Pharmacological intervention in oxidative stress as a therapeutic target in neurological disorders

Chitosan-graft-poly(lactide) nanocarriers: An efficient antioxidant delivery system for combating oxidative stress

Oxidative stress is a key factor in various diseases, and thus exogenous antioxidants offer effective therapeutic potential. While astaxanthin (ATX) is a potent natural antioxidant, its poor water solubility, bioavailability, and stability hinder its application. This study aimed to develop an amphiphilic chitosan-graft-poly(lactide) (CS-g-PLA) copolymer utilizing a new strategy by ring-opening polymerization of D, l-lactide via organosoluble CS/sodium dodecyl sulfate complex. Subsequently, CS-g-PLA micelles were prepared for efficient encapsulation and delivery of ATX. CS-g-PLA copolymers were characterized by FT-IR and 1H NMR. Transmission electron microscopy and dynamic light scattering revealed micellar morphology and size distribution. The antioxidant activity of CS-g-PLA/ATX was assessed using the DPPH assay, demonstrating significant improvement compared to free ATX. Furthermore, the cytotoxicity of micellar ATX was evaluated on H2O2-treated bone marrow mesenchymal stem cells (BMSCs) using MTT assay. Annexin V staining and mitochondrial membrane potential (∆Ψm) analysis revealed reduced apoptosis and enhanced protection by ATX-loaded micelles compared to free ATX. These findings suggest CS-g-PLA micelles as promising nanocarriers for ATX delivery, putatively enhancing its antioxidant potential and protecting stem cells in oxidative stress environments. This approach could hold significant implications for stem cell therapy in diseases associated with oxidative stress.

Synthesis, Antioxidant Activity, and Molecular Docking of Novel Paeoniflorin Derivatives

Paeoniflorin (PF) is one of the active constituents of the traditional Chinese medicine Paeoniae Radix Rubra and has been actively explored in the pharmaceutical area due to its numerous pharmacological effects. However, severe difficulties such as limited bioavailability and low permeability limit its utilization. Therefore, this study developed and synthesized 25 derivatives of PF, characterized them by 1H NMR, 13C NMR, and HR-MS, and evaluated their antioxidant activity. Firstly, the antioxidant capacity of PF derivatives was investigated through DPPH radical scavenging experiment, ABTS radical scavenging experiment, reducing ability experiment, and O2 .- radical scavenging experiment. PC12 cells are routinely used to evaluate the antioxidant activity of medicines, therefore we utilize it to establish a cellular model of oxidative stress. Among all derivatives, compound 22 demonstrates high DPPH radical scavenging capacity, ABTS radical scavenging ability, reduction ability, and O2 .- radical scavenging ability. The results of cell tests reveal that compound 22 has a non-toxic effect on PC12 cells and a protective effect on H2O2-induced oxidative stress models. This might be due to the introduction of 2, 5-difluorobenzene sulfonate group in PF, which helps in scavenging free radicals under oxidative stress. Western blot and molecular docking indicated that compound 22 may exert antioxidant activity by activating Nrf2 protein expression. As noted in the study, compound 22 has the potential to be a novel antioxidant.

Curcumin Derivatives Linked to a Reduction of Oxidative Stress in Mental Dysfunctions and Inflammatory Disorders

Stress is a critical factor in the etiology of inflammation and neurodegeneration. The risk factor for the majority of psychiatric disorders is oxidative stress-induced depression. Mitochondrial damage and oxidative stress are associated with the development of neurodegenerative disorders. During aging, the brain and associated regions become more susceptible due to oxidative stress. The leading cause of oxidative stress is the continuous generation of ROS (reactive oxygen species) and RNS (Reactive nitrogen species) endogenously or exogenously. In this review, discussion on a potent antioxidant natural constituent "curcumin" has been made to alleviate many pathological and neurological disorders. A focused compilation of vast and informative research on the potential of curcumin as a magical moiety used therapeutically has been done in search of its role in controlling the neurological and similar disorders induced by oxidative stress.

The flavonoid luteolin reduces mutant huntingtin aggregation and cytotoxicity in huntingtin-mutated neuroblastoma cells

Background

Huntington's disease is an inherited progressive neurodegenerative disorder caused by an expansion of the polyglutamine tract leading to malformation and aggregation of the mutant huntingtin protein in the cell cytoplasm and nucleus of affected brain regions. The development of neuroprotective agents from plants has received considerable research attention.

