RESUMO
Curcumin, the extract of the rhizome of Curcuma longa, is known for its health-promoting properties in traditional medicine. It has anti-inflammatory, antitumor and antioxidant properties and stimulates appetite. In the present study, we investigated the stability of curcumin and its effect on cytotoxicity, apoptosis and melanin content in melanoma cells and the effect on atrophic C2C12 muscle cells. Cytotoxicity of curcumin was dose-dependent and the EC50 for 24-h incubation was 69 µM. Saturation was reached at 30 µM for a 48-h incubation. The EC50 for 24-h incubation with degraded curcumin solution was 116 µM and that for 48-h was 94 µM. Curcumin induced a strong increase in caspase-3/7 activity at 30-40 µM. Electrical impedance measurements showed that sub-toxic doses of curcumin counteracted atrophy in an in vitro model system. These findings indicate not only the positive effects of curcumin on melanoma cells in vitro, but also that curcumin was able to considerably trigger anti-cachectic effects in vitro. However, the importance of the stability of curcumin and its tumoricidal and anti-cachectic potential might play a pivotal role in its use in the nutrition and health industrie since it degrades rapidly in aqueous solutions.