2. Materials and methods
2.1. Preparation of medicinal herb extracts
Twelve herbs were purchased from the local market, and the
details were shown in Table 1. The herbs were identified by an
expert in the Department of Pharmacognosy and Pharmaceutical
Botany, Faculty of Pharmaceutical Sciences, Prince of Songkla University,
Songkhla, Thailand, where voucher specimens (Table 1)
were deposited in the herbarium. Dried plants were macerated
with ethanol for 3 days, and then filtrated through Whatman No. 4
filter paper. Each filtrate was dried using a rotary evaporator at
40 C and kept at 20 C. For testing, 0.1 mg of each dried extract
was initially dissolved with 100 mL of dimethyl sulfoxide (DMSO)
and then adjusted to 1 mL by adding sterile distilled water, giving a
final concentration of 10% (w/v) extract in 10% (v/v) dimethyl
sulfoxide (DMSO).