Prospecting of the Antioxidant Activity from Extracts Obtained from Chañar (Geoffroea decorticans) Seeds Evaluated In Vitro and In Vivo Using the Tenebrio molitor Model

<i>Geoffroea decorticans,</i> commonly known as Chañar, is a native Chilean plant widely used in folk medicine for its expectorant, pain relief, and antinociceptive properties. This study explored the antioxidant, cytotoxic, and protective effects of its ethanolic (EE) and aqueous (EA) seed extracts against oxidative stress induced by copper sulfate, using both in vitro and in vivo approaches. Phytochemical analyses revealed the presence of phenolic compounds and flavonoids in the extracts. High-Performance Liquid Chromatography (HPLC) coupled with Gas Chromatography-Mass Spectrometry/Mass Spectrometry (GC-MS/MS) identified significant components such as phytol, alpha-tocopherol, vitexin, and rutin, with the EE being particularly rich in phytol and vitexin. Antioxidant assays-measuring the total antioxidant capacity (TAC), reducing power, DPPH radical scavenging, and copper and iron chelation-confirmed their potent antioxidant capabilities. Both extracts were non-cytotoxic and provided protection against CuSO₄-induced oxidative stress in the 3T3 cell line. Additionally, the use of <i>Tenebrio molitor</i> as an invertebrate model underscored the extracts' antioxidant and protective potentials, especially that of the EE. In conclusion, this study highlights the significant antioxidant and protective properties of Chañar seed extracts, particularly the ethanolic extract, in both in vitro and in vivo models.