Protective Effects of Ulva lactuca Polysaccharide Extract on Oxidative Stress and Kidney Injury Induced by D-Galactose in Mice

Reactive oxygen species (ROS) are the key factors that cause many diseases in the human body. Polysaccharides from seaweed have been shown to have significant antioxidant activity both in vivo and in vitro. The ameliorative effect of Ulva lactuca polysaccharide extract (UPE) on renal injury induced by oxidative stress was analyzed. As shown by hematoxylin–eosin staining results, UPE can significantly improve the kidney injury induced by D-galactose (D-gal). Additionally, the protective mechanism of UPE on the kidney was explored. The results showed that UPE could decrease the levels of serum creatinine (Scr), blood urea nitrogen (BUN), serum cystatin C (Cys-C), lipid peroxidation, protein carbonylation, and DNA oxidative damage (8-OHdG) and improve kidney glutathione content. Moreover, UPE significantly increased the activities of superoxide dismutase and glutathione peroxidase and total antioxidant activity in mice. UPE also decreased the levels of inflammatory cytokines TNF-α and IL-6. Further investigation into the expression of apoptotic protein caspase-3 showed that UPE decreased the expression of apoptotic protein caspase-3. These results indicate that UPE has a potential therapeutic effect on renal injury caused by oxidative stress, providing a new theoretical basis for the treatment of oxidative damage diseases in the future.     

烟台金沙滩绿潮爆发的基本状况与应对措施

2007年5～6月烟台开发区金沙滩海域发生大面积石莼引起的绿潮事件,通过对绿潮发生前后相关因子监测分析发现,石莼的最适生长盐度范围为10～15,水温为15.0～20.0℃,水体富营养程度决定石莼生物量。调查发现,急剧变化的水温是这次绿潮消亡的主要因素。加强监测、及时捕捞和采取科学合理的应对措施将有效抑制绿潮的爆发。     

紫色叶用莴苣色泽参数及花色苷含量的相关研究

为获得目前紫色叶用莴苣的叶色相关数据,建立分级标准,利用色差仪及高效液相色谱仪对40个品种的叶用莴苣叶片颜色及花色苷含量进行测定,对数据进行相关分析,并建立分级系统。结果表明,根据色泽参数和花色苷的含量可将紫色叶用莴苣的分成绿色、浅紫色、中紫色、深紫色和特紫色5 个等级。据此建立了一个叶色分级标准,根据紫色部分在叶片分布特征可将紫色叶用莴苣分成裙边紫、渐变紫、全叶紫、花斑紫4 类。试验结果提供测量、评价叶片颜色性状的科学方法,有助于培育、筛选出外观品质优良的新品种。