Antioxidant activity of Peumus boldus extract and alkaloid boldine against damage induced by Fe(II)–citrate in rat liver mitochondria in vitro

• P. boldus tea blunts iron induced oxidative stress in liver mitochondria.
• Boldine had a modest antioxidant effect in isolated mitochondria.
• Boldine was a better scavenger of DPPH radical than P. boldus tea.
• P. boldus and boldine can have synergic antioxidant properties.
• P. boldus and boldine can have synergic antioxidant properties as well as synergic effects in hepatoprotection.

Peumus boldus is a medicinal plant used in the treatment of liver diseases. Chronic liver disease can be associated with oxidative stress and iron overload. The aim of this study was to evaluate the effects of P. boldus leaf extract and boldine against Fe2+–citrate induced mitochondrial oxidative damage systems. P. boldus was more efficient antioxidant than boldine, when mitochondria were used (hepatic mitochondrial swelling, DFCH oxidation and lipid peroxidation). P. boldus (100 μg/mL) inhibited Fenton reaction by 94% and chelated about 70% of Fe2+. Boldine (3.27 μg/mL) exhibited a higher reducing power (447%) and scavenged more efficiently DPPH than P. boldus 100 μg/mL (44.7% vs 60.7%, respectively). The antioxidant effects of P. boldus extract (PbE) can be attributed to its polyphenolic compounds, determined by HPLC. Thus PbE and boldine can have synergic antioxidant properties and contribute to the protective effect of P. boldus against liver diseases associated with oxidative stress and free iron.