Chemopreventive Potential of Artemisinin and Rubus occidentalis in the Progression of Oral Leukoplakia to Oral Cancer: A Preclinical Murine Study

Oral leukoplakia (OL) is the most common potentially malignant oral disorder, with variable risk of progression to oral squamous cell carcinoma (OSCC). This study evaluated the chemopreventive and immunomodulatory potential of Artemisinin (ART) and <i>Rubus occidentalis</i> (RO), alone or combined (ARO), in a 4NQO-induced murine model. Mice received 4NQO (100 µg/mL) in drinking water, and treatments began at week 8. Animals were euthanized at weeks 12 and 16 for histological, apoptotic (caspases-3, -8, -9; calreticulin), inflammatory (IL-1β, IL-10, HMGB1), and immune (CD8, CD68, CD56, IFN-γ, GM-CSF) marker analyses. RO-treated animals showed delayed malignant transformation, with no carcinomas at week 16 and increased expression of caspase-9, calreticulin, HMGB1, IFN-γ, and GM-CSF, indicating transient activation of antitumor immune responses. ART-treated mice showed increased CD68 and reduced CD56 expression, suggesting an immunosuppressive profile and higher carcinoma incidence. The ARO combination did not improve outcomes beyond ART alone. These findings support the immunomodulatory and pro-apoptotic effects of RO in delaying OL progression, highlighting its chemopreventive potential. ART showed limited benefit under current conditions, warranting further investigation into dose optimization and synergistic strategies.