Phenolic Profile and Antioxidant Capacity of Extracts from Papache (Randia echinocarpa Moc. & Sessé Ex DC), a Plant Used in Traditional Mexican Medicine

Randia echinocarpa is an endemic shrub species of Mexico, commonly known as papache in the state of Sinaloa, where it has traditionally been used in medicinal practices. The present study evaluated the phenolic profile and antioxidant capacity of different tissues (leaf, bark, and fruit pulp) of R. echinocarpa. Phenolic compounds were characterized using HPLC–PDA–MS, which allowed the identification of seven compounds in the leaf, six in the bark, and six in the fruit pulp. Chlorogenic acid, ellagic acid, and rutin were among the most abundant compounds detected. Total phenolic content varied depending on tissue and season, with the highest concentration observed in leaves during autumn (2.770 ± 0.011 mg GAE g−1) and the lowest in bark during winter (0.437 ± 0.009 mg GAE g−1). This study also reports, for the first time, the concentrations of tannins and flavonoids in R. echinocarpa, with the highest content found in leaves during autumn (0.261 ± 0.003 mg EE g−1 and 2.186 ± 0.005 mg RE g−1, respectively). Antioxidant capacity was evaluated using DPPH and ABTS radical scavenging assays, with leaf extracts showing the highest activity, with IC50 values of 0.82 mg mL−1 and 1.21 mg mL−1, respectively. These results provide new information on the phenolic composition and antioxidant potential of R. echinocarpa, contributing to the phytochemical characterization of this traditionally used medicinal species.