Antioxidant Activity and Dose-Dependent Toxicity of a Traditionally Consumed Ipomoea pes-caprae Infusion Evaluated in...

Background/Objectives: Triple-negative breast cancer (TNBC) is one of the most aggressive breast cancer subtypes and remains associated with limited therapeutic options and high systemic toxicity from conventional chemotherapy. Ipomoea pes-caprae is a coastal medicinal plant traditionally consumed in Mexico for inflammatory and renal disorders and contains bioactive metabolites with reported antioxidant and pharmacological properties. However, its antitumoral activity and systemic safety profile remain poorly understood. This study aimed to characterize the phytochemical composition, antioxidant capacity, antitumoral activity, and toxicity of a traditionally prepared aqueous infusion of I. pes-caprae leaves (IPCAE). Methods: IPCAE was characterized using phytochemical screening and complementary instrumental analyses. Antioxidant activity was evaluated using the DPPH assay. A randomized preclinical study was performed in mice bearing MDA-MB-231 xenografts treated with IPCAE, cisplatin, or saline control. Results: The infusion showed measurable antioxidant activity (72.25 ± 1.25% DPPH inhibition at 1 mg/mL) and a total polyphenol content of 7.29 µg/mg gallic acid equivalents. Phytochemical screening revealed abundant flavonoids and reducing sugars, with moderate saponin content. In vivo, IPCAE produced only a transient and non-significant trend toward slower tumor progression compared with control (p = 0.214) and cisplatin (p = 0.377). However, marked systemic toxicity was observed, including severe thoracic dermal lesions in 40% of animals and 70% mortality by day 15. Survival was significantly reduced compared with control and cisplatin groups (p < 0.001). Conclusions: Although IPCAE exhibited antioxidant activity, no statistically significant antitumoral effect was observed under the evaluated conditions. Furthermore, repeated oral administration resulted in marked systemic toxicity, characterized by visible dermal lesions, clinical deterioration, and increased mortality. Therefore, the present findings do not support the use of the evaluated crude preparation as an anticancer intervention. Future studies should focus on detailed toxicological characterization, bioassay-guided fractionation, dose optimization, and identification of the individual metabolites responsible for the observed biological effects. The antioxidant activity demonstrated in this study should be interpreted independently from antitumoral activity, as no causal relationship between these findings was established.