Combined Effects of Sulforaphane and Centella asiatica in T98G Glioblastoma Cells: Functional and Immunocytochemical Evaluation

Glioblastoma (GBM) remains difficult to treat because of its aggressive growth and resistance to current therapies. This study evaluated the individual and combined effects of sulforaphane (SFN) and Centella asiatica (CA) in T98G glioblastoma cells. Relative cell viability was assessed using the MTT assay after 24-h treatment, and combination effects were explored using descriptive Bliss independence analysis. Wound-healing and colony formation assays assessed wound closure and clonogenic capacity. Immunocytochemistry was used to evaluate p-Akt, p-mTOR, Ki-67, cleaved caspase-3, and Beclin-1, while extracellular total oxidant status and lactate were measured using commercial kits. Experiments were performed in three independent biological replicates. CA reduced MTT-based relative viability, whereas SFN produced increased signals at low concentrations and decreased signals at higher concentrations. Combo A (10 µM SFN + 50 µg/mL CA) yielded 36.56% relative viability and the largest positive excess over Bliss (15.23 percentage points), suggesting a potential synergistic interaction. Combo A significantly reduced viability compared with control and CA alone, but not matched-dose SFN. Percentage wound closure did not differ significantly among the groups at 6 or 24 h. Combo A also reduced colony formation compared with control (p = 0.030) and p-mTOR immunoreactivity compared with CA alone. No significant differences were detected in the remaining markers, oxidant status, or lactate. These findings provide a basis for further studies on the combined effects of SFN and CA and the molecular processes underlying the treatment response. Validation in additional cell lines and in vivo models is needed.