal astaxanthin ameliorates Aβ neurotoxicity and Alzheimer-related phenotypes by scavenging formaldehyde

Alzheimer's disease (AD), which is a prevailing type of dementia, presents a significant global health concern. The current therapies do not meet clinical expectations. Amyloid-beta (Aβ) has been found to induce endogenous formaldehyde (FA) accumulation by inactivating FA dehydrogenase (FDH); in turn, excessive FA triggers Aβ aggregation that eventually leads to AD onset. Hence, scavenging FA by astaxanthin (ATX, a strong exogenous antioxidant) may be pursued as a promising disease-modifying approach. Here, we report that liposomal nanoparticles coupled with PEG (PEG-ATX@NPs) could enhance water-solubility of ATX and alleviate cognitive impairments by scavenging FA and reducing Aβ deposition. To enable drug delivery to the brain, liposomes were used to encapsulate ATX and then coupled with PEG, which produced liposomal nanoparticles (PEGATX@NPs) with a diameter of <100 nm. The PEG-ATX@NPs reduced Aβ neurotoxicity by both degrading FA and reducing FA-induced Aβ assembly in vitro. Intraperitoneal administration of PEG-ATX@NPs in APPswe/PS1dE9 mice (APP/PS1, a familial model of AD), not only decreased the levels of brain FA and malondialdehyde (MDA, a typical product of oxidative stress), but also attenuated both intracellular Aβ oligomerization and extracellular Aβ-related senile plaque (SP) formation. These pathological changes were accompanied by rescued ability of spatial learning and memory. Collectively, PEG-ATX@NPs improved the water-solubility, bioavailability, and effectiveness of ATX. Thus, it has the potential to be developed as a safe and effective strategy for treating AD.

Mechanism of Action of Natural Compounds in Peripheral Multiorgan Dysfunction and Hippocampal Neuroinflammation Induced by Sepsis

Bacterial sepsis induces the production of excessive pro-inflammatory cytokines and oxidative stress, resulting in tissue injury and hyperinflammation. Patients recovering from sepsis have increased rates of central nervous system (CNS) morbidities, which are linked to long-term cognitive impairment, such as neurodegenerative pathologies. This paper focuses on the tissue injury and hyperinflammation observed in the acute phase of sepsis and on the development of long-term neuroinflammation associated with septicemia. Here we evaluate the effects of Coriolus versicolor administration as a novel approach to treat polymicrobial sepsis. Rats underwent cecal ligation and perforation (CLP), and Coriolus versicolor (200 mg/kg in saline) was administered daily by gavage. Survival was monitored, and tissues from vital organs that easily succumb to infection were harvested after 72 h to evaluate the histological changes. Twenty-eight days after CLP, behavioral analyses were performed, and serum and brain (hippocampus) samples were harvested at four weeks from surgery. Coriolus versicolor increased survival and reduced acute tissue injury. Indeed, it reduced the release of pro-inflammatory cytokines in the bloodstream, leading to a reduced chronic inflammation. In the hippocampus, Coriolus versicolor administration restored tight junction expressions, reduce cytokines accumulation and glia activation. It also reduced toll-like receptor 4 (TLR4) and neuronal nitric oxide synthase (nNOS) and the NLR family pyrin domain containing 3 (NLRP3) inflammasome components expression. Coriolus versicolor showed antioxidant activities, restoring glutathione (GSH) levels and catalase and superoxide dismutase (SOD) activities and reducing lipid peroxidation, nitrite and reactive oxygen species (ROS) levels. Importantly, Coriolus versicolor reduced amyloid precursor protein (APP), phosphorylated-Tau (p-Tau), pathologically phosphorylated tau (PHF1), phosphorylated tau (Ser202 and Thr205) (AT8), interferon-induced transmembrane protein 3 (IFITM3) expression, and β-amyloid accumulation induced by CLP. Indeed, Coriolus versicolor restored synaptic dysfunction and behavioral alterations. This research shows the effects of Coriolus versicolor administration on the long-term development of neuroinflammation and brain dysfunction induced by sepsis. Overall, our results demonstrated that Coriolus versicolor administration was able to counteract the degenerative process triggered by sepsis.