Optimization of Degradation Conditions with PRG, a Polysaccharide from Phellinus ribis, by RSM and the Neuroprotective Activity in PC12 Cells Damaged by Aβ25–35

Abstract

In the previous work, we found PRG, a polysaccharide from Phellinus ribis, exhibited neurotrophic activity. To obtain an active structural unit with lower molecular weight, PRG was degraded to prepare the degraded PRG (DPRG) using ascorbic acid and H2O2. The aim of the paper was to obtain DPRG by optimizing the degradation conditions using response surface methodology (RSM) and to study its protective effects of PC12 cells induced by Aβ25–35. The optimum conditions were as follows; the concentration of H2O2-Vc was 17 mM and degradation temperature was 50 °C; when degradation time was 1.6 h, the experimental response value of PC12 cell viability was 83.4 ± 0.15%, which was in accordance with the predicted value (83.5%). We also studied the protective effects of DPRG against the Aβ25–35-induced neurotoxicity and explored the underlying mechanism. The results showed that treatment with DPRG could attenuate PC12 cells death. The mechanism was relative to the inhibition of cell apoptosis by increasing the MMP level and decreasing the protein expression of cytochrome C (Cytc) in PC12 cells. In conclusion, DPRG with lower molecular weight was obtained successfully. It possessed neuroprotective properties and might be a candidate for neurodegenerative disease treatment.

Design and Synthesis of New Benzo[d]oxazole-Based Derivatives and Their Neuroprotective Effects on β-Amyloid-Induced PC12 Cells

“…Briefly, 1 mg of Aβ 25-35 was dissolved in 1 mL of purified water. It was polymerized in a 37 °C incubator for 96 h to obtain an oligomeric Aβ 25-35 fragment, which was frozen at −80 °C until use [ 14 ].…”

“…Aβ-induced hyperphosphorylation of tau has been recognized as a contributor to AD pathogenesis and progression, and abnormal accumulation of intracellular Aβ aggregates or particles in the brain of AD patients induces cell apoptosis and even directly triggers neuronal cell death [ 12 , 13 ]. Aβ 25-35 is a toxic peptide fragment of the full-length Aβ peptide, and it could induce a direct toxic effect in nerve cells and lead to their apoptosis [ 14 ]. Thus, Aβ plays a crucial role in the pathogenesis of AD.…”

Current advances and potential trends of the polysaccharides derived from medicinal mushrooms sanghuang

“…(Ferreira et al, 2015 ; Ruthes et al, 2016 ; Wang J. Q. et al, 2016 ; Xie et al, 2020 ). Although there exist some restrictions for accessing the fine structures in all hierarchies due to the structural diversity and variability of macromolecules, the basic chemical structures of purified sanghuang polysaccharides have been probed and identified by combined means of the chemical, instrumental, and biological techniques, including hydrolysis (Cao et al, 2019 ), methylation analysis (Sun et al, 2021 ), periodate oxidation (Nypelö et al, 2021 ), Smith degradation (Villares et al, 2012 ), Congo Red test (Guo X. Y. et al, 2021 ), capillary viscometer (Yuan et al, 2018 ), Zeta-sizer Nano instrument (Miao et al, 2020 ), UV-visible spectrophotometry (Guo X. Y. et al, 2021 ), HPLC (Yang et al, 2007 ), HPSEC (Wang et al, 2014b ), HPSEC-MALLS-RI (Cheong et al, 2015 ), HPGPC (Ren et al, 2019 ), TLC (Yang P. et al, 2019 ), GC (Lo et al, 2011 ), MS (Liu et al, 2021 ), GC-MS (Ma et al, 2016 ), HPAEC (Zhang Z. F. et al, 2015 ), FT-IR (Qian et al, 2009 ), NMR spectroscopy ( 1 H, 13 C, COSY, DEPT, HMBC, HMQC, HSQC, NOESY, and TOCSY) (Doost et al, 2019 ; Yao et al, 2021 ), XRD (Qian et al, 2009 ; Guo X. Y. et al, 2021 ), DLS (Wang Z. B. et al, 2014 ), DSC (Guo X. Y. et al, 2021 ), TGA (Guo X. Y. et al, 2021 ), AFM (Guo X. Y. et al, 2021 ), enzymatic analysis (Karaki et al, 2016 ; Mitchell et al, 2021 ), immune analysis (Sharma et al, 2019 ), etc.…”

“…People are urgent to find more alternative active ingredients in our daily food and health care products, and sanghuang polysaccharides are in line with this (Aida et al, 2009 ; Yang M. Y. et al, 2019 ; Li N. Y. et al, 2021 ; Martinez-Medina et al, 2021 ; Yadav and Negi, 2021 ). Innumerable works, in vitro and in vivo , have been implemented to substantiate that the sanghuang polysaccharides have multiple biological activities and health benefits, such as antioxidant and anti-aging (Wang et al, 2014a ; Yuan et al, 2018 ; Zuo et al, 2021 ), anti-tumor and immunomodulatory (Chen et al, 2011 ; Liu et al, 2018 ; Wan et al, 2020 ), anti-inflammatory and anti-nociceptive (Li et al, 2015 ; Wang et al, 2019 ; Sun et al, 2021 ), anti-diabetic (Kim et al, 2010 ; Wu et al, 2016 ; Khursheed et al, 2020 ), anti-microbial (Lee S. M. et al, 2010 ; Reis et al, 2014 ), anti-fatigue (Zhong, 2020 ), hepatoprotective (Liu et al, 2019b ; Zhang et al, 2019 ; Chen C. et al, 2020 ), neuroprotective (Liu Y. H. et al, 2015 ; Yang P. et al, 2019 ) activities, etc. Even though the bioactivities of sanghuang polysaccharides are intensively mined, scientific research focusing on deciphering the structure-bioactivity relationships and underlying mechanisms is still relatively insufficient.…”

Luteolin Protects Pheochromocytoma (PC‐12) Cells against Aβ25-35‐Induced Cell Apoptosis through the ER/ERK/MAPK Signalling Pathway

“…Therefore, A β 25-35 is usually used to induce an in vitro model of AD [ 6 ]. A β 25-35 clusters around neurons, which not only has a direct toxic effect on the neurons but also enhances the sensitivity of neurons to oxidative stress and free radicals, leading to neuron apoptosis [ 1 , 7 ]. Therefore, the inhibition of A β 25-35 -induced cell apoptosis may provide a promising approach for the prevention and treatment of AD.…”