From Berry to Bedside: Translational Potential of Berry-Derived Phytochemicals in HNSCC

Head and neck squamous cell carcinoma (HNSCC) remains an immunosuppressive and metabolically dysregulated malignancy, contributing to tumor progression and resistance to conventional therapies. Natural compounds offer a unique multi-target opportunity to address these challenges, with berry-derived phytochemicals emerging as particularly promising candidates. Preclinical evidence demonstrates that these compounds modulate dendritic cell activation, macrophage polarization, regulatory T cell function, and cytokine signaling, restoring immune balance while simultaneously regulating tumor metabolism and reducing chronic inflammation. Beyond these immunometabolic effects, berry-derived compounds influence glucocorticoid signaling at the endocrine-immune interface, alleviating additional immunosuppressive pressures within the tumor microenvironment. Early clinical studies support the feasibility of standardized berry-derived formulations as adjunctive agents. In patients with oral premalignant lesions and HNSCC, black-raspberry-based interventions including topical gels and oral troches, have demonstrated favorable safety profiles, measurable tissue uptake of bioactive phytochemicals, modulation of proliferation and inflammation-associated biomarkers (e.g., Ki-67, COX-2, and NF-κB), and partial histologic regression in a subset of lesions. Collectively, these pleiotropic actions highlight chemopreventive potential and provide a mechanistic rationale for combinatorial strategies with immune checkpoint inhibitors targeting PD-1/PD-L1 and CTLA-4. Opportunities for both local and systemic delivery may further enhance therapeutic efficacy. Integrating these natural compounds into precision chemoprevention and immunotherapy paradigms could inform rational drug discovery, biomarker-driven patient stratification, and combination therapy design. This review highlights the convergent immunologic, metabolic, and endocrine-targeted mechanisms of berry-derived phytochemicals in HNSCC and emphasizes their translational potential as integrative modulators of antitumor immunity.