Antioxidant, Cytotoxic and Antibacterial Activity and Total Phenol Contents of the Roots and the Shoots of Euphorbia macrostegia and Euphorbia microsciadia

Abstract

The roots and the shoots of Euphorbia macrostegia and E. microsciadia were extracted using different solvents; dichloromethane (DCM), methanol (MeOH) and MeOH: water (80:20) and the extracts were screened for their cytotoxic, antioxidant and antimicrobial properties as well as total phenolic content. Cytotoxicity of the extracts was evaluated against human acute lymphoblastic leukemia (MOLT-4) cells by MTT reduction assay. The extracts were also subjected to the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and Folin-Ciocalteu total phenolic assays. The MeOH extract of the shoots of E. microsciadia and DCM extract of the roots of E. macrostegia were the most cytotoxic ones with IC50 values of 10.5 ± 2.6 and 7.0 ± 1.2 µg/mL, respectively. The MeOH extract of the shoots of E. microsciadia showed considerable antioxidant activity (IC50 = 9.95 ± 1.00 µg plant extracted to scavenge 1 mL of a 0.1 mM DPPH solution), which was consistent with its highest phenolic content (288.50 ± 29.38 mg equivalent of gallic acid in 1g dry plant material: mg EG/g PM). Determination of minimum inhibitory concentrations (MICs) using the broth dilution method, confirmed that all the extracts from the plants gave various degrees of antibacterial activity against all tested microorganisms. In thin layer chromatography (TLC) investigations, some compounds previously isolated from Euphorbia species inclduing cycloartenol, 24-methylenecycloartan-3β-ol, β-sitosterol and euphol were tested and suggested to be responsible for the above-mentioned biological activities in the plants. Therefore, we suggest E. macrostegia and especially E. microsciadia as new sources for isolation and identification of various bioactive compounds.