In vivo and in vitro effects of curcumin on head and neck carcinoma: a systematic review.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) contributes globally to a great number of deaths and morbidity, in spite of new therapeutic strategies. There is a great need of new drugs that are significantly effective and less deleterious to the patients' general health. In this sense, phytotherapy is a tendency, with results pointing to its use as a chemo-preventive and adjuvant therapy. Therefore, the objective of this systematic review was to investigate the effects of curcumin on proliferation and survival of HNSCC. MATERIALS AND METHODS: The search was conducted on six databases: Cochrane, LILACS, EMBASE, MEDLINE, PubMed, and Web of Science. In vitro and in vivo studies that evaluated the effects of curcumin on cell viability, tumor growth, cell cycle and/or cell death pattern in HNSCC cell lines or animal models were selected. RESULTS: Of the 525 initially gathered studies, 30 met the inclusion criteria. These studies demonstrated that curcumin induces cytotoxicity, apoptosis (via intrinsic pathway), and cell cycle arrest in G2 /M phase in HSNCC cell lines. It also reduces tumor measurements in animal models. These events were mostly studied through MTT assay, flow cytometry, and cell cycle- and apoptosis-related proteins expression. CONCLUSION: This systematic review demonstrated that curcumin is effective on HNSCC cell proliferation and survival, reinforcing the currently available evidence that curcumin could be an adjuvant drug in HNSCC treatment.