Marrubiin Inhibits Cell Growth and Activating Apoptosis via Expression of Inflammatory Markers in Oral Squamous Carcinoma KB Cells

Background: Oral cancer is a major type of head and neck cancer that mostly affects the lips, tongue, buccal mucosa, and salivary glands. It is a malignant tumor affecting the oral cavity with an annual incidence of over half a million new cases. Objectives: The major aim of the current work is to evaluate the anti-cancer potential of marrubiin against oral cancer KB cells. Materials and Methods: The effect of marrubiin (2.5–160 μg/mL) on KB cell growth was assessed by the MTT assay. The mitochondrial membrane potential (MMP) and apoptosis in the marrubiin-treated and control cells were studied using respective fluorescent staining assays. The angiogenic marker vascular endothelial growth factor (VEGF) and inflammatory cytokines tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) levels were studied using the assay kits. Results: The MTT assay results prove that the marrubiin treatment effectively decreased KB cell growth dose-dependently. The treatment of marrubiin at an inhibitory concentration (IC50 33.15 μg/mL) effectively induced apoptosis and reduced MMP levels in the KB cells. The VEGF, TNF-α, and IL-6 levels were effectively reduced in the KB cells after treatment with the IC50 concentration of marrubiin. Conclusion: The present results demonstrate that marrubiin inhibits cell viability and promotes apoptosis in KB cells via decreasing VEGF and inflammatory cytokine levels. Thus, it holds potential as a promising anti-cancer agent for treating oral cancer.