Sariga Zaeoung, Anuchit Plubrukarn, and Niwat Keawpradub

pp. 799 - 812

Abstract

Methanol extracts, water extracts and volatile oils of the fresh rhizomes of Alpinia galanga, Boesenbergia
pandurata, Curcuma longa, Kaempferia galanga and Zingiber officinale have been assessed for free radical
scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and cytotoxic activity against
MCF7 (breast adenocarcinoma) and LS174T (colon adenocarcinoma) cell lines. Methanol extract of C.
longa exhibited the most pronounced radical scavenging activity with an EC₅₀ value of 9.7 µg/ml, whereas
the water extracts and volatile oils showed weak activity. All volatile oils and the methanol extract of C.
longa showed strong activity against MCF7 and LS174T with IC₅₀ less than 50 µg/ml. The oils of A. galanga
(AGV), B. pandurata (BPV), C. longa (CLV), K. galanga (KGV) and Z. officinale (ZOV) were analyzed by
GC/MS. Trans-3-acetoxy-1,8-cineole, camphor, ar-turmerone, ethyl cinnamate and geranial (E-citral) were
detected as main compounds in AGV, BPV, CLV, KGV and ZOV, respectively. The novel compound, pcoumaryl-9-methyl ether, was isolated from methanol extract of A. galanga. ar-Turmerone, curcumin,
demethoxycurcumin and bisdemethoxycurcumin were isolated from the methanol extract of C. longa while
6-shogaol, 6-dehydrogingerdione (or 1-dehydrogingerdione) and 6-gingerol were isolated from the methanol extract of Z. officinale. Curcumin was the most potent compound for free radical scavenging activity with
an EC₅₀ value of 2.0 µg/ml. Demethoxycurcumin was found to be the most active compound against LS174T
with an IC₅₀ value of 0.8 µg/ml and 6-shogaol was the most potent compound against MCF7 with an IC₅₀
value of 1.7 µg/ml.