Parkinson’s disease (PD) is a movement disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN). Recent studies have shown that necroptosis is involved in the development of inflammatory and neurodegenerative diseases. Receptor-interacting protein kinase (RIPK)1, RIPK3, and mixed lineage kinase domain-like protein (MLKL) play key roles in necroptosis, with MLKL being the final executor of necroptosis. Necrosulfonamide (NSA) is a specific inhibitor of MLKL, and its therapeutic effects in various inflammatory and neurological disorders have been previously reported. However, its role in PD has not yet been clearly demonstrated. In this study, we examined the effects of NSA in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. NSA reduced dopaminergic cell death and restored the expression of neurotrophic factors, such as BDNF, GDNF, and PGC-1α, in the SN region of MPTP mice. In addition, NSA inhibited microglial/ astrocyte activation and the expression of proinflammatory markers, such as iNOS, TNF-α, IL-1β, and IL-6. NSA also reduced oxidative stress markers, such as 8-OHdG and 4-HNE, while enhancing Nrf2-driven antioxidant enzymes, including HO-1, catalase, MnSOD, GCLC, and GCLM. We found that NSA inhibited MLKL phosphorylation in dopaminergic neurons and microglia, which may have reduced neuronal cell death and inflammation. Therefore, NSA-mediated suppression of dopaminergic neuronal cell death, inflammation, and oxidative stress may have therapeutic potential in PD.

Parkinson’s disease (PD) is a movement disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN). Recent studies have shown that necroptosis is involved in the development of inflammatory and neurodegenerative diseases. Receptor-interacting protein kinase (RIPK)1, RIPK3, and mixed lineage kinase domain-like protein (MLKL) play key roles in necroptosis, with MLKL being the final executor of necroptosis. Necrosulfonamide (NSA) is a specific inhibitor of MLKL, and its therapeutic effects in various inflammatory and neurological disorders have been previously reported. However, its role in PD has not yet been clearly demonstrated. In this study, we examined the effects of NSA in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. NSA reduced dopaminergic cell death and restored the expression of neurotrophic factors, such as BDNF, GDNF, and PGC-1α, in the SN region of MPTP mice. In addition, NSA inhibited microglial/ astrocyte activation and the expression of proinflammatory markers, such as iNOS, TNF-α, IL-1β, and IL-6. NSA also reduced oxidative stress markers, such as 8-OHdG and 4-HNE, while enhancing Nrf2-driven antioxidant enzymes, including HO-1, catalase, MnSOD, GCLC, and GCLM. We found that NSA inhibited MLKL phosphorylation in dopaminergic neurons and microglia, which may have reduced neuronal cell death and inflammation. Therefore, NSA-mediated suppression of dopaminergic neuronal cell death, inflammation, and oxidative stress may have therapeutic potential in PD.

Parkinson’s disease (PD) is a movement disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN). Recent studies have shown that necroptosis is involved in the development of inflammatory and neurodegenerative diseases. Receptor-interacting protein kinase (RIPK)1, RIPK3, and mixed lineage kinase domain-like protein (MLKL) play key roles in necroptosis, with MLKL being the final executor of necroptosis. Necrosulfonamide (NSA) is a specific inhibitor of MLKL, and its therapeutic effects in various inflammatory and neurological disorders have been previously reported. However, its role in PD has not yet been clearly demonstrated. In this study, we examined the effects of NSA in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. NSA reduced dopaminergic cell death and restored the expression of neurotrophic factors, such as BDNF, GDNF, and PGC-1α, in the SN region of MPTP mice. In addition, NSA inhibited microglial/ astrocyte activation and the expression of proinflammatory markers, such as iNOS, TNF-α, IL-1β, and IL-6. NSA also reduced oxidative stress markers, such as 8-OHdG and 4-HNE, while enhancing Nrf2-driven antioxidant enzymes, including HO-1, catalase, MnSOD, GCLC, and GCLM. We found that NSA inhibited MLKL phosphorylation in dopaminergic neurons and microglia, which may have reduced neuronal cell death and inflammation. Therefore, NSA-mediated suppression of dopaminergic neuronal cell death, inflammation, and oxidative stress may have therapeutic potential in PD.

Oxidative stress contributes to the onset of chronic diseases in various organs, including muscles. Morroniside, a type of iridoid glycoside contained in Cornus officinalis, is reported to have advantages as a natural compound that prevents various diseases.However, the question of whether this phytochemical exerts any inhibitory effect against oxidative stress in muscle cells has not been well reported. Therefore, the current study aimed to evaluate whether morroniside can protect against oxidative damage induced by hydrogen peroxide (H 2O2) in murine C2C12 myoblasts. Our results demonstrate that morroniside pretreatment was able to inhibit cytotoxicity while suppressing H2O2-induced DNA damage and apoptosis. Morroniside also significantly improved the antioxidant capacity in H2O2-challenged C2C12 cells by blocking the production of cellular reactive oxygen species and mitochondrial superoxide and increasing glutathione production. In addition, H2O2-induced mitochondrial damage and endoplasmic reticulum (ER) stress were effectively attenuated by morroniside pretreatment, inhibiting cytoplasmic leakage of cytochrome c and expression of ER stress-related proteins. Furthermore, morroniside neutralized H2O2-mediated calcium (Ca2+ ) overload in mitochondria and mitigated the expression of calpains, cytosolic Ca2+ -dependent proteases. Collectively, these findings demonstrate that morroniside protected against mitochondrial impairment and Ca2+ -mediated ER stress by minimizing oxidative stress, thereby inhibiting H2O2-induced cytotoxicity in C2C12 myoblasts.