Resveratrol protects against oxidative stress by activating the Keap-1/Nrf2 antioxidant defense system in obese-asthmatic rats.

The aim of the present study was to investigate the potential mechanism underlying the anti-obesity-asthmatic effects of resveratrol (RSV) in a rat model of obese-asthma. Rat models of obesity and asthma were established using a high-fat diet and the administration of ovalbumin, respectively. Rats were divided into 7 different groups: A normal control, a normal obese, a normal asthma, a normal obese + asthma, a RSV obese, a RSV asthma and a RSV obese + asthma group. Body weight, Lee index, body fat and lung histopathological changes were evaluated. Serum lipid levels were evaluated using calorimetric methods. Levels of reactive oxygen species (ROS) were examined using enzyme-linked immunosorbent assays. Cellular antioxidant enzyme activities were measured using commercial kits. Levels of kelch-like ECH associated protein 1 (Keap-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) was examined using western blot analysis. The results indicated that obese and asthma rat models were successfully established. It was also demonstrated that RSV decreased fasting blood glucose in obese, asthmatic and obese-asthmatic rats. RSV altered serum lipid levels; it significantly increased high density lipoprotein cholesterol levels and significantly decreased serum triglyceride, serum total cholesterol and very low density lipoprotein levels, compared with untreated obese, asthmatic and obese-asthmatic rats (P<0.05). ROS levels were significantly decreased in the RSV treatment group compared with obese, asthmatic and obese-asthmatic rats (P<0.05). RSV treatment significantly increased catalase, glutathione, glutathione peroxidase and total superoxide dismutase levels compared with untreated obese, asthmatic and obese-asthmatic rats (P<0.05). Furthermore, RSV treatment significantly downregulated Keap-1 and upregulated Nrf2 levels in the heart, lung and kidney tissues of rats compared with untreated controls. Therefore, the results demonstrate that RSV protects against oxidative stress by activating the Keap-1/Nrf2 antioxidant defense system in obese-asthmatic rat models.

[Cyanidin-3-glucoside attenuates body weight gain, serum lipid concentrations and insulin resistance in high-fat diet-induced obese rats].

OBJECTIVE: Cyanidin-3-glucoside (C3G) is the main active ingredient of anthocyanidin. This study aimed to evaluate the effects of C3G on body weight gain, visceral adiposity, lipid profiles and insulin resistance in high-fat diet-induced obese rats. METHODS: Thirty male Sprague-Dawley rats were randomly divided into a control group (n=8) and a high fat diet group (n=22), and were fed with standard diet or high fat diet. Five weeks later, 17 high-fat diet-induced obese rats were randomly given C3G [100 mg/(kg·d)] or normal saline via intragastric administration for 5 weeks. Five weeks later, body weight, visceral adiposity and food intake were measured. Blood samples were collected for detecting fasting glucose, serum insulin, lipid profiles and adiponectin. Insulin resistance index, atherosclerosis index and average feed efficiency ratio were calculated. RESULTS: C3G supplementation markedly decreased body weight, visceral adiposity, average feed efficiency ratio, triglyceride, total cholesterol, low density lipoprotein cholesterol, fasting glucose, serum insulin, insulin resistance index and atherosclerosis index in high-fat diet-induced obese rats. C3G supplementation normalized serum adiponectin and high density lipoprotein cholesterol levels in high-fat diet-induced obese rats. CONCLUSIONS: Cyanidin-3-glucoside can reduce body weight gain, and attenuate obesity-associated dyslipidemia and insulin resistance in high-fat diet-fed rats via up-regulating serum adiponectin level.

[Probiotics improve obesity-associated dyslipidemia and insulin resistance in high-fat diet-fed rats].

