[Antitumor activity of natural substances: lectins and saffron]

A major problem in the use of chemopreventing agents in cancer treatment is the potential toxicity of these drugs to normal cells. One approach to solve this problem is to employ the inhibitors of tumorigenesis which have a natural origin. Within the past few years, natural extracts or purified compounds have become a well-established means for studying varied aspects of cancer. The recent development in plant lectins research is characterized by increasing interest in the biological activities of these lectins, specially in their antitumor effect. Another natural spice-saffron-also become the focus of recent interest as antitumor agent. This review will briefly summarize research on the study of antitumor and anticarcinogenic effects of plant lectins and saffron extract or their constituents. These findings are interpreted and the possible mechanism of antitumor effects of plant lectins and saffron are discussed.