Flos Puerariae Extract Ameliorates Cognitive Impairment in Streptozotocin-Induced Diabetic Mice.

Objective. The effects of Flos Puerariae extract (FPE) on cognitive impairment associated with diabetes were assessed in C57BL/6J mice. Methods. Experimental diabetic mice model was induced by one injection of 50 mg/kg streptozotocin (STZ) for 5 days consecutively. FPE was orally administrated at the dosages of 50, 100, or 200 mg/kg/day, respectively. The learning and memory ability was assessed by Morris water maze test. Body weight, blood glucose, free fatty acid (FFA) and total cholesterol (TCH) in serum, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and acetylcholinesterase (AChE) activities in cerebral cortex and hippocampus were also measured. Results. Oral administration of FPE significantly improved cognitive deficits in STZ-induced diabetic mice. FPE treatment also maintained body weight and ameliorated hyperglycemia and dyslipidemia in diabetic mice. Additionally, decreased MDA level, enhanced CAT, and GSH-Px activities in cerebral cortex or hippocampus, as well as alleviated AChE activity in cerebral cortex, were found in diabetic mice supplemented with FPE. Conclusion. This study suggests that FPE ameliorates memory deficits in experimental diabetic mice, at least partly through the normalization of metabolic abnormalities, ameliorated oxidative stress, and AChE activity in brain.

Flos Puerariae extract prevents myocardial apoptosis via attenuation oxidative stress in streptozotocin-induced diabetic mice.

BACKGROUND: Diabetic cardiomyopathy (DCM) suggests a direct cellular insult to myocardium. Apoptosis is considered as one of the hallmarks of DCM. Oxidative stress plays a key role in the pathogenesis of DCM. In this study, we explored the prevention of myocardial apoptosis by crude extract from Flos Puerariae (FPE) in experimental diabetic mice. METHODS: Experimental diabetic model was induced by intraperitoneally injection of streptozotocin (STZ, 50 mg/kg/day) for five consecutive days in C57BL/6J mice. FPE (100, 200 mg/kg) was orally administrated once a day for ten weeks. Cardiac structure changes, apoptosis, superoxide production, NADPH oxidase subunits expression (gp91phox, p47phox, and p67phox), and related regulatory factors were assessed in the heart of mice. RESULTS: Diabetic mice were characterized by high blood glucose (≥11.1 mmol/L) and reduced body weight. In the end of the experiment, aberrant myofilament structure, as well as TUNEL positive cardiac cells coupled with increased Bax/Bcl-2 ratio and Caspase-3 expression was found in diabetic mice. Moreover, ROS formation, the ratio of NADP+/NADPH and NADPH oxidase subunits expression of gp91phox and p47phox, lipid peroxidation level was significantly increased, while antioxidant enzyme SOD and GSH-Px activity were reduced in the myocardial tissue of diabetic mice. In contrast, treatment with FPE resulted in a normalized glucose and weight profile. FPE administration also preserved myocardial structure and reduced apoptotic cardiac cell death in diabetic mice. The elevated markers of oxidative stress were significantly reversed by FPE supplementation. Further, FPE treatment markedly inhibited the increased Bax/Bcl-2 ratio and Caspase-3 expression, as well as suppressed JNK and P38 MAPK activation in the heart of diabetic mice. CONCLUSIONS: Our data demonstrate for the first time that FPE may have therapeutic potential for STZ-induced diabetic cardiomyopathy through preventing myocardial apoptosis via attenuation oxidative stress. And this effect is probably mediated by JNK and P38 MAPK signaling pathway.

Protective effects of total flavonoids from Flos Puerariae on retinal neuronal damage in diabetic mice.

PURPOSE: To investigate the potential protective effects of total flavonoids from Flos Puerariae (TFF) on retinal neural cells in diabetic mice. METHODS: C57BL/6J mice were intraperitoneally injected with streptozotocin to generate type I diabetes in a murine model, as indicated by blood glucose levels ≥11.1 mmol/l. TFF was administered intragastrically at a dose of 50, 100, or 200 mg/kg/day. After 10 weeks of administration, the mice were euthanized, and the eyes were dissected. Retinal histology was examined, and the thickness of the retina was measured. Ultrastructural changes in the retinal ganglion cells and capillary basement membrane were observed with electron microscopy. Apoptosis of retinal neural cells was determined with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling assay. Bax and Bcl-2 expression in the retinal tissues was determined with immunohistochemical staining and western blotting. RESULTS: Compared with the diabetic mice, the blood glucose level decreased (p<0.01) and the bodyweight increased (p<0.05) in the 100 and 200 mg/kg TFF-treated groups. The thickness of the retina significantly increased (p<0.01), and the retinal capillary basement membrane (BM) thickness was reduced in the 100 and 200 mg/kg TFF-treated diabetic mice (DM). The 100 and 200 mg/kg TFF treatments also attenuated the diabetes-induced apoptosis of retinal neural cells. Consistent with these effects, TFF treatment decreased the Bax expression level and, concurrently, increased the ratio of Bcl-2 to Bax. CONCLUSIONS: TFF attenuated diabetes-induced apoptosis in retinal neurons by inhibiting Bax expression and increasing the ratio of Bcl-2 to Bax, which suggests that TFF might prevent retinal neuronal damage in diabetes mellitus.