Dl methionine

Male Wistar rats (Charles River Lab., Yokohama, Japan) were maintained in a 12-h light : dark cycle at 24 ± 2°C and 55 ± 10% relative humidity. Because we examined the effects of Polygonum tinctorium Lour (PTL) on adult stage of rat, 5-weeks-old rats (150-160 g) were purchased and given AIN93 standard diet (Oriental Yeast Co., Ltd., Chiba, Japan) until 12 weeks old. The composition of experimental food for the rats was 25.7% casein, 23.5% α-starch (Oriental Yeast Co.), 9% sucrose (Mitsui Sugar Co., Ltd., Osaka, Japan), 23.8% lard (Oriental Yeast Co.), 7% soy been oil (WAKO, Osaka, Japan), 5% cellulose, 3.5% mineral mixture, 1% vitamin mixture (Oriental Yeast Co.), 0.3% DL-methionine (WAKO), 0.25% choline bitartrate (WAKO), 0.3% L-cystein (WAKO), 0.0014% tert-butylhydroquion (WAKO) and 1% dextrin (WAKO). PTL was supplied as a powder from BON ARM Co. Ltd. (Tokushima, Japan). PTL contains about 2% of polyphenols and the major components are shown in Table 1. In the experimental diet, PTL was added to the control diet at a dose of 1.0% (W/W) instead of dextrin. All experimental procedures were approved by the Animal Research Committee of the Shikoku University.

Mice and Diet Male C57BL/6J mice (Japan SLC, Shizuoka, Japan) were maintained under specific pathogen-free conditions with a 12-h light : dark cycle at 25±2°C and 55±10% relative humidity. The composition of food was 27.5% casein, 17.6% α-starch (Oriental Yeast Co., Ltd., Chiba, Japan), 8.3% sucrose (Mitsui Sugar Co., Ltd., Osaka, Japan), 36.0% lard (Oriental Yeast Co.), 2% cellulose, 5% mineral mixture, 1% vitamin mixture (Oriental Yeast Co., Ltd.), 0.3% DL-methio- nine (Wako Pure Chemical Industries, Ltd., Osaka, Japan), 0.2% choline bitartrate (Wako) and 2% dextrin (Wako). Brazilian propolis was supplied as a powder by Yamada Bee Farm (Okayama, Japan). Brazilian propolis is produced in Southeast Brazil, and Baccharis dracunculifolia is the main botanical source. It contains mainly prenylated derivatives of cinnamic acid including artepillin C as a major component (6.1%). In the experimental diet, propolis was added to the control diet at a dose of 2.0% (w/w) instead of dextrin. All experimental procedures were approved by the Animal Research Committee of the University of Tokushima.