Antiproliferative Effects of Polar Extracts of the Aerial Parts of Fuchsia standishii J. Harrison

<i>Fuchsia standishii</i> J.Harrison is a species widely used in traditional medicine in southern Ecuador for treating various ailments, including high blood pressure, as an antacid and a relaxant. The pharmacological basis for these traditional uses is unknown. Given the reported anti-inflammatory and cytotoxic properties of the <i>Onagraceae</i> family, we investigated the plant's potential for addressing chronic conditions. This study explored the bioactive potential of polar extracts from the aerial parts of <i>F. standishii</i>, focusing on antiproliferative activity against a panel of human tumor cell lines (A549, HBL-100, HeLa, SW1573, T-47D). The plant material was sequentially extracted and partitioned into nine fractions. All fractions were screened for antiproliferative activity, and the most active fractions were further evaluated for their mechanism of cell death (apoptosis/necrosis), genotoxicity, and induction of oxidative stress. Specialized metabolites in the fractions were characterized using UHPLC-DAD-MS³ analysis. <i>F. standishii</i> extracts showed potent antiproliferative activity. The dichloromethane fraction (MW_D) was the most active (GI₅₀ range: 8.5-39 µg/mL), demonstrating the ability to induce apoptosis in tumor cells and cause genotoxic damage linked to oxidative stress. The UHPLC-DAD-MS³ analysis successfully characterized the specialized metabolites present in the active fractions. The initial aqueous extract yielded a total of 47 secondary metabolites, 15 of which remained unassigned. <i>F. standishii</i> possesses a promising pharmacological profile that extends beyond its documented traditional uses. The MW_D fraction represents a plausible source of novel anti-cancer agents due to its ability to induce apoptosis, supporting further bioguided investigation of this ethnobotanically relevant species.