Antioxidant and anti-inflammatory compounds in the popular landscape plant Berberis thunbergii var. atropurpurea.

Berberis thunbergii var, atropurpurea. DC is one of the popular landscape plants in the USA, but until now lacked report on its chemical composition and biological properties. In this study, the antioxidant and anti-inflammatory activities of the methanolic extract and pure isolates of B. thunbergii var. atropurpurea, Crimson Pygmy, roots were evaluated using established bioassay procedures. The methanolic extract gave an absorbance value of 0.44 at 250 microg/mL concentration in the MTT assay. In addition, the extract inhibited lipid peroxidation (LPO) by 93% and the cyclooxygenase enzymes, COX-1 by 54 and COX-2 by 34%, at 100 microg/mL concentration. Therefore, a bioactivity-guided purification was carried out yielding pure isolates, out of which compounds 3-6 inhibited LPO by 34-66% at 100 microg/mL concentration. Similarly, compounds 1-6 inhibited COX-1 and -2 by 24-65 and 23-43% at 25 microg/mL concentration, respectively. This is the first report of the chemical constituents and biological activities of this plant.