Objective

Our study aims to investigate the neuroprotective effects of luteolin and the mechanisms that underline its potential mediated protection in the mutant htt neuroblastoma cells.

Methods

The mutant htt neuroblastoma cells were transfected with 160Q, and the control wild-type neuroblastoma cells were transfected with 20Q htt for 24 h and later treated with luteolin. Cell viability was determined by MTT and PI staining in both groups, while western blotting was used to evaluate caspase 3 protein expression. Aggregation formation was assessed via immunofluorescence microscopy. Also, western blotting was utilized to measure the protein expression of mutant htt aggregated and soluble protein, Nrf2 and HO-1. The impact of Nrf2 on luteolin-treated neuroblastoma cells was assessed using small interfering RNAs.

Results

Our study reports that luteolin can protect cultured cells from mutant huntingtin cytotoxicity, evidenced by increased viability and decreased apoptosis. Also, luteolin reduced the accumulation of soluble and insoluble mutant huntingtin aggregates in mutant htt neuroblastoma cells transfected with 160Q compared to the control wild-type. The mutant htt aggregate reduction mediated by luteolin appeared to be independent of the Nrf2 -HO-1 antioxidant pathway.

Conclusion

Luteolin presents a new potential therapeutic and protective agent for the treatment and decreasing the cytotoxicity in neurodegenerative diseases such as Huntington's disease.

From imbalance to impairment: the central role of reactive oxygen species in oxidative stress-induced disorders and therapeutic exploration

Increased production and buildup of reactive oxygen species (ROS) can lead to various health issues, including metabolic problems, cancers, and neurological conditions. Our bodies counteract ROS with biological antioxidants such as SOD, CAT, and GPx, which help prevent cellular damage. However, if there is an imbalance between ROS and these antioxidants, it can result in oxidative stress. This can cause genetic and epigenetic changes at the molecular level. This review delves into how ROS plays a role in disorders caused by oxidative stress. We also look at animal models used for researching ROS pathways. This study offers insights into the mechanism, pathology, epigenetic changes, and animal models to assist in drug development and disease understanding.

Nanobubble technologies: Applications in therapy from molecular to cellular level

Nanobubbles are gaseous entities suspended in bulk liquids that have widespread beneficial usage in many industries. Nanobubbles are already proving to be versatile in furthering the effectiveness of disease treatment on cellular and molecular levels. They are functionalized with biocompatible and stealth surfaces to aid in the delivery of drugs. At the same time, nanobubbles serve as imaging agents due to the echogenic properties of the gas core, which can also be utilized for controlled and targeted delivery. This review provides an overview of the biomedical applications of nanobubbles, covering their preparation and characterization methods, discussing where the research is currently focused, and how they will help shape the future of biomedicine.

Protective Effect of NGR1 against Glutamate-Induced Cytotoxicity in HT22 Hippocampal Neuronal Cells by Upregulating the SIRT1/Wnt/β-Catenin Pathway

Notoginsenoside R1 (NGR1) is an active compound isolated from Panax notoginseng. Despite the NGR1 having been used as a traditional medicine, little is known about the neuroprotective effects. In this study, we investigate the protective effects of NGR1 against glutamate-induced cytotoxicity in HT22 cells and its possible molecular mechanism. We assessed the toxicity of NGR1 and the protective activity by MTT assay. The levels of oxidative stress indices superoxide dismutase (SOD), glutathione (GSH), and mitochondrial membrane potential (MMP) were measured by the kits. The levels of reactive oxygen species (ROS) and Ca²⁺ concentration were measured by flow cytometry. Furthermore, we determined the expression of mitochondrial dysfunction related protein PINK1, Parkin, silent mating type information regulation 2 homolog-1 (sirtuin 1; SIRT1), and Wnt/β-catenin by Western blotting. Here, we discovered that glutamate treatment led to cell viability loss, apoptosis facilitation, Ca²⁺ upregulation, MMP fluorescence intensity downregulation, and ROS generation of HT22 cells. In parallel, expression of Parkin was declined by glutamate. While, NGR1 treatment alleviated all the above phenomena. We further clarified that NGR1 alleviated glutamate-induced oxidative stress, apoptosis, and mitochondrial dysfunction by upregulating SIRT1 to activate Wnt/β-catenin pathways. These findings demonstrate that NGR1 alleviated glutamate-induced cell damage, and NGR1 may play a protective role in neurological complications.