School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, Hebei Province 066004, China.
Food Funct. 2017 Jul 19;8(7):2566-2572. doi: 10.1039/c6fo01818a.
Potassium bromate (KBrO) is widely used as a food additive and is a major by-product of water disinfection. The aim of this study was to investigate the protective effects of fraction 4a of polysaccharides isolated from Lycium barbarum (LBP-4a) against renal damage induced by KBrO in rats and to determine the relevant mechanisms behind these effects. Male Wistar rats were divided into a normal control group, a KBrO control group, and LBP-4a(L) and LBP-4a(H) groups. With the exception of the normal control group, the rats in the other three groups were administered KBrO by intraperitoneal injection to induce renal damage. Before the induction of renal damage, rats in the LBP-4a(L) and LBP-4a(H) groups were pretreated with 50 mg per kg b.w. or 100 mg per kg b.w. LBP-4a, respectively, by intragastric administration. Clinical biochemical parameters and markers of oxidative damage were also determined. Treatment by administration of LBP-4a prior to challenge with KBrO prevented increases in the levels of nitrite, creatinine, urea nitrogen and uric acid in serum and increased the activities of antioxidant enzymes in kidney tissues. A comet assay and FCS results showed that pretreatment with LBP-4a also alleviated DNA damage and decreases in mitochondrial membrane potentials in renal cells. Histological studies further supported the above results and showed extensive renal damage in animals treated with KBrO and greatly reduced tissue injury in groups pretreated with LBP-4a. In conclusion, LBP-4a exhibited protective effects against renal damage induced by KBrO, and the mechanism was closely correlated with a reduction in levels of lipid peroxidation and an increase in the activities of antioxidant enzymes in kidney tissues, which alleviated DNA damage and increased mitochondrial membrane potentials in renal cells. These observations provide the background for the further development of LBP-4a as a protective agent for use in the treatment of renal damage.
溴酸钾（KBrO）被广泛用作食品添加剂，也是水消毒的主要副产物。本研究旨在探讨从枸杞中分离得到的多糖的 4a 级分（LBP-4a）对溴酸钾诱导的大鼠肾损伤的保护作用，并确定其相关机制。雄性 Wistar 大鼠分为正常对照组、KBrO 对照组和 LBP-4a（L）和 LBP-4a（H）组。除正常对照组外，其他三组大鼠均通过腹腔注射 KBrO 诱导肾损伤。在诱导肾损伤之前，LBP-4a（L）和 LBP-4a（H）组大鼠分别通过灌胃给予 50mg/kg b.w.或 100mg/kg b.w.的 LBP-4a 预处理。还测定了临床生化参数和氧化损伤标志物。在受到 KBrO 挑战之前给予 LBP-4a 治疗可防止血清中亚硝酸盐、肌酐、尿素氮和尿酸水平的升高，并增加肾组织中抗氧化酶的活性。彗星试验和 FCS 结果表明，LBP-4a 预处理还减轻了肾细胞中 DNA 损伤和线粒体膜电位的降低。组织学研究进一步支持了上述结果，并表明 KBrO 处理的动物肾脏广泛受损，而 LBP-4a 预处理组的组织损伤大大减少。总之，LBP-4a 对 KBrO 诱导的肾损伤具有保护作用，其机制与肾组织中脂质过氧化水平降低和抗氧化酶活性增加密切相关，这减轻了肾细胞中的 DNA 损伤并增加了线粒体膜电位。这些观察结果为进一步开发 LBP-4a 作为治疗肾损伤的保护剂提供了背景。
