in vitro Implications of Digallic Acid on Tongue Squamous Cell Carcinoma

Objectives: BACKGROUND.- Digallic acid is present in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Digallic acid becomes intriguing by its antioxidant, antimutagenic and anticarcinogenic properties. At its natural acidic pH, behaves as a weak reducing and stabilizing agent under alkaline conditions at room temperature. The properties of digallic acid are owe to the numerous phenolic groups in its structure and the capacity for reduce the oxidised metal ions into metal salts. Numerous studies inform that digallic acid, harbours an inhibitory action against skin, lung, and forestomach tumors but there is not information related with oral cancer, issue of the present study.
OBJECTIVE.- Determine in vitro effects of digallic acid on tongue squamous cell carcinoma (SCC-9) against keratinocytes from adult human skin (HaCat).
Methods: MATERIALS.- Human cells SCC-9 and HaCat (ATCC®), were cultured in complete IMDM medium. Subconfluent cells were counted and cellular density was adjusted for 48-well culture plates. Experimental groups were stimulated with gradual concentrations of digallic acid (triplicate assays). Migration and MTT assays were performed on short and long time courses to determine the proliferation, viability and cytotoxic effects of digallic acid. Comparative tests were performed with SigmaStat 4.0 software, revealing important differences.
Results: RESULTS.- Digallic acid prevent SSC-9 proliferation with an IC50 of 3.4 μM, higher concentrations enable up to ~80% of inhibition compared with control cells (HaCat). A significant impact for reducing the viability and migration capacity of cancer cells was observed. Those effects were irreversibles. It was observed an important amount of protein precipitation.
Conclusions: CONCLUSIONS.- Results provide new evidence about the effects of digallic acid, revealing the potential therapeutic applications to disturb the normal biology activities of oral cancer cells.