Preparation of glutathione loaded nanoemulsions and testing of hepatoprotective activity on THLE-2 cells

Maleimide functionalized polycaprolactone micelles for glutathione quenching and doxorubicin delivery

High glutathione production is known to be one of the defense mechanisms by which many cancer cells survive elevated oxidative stress. By explicitly targeting glutathione in these cancer cells and diminishing its levels, oxidative stress can be intensified, ultimately triggering apoptosis or programmed cell death. Herein, we developed a novel approach by creating maleimide-functionalized polycaprolactone polymers, specifically using 2,3-diiodomaleimide functionality to reduce the level of glutathione in cancer cells. Polycaprolactone was chosen to conjugate the 2,3-diiodomaleimide functionality due to its biodegradable and biocompatible properties. The amphiphilic block copolymer was synthesized using PEG as a macroinitiator to make corresponding polymeric micelles. The resulting 2,3-diiodomaleimide-conjugated polycaprolactone micelles effectively quenched glutathione, even at low concentrations (0.01 mg mL-1). Furthermore, we loaded these micelles with the anticancer drug doxorubicin (DOX), which exhibited pH-dependent drug release. We obtained a loading capacity (LC) of 3.5% for the micelles, one of the highest LC reported among functional PCL-based micelles. Moreover, the enhanced LC doesn't affect their release profile. Cytotoxicity experiments demonstrated that empty and DOX-loaded micelles inhibited cancer cell growth, with the DOX-loaded micelles displaying the highest cytotoxicity. The ability of the polymer to quench intracellular GSH was also confirmed. This approach of attaching maleimide to polycaprolactone polymers shows promise in depleting elevated glutathione levels in cancer cells, potentially improving cancer treatment efficacy.

New Insights on Glutathione's Supramolecular Arrangement and Its In Silico Analysis as an Angiotensin-Converting Enzyme Inhibitor

Angiotensin-converting enzyme (ACE) inhibitors are one of the most active classes for cardiovascular diseases and hypertension treatment. In this regard, developing active and non-toxic ACE inhibitors is still a continuous challenge. Furthermore, the literature survey shows that oxidative stress plays a significant role in the development of hypertension. Herein, glutathione's molecular structure and supramolecular arrangements are evaluated as a potential ACE inhibitor. The tripeptide molecular modeling by density functional theory, the electronic structure by the frontier molecular orbitals, and the molecular electrostatic potential map to understand the biochemical processes inside the cell were analyzed. The supramolecular arrangements were studied by Hirshfeld surfaces, quantum theory of atoms in molecules, and natural bond orbital analyses. They showed distinct patterns of intermolecular interactions in each polymorph, as well as distinct stabilizations of these. Additionally, the molecular docking study presented the interactions between the active site residues of the ACE and glutathione via seven hydrogen bonds. The pharmacophore design indicated that the hydrogen bond acceptors are necessary for the interaction of this ligand with the binding site. The results provide useful information for the development of GSH analogs with higher ACE inhibitor activity.

Amelioration of oxidative stress utilizing nanoemulsion loaded with bromocriptine and glutathione for the management of Parkinson's disease

Parkinson's disease (PD) is triggered by the formation of free radicals in dopaminergic neurons, which results in oxidative stress-induced neurodegeneration. The objective of the work was to relieve oxidative stress by employing intranasal delivery of Bromocriptine Mesylate (BRM) and Glutathione (GSH) loaded nanoemulsion for the better management of PD. The depth of permeation of the nanoemulsion was assessed through confocal laser scanning microscopy (CLSM) which revealed higher nanoemulsion permeation in contrast to suspension. Biocompatibility of nanoemulsion was confirmed by nasal cilio toxicity study. The DPPH study showed that the nanoemulsion had significant antioxidant activity. Biochemical estimation studies in Wistar rats were carried out in order to determine the effect of nanoemulsion on oxidative stress. The levels of GSH, superoxide dismutase (SOD), and catalase (CAT) were significantly enhanced; and the level of thiobarbituric acid reactive substances (TBARS) was significantly reduced after the intranasal administration of nanoemulsion in the haloperidol-induced model of PD. Furthermore, the levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were also determined which reduced significantly after the administration of nanoemulsion. The oxidative stress levels were lowered with nanoemulsion, showing the combined antioxidant capability of BRM and GSH. The neuroprotective effect of the prepared nanoemulsion was confirmed by histopathological studies. Pharmacokinetic study revealed a higher concentration of BRM and GSH in the brain of Wistar rats after intranasal administration of nanoemulsion with a higher Brain/Plasma ratio. A higher value of AUC_(0-8) of nanoemulsion in the brain after intranasal administration revealed that BRM and GSH remained in the brain for a longer period due to sustained release from nanoemulsion. According to the findings, BRM and GSH loaded nanoemulsion has the potential to provide a combined and synergistic anti-oxidant effect for efficient management of PD.