Chaga mushroom (Inonotus obliquus) is a pathogenic fungus that grows mostly on birch species (Betula pendula Roth and B. pubescens Ehrh.) and has traditionally been used as an anticancer medicine. ...This study aimed to compare the chemical composition and cytotoxic activity of chagas growing on both Betula spp. on various cancer cell lines. The freeze-dried extracts contained triterpenes inotodiol, lanosterol betulin, and betulinic acid typical to conks growing on Betula species. The cytotoxic activity of chaga growing on Betula pendula and B. pubescens 80% ethanolic extracts against 31 human cancer cell lines was evaluated by a sulforhodamine B assay. Chaga extract showed moderate activity against all cancer cell lines examined; it did not result in high cytotoxicity (IC50 ≤ 20 µg/mL). The strongest inhibitions were observed with chaga (growing on B. pendula) extract on the HepG2 and CAL-62 cell line and with chaga (from B. pubescens) extract on the HepG2 cell line, with IC50 values of 37.71, 43.30, and 49.99 μg/mL, respectively. The chaga extracts from B. pendula exert somewhat stronger effects on most cancer cell lines studied than B. pubescens extracts, which can be attributed to a higher content of inotodiol in B. pendula extracts. This study highlights the potential of chaga as a source of bioactive compounds with selective anticancer properties. To the best of our knowledge, this study is the first investigation of the chemical composition of I. obliquus parasitizing on B. pubescens.
Inonotus obliquus, a well-known forest fungal pathogen, started gaining attention for its potential medicinal uses. Known as Chaga, the fungus has become prominent due to the bioactive compounds ...present in its conks. Forest owners are cultivating it to produce conks as a source of non-timber profit. However, not much is known about the natural occurrence of this pathogen, its formation of conks, the extent of decay in the infected trees, and the distribution of its basidiospores. Across 80 forest stands in Estonia dominated by Betula pendula, B. pubescens, Alnus incana, and A. glutinosa, the conks of I. obliquus were documented in 17 stands. The conks were more common in continental Estonia compared to the western islands. Among 800 randomly chosen trees, I. obliquus conks were documented on ten trees. Additionally, an asymptomatic I. obliquus infection was detected in one tree. After two years of spore trapping, I. obliquus basidiospores were detected only on four occasions, between the end of July and the beginning of September, and only at night. The proportion of rot damage in the total volume of model tree wood ranged from 8.6% to 58.5%. For fast and reliable detection of I. obliquus, TaqMan species-specific qPCR primers were developed and tested.
•The rot damage caused by I. obliquus ranged from 8.6% to 58.5% of the host tree volume.•obliquus propagates its basidiospores only at night.•The basidiospores were released from the end of July to the beginning of September.•The conks of I. obliquus are equally likely to be found in Betula and Alnus stands.•1.25% of host trees were having I. obliquus conks.
Interest in the cultivation of mushrooms, including medicinal mushrooms like Chaga (Inonotus obliquus) has increased in recent years. To provide commercial cultivators with vigorous and productive ...strains of I. obliquus, 38 strains were isolated from the conks in Estonia and Finland. The growth rates of these isolates were determined on Malt Extract Agar (MEA), and on wood sticks of Betula pendula, B. pubescens, Alnus incana and A. glutinosa. Growth rates differed for the various isolates, depending on temperature as well as substrate. On the MEA at 9°C the fastest-growing strain of I. obliquus was PAT21061, at 18°C PAT22871 and at 22°C PAT21058. On B. pendula, the I. obliquus strain, PATKJ180 had the highest growth rate; on B. pubescens, PAT21061; on A. glutinosa, PATKA880; and on A. incana, PATKA2679 exhibited the highest growth rate. But the growth rate characteristics of I. obliquus were not correlated with the host species origin of the fungus isolate. Still, the ability of strains to form conks is unknown and needs to be tested in vivo. Because I. obliquus grows faster in Betula wood than Alnus, the use of Betula wood for producing inoculation dowels is recommended in order to shorten the production time.
