This study was conducted to compare the antioxidant, anticytotoxic, and anti-inflammatory properties of Euphorbia maculata ethanol extract with those of E. supina ethanol extract. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical and superoxide scavenging activities of E. maculata at 50 μg/mL were 38.3 ± 3.7 and 21.5 ± 1.2%, respectively, whereas those of E. supina at the same concentration were 109.4 ± 0.9 and 59.5 ± 4.8%, respectively. Oxygen radical absorbance capacities of E. maculata and E. supina at 10 μg/mL were 14.70 ± 0.63 and 26.17 ± 1.36 nmol/mL Trolox, respectively. Cupric reducing antioxidant capacities of E. maculata and E. supina at 10 μg/mL were 10.22 ± 0.97 and 62.99 ± 5.28 nmol/mL Trolox, respectively. Total phenolic contents of E. maculata and E. supina at 50 μg/mL were 29.03 ± 0.14 and 87.89 ± 0.20 nmol/mL gallic acid, respectively. E. maculata and E. supina were reported to prevent supercoiled DNA breakage induced by peroxyl and hydroxyl radicals in a concentration-dependent manner, where protection against the supercoiled DNA breakage provided by E. supina was greater than that provided by E. maculata. E. maculata and E. supina at 100 μg/mL inhibited tert-butyl hydroperoxide-induced cytotoxicity in HepG2 cells by 49.4 ± 4.3 and 87.3 ± 4.5%, respectively. E. maculata and E. supina at 500 μg/mL inhibited lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells by 63.1 ± 7.0 and 85.2 ± 1.6%, respectively. The antioxidant capacities including DPPH radical scavenging, superoxide scavenging, oxygen radical absorbance, and cupric reducing antioxidant activity were found to be highly correlated with total phenolic content (0.896 < r < 0.983, p < 0.01) and anticytotoxic activities (0.915 < r < 0.960, p < 0.01). However, the superoxide scavenging activity was not significantly correlated (r = 0.604, p > 0.05) with the anti-inflammatory activity. Thus, these findings demonstrated that the radical scavenging, anticytotoxic, and anti-inflammatory capacities of E. supina were more potent than those of E. maculata. Further studies are needed to elucidate the properties of polyphenolic constituents in E. supina responsible for these effects and the underlying mechanisms.

The objective of this study was to investigate anticytotoxic and antioxidatative capacities of ethanol extracts from Acer tegmentosum Maxim (A. tegmentosum) stem in vitro. The extract at concentration of 200 ug/mL inhibited 10 and 20 ug/mL arsenic trioxide-induced cytotoxicity of HepG2 cells by 79.3 and 57.5%, respectively. The extract at concentration of 200 ug/mL inhibited 0.2 and 0.5 mM t-BHP-induced cytotoxicity of HepG2 cells by 66.3 and 35.7%, respectively. Antioxidative effects of the extract were examined via measurement of ABTS, superoxide, and peroxyl radical scavenging activities. ABTS radical scavenging activity of the extract was higher than that of α-tocopherol. Superoxide scavenging activity of the extract was higher than that of catechin. Oxygen radical absorbance capacity of the extract was higher than that of ascorbic acid. Cupric reducing antioxidant capacity of the extract was higher than that of α-tocopherol. The extract at concentrations of 100 and 500 μg/mL inhibited 10 mM t-BHP-induced lipid peroxidation of HepG2 cells by 38.2 and 80.7%, respectively. The extract prevented supercoiled DNA strand breakage induced by hydroxyl or peroxyl radical. Total phenolic and flavonoid contents of the extract at concentration of 100 μg/mL were 71.3 nmol/mL gallic acid and 18.8 nmol/mL catechin equivalents, respectively. Thus, strong cytoprotective and antioxidant effects of A. tegmentosum stem extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation as well as high levels in polyphenolic contents.