Abstract

The acetone extracts and fractions prepared from the roots of Euphorbia hylonoma were investigated for 1, 1-diphenyl-2-pycrylhydrazyl (DPPH) free radical, superoxide anion and hydroxyl radical scavenging activity and cytotoxic activity against the human hepatoma cell line SMMC-7721, human cervix epitheloid carcinoma cell line HeLa and the human gastric cancer cell line SGC-7901. The acetone extract and fraction of EtOAc showed high antioxidant activities. The acetone extract and fraction of water showed a stronger cytotoxic effect on all tested cells, with IC50 values being less than 20 μg/mL. The acetone extract and fraction of water induced cell cycle arrest in G1 phase in SMMC-7721 cells. The major compounds isolated from the acetone extract were ellagic acid derivatives and showed weak cytotoxic activities on the tested cell lines, and these compound were 3,3ï‚¢,4-tri-O-methylellagic acid (1), 3,3ï‚¢-di-O-methylellagic acid (2), 3-O-methylellagic acid (3) and 3,3ï‚¢-di-O-methylellagic acid-4ï‚¢-O-β-dxylopyranosid (4). Compound 3 showed better obvious radical scavenging activity than other tested compounds.

Key words: Euphorbia hylonorma Hand-Mazz, antioxidant activity, cytotoxic activity, chemical constituents.

Abbreviation

DPPH ,1, 1-Diphenyl-2-pycrylhydrazyl; MTT, thiazolyl tetrazolium; DMSO,dimethyl sulfoxide; EDTA, ethylenediaminetetraacetic acid; IC_50, inhibition concentration;FBS, fetal bovine serum; PBS, phosphate buffer saline.