Ethanolic Extract from Fruits of Pintoa chilensis , a Chilean Extremophile Plant. Assessment of Antioxidant Activity and In Vitro Cytotoxicity.

Pintoa chilensis is a shrub with yellow flowers that reach up to two meters high, endemic of the Atacama Region in Chile. This species grows under special environmental conditions such as low altitude, arid areas, and directly sun-exposed habitats. In the present study, ethanolic extract was obtained from fruits of P. chilensis , and then partitioned in solvents of increasing polarity to obtain five fractions: hexane (HF), dichloromethane (DF), ethyl acetate (AF), and the residual water fraction (QF). The antioxidant activity of extracts was evaluated by using the DPPH, ABTS, and FRAP methods. The results show that the antioxidant capacity of P. chilensis is higher than that reported for other plants growing in similar environments. This effect is attributed to the highest content of flavonoids and total phenols found in P. chilensis. On the other hand, the cell viability of a breast cancer cell line (MCF-7) and a non-tumor cell line (MCF-10A) was assessed in the presence of different extract fractions. The results indicate that the hexane fraction (HF) exhibits the highest cytotoxicity on both cell lines (IC 50 values equal to 35 and 45 µg/mL), whereas the dichloromethane fraction (DF) is the most selective one. The GC-MS analysis of the dichloromethane fraction (DF) shows the presence of fatty acids, sugars, and polyols as major components.