To investigate the effects of paeoniflorin on insulin resistance and myocardial injury in rats with gestational diabetes mellitus and its mechanism.

Female rats were randomly divided into control group (normal diet), model group [male rats fed with high-fat diet and intraperitoneally injected 30 mg·kg^-1 streptozotocin (STZ) after close cages], experimental group (after modeling, 50 mg·kg^-1 paeoniflorin was given by gavage), si-NC group (50 mg·kg^-1 paeoniflorin + si-NC plasmid injected into tail vein after modeling), si-IGFBP2 group (50 mg·kg^-1 paeoniflorin + si-IGFBP2 plasmid injected into tail vein after modeling), each group of 10 rats. After 2 weeks of continuous treatment, fasting blood glucose (FBG) was measured with a glucose meter. Serum insulin-like growth factor binding protein 2 (IGFBP2), fasting insulin (FINS), cardiac troponin Ⅰ (cTnⅠ), creatine kinase isoenzyme MB (CK-MB) related factors were detected by enzyme-linked immunosorbent assay (ELISA), insulin resistance index (HOMA-IRI) was calculated, and the expression of signal pathway-related proteins was detected by Western blot assay.

The levels of FBG in control group, model group, experimental group, si-NC group and si-IGFBP2 group were: (5.62±0.56), (18.10±1.76), (9.81±1.46), (10.02±1.38) and (16.32±1.87) mmol·L^-1, respectively; IGFBP2 levels were (39.47±2.64), (20.65±1.86), (27.18±1.85), (27.95±1.74) and (15.28±1.22) ng·mL^-1, respectively; FINS levels were (8.72±0.75), (21.11±2.50), (16.88±1.86), (16.06±1.39) and (20.01±2.94) mU·L^-1, respectively; cTnⅠ levels were (406.04±29.98), (788.11±84.43), (513.70±57.62), (526.85±38.03) and (756.51±63.88) pg·mL^-1, respectively; CK-MB levels were (7.98±0.07), (15.15±1.26), (11.59±1.23), (11.37±1.79) and (13.49±1.54) U·L^-1, respectively; HOMA-IRI levels were 2.17±0.26, 16.92±2.12, 6.24±0.95, 6.60±1.10 and 12.83±1.68, respectively; the relative expression levels of phosphorylate-phosphatidylinositol 3-kinase (p-PI3K) protein were 0.68±0.11, 0.39±0.04, 0.53±0.05, 0.51±0.06 and 0.43±0.04, respectively; the above indexes in the model group were compared with the control group, the experimental group were compared with the model group, and the si-IGFBP2 group were compared with the si-NC group, the differences were statistically significant (all P<0.05).

Paeoniflorin may improve insulin resistance and myocardium injury in gestational diabetes mellitus rats by up-regulating IGFBP2 expression.