Abstract: Objective To observe the state of insulin resistance and chronic inflammatory in C57BKS db/db mice, and to investigate the role of sesquiterpene lactones (pathenolide, PTN). Methods The db/m mice were injected with normal saline (db/m+NS) as control group, db/db mice with normal saline (db/db+NS) as experimental group and db/db mice with intraperitoneal injection of PTN（1.0 mg/kg qod）as intervention group (db/db+PTN). In 8, 12 and 16 weeks the blood, urine sample, kidney and liver were taken from the mice. Tests had been made on albumin, creatinine, glucose, lipids, insulin (radioimmunoassay), MCP-1, IL-6 (ELISA) in serum and albumin, creatinine in urine. And the semi-quantitive analysis of tissue MCP-1 and NF-кB levels were also done through immunohistochemistry method. Results 1) db/db mice had elevated blood lipids, fatty liver and other metabolic abnormalities such as hyperglycemia, hyperinsulinemia and insulin resistance. The level of urinary albumin was increased and pathology showed enlargement of glomerulus and matrix. And inflammation factor increased significantly both in serum and kidney. 2) After the therapy of PTN, both the serum MCP-1, IL-6, NF-kB and the NF-кB, MCP-1 expression in the kidney in 12 weeks old db/db mice were significantly lower than the db/db group. The level of HOMA-IR in db/db+PTN group in 12 weeks old was significantly lower than the db/db group, and the degree of fatty liver was significantly relieved. Conclusions PTN can reduce the inflammatory reaction, alleviate insulin resistance, and improve fat liver and prognosis of early diabetic nephropathy.

Key words: Keywords:diabetic nephropathy, insulin resistance, chronic inflammation, sesquiterpene lactones