Plantago asiatica L. (PA), which is widely distributed in Korea, Japan and China, has traditionally been used as a popular folk medicine for the treatment of liver diseases. A variety of activities of PA was reported, that is hepatoprotective, anti-inflammatory, anti-glycation and anti-oxidant effect. Ferric nitrilotriacetate (Fe-NTA) is a potent nephrotoxic agent and has been reported to induce renal proximal tubular necrosis. In the present study, pretreatment with PA extract (PAE) in Wistar rat followed by Fe-NTA i.p. treatment (13.5 mg Fe/kg body weight) was performed to detect the renal protective effect of PAE. Only Fe-NTA treated group showed increases in the level of serum blood urea nitrogen (BUN) and serum creatinine (Cr), and renal tissue malondialdehyde (MDA), product of lipid peroxidation. Moreover, the level of biomarkers indicate the antioxidants status, reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GR) were decreased. However, PAE pre-treated group showed decreases in the levels of serum BUN, serum Cr and renal tissue MDA in concentration dependent manner and increases in the level of GSH, GST and GR. These results are significantly different (p < 0.05) to the other groups. Our data suggest that PAE may be used as an chemopreventive material against Fe-NTA-mediated renal oxidative stress.

In this study, we assessed the effects of dietary supplementation with Ecklonia cava on blood glucose, lipid metabolism, and renal oxidative stress in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were divided into a normal rat group fed on a control diet and diabetic rats fed on a control diet or supplemented with powder (15% w/w) or water extract of Ecklonia cava (2.5% w/w). Diabetes was induced by a single injection of STZ (60 mg/kg, ip) in citrate buffer. The animals were fed ad libitum with the experimental diet and water for 5 weeks. Dietary supplementation of Ecklonia cava powder and water extract was shown to reduce blood glucose levels in the diabetic rats, and the water extract was more effective than the powder. Dietary supplementation with Ecklonia cava also reduced LDL cholesterol and increased HDL-cholesterol levels in the diabetic rats. Renal glutathione S-transferase activity was increased in the diabetic rats as compared to the normal rats, but reverted to near control values as the result of dietary supplementation with Ecklonia cava. These results show that Eklonia cava exerts an anti-diabetic effect by improving blood glucose concentrations, LDL/HDL-cholesterol ratios, and antioxidative effects on the kidney in diabetic rats.

Diabetic nephropathy has been increasing, although blood glucose and blood pressure can be controlled by angiotensin converting enzyme(ACE) or advanced glycosylation end products(AGE) inhibitors in the diabetic patients. We investigated the effect of dietary supplementation of sea tangle on the blood glucose, and pathological scoring of diabetic kidneys in the streptozotocin(STZ) induced diabetic rats. Male Sprague-Dawley rats were divided into normal rats fed control diet and diabetic rats fed control diet or control diet supplemented with powder or oater extract of sea tangle. Diabetes was induced by a single injection of STZ(60mg/kg, ip) in citrate buffer. The animals were fed the experimental diet and water for 13 weeks. Dietary supplementation of sea tangle decreased blood glucose in the diabetic rats. However, dietary supplementation of sea tangle did not affect the antioxidant enzyme activities, MDA content and pathology of diabetic kidneys. These results indicate that decreased blood glucose by sea tangle could not delay the progression of diabetic kidney disease.