Diarylheptanoids with Free Radical Scavenging and Hepatoprotective Activity in vitro from Curcuma longa

Abstract

Assay-guided fractionation of the EtOAc soluble fraction of the rhizomes of Curcuma longa furnished three DPPH free radical scavenging diarylheptanoids, curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3). Compounds 1 - 3 showed the DPPH radical scavenging effects with IC₅₀ values of 2.8, 39.2, 308.7 μM, respectively. L-Ascorbic acid and resveratrol as positive controls exhibited IC₅₀ values of 22.5 and 25.0 μM, respectively. Compounds 1 - 3 showed significant hepatoprotective effects on tacrine-induced cytotoxicity in human liver-derived Hep G2 cells. The EC₅₀ values of 1 - 3 are 86.9, 70.7, and 50.2 μM, respectively. Silybin (EC₅₀ = 69.0 μM) and silychristin (EC₅₀ = 82.7 μM) were used as positive controls.

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