Songklanakarin Journal of Science and Technology (SJST) (Jul 2005)
Cytotoxic and free radical scavenging activities of Zingiberaceous rhizomes
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.
