Effect of puerarin on myocardial damage in STZ-induced diabetic rats / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effect of puerarin on diabetic myocardial damage and to explore its possible mechanisms in rats. METHODS: The male Sprague-Dawley rats were randomly divided into normal control group, diabetic group, high dose puerarin (160 mg/kg), middle dose puerarin (120 mg/kg), low dose puerarin (80 mg/kg) treatment groups and aminoguanidine (100 mg/kg) treatment group. Corresponding drugs were intraperitoneally injected once a day. The animals in normal control group and diabetic group were given equal propylene glycol. 12 weeks later, the rats were sacrificed and their cardiac muscles were collected. Myocardial structure was observed under transmission electron microscope (TEM). The blood glucose concentration and the activities of superoxide dismutase (SOD), Ca~(2+)-ATPase, Na~+-K~+-ATPase and the content of malondialdehyde (MDA) in myocardial homogenate were measured biochemically. In addition, the mRNA expressions of peroxisome proliferator activated receptor γ (PPAR-γ), glucose transporter-4 (GLUT-4) and aldose reductase (AR) in myocardial tissues were determined by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: It is observed that the myofibrils were diminished, broken or fused, some lipid droplets deposited in the cytoplasm of cardiocytes and part of cristae of mitochondria were broken or disappeared under TEM in diabetic group. The activities of SOD, Ca~(2+)-ATPase, Na~+-K~+-ATPase as well as the mRNA expressions of PPAR-γ and GLUT-4 decreased significantly (all P<0.01). The blood glucose concentration and the MDA level and the AR mRNA expression increased obviously (all P<0.01) in diabetic group as compared to those in normal control group. How-ever, in puerarin treatment groups, the above changes were reversed, a significant differences of those were found as compared to those in diabetic group (P<0.05 or P<0.01, respectively). The pathological change of cardiac muscles was relieved. It showed that myofibrils were well-arranged and only few lipid droplets deposited in the cytoplasm of cardiocytes and most mitochondria had clear and regular cristae under TEM in puerarin treatment groups. CONCLUSION: Puerarin exerts preventive and remedial effects on the diabetic myocardium, which may be related to up-regulating the mRNA expressions of PPAR-γ and GLUT-4, promoting glucose uptake and relieving oxidative stress damage.