Oxidative stress plays an important role in the development of diabetic cardiomyopathy. In the present study, we determined whether the effect of astragalus polysaccharides (APS) on diabetic cardiomyopathy was associated with its impact on oxidative stress. Streptozotocin (STZ)-induced diabetic mice and heterozygous superoxide dismutase (SOD2+/-) knockout mice were administered APS. The hemodynamics, cardiac ultrastructure, and the apoptosis, necrosis and proliferation of cardiomyocytes were assessed to evaluate the effect of APS on diabetic and oxidative cardiomyopathy. Furthermore, H2O2 formation, oxidative stress/damage, and SOD activity in cardiomyocytes were evaluated to determine the effects of APS on cardiac oxidative stress. APS therapy improved hemodynamics and myocardial ultrastructure with reduced apoptosis/necrosis, and enhanced proliferation in cardiomyocytes from both STZ-induced diabetic mice and heterozygous SOD2+/- knockout mice. In addition, APS therapy reduced H2O2 formation and oxidative stress/damage, and enhanced SOD activity in both groups of mice. Our findings suggest that APS had benefits in diabetic cardiomyopathy, which may be partly associated with its impact on cardiac oxidative stress.

ABSTRACTThis experiment was conducted to evaluate the combination effect of low dietary non-phytate phosphorus (NPP) concentrations, phytase (PHY) levels, and 25-hydroxycholecalciferol (25-OH-D3) levels on the growth performance and meat quality of broilers. Two levels of NPP, two levels of PHY, and two levels of 25-OH-D3 resulted in a 2�2�2 factorial arrangements, with eight treatments (TRT). The birds on TRT 1-4 were fed diet 1 (NRC NPP was reduced by 0.1) and the birds on TRT 5-8 were fed with diet 2 (NRC NPP was reduced by 0.2). Each diet was mixed with different levels PHY and 25-OH-D3. Performance and meat quality parameters were measured. Results showed that during entire experiment the most advantageous effects were obtained with TRT 3 (NRC NPP reduced by 0.1 + 600 U/kg phytase + 34.5�g/kg 25-OH-D3) and TRT 4 (NRC NPP reduced by 0.1 + 600 U/kg phytase + 69�g/kg 25-OH-D3). The lowest body weight gain (BWG) and feed intake(FI) were observed with TRT 5 (NRC NPP reduced by 0.2 + 300 U/kg phytase + 34.5�g/kg 25-OH-D3). Lowering NRC NPP by 0.1 to 0.2 significantly reduced weight gain (WG) (p< 0.05) and FI (p< 0.05) during the starter phase (ST), while during grower phase (GF) lowering NRC NPP by 0.1 to 0.2 did not affect WG (p>0.05) and produced small decrease in FI. BWG, FI and feed conversion ratio were not influenced (p>0.05) by different PHY or 25-OH-D3 levels. In addition, the meat color, pH, and shear force were not affected by the different NPP, PHY or 25-OH-D3levels.

Annual leaf segments of eight Camellia species were used to study the heat tolerance by an electrical conductivity method, in combination with a Logistic equation to ascertain the semi-lethal high temperature by fitting the cell injury rate curve. Te relationship between the processing temperature and the cell injury rate in Camellia showed a typical "S" shaped curve, following the Logistic model. Te correlation coeficient was above 0.95. Te semi-lethal high temperature LT50 of the eight Camellia species, determined by the infection point on the curve, varied from 50 to 57 LT50 / °C, following the descending order: Camellia oleifera > C. japonica > C. polyodonta > C. semiserrata > C. nitidissima > C. gigantocarpa > C. nanyongensis > C. vietnamensis. Te semi-lethal high temperature of C. oleifera was 56.8 °C, and that of C. vietnamensis was 50.6 °C. Results showed C. oleifera appeared as the best suitable species for introduction in high-heat zones. Camellia vietnamensis appeared more suitable for planting in temperate regions at lower temperatures. These results can provide theoretical basis for breeding and introduction of heat-tolerant oil-tea cultivars.

Se utilizaron segmentos foliares anuales de ocho especies de Camellia para estudiar la tolerancia al calor por un método de conductividad eléctrica, en combinación con una ecuación logística para dilucidar la temperatura alta semi-letal ajustando la curva de tasa de daño celular. La relación entre la temperatura y la tasa de daño celular en Camellia mostró una curva con forma de "S'' típica, siguiendo el modelo logístico. El coeficiente de correlación estuvo por encima de 0,95. La temperatura alta semi-letal LT50 de las ocho especies de Camellia, determinada por el punto de inflexión en la curva, varió entre 50 y 57 LT50 / °C de acuerdo con el siguiente orden descendente:Camellia oleifera > C. japónica > C. polyodonta > C. semiserrata > C. nitidissima > C. gigantocarpa > C. nanyongensis > C. vietnamensis. La temperatura alta semi-letal de C. oleifera fue 56,8 °C, y la de C. vietnamensis 50,6 °C. Los resultados mostraron que C. oleifera parece ser una especie más adecuada para introducir en zonas donde se registren altas temperaturas. Camellia vietnamensis parece más adecuada para ser plantada en regiones templadas, a temperaturas más bajas. Estos resultados pueden proveer una base teórica en programas de cruzamiento genético e introducción de cultivares de aceite-té tolerantes al calor.