The effects of isoflavones on lipid profile and oxidative stress in diabetic rats / 国际中医中药杂志

ABSTRACT

Objective To investigate the effects of soybean isoflavone(SI) regulating plasma lipid and improving antioxidant ability in diabetic rats.Methods 120 SD rats were randomly devided into a normal group, a diabetes model group, a SI 40, 80, 160 and 320 mg/kg treated group, with 20 expermental animals in each group. Expect the normal group, the diabetic model was setup by intraperitoneal injecting STZ, and the drugs were given by intraperitoneal injection. At 0, 14, 28, 42, 56 days after experiment, the level of plasma glucose were determined. 8 weeks later, the content of TC, TG, LDL-C, HDL-C, the activity of AST, CK, LDHand the T-AOC in serum were determined; the activity of SOD, GSH-Px and the content of MDA in myocardial tissue were determined; and the histopathological changes of myocardial tissue were observed by HE staining. ResultsCompared with the diabetes model control group, the activity of AST in serum of SI 80, 160 and 320 mg/kg treated groups were significantly decreased(104.25 ± 24.92 U/L, 93.71 ± 22.58 U/L, 88.26 ± 23.80 U/Lvs. 127.65 ± 38.17 U/L;P<0.05,P<0.01), the activity of CK were significantly decreased (887.1 ± 185.4 U/L, 831.9 ± 182.8 U/L, 796.2 ± 165.8 U/Lvs. 973.6 ± 211.4 U/L;P<0.05,P<0.01), the activity of LDH were significantly decreased (954.7 ± 153.5 U/L, 868.7 ± 136.2 U/L, 834.1 ± 146.3 U/Lvs. 1 097.6 ± 184.2 U/L;P<0.05,P<0.01); the activity of SOD in myocardial tissue were significantly increased(9.96 ± 2.05 U/mg, 10.47 ± 2.32 U/mg, 11.06 ± 2.29 U/mgvs. 8.72 ± 1.70 U/mg;P<0.05,P<0.01), the content of MDA in myocardial tissue were significantly decreased(5.98 ± 1.35 nmol/mg, 5.47 ± 1.42 nmol/mg, 5.16 ± 1.53 nmol/mgvs. 6.58 ± 1.54 nmol/mg;P<0.05, P<0.01). The plasma glucose level of SI (160 and 320 mg/kg) treated groups were significantly decreased(15.2 ± 0.9 mmol/L, 14.8 ± 0.8 mmol/Lvs. 18.6 ± 1.2 mmol/L;P<0.05,P<0.01), the content of TC in serum were significantly decreased (2.69 ± 0.85 mmol/L, 2.43 ± 0.76 mmol/Lvs. 3.42 ± 0.81 mmol/L;P<0.05,P<0.01), the content of TG were significantly decreased (1.36 ± 0.40 mmol/L, 1.18 ± 0.23 mmol/Lvs. 1.70 ± 0.53 mmol/L;P<0.05,P<0.01), the content of LDL-C were significantly decreased (1.02 ± 0.26 mmol/L, 0.95 ± 0.28 mmol/Lvs. 1.18 ± 0.27 mmol/L;P<0.05), and the content of HDL-C were significantly increased (0.73 ± 0.20 mmol/L, 0.78 ± 0.22 mmol/Lvs. 0.62 ± 0.14 mmol/L;P<0.05), the T-AOC was significantly increased (10.15 ± 2.76 U/L, 11.29 ± 3.47 U/Lvs. 7.95 ± 2.26 U/L;P<0.05), and the activity of GSH-Px was significantly increased(13.79 ± 2.62 U/mg, 14.21 ± 2.87 U/mgvs. 11.90 ± 2.03 U/mg,P<0.05,P<0.01). The histopathological changes of myocardial tissue in SI 160 and 320 mg/kg treated groups were significantly improved.Conclusions SI could effectively lower the plasma glucose level and the blood lipid, improve antioxidant ability, improve antioxidant ability, reduce the damage of free radical, and inhibit the histopathological changes, which suggesting that SI had protective effects on diabetic rats.