Abstract
An important representative of biologically active natural substances, Chan Su, has recently been the focus of great interest in evidence-based scientific research. While until 1994 no more than single papers on this topic were published annually, in the period 1995-2010 there appeared tens, and in recent years several tens.
This indicates a great interest of experts in the components of Chan Su, and thus in bufadienolides and especially in their influence on various types of tumours. The corresponding medicinal drug, being used for several thousand years, is still rightly in the centre of attention.
In the toad venom (Venenum bufonis), nature has created a real library of biologically active substances, which people in the Orient learned to use thousands of years ago and which they produce, use and examine to this day.