The use of medicinal plants in the world, and especially in South
America, plays a significant role in informal primary health care
practices. In Brazil, numerous plants are used in the form of crude
extracts, infusions or sticking plasters to treat common infections
without any scientific evidence of efficacy (Holetz et al., 2002).
The Brazilian flora has a high biodiversity, and is a potential field
to discover new phytotherapeutic agents. Over millions of years
throughout their evolutive process, plants have developed the
capacity to synthesize a diverse array of chemicals. In general,
these phytochemicals are potent biologic agents that may play a
role in cancer risk via several complementary and overlapping
mechanisms (Lampe, 2003). A wide array of phenolic substances,
particularly those present in edible and medicinal plants, have
been reported to exert substantial anticarcinogenic and antimutagenic
activities.