Jabuticaba (Myrciaria cauliflora) Leaf Extract Impairs Tumor Spheroid Viability and Promotes Apoptosis in Human Liver and Colorectal Cancer Cells

Plant-derived phenolic compounds have attracted increasing interest as potential chemopreventive agents because of their ability to modulate cellular processes associated with genomic stability and tumor progression. Myrciaria cauliflora (jabuticaba), a fruit species native to Brazil, leaves are a promising but still poorly explored source of bioactive molecules. This study evaluated the cytotoxic, pro-apoptotic, and anti-migratory effects of a crude leaf extract in human hepatocellular (HepG2) and colorectal (HT-29) carcinoma cells. HepG2 and HT-29 cells were exposed to increasing concentrations of leaf extract (5–500 µg GAE/mL) to assess cell viability in both two-dimensional (2D) cultures and three-dimensional (3D) multicellular tumor spheroids. Apoptosis was evaluated by Annexin V staining after 72 h, and cell migration was assessed using the wound-healing assay at 6, 12, and 24 h. The extract exhibited time- and dose-dependent cytotoxicity in both cell lines. In HepG2 cells, IC₅₀ values decreased from 228.1 to 151.1 and 90.11 µg GAE/mL at 24, 48, and 72 h, respectively. In HT-29 cells, IC₅₀ values were 141.1, 97.80, and 69.97 µg GAE/mL at the same time points, indicating higher sensitivity compared to HepG2. In 3D models, the extract reduced spheroid viability after 72 h, with IC₅₀ values of 149.6 µg GAE/mL (HepG2) and 174.7 µg GAE/mL (HT-29), accompanied by reductions in spheroid diameter and morphological alterations. The extract also promoted a concentration-dependent increase in apoptosis after 72 h, reaching approximately 49% Annexin V-positive HepG2 cells at 45 µg GAE/mL and 42% in HT-29 cells at 35 µg GAE/mL, compared with approximately 20% and 8% in the respective negative controls (p<0.05). In parallel, cell migration was significantly inhibited, particularly after 24 h, decreasing from approximately 25% to 3% in HepG2 cells and from 33% to 6% in HT-29 cells at the highest concentrations tested (p<0.05). The extract exerts cytotoxic effects associated with apoptosis induction and inhibition of tumor cell migration. The coordinated increase in apoptotic cells and reduction in migratory capacity suggests that activation of programmed cell death pathways may contribute to the antitumor activity of the extract, while its high phenolic content may modulate signaling pathways involved in cell survival and migration. These findings support further investigation of the molecular events underlying its cytotoxic and genotoxic effects.

Acknowledgements: São Paulo Research Foundation (FAPESP): Grant 2022/15267-1, Grant 2024/08830-7 and Grant 2025/06709-9.