OBJECTIVE: To evaluate the effect of probiotics (bifidobacterium breve and lactobacillus acidophilus) on serum lipid, serum insulin and insulin resistance in high-fat diet (HFD)-induced obese rats. METHODS: Fifty male Sprague-Dawley rats were randomly assigned to a control (n=10) and a high fat diet groups (n=40) and were fed with standard diet and HFD respectively. Four weeks later, thirty-six HFD-induced obese rats were randomly administered with normal saline (NS), bifidobacterium breve and lactobacillus acidophilus daily (n=12 each). Four weeks later, body lengths, body weights and abdomen circumference of rats were measured, blood lipid, glucose and insulin levels were measured, and Lee's index and insulin resistance index were calculated. RESULTS: Body weight, abdomen circumference, Lee's index, fasting glucose, triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL) in the NS-treated HFD group were significantly higher than the control group (P<0.05). The bifidobacterium breve and lactobacillus acidophilus-treated groups had significantly lower levels of body weight, abdomen circumference, Lee's index, fasting glucose, TC, TG and LDL than the NS-treated HFD group (P<0.05), but the levels of the parameters in the bifidobacterium breve and lactobacillus acidophilus-treated groups were significantly higher than the control group (P<0.05). High density lipoprotein (HDL) and insulin sensitivity index in the NS-treated HFD group were significantly lower than the control group (P<0.05). Bifidobacterium breve and lactobacillus acidophilus treatment dramatically increased HDL levels and insulin sensitivity index compared with the NS-treated HFD group (P<0.05), although the levels of the two parameters did not reach to the levels of the control group. There were significant differences in the levels of fasting insulin, insulin resistance index and insulin secretion index between the bifidobacterium breve and lactobacillus acidophilus groups (P<0.05). CONCLUSIONS: Lactobacillus acidophilus and bifidobacterium breve can decrease serum levels of lipid and glucose and improve insulin resistance in obese rats. Bifidobacterium breve seems to be more effective on attenuating insulin resistance than lactobacillus acidophilus.

[Dynamic change of Yulania sap flow before dormancy in response to environmental factors].

From September 26 to November 5, 2011, the sap flow of Yulania wufengensis trees including cold-resistance type (HK) and non cold-resistance type (HF), Y. 'Sunspire' (HY), and Yulania x soulangeana (EQ) which were introduced into Beijing four years before was monitored by Flow-32 stem heat balance sensor, and, in combining with the environmental factors monitored synchronically, the changes of the sap flow before dormancy and the environmental factors were analyzed, with the responses of the sap flow to the environmental factors investigated at the scales of 0.5 h and 1 day. The sap flow of the Yulanias trees before dormancy displayed an obvious trend of declining day by day. The environmental factors affecting the sap flow could be divided into two categories, i. e., meteorological index (MI) and soil index (SI). The sap flow of the Yulanias trees had a synchronous variation rhythm with MI, and declined in parallel to SI. The combined effect of MI and SI on the diurnal changes of the sap flow was 69% - 73%. At both 0.5 h and 1 day scales, the sap flow showed significantly correlations with total radiation (Rs), air vapor pressure deficit (D), air relative humidity (RH), air temperature (Ta), and wind speed (w). The sap flow showed no significant correlations with soil temperature (Ts) and soil water content (SWC) at 0. 5 h scale, but had significant correlations with Ts, SWC, and day length (Z) at 1 day scale (the correlation efficient was about 0.8). Only Rs, Z, and D were included into the model at 1 day scale, but almost all environmental factors (except SWC and Ts) were included in the model at 0.5 h scale. Except for HF type, the regression coefficients of the model for the Yulanias trees at 1 day scale (0.92-0.96) were larger than those at 0.5 h scale (0.77-0.87), and the correlations between the dynamic changes of sap flow and the environmental factor were consistent, which was in accord with the fact that the HF could not overwinter in Beijing but the others could.

[Effects of controlled-release fertilizer and organic amendment on the construction of nutrients reserves in Larix olgensis container seedlings].

A 2 x 2 factorial experiment was conducted to study the effect of fertilization on Larix olgensis container seedlings. 36.36 or 18.18 mg controlled-release fertilizer (CRF) N and 0 or 1.82 g FM organic amendment (OA) per seedling were applied. There were no significant responses to fertilization in the seedling height, collar diameter, biomass, and potassium (K) uptake. Applying FM OA increased the number of first-order lateral roots with a length > 1 cm (P = 0.040), the tap root length (TRL) (P = 0.012), and the ratio of TRL to seedling height (P = 0.008). Comparing with low application rate CRF N, high application rate CRF N increased the N concentration in root (P = 0.035) as well as the N reserves in stem (P = 0.005), root (P = 0.037), and stem plus root (P = 0.030), and the P reserves in stem (P = 0.047). Applying 36.36 mg CRF N plus 1.82 g FM OA increased the N concentrations in leaf and in stem plus root by 137% (P = 0.040) and 21% (P = 0.013), respectively, and the N reserves in stem (P = 0.020), root (P = 0.017), and stem plus root (P = 0.013). Vector analysis revealed that high application rate of CRF N led to the excess of seedlings N and P, while applying FM OA alleviated the N and P deficiency but led to the K depletion. For nursing L. olgensis container seedlings, a solution of CRF 18 mg N combined with 1.82 g FM OA per seedling was recommended.