Evaluation of the anti-osteoporosis and antioxidant activities of phenolic compounds from Euphorbia maculata

Antioxidant and anti-osteoporosis activities of extracts and chemical constituents from the whole plant of Euphorbia maculata were investigated. The MeOH extract, as well as EtOAc and H 2 O fractions (10.0 μg/mL), exhibited potent antioxidant activities. Their oxygen radical absorbance capacity and cupric ion reducing antioxidant capacity values were 27.07±0.31 to 28.47±0.36 and 43.86±0.26 to 46.67±0.34 fold higher than those of 1.0 μM Trolox, respectively. The MeOH extract and EtOAc fraction (at 10.0 μg/mL) also significantly suppressed excessive bone resorption by osteoclasts with tartrate-resistant acid phosphatase (TRAP) activity values of 154.90±4.25 and 163.95±9.77%, respectively. Bioassay guided isolation of the EtOAc and H 2 O fractions afforded 19 known compounds ( 1 – 19 ). Of these, compounds 18 , and 13 – 15 showed good antioxidant activity based on peroxyl radical-scavenging and reducing capacity assays, whereas compounds 1 , 4 , 7 , and 14 showed the most significant inhibitory effect with TRAP activity values ranging from 121.31±1.41 to 110.00±3.74% relative to the control.