Selective Toxicity and Type of Cell Death Induced by Various Natural and Synthetic Compounds in Oral Squamous Cell Carcinoma

This article reviews the selective toxicity and type of cell death induced in oral squamous cell carcinoma (OSCC) by hundreds of natural and synthetic compounds. Flavonoids, coumarins, tannins, ketones and other synthetic compounds showed low to moderate tumor-specific cytotoxicity against human OSCC cell lines as compared with normal human oral cells (gingival fibroblast, pulp cell, periodontal ligament fibroblast), whereas anthracyclines, nocobactins and cyclic ·,‚-unsaturated compounds showed much higher tumor- specific cytotoxicity. No strict relationship was found between the tumor-specific cytotoxicity and apoptosis induction. There was a considerable variation in drug-sensitivity among 5 OSCC cell lines. OSCC cell lines were generally resistant to apoptosis induction. The cytotoxic activity of antitumor agents is affected by various factors related to the compounds themselves, the cells and their environments. Systematization of the relationship between these factors and tumor-specificity may contribute in the quest for more active compounds. Oral squamous cell carcinoma (OSCC) is the fifth most common cancer worldwide, with the number of cases consistently increasing in developing countries. OSCC, like other types of cancer, is a genetic disease, resulting in the