Betulin and betulinic acid in cancer research

Introduction.Terpenes are the largest known class of organic compounds, widely distributed in plants.They are grouped considering the number of isoprene units in their structure; hence, the group consisting of 30 carbon atoms is called triterpenes.These compounds have a wide range of biological features.Objective.The aim of this review was to comprehensively discuss the role of betulin and betulinic acid as potent anticancer agents, including various studies determining their efficiency in cancer treatment and enumerating the types of cancer susceptible to this kind of therapy. State of knowledge.Betulin is a naturally occurring lupane-type pentacyclic triterpene, wildly distributed in plants, especially Betulinaceae.One of its derivatives, formed by oxidation, is betulinic acid.Both compounds are abundantly present in the outer bark of white birch, with betulin forming up to 34% its dry mass and are known for their valuable biological properties, including anti-cancer effect.By inducing the internal apoptosis pathway in cancer cells while sparing normal cells, they are a great help in the treatment of most malignancies, alone or in combination with radio-or chemotherapy.Summary.Compounds that have a direct effect on mitochondria are promising experimental anticancer drugs, since they are able to cause cell death in conditions in which conventional therapies, including chemotherapeutics, usually fail.Therefore, mitochondrial targeting agents such as betulin and betulinic acid are a promise of a new therapeutic strategy for the treatment of human tumours.