Proceedings of the International Conference “Environmentally friendly and safe
technologies for quality of fruit and vegetables”, held in Universidade do Algarve, Faro,
Portugal, on January 14-16, 2009. This Conference was a join activity with COST Action 924.Treatment of cancer with chemotherapy has two main problems: toxicity to normal cells and failure to
kill cancer cells. Cancer cells are characterized by uncontrolled cells proliferation and unlimited life
span. Development of anti-cancer drug should involve the search for compounds capable of halting
cell proliferation and/or leading to cell death. Combination of both types of drugs will make efficient
chemotherapy. The compounds selected in this study are unique in their mode of action: they activate
the protein procaspase-3, a critical enzyme in cell death process known as: apoptosis or programmed cell
death. Although programmed cell death occurs naturally, too much or too little apoptosis cause diseases.
Not enough apoptosis cause cancer. Apoptosis involves a cascade of enzymes (caspases) that are made as
latent zymogens (pro-enzymes); procaspases activated following apoptotic death stimuli, lead to cleavage
of cellular proteins, cleavage of DNA and cell death. The enzyme caspase-3 acts in a point of no return in
this cascade. As such, compounds that will activate caspase-3 will be considered as potential anti-cancer
drugs. In practice, for a compound to be considered as a potential lead drug, it should be a small molecule,
stable, selective, and able to penetrate cellular membranes effectively. Following screening of plant extracts
against several cancer models and through development of an assay that can detect compounds which
activate caspase-3, several extracts capable of killing cancer cells by activating caspase-3 were identified