Cancer, characterized by uncontrolled cell proliferation and evasion of cell death mechanisms, remains one of the leading causes of global mortality and morbidity, particularly in aggressive neoplasms such as acute lymphoblastic leukemia (ALL), glioblastoma, and osteosarcoma. Conventional therapies, although effective, face limitations related to tumor resistance and systemic toxicity. In this context, natural products with high tumor selectivity emerge as promising alternatives. Alpinia purpurata (red ginger), traditionally used in ethnomedicine to treat inflammation and infections, contains bioactive compounds with anticancer potential, including previously demonstrated antileukemic activity from isolated lectins.

To evaluate the cytotoxicity and selectivity of different Alpinia purpurata extracts in cell models of B-cell acute lymphoblastic leukemia, glioblastoma, and osteosarcoma.

Alpinia purpurata plant material was collected in Pará, Brazil (01°32′039″S; 49°11′053″W), identified (voucher MSF011453), and subjected to ethanolic extraction (95%) in an ultrasonic bath (40°C, 40 min), yielding leaf (AZFA) and flower (AZFR) extracts. NALM-6, T98, U2OS, and HEK-293 cells were treated for 72 hours with serial concentrations, and cell viability was assessed by MTT assay at 570 nm. IC₅₀ values were calculated by nonlinear regression (GraphPad Prism v9). The Selectivity Index (SI) was determined by dividing the IC₅₀ of the non-tumor cell line by the IC₅₀ of the tumor cell line. Group comparisons were performed using one-way ANOVA followed by Tukey’s post-test (p ≤ 0.05).

AZFA showed an IC₅₀ of 10.8 µg/mL (SI = 18.1) for NALM-6, 35.4 µg/mL (SI = 5.5) for T98, and 31.2 µg/mL (SI = 6.3) for U2OS. AZFR exhibited an IC₅₀ of 15.9 µg/mL (SI = 12.6) for NALM-6, 38.8 µg/mL (SI = 5.1) for T98, and 43.9 µg/mL (SI = 4.5) for U2OS. In HEK-293 cells, IC₅₀ values were 195.6 µg/mL (AZFA) and > 200 µg/mL (AZFR), indicating low toxicity in non-neoplastic cells. The NALM-6 model demonstrated the highest sensitivity to both treatments, with a significant reduction in viability at the lowest concentrations tested (p < 0.0001), while T98 and U2OS showed moderate responses and HEK-293 maintained high viability even at the highest concentrations.

Alpinia purpurata extracts exhibited remarkable selective cytotoxic activity, particularly against the NALM-6 (B-ALL) cell line, which showed high sensitivity even at low concentrations. This profile suggests the presence of bioactive compounds with preferential action against leukemic cells, possibly related to specific molecular targets or unique metabolic characteristics of these cells. The moderate activity observed in T98 (glioblastoma) and U2OS (osteosarcoma) expands the potential application to other aggressive tumors, while the low toxicity in HEK-293 indicates a favorable therapeutic margin. Importantly, our findings corroborate previous reports in the literature that have demonstrated the antileukemic activity of extracts from this species, reinforcing its potential as a source of molecules for the development of safer and more targeted anticancer therapies. These results support further studies involving chemical fractionation, identification of active principles, and elucidation of mechanisms of action.