Polygonatum cyrtonema polysaccharide

Parkinson's disease (PD) has become a global health threat as a progressive neurodegenerative disorder. Polygonatum cyrtonema polysaccharide (PCP), the main bioactive constituent in P. cyrtonema rhizome, displays various biological activities. However, its antiparkinsonian effect is elusive. Here, the effect of PCP on PD-like pathology was evaluated in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model and its molecular mechanism was further investigated. The results showed that PCP at different dosages significantly improved MPTP-induced weight loss and dyskinesia in PD mice. Moreover, PCP treatment mitigated the dopaminergic neuron loss in the substantia nigra pars compacta (SNc). Analysis of apoptosis-related proteins revealed that PCP markedly decreased the expression levels of Bax and cleaved-caspase 3, and increased the expression level of Bcl-2 in PD mice. Meanwhile, PCP markedly enhanced the activities of antioxidant enzymes superoxidase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), reduced malondialdehyde (MDA) content, and reversed the expression of oxidant stress-related proteins Nrf2 and Keap1, in the SNc of PD mice. Furthermore, PCP treatment significantly reduced the MPTP-mediated increase of endoplasmic reticulum (ER) stress-related proteins. These findings suggest that PCP protects against PD-like pathology by mitigating oxidant stress and ER stress-mediated apoptosis of dopaminergic neurons, highlighting its potential as a therapeutic agent for PD.

Aqueous Fe(II)-catalyzed activation commonly deteriorates the oxidation performance of persulfate (PS) to the treatment of organic contaminants. In this study, a PS-doped layered bimetallic hydroxide (Fe-Mn hydroxide) was synthesized to construct a heterogeneously catalytic system to solve the issue brought by homogeneity. The molar ratio of Fe(II) to Mn(II) and the mass ratio of PS to Fe-Mn hydroxide both had a significant impact on the catalytic degradation of p-CP. Reaction temperatures engaged in the most essential role in influencing the degradation and removal of p-chlorophenol (p-CP). The optimal combination of factors for the preparation of PS-hydroxide and the treatment of p-CP was finally determined by significance analysis. The degradation process was appropriately fitted by the pseudo-first-order kinetic model. The benzene ring in p-CP was broken by PS-hydroxide during the adsorption. The surface modification of PS-hydroxide caused by the valence transition of Mn was beneficial to the adsorption and catalytic degradation of p-CP.