2. Materials and methods
2.1. Preparation of plant extracts
The 19 plant materials used in this study were collected
from various locations in Thailand. Authentication of the
plant materialswas done by comparison with plant specimens
located at Bangkok Herbarium and the Botanical Section of
the Botany andWeed Science Division, Department of Agriculture,
Bangkok, Thailand. The specimens were deposited at
Department of Pharmacognosy, Faculty of Pharmacy, Mahidol
University, Bangkok, Thailand.