1. Laboratory of Pharmacology, Chulabhorn Research Institute (CRI), Vipavadee-Rangsit Highway, Laksi, Bangkok 10210, Thailand, Nutrition Division, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK, and Department of Pharmacology, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand