Background:
Inonotus obliquus, also known as Chaga, is a parasitic fungus
growing on birches and used in traditional medicine (especially by Khanty
people) to treat various health problems. In this study, we aimed to quantify
the 3 metabolites frequently cited in literature, that is, betulin, betulinic
acid, and inotodiol in the Chaga recently discovered in forests located in
Normandy (France), and to compare their concentrations with Ukrainian and
Canadian Chaga. This study also explores the cytotoxicity of the French Chaga
against cancer-derived cells and transformed cells. Methods: A
quantification method by HPLC-MS-MS (high-performance liquid
chromatography–tandem mass spectrometry) of betulin, betulinic acid, and
inotodiol was developed to study the French Chaga and compare the concentration
of these metabolites with extracts provided from Chaga growing in Canada and
Ukraine. This method was also used to identify and quantify those 3 compounds in
other traditional preparations of Chaga (aqueous extract, infusion, and
decoction). Among these preparations, the aqueous extract that contains betulin,
betulinic acid, and inotodiol was chosen to evaluate and compare its cytotoxic
activity toward human lung adenocarcinoma cells (A549 line) and human bronchial
epithelial cells (BEAS-2B line). Results: French Chaga contains
betulin and betulinic acid at higher levels than in other Chaga, whereas the
concentration of inotodiol is greater in the Canadian Chaga. Moreover, the
results highlighted a cytotoxic activity of the Chaga’s aqueous extract after 48
and 72 hours of exposure with a higher effect on cancer-derived cells A549 than
on normal transformed cells BEAS-2B (P = 0.025 after 48 hours
of exposure and P = 0.004 after 72 hours of exposure).