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Evidence-Based Complementary and Alternative Medicine
Volume 2012 (2012), Article ID 438356, 10 pages
http://dx.doi.org/10.1155/2012/438356
Research Article

Correlation between Chemical Composition of Curcuma domestica and Curcuma xanthorrhiza and Their Antioxidant Effect on Human Low-Density Lipoprotein Oxidation

1Drug and Herbal Research Center, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
2Faculty of Pharmacy, Universitas Indonesia, Kampus UI, Depok 16424, Indonesia
3Faculty of Pharmacy, University of Sargodha, University Road, Sargodha, Lahore 40100, Pakistan

Received 4 August 2012; Accepted 17 October 2012

Academic Editor: Khalid Rahman

Copyright © 2012 Ibrahim Jantan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The antioxidant activity of the curcuminoids of Curcuma domestica L. and C. xanthorrhiza Roxb. and eight compounds which are prevalent constituents of their rhizome oils were investigated in an effort to correlate human low-density lipoprotein (LDL) antioxidant activity with the effect of the herbs and their components. The antioxidant activity was examined using thiobarbituric acid reactive substances (TBARSs) assay with human LDL as the oxidation substrate. The methanol extracts and rhizome oils of C. xanthorrhiza and C. domestica showed strong inhibitory activity on copper-mediated oxidation of LDL. Curcumin, demethoxycurcumin, and bisdemethoxycurcumin, isolated from the methanol extracts of both plants, exhibited stronger activity than probucol (IC50 value 0.57 μmol/L) as reference, with IC50 values ranging from 0.15 to 0.33 μmol/L. Xanthorrhizol, the most abundant component (31.9%) of the oil of C. xanthorrhiza, showed relatively strong activity with an IC50 value of 1.93 μmol/L. The major components of C. domestica, ar-turmerone (45.8%) and zerumbone (3.5%), exhibited IC50 values of 10.18 and 24.90 μmol/L, respectively. The high levels of curcuminoids in the methanol extracts and xanthorrhizol, ar-turmerone and zerumbone in the oils, and in combination with the minor components were responsible for the high LDL antioxidant activity of the herbs.