RESUMO
ß-Glucans extracted from barley, which mainly contains ß-(1,3-1,4)-D-glucan, are used extensively as supplements and food additives due to their wide biologic activities, including a reduction in blood lipid level. In this study, the antioxidant activity of ß-glucan was examined to assess potential new benefits associated with ß-glucan, because oxidative stress is considered one of the primary causal factors for various diseases and aging. ß-Glucan extracted from barley was found to possess significant antioxidant activity. The amount of antioxidant activity was influenced by different physiologic properties (e.g., structure and molecular size) of ß-glucan, which varied depending on the source and extraction method used. The antioxidant activity of ß-glucan was significantly higher than that of various polymers that are used as food additives. These results indicate that ß-glucan has promise as a polymeric excipient for supplement and food additive with antioxidant and other benefits, which may contribute to enhancing health and beauty.
RESUMO
Effects of dose and duration of phenobarbital (PB) administration and those of co-administration of PB and vitamin K on blood coagulation-related parameters were examined in specific pathogen-free (SPF) rats of Sprague-Dawley strain kept on an ordinary diet. In Experiment 1, oral administration of PB (0, 25, 50, 100 or 150 mg/kg/day) for 2 weeks induced increases in hepatic cytochrome P450 content and CYP2B expression, prolongation of coagulation time (activated partial thromboplastin time (APTT) and Thrombotest (TBT)) and an increase in anti-thrombin III (AT III) concentration in a dose-dependent manner. In Experiment 2, PB administration (100 mg/kg/day) for up to 14 days produced time-dependent increases in hepatic cytochrome P450 content and CYP2B (CYP2B1 and CYP2B2) expression. APTT was prolonged from day 1 and AT III concentration was increased from day 2, whereas the coagulation time (TBT) was prolonged from day 7. In Experiment 3, APTT prolonged by PB (100 mg/kg/day) was shortened after vitamin K(2) (30 mg/kg/day) co-administration, although AT III concentration was still increased. This suggests that not AT III but PB-induced vitamin K deficiency may play an important role in PB-induced prolongation of coagulation time in SPF rats kept on an ordinary diet.