glutathione

Overview

Glutathione (GSH) is a small thiol-containing tripeptide composed of glutamate, cysteine, and glycine. It is one of the most abundant intracellular antioxidants in mammalian cells and is central to redox homeostasis, detoxification, and protection against oxidative damage. By directly scavenging reactive species and serving as a substrate for glutathione peroxidases and glutathione S-transferases (GSTs), it helps regulate lipid peroxidation, protein oxidation, and cellular responses to electrophilic stress.

In biomedical research, glutathione is frequently treated as both a biomarker and a functional target. Elevated or depleted GSH levels are used to characterize oxidative stress, ferroptosis susceptibility, inflammatory injury, and drug resistance. Because many tumors maintain high intracellular GSH to buffer oxidative stress, glutathione has become a major focus in cancer nanomedicine and redox-responsive drug delivery, where GSH-cleavable disulfide bonds, GSH-triggered release systems, and GSH depletion strategies are used to amplify photodynamic therapy, chemodynamic therapy, cuproptosis, and ferroptosis.

Focus of Latest Publications

Recent publications portray glutathione as a major determinant of cellular redox balance and a practical target for therapy design. In multiple cancer studies, high glutathione levels in the tumor microenvironment were exploited as a trigger for drug release or as a metabolic weakness to induce ferroptosis. For example, GSH-responsive disulfide linkers were used in peptide-drug conjugates and self-assembling prodrugs to enable selective intracellular release in rheumatoid arthritis and ovarian cancer-related delivery systems. Similarly, several nanoplatforms were engineered to respond to elevated tumor glutathione, including glutathione-cleavable phototheranostic systems, redox-triggered polyprodrugs, and bioorthogonal nanocatalysts that used GSH to drive Cu(II)/Cu(I) cycling, deplete intracellular GSH, amplify lipid peroxidation, and induce ferroptotic cell death.

A major theme across the cancer literature was glutathione depletion as a mechanism to overcome antioxidant defenses. Studies in colorectal cancer, triple-negative breast cancer, hepatocellular carcinoma, esophageal cancer, gastric cancer, melanoma, and bladder cancer reported that lowering GSH enhanced reactive oxygen species accumulation, lipid peroxidation, mitochondrial dysfunction, and immunogenic stress signaling. Several reports linked GSH depletion to downregulation of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), reinforcing the role of glutathione metabolism in ferroptosis. Other studies combined glutathione depletion with photodynamic therapy, chemodynamic therapy, sonodynamic therapy, or checkpoint inhibitor, including atezolizumab-based and PD-L1-related strategies, to intensify antitumor effects.

Outside oncology, glutathione was repeatedly used as a biomarker of oxidative status and neuroprotection. In rat models of Alzheimer’s disease, Huntington’s disease, traumatic brain injury, MDMA exposure, cadmium-induced neurotoxicity, and ischemic stroke, reduced glutathione levels were associated with oxidative injury, inflammation, and apoptosis, while interventions such as resveratrol, genistein, pinostrobin, clemizole, silibinin meglumine, and diosgenin were reported to restore GSH alongside superoxide dismutase, catalase, and other antioxidant defenses. In these studies, glutathione was measured together with malondialdehyde, nitric oxide, acetylcholinesterase activity, Beta amyloid, brain-derived neurotrophic factor, and inflammatory mediators such as tumour necrosis factor-α and proinflammatory cytokines.

Glutathione also appeared in studies of antibacterial materials, pesticide delivery, wound dressings, and food-related nanocapsules, where it served as a redox-responsive trigger or a readout of oxidative protection. In one oral antibacterial platform, glutathione depletion contributed to bacterial death by enhancing reactive oxygen species generation. In another study, foliar-adhering microcapsules released pesticide more rapidly under higher glutathione concentrations, demonstrating GSH-sensitive environmental responsiveness. Across these diverse contexts, glutathione remained a central indicator of cellular stress, a mechanistic switch for controlled release, and a therapeutic target in redox-based intervention.