Protection of morroniside on STZ-induded diabetic nephropathy aggravated by AGEs in mice and its mechanism / 中草药

ABSTRACT

Objective: To observe the protective mechanism of morroniside (an active component in Cornus officinalis) on the diabetic nephropathy (DN) mice induced by streptozocin (STZ) and aggravated by advanced glycation end products (AGEs). Methods: The DN mice were fed with high-AGEs fodders, and ig administered with aminoguanidine (0.1 g/kg), metformin (0.2 g/kg), captopril (0.02 g/kg), low-dose morroniside (0.02 g/kg), and high-dose morroniside (0.10 g/kg) for 12 weeks. After that, the fasting glucose, insulin, serum creatinine, urea nitrogen, serum and renal AGEs, 24 h urine protein, etc were measured, the RT-PCR method was used to detect the levels of receptor for advanced glycation end products (RAGE) mRNA, the Western blotting technique was used to test the protein expression levels, and the pathologic changes of mice pancreas and kidney were observed. Results: Morroniside could significantly decrease the fasting blood glucose levels, alleviate the symptoms of polydipsia, polyphagia, polyuria, and weight loss, increase the insulin production, and reduce the levels of 24 h urine protein, serum urea nitrogen, creatinine, serum and renal AGEs. Furthermore, morroniside could also anesis the lesions of pancreas and kidney and reduce the levels of RAGE mRNA and protein expression in renal cortex. Conclusion: Morroniside has the protactive effects on DN mice and high-dose morroniside was much better. The mechanism may be related to the reduced levels of AGEs and RAGE mRNA and protein expression.