Nordihydroguaiaretic acid induces astroglial death via glutathione depletion.
Nordihydroguaiaretic acid (NDGA) is known to cause cell death in certain cell types that is independent of its activity as a lipoxygenase inhibitor; however, the underlying mechanisms are not fully understood. In the present study, we examined the cellular responses of cultured primary astroglia to NDGA treatment. Continuous treatment of primary astroglia with 30 microM NDGA caused >85% cell death within 24 hr. Cotreatment with the lipoxygenase products 5-HETE, 12-HETE, and 15-HETE did not override the cytotoxic effects of NDGA. In assays employing the mitochondrial membrane potential-sensitive dye JC-1, NDGA was found to induce a rapid and almost complete loss of mitochondrial membrane potential. However, the mitochondrial permeability transition pore inhibitors cyclosporin A and bongkrekic acid did not block NDGA-induced astroglial death. We found that treatment with N-acetyl cysteine (NAC), glutathione (GSH), and GSH ethyl ester (GSH-EE) did inhibit NDGA-induced astroglial death. Consistently, NDGA-induced astroglial death proceeded in parallel with intracellular GSH depletion. Pretreatment with GSH-EE and NAC did not block NDGA-induced mitochondrial membrane potential loss, and there was no evidence that reactive oxygen species (ROS) production was involved in NDGA-induced astroglial death. Together, these results suggest that NDGA-induced astroglial death occurs via a mechanism that involves GSH depletion independent of lipoxygenase activity inhibition and ROS stress.
Im
Joo-Young
JY
Division of Nano Sciences and Brain Disease Research Institute, Ewha Womans University, Seoul, Republic of Korea.
Han
Pyung-Lim
PL
D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001253:Astrocytes / Q000187:drug effects*; D016923:Cell Death / Q000187:drug effects; D002540:Cerebral Cortex / Q000166:cytology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004622:Embryo, Mammalian; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism*; D009637:Masoprocol / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D009474:Neurons / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
D000975:Antioxidants; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D009637:Masoprocol; D005978:Glutathione