Immunomodulating polysaccharides, triterpenoids and melanin from the medicinal fungus Inonotus obliquus (Chaga)

Inonotus obliquus (Chaga) is a strange-looking fungus growing on birch trees in the Northern Hemisphere. Chaga is perhaps best known for its use in traditional medicine, where the fungus is used as an herbal tea against diseases such as cancer and gastrointestinal disorders. In Norway, the Sámi people use Chaga in ceremonies and as a replacement for tea and coffee during winter. Despite its widespread use in European and Asian countries, the immunological effects of Chaga have been poorly investigated. As such, the main goals of this thesis were to isolate chemical compounds from Chaga and investigate if they had immunological effects. The results showed that complex carbohydrates isolated from Chaga could activate certain immune cells into destroying cancer cells. Further, chemical compounds known as triterpenoids were able to kill cancer cells directly. Some of these compounds also activated a part of the immune system known as the complement system. In addition, a melanin pigment with an unusual chemical structure was shown to have anti-inflammatory effects in several types of experiments. The results demonstrate that the use of Chaga in traditional medicine has some merit, and that the fungus is a source for potential new pharmaceutical compounds worthwhile investigating further