Antioxidant and antiinflammatory effect of Epilobium parviflorum Schreb

Epilobium parviflorum Schreb. (Onagraceae) is used for the treatment of benign prostatic hyperplasia (BPH), but its biological action is not entirely identified. This paper aims to report data on E. parviflorum with respect to its antioxidant and antiinflammatory effects. The aqueous acetone extract of E. parviflorum showed higher antioxidant effect in the DPPH assay than well known antioxidants and inhibited the lipid peroxidation determined by the TBA assay (IC(50) = 2.37 +/- 0.12 mg/mL). In concentrations of 0.2-15.0 microg/mL the extract possessed a protective effect, comparable to catalase (250 IU/mL), against oxidative damage, generated in fibroblast cells. In the COX inhibition assay E. parviflorum decreased the PGE(2) release, so showing inhibition of the COX-enzyme (IC(50) = 1.4 +/- 0.1 microg/mL).

Antioxidant activity of Knipholone anthrone

Knipholone (KP) and knipholone anthrone (KA) are natural 4-phenylanthraquinone structural analogues with established differential biological activities including in vitro antioxidant and cytotoxic properties. By using DNA damage as an experimental model, the comparative Cu(II)-dependent prooxidant action of these two compounds were studied. In the presence of Cu(II) ions, the antioxidant KA (3.1-200 microM) but not KP (6-384 microM) caused a concentration-dependent pBR322 plasmid DNA strand scission. The DNA damage induced by KA could be abolished by reactive oxygen species scavengers, glutathione and catalase as well as EDTA and a specific Cu(I) chelator bathocuproine disulfonic acid. In addition to Cu(II) chelating activity, KA readily reduces Cu(II) to Cu(I). Copper-dependent generation of reactive oxygen species and the subsequent macromolecular damage may be involved in the antimicrobial and cytotoxic activity of KA.