Abstract
Background:
Natural plant-derived compounds are increasingly explored as safer alternatives to chemotherapy due to their multi-targeted anticancer properties. Despite Oman’s rich floral biodiversity, data on the anticancer potential of its native species remain limited. Ocimum basilicum has emerged as a plant with promising bioactivities.

Aim:
This study examined the cytotoxic, anti-migratory, and anti-adhesive effects of Ocimum basilicum ethanolic extract on HCT116 colorectal cancer cells.

Methods:
Ocimum basilicum collected from South Al Sharqiyah, Oman, was ethanol-extracted and tested against HCT116 cells at concentrations of 0-200 µg/mL. Cytotoxicity was evaluated using the MTT assay, while cell adhesion and migration were assessed on fibrinogen/fibronectin-coated matrices and the wound-healing assay, respectively. Data were analyzed using one-way ANOVA.

Results:
The ethanolic extract was rich in 1,3-di-O-caffeoylquinic acid (23,366 ppm), rosmarinic acid (3,808 ppm), rutin (2,379 ppm), and luteolin (1,196 ppm). The extract significantly reduced HCT116 cell viability in a dose-dependent manner, from 87.7% at 50 µg/mL to 32.4% at 200 µg/mL (p < 0.0001). Migration was moderately inhibited at 50 µg/mL and strongly suppressed at concentrations ≥ 100 µg/mL (p < 0.0001), while adhesion remained unaffected at 50 µg/mL but was significantly decreased at higher concentrations (p < 0.0001). A strong dose–response correlation was observed across all assays (R² > 0.89).

Conclusion:
Ocimum basilicum ethanolic extract exhibits pronounced cytotoxic and anti-migratory activities against HCT116 CRC cells, highlighting its potential as a natural anticancer candidate.

Key words: Ocimum basilicum, colorectal cancer, HCT116 cells, Natural anticancer agent, cell viability, cell migration, cell adhesion, Oman.