Antioxidant activity of sulfated Porphyra yezoensis polysaccharides and their regulating effect on calcium oxalate crystal growth
Antioxidant activity of sulfated Porphyra yezoensis polysaccharides and their regulating effect on calcium oxalate crystal growth
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DOI：
10.1016/j.msec.2021.112338
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发表时间：
2021-08-02
影响因子：
7.9
通讯作者：
Ouyang, Jian-Ming
中科院分区：
文献类型：
--
作者：
Chen, Xue-Wu;Huang, Wei-Bo;Ouyang, Jian-Ming
草酸钙(CaOx)晶体的成核、生长和聚集以及肾小管上皮细胞的氧化损伤是诱发肾结石的关键因素。本研究采用三氧化硫-吡啶法对硫酸基团（-OSO3-）含量为14.14%的降解条斑紫菜多糖（PYP0）进行改性，得到-OSO3-基团含量为17.11%的3种硫酸化条斑紫菜多糖（PYPs），即PYPS1、PYPS2和PYPS3，分别为20.28%、27.14%。傅里叶变换红外光谱、1H NMR和C-13 NMR分析表明-OSO3-基团取代了(1→3)-连接的β-D-半乳糖(PYP0的基本结构骨架单元)上C2、C4和C6位置上的羟基。硫酸化后PYPSs的抗氧化活性增强，其清除(OH)-O-中心点和DPPH自由基的能力随着-OSO3-基团含量的增加而增强。草酸钙（CaOx）晶体生长实验表明，硫酸化PYP促进热力学稳定且尖锐的一水氧化钙（COM）晶体转化为热力学不稳定且圆形的二水氧化钙晶体。随着多糖中-OSO3-基团含量的增加，上清液中可溶性Ca2+离子浓度增加，CaOx沉淀量减少。 PYPs对人肾近端肾小管上皮细胞（HK-2）无毒，可以保护HK-2免受纳米COM引起的氧化损伤，并降低细胞内活性氧的水平。 PYPS3硫酸化程度最高，防护能力最好。这项工作的结果表明硫酸化提高了 PYP 的生物活性。该研究可为预防和治疗肾结石新药的开发提供启发。
The nucleation, growth and aggregation of calcium oxalate (CaOx) crystals and the oxidative damage of renal tubular epithelial cells are the key factors to induce kidney stones. In this study, degraded Porphyra yezoensis polysaccharide (PYP0) with 14.14% sulfate group (-OSO3-) content was modified via the sulfur trioxide-pyridine method to obtain three kinds of sulfated P. yezoensis polysaccharides (PYPs), namely, PYPS1, PYPS2, and PYPS3, with -OSO3- group contents of 17.11%, 20.28%, and 27.14% respectively. Fourier transform infrared spectroscopy, 1H NMR, and C-13 NMR analyses showed that the -OSO3- groups replaced the hydroxyl groups at the C2, C4, and C6 positions on (1 -> 3)-linked beta-D-galactose, the basic structural skeleton unit of PYP0. The antioxidant activity of the PYPSs increased after sulfation, and their scavenging capacity for (OH)-O-center dot and DPPH free radicals was enhanced with the increase in their -OSO3- group content. Calcium oxalate (CaOx) crystal growth experiments showed that sulfated PYPs promoted the conversion of the thermodynamically stable and sharp CaOx monohydrate (COM) crystals into the thermodynamically unstable and round CaOx dihydrate crystals. With the increase in the -OSO3- group content of the polysaccharides, the concentration of soluble Ca2+ ions in the supernatant increased and the amount of CaOx precipitate decreased. PYPs were nontoxic to human kidney proximal tubular epithelial cells (HK-2) and could protect HK-2 from oxidative damage caused by nano-COM and reduce the level of reactive oxygen species in cells. PYPS3, which had the highest degree of sulfation, had the best protective capability. The results of this work showed that sulfation improved the biological activity of PYPs. This study could provide inspiration for the development of new drugs for the prevention and treatment of kidney stones.