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Trans-resveratrol and resveratrol glucoside are natural phenolic compounds existed in a wide variety of plant species, which are extensively consumed in many countries. The existing studies excessively focused on grapes and their products, and little about daily vegetable foods. Actually, in much more countries, vegetable foods are residents' principal food and nutrient origins. This study was to investigate the levels of trans-resveratrol and trans-piceid in daily vegetable foods of China using high-performance liquid chromatography (HPLC) method with fluorescence detection (FLD). Trans-piceid was the major form existing in most vegetable foods, and most of the samples contained higher trans-piceid than trans-resveratrol. The contents of trans-resveratrol and trans-piceid in different varieties and regions were different. Moreover, peculiar vegetable foods to some region were also one of the most important sources of trans-resveratrol and trans-piceid. Therefore, vegetable foods were other significant sources of trans-resveratrol and trans-piceid except the foods published. [ABSTRACT FROM AUTHOR]

The diabetogenic impact of ethanol remains as a focal point of basic and clinical investigations. In this study, Wistar rats were subjected to daily intragastric ethanol administration (10 ml/kg body weight injection with 0 (control), 10, 20 and 33 % (v/v) ethanol in the injections, respectively) for 19 weeks. At the end of the administration, we found that the fasting plasma glucose level of the 33 % (v/v) ethanol-loaded group was 18 % higher than the control. Insulin sensitivity was decreased in a dose-dependent manner in all the ethanol-loaded groups (r − 0·842, P < 0·001) during intraperitoneal insulin tolerance test. Necrotic/haemorrhagic injury was detected in the pancreas and islet β-cell mass was significantly reduced in the 33 % (v/v) ethanol-loaded rats by immunohistochemical and morphometric analysis. At the molecular level, we detected a dose-dependent attenuation of phosphatidylinositol 3-kinase activity (r − 0·956, P < 0·001) and GLUT-4 expression (GLUT-4 mRNA, r − 0·899, P < 0·001; GLUT-4 protein, r − 0·964, P < 0·001) in skeletal muscle. These results demonstrated that drinking is a conditional aetiological factor for diabetes and excessive ethanol intake is negatively associated with both insulin sensitivity and β-cell mass. The whole-body insulin resistance might result from the ethanol-induced insulin signalling defects in muscle. [ABSTRACT FROM PUBLISHER]

The diabetogenic impact of ethanol remains as a focal point of basic and clinical investigations. In this study, Wistar rats were subjected to daily intragastric ethanol administration (10 ml/kg body weight injection with 0 (control), 10, 20 and 33 % (v/v) ethanol in the injections, respectively) for 19 weeks. At the end of the administration, we found that the fasting plasma glucose level of the 33 % (v/v) ethanol-loaded group was 18 % higher than the control. Insulin sensitivity was decreased in a dose-dependent manner in all the ethanol-loaded groups (r - 0.842, P < 0.001) during intraperitoneal insulin tolerance test. Necrotic/haemorrhagic injury was detected in the pancreas and islet beta-cell mass was significantly reduced in the 33 % (v/v) ethanol-loaded rats by immunohistochemical and morphometric analysis. At the molecular level, we detected a dose-dependent attenuation of phosphatidylinositol 3-kinase activity (r - 0.956, P < 0.001) and GLUT-4 expression (GLUT-4 mRNA, r - 0.899, P < 0.001; GLUT-4 protein, r - 0.964, P < 0.001) in skeletal muscle. These results demonstrated that drinking is a conditional aetiological factor for diabetes and excessive ethanol intake is negatively associated with both insulin sensitivity and beta-cell mass. The whole-body insulin resistance might result from the ethanol-induced insulin signalling defects in muscle.

Objective: To decide whether ethanol induce apoptosis in mouse insulinoma cells (NIT-1) and the potential mechanism involved., Methods: After NIT-1 cells were exposed to various concentrations of ethanol, agarose gel electrophoresis was used to detected DNA fragmentation. malondialdehyde (MDA) content, glutathione (GSH) level, superoxide dismutase(SOD) and glutathione peroxidase (GSH-Px) were measured in NIT-1 cells to evaluate the oxidative damage degree. Caspase-3 relative activity was determined by colorimetric assay., Results: The results showed a "DNA ladder" pattern after treated with ethanol in NIT-1 cells. The MDA content was higher, the SOD activity, GSH-Px activity and GSH content were lower in ethanol group than those of control group. Ethanol increased the caspase-3 activity by a dose and time dependent manner., Conclusion: Higher concentration of ethanol induces imbalance of oxidation and antioxidative ability in NIT-1 cells, and oxidative stress further leads to apoptosis which may be related to the increased caspase-3 activity.

Objective: To investigate the molecular mechanism of the effect of alcohol on insulin sensitivity., Methods: Four groups of Wistar rats were used, i.e. control (C) group, and low (L), moderate (M) and high (H) alcohol group. Alcohol doses of each group were 0, 0.6, 1.8 and 3.0 ml.(kg.bw)(-1).day(-1). Each group was comprised of 10 male and 10 female rats. Alcohol was given to rats by gastric intubation. Thirteen weeks later, serum was collected for testing of fasting plasma glucose and insulin. HOMA-IR index of each group were calculated. Total muscle RNA was extracted using Trizol Reagent (Promega). The expression level of IRS-1 mRNA in muscle was detected by RT-PCR., Results: In female rats, the fasting plasma glucose of group (8.36 +/- 0.57) mmol/L was higher and the fasting plasma insulin (15.25 +/- 3.32) was lower than those of group C (7.56 +/- 0.85, 20.80 +/- 3.25). The HOMA-IR of group L (1.775 3 +/- 0.138 1) was lower than that of group C (1.982 6 +/- 0.124 6) (P < 0.05), while IRS-1 mRNA (0.766 1 +/- 0.076 9) was up-regulated (P < 0.05); HOMA-IR of group M (2.202 2 +/- 0.271 0) was higher than that of group C (P < 0.01), while IRS-1 mRNA (0.501 8 +/- 0.049 2) was suppressed (P < 0.01); HOMA-IR of group H (1.850 1 +/- 0.162 8) was not significantly changed as compared with that of group C (1.982 6 +/- 0.124 6) (P > 0.05), while IRS-1 mRNA (0.418 1 +/- 0.049 1) was significantly suppressed (P < 0.01). In male rats, the fasting plasma glucose and insulin had the similar change as those of female rats. The HOMA-IR of group M (1.878 5 +/- 0.250 2) was lower than that of C group (2.147 3 +/- 0.330 8) (P < 0.05), IRS-1 mRNA was up-regulated (0.824 9 +/- 0.064 7) (P < 0.05)., Conclusions: The present study showed that low-to-moderate dose of alcohol could increase insulin sensitivity; while alcohol abuse could decrease insulin sensitivity. Sex difference in this effect was found. Changes of IRS-1 mRNA expression may be involved in the molecular mechanism of the effects of alcohol on insulin sensitivity.

Objective: Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells., Methods: Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method., Results: Tea polyphenols of 0.4 microg/mL and 4.0 microg/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P < 0.05), and up-regulated the expressions of catalase (P < 0.05)., Conclusions: Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.