1. Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan, Food Research Laboratories, Mitsui Norin Company, Limited, 223-1 Miyabara, Fujieda, Shizuoka 426-0133, Japan, and National Institute for Longevity Sciences, 36-3 Gengo, Morioka-cho, Obu 474-0031, Japan