In vivo oral toxicity and antioxidant capacity of Nothofagus antartica (ñire) leaves

Abstract

Nothofagus antartica (NA) is a native tree of the Patagonian Andes forests. Although its leaves have been ancestrally used in infusions for medical and food purposes, there are no deep insights on its toxicity. The aim of the paper was to assess the safety and antioxidant activity of infusions of NA leaves. The determination of acute and subacute oral toxicity was assessed using Swiss albino mice. A single limit dose (2000 mg/kg) was administered for acute toxicity assays, and a repeated dose (800 mg/kg), for subacute tests. For the measurement of antioxidant activity, the ABTS scavenging activity was determined. The effects of NA infusion were evaluated on the animal weight and on the functionality and histology of key organs (e.g., liver, kidney, intestine). The antioxidant activity of NA infusion was determined in vitro and also in feces and serum of treated animals. After the acute and subacute toxicity tests, no death or signs of toxicity were observed. In addition, no significant differences in biochemical parameters or tissue structure were registered between control and treated mice. On the other hand, the antioxidant activity of the NA infusion was greater than that observed for the standard of ascorbic acid. Moreover, the periodic administration of NA infusion could increase the internal antioxidant capacity in mice at intestinal level. Results support the safe of consuming NA leaves infusions by humans and suggest their contribution for modulating the oxidative stress at the gut level.