It may not be magical, but the chaga mushroom has been used medicinally for a long time in Eastern Europe. This Brunswick Labs deep look at chaga suggests that it offers some strong properties that could make it candidate for further health applications today.
Among the many medicinal mushroom species, chaga (Inonotus obliquus Pilát) has drawn significant attention from the scientific community in the past several decades. Chaga belongs to the Hymenocataceae family, which includes other dark, woody fungi that inhabit tree trunks or decaying trees as parasites.1 Chaga mushrooms typically grow on birch trees in the cold climates of Europe, Asia and North America. They range from 8 to 12 inches in diameter, have a characteristic rough, woody surface and can reach weight of over 30 pounds. Interestingly, chaga often form a symbiotic relationship with the birch trees on which they feed, helping them heal damaged regions on the trunk.2 Protocols for growing laboratory-cultured chaga mycelia have been established as a step toward preserving this important species from overharvesting in the wild.
Chaga has a history of use in traditional medicine in Russia, Poland and most of the Baltic countries, in a variety of ailments ranging from stomach diseases to tumors.3 In the recent years, numerous independent studies have focused on elucidating the biological effects of chaga preparations. The following functions of I. obliquus extracts and preparations have been reported in the literature: antimicrobial, antioxidant, anti-inflammatory, immunomodulatory and anticancer. The observed effects have been attributed to a wide range of functional components present in this species, including: phenolics, terpenoids, peptides, polysaccharides, b-glucan, and inotodiol.4 While the majority of more than 200 mycochemicals found in chaga are synthesized by the fungus, this species is also effective in extracting betulin and betulinic acid, both terpenes, from the bark of the birch trees on which it feeds, and depositing them in the outer layer of its sclerotium.
Antimicrobial action. Chaga extracts have been shown to exhibit activity against several common types of viruses in in vitro studies. In one study, the water-based extract of chaga exhibited antiviral activity against the hepatitis C virus,5 while another study reported 100 percent inhibition of the external surface of fungus against two strains of the human influenza virus (A and B).6 The authors postulated that the observed antiviral activity is due to betulin, lupeol and mycosterols. In addition, aqueous extract of I. obliquus exhibited anti-herpes simplex virus activity in two in vitro assays, through inhibition of viral-induced membrane fusion in the early stage of viral infection.1
Antioxidant action. In the ORAC test performed by Brunswick Laboratories, chaga aqueous extract received a score of 146,700 micromole TE/100 grams, showing a good indication of rich antioxidant content. In addition, both hot water and alcohol chaga extracts display superoxide dismutase (SOD) – type activity in scavenging free radicals.7 SOD is an endogenous antioxidant enzyme whose main function is dismutation of the superoxide anion to hydrogen peroxide, which prevents further generation of free radicals.
Anti-inflammatory properties. Chronic inflammatory processes in the body obstruct normal immune system function and are believed to play a role in the onset of a large number of diseases, including some forms of cancer. One study demonstrated the effectiveness of water-based and ethanol chaga extracts in reducing nitric oxide production in murine macrophage cell assay, thus disabling an important inflammatory pathway.8 Another group of authors reported similar findings, indicating that the anti-inflammatory properties of I. obliquus extracts may be due to the inhibition of two important proteins: NO synthase and cyclooxygenase.9
Immunomodulatory effects. Certain mushroom polysaccharides have the capability to modulate the response of the host immune system, and, depending on the conditions, stimulate or suppress the immune response. Immunostimulating effects of polysaccharides isolated from I. obliquus have been observed in several published studies.10,11 These effects may have important implications on the body’s ability to fight disease or counteract the effects of immune suppressing chemicals.
Anticancer effects. The cytotoxic and/or apoptotic effects of chaga extracts have been demonstrated in numerous in vitro studies in cancer cell lines, including the human colon cancer cells12 and the human hepatoma HepG2 cells.13 One study reported the antiproliferative activity of a fraction isolated from the fruiting bodies of I. obliquus in human lung carcinoma, human colon adenocarcinoma, and rat glioma cells.3 In this particular study, the effect of chaga extract was selectively observed in cancer cells with no significant effects in normal cells.
This article represents only a brief overview of several important biological effects attributed to I. obliquus in a range of cellular and enzymatic in vitro studies. While these studies are valuable as initial screening tools, a thorough investigation in the clinical setting, via clinical studies/trials specially designed for nutraceutical functions, is necessary to confirm any beneficial in vivo effects. Due to the continuing interest in this species’ biological properties, future studies will likely shed new light on the effectiveness of chaga in specific disease models and medical conditions.
- 1. Pan H-H, Yu X-T, Li T, et al. Aqueous Extract from a Chaga Medicinal Mushroom, Inonotus obliquus (Higher Basidiomyetes), Prevents Herpes Simplex Virus Entry Through Inhibition of Viral-Induced Membrane Fusion. Int J Med Mushrooms. 2013;15(1):29-38.
- 2. Faass N. The Healing Powers of Wild Chaga. An Interview with Cass Ingram, MD. Journal of Health and Healing. 2011/2012;35(4):6-11.
- 3. Lemieszek MK, Langner E, Kaczor J, et al. Anticancer Effects of Fraction Isolated from Fruiting Bodies of Chaga Medicinal Mushroom, Inonotus obliquus (Pers.:Fr.) Pilát (Aphyllophoromycetideae): In Vitro Studies. Int J Med Mushrooms. 2011;13(2):131-143.
- 4. Rogers, R. 2011. The Fungal Pharmacy. North Atlantic Books, Berkeley, CA.
- 5. Shibnev VA, Mishin DV, Garaev TM, et al. Antiviral activity of Inonotus obliquus fungus extract towards infection caused by hepatitis C virus in cell cultures. Bull Exp Biol Med. 2011;151:612-614.
- 6. Kahlos, K. Preliminary test of antiviral activity of two Inonotus obliquus strains. Fitoterapia.1996;67:344–347.
- 7. Hu H, Zhang Z, Lei Z, et al. Comparative study of antioxidant activity and antiproliferative effect of hot water and ethanol extracts from the mushroom Inonotus obliquus. J Biosci Bioeng. 2009;107:42–48.
- 8. Van Q, Nayaka BN, Reimera M, et al. Antiinflammatory effect of Inonotus obliquus, Polygala senega L., and Viburnum trilobum in a cell screening assay. J Ethnopharmacol. 2009;125:487–493.
- 9. Kim H-G, Yoon D-H, Kim C-H, et al. Ethanol extract of Inonotus obliquus inhibits lipopolysaccharide-induced inflammation in RAW 264.7 macrophage cells. J Med Food.2007;10:80–89.
- 10. Won DP, Lee JS, Kwon DS, et al. Immunostimulating activity by polysaccharides isolated from fruiting body of Inonotus obliquus. Mol Cells. 2011;31(2):165-173.
- 11. Kim YO, Han SB, Lee HW, et al. Immuno-stimulating effect of the endo-polysaccharide produced by submerged culture of Inonotus obliquus. Life Sci. 2005;77(19):2438-2456.
- 12. Lee SH, Hwang HS, Yun JW. Antitumor activity of water extract of a mushroom, Inonotus obliquus, against HT-29 human colon cancer cells. Phytother Res. 2009;23(12):1784-1789.
- 13. Youn, MJ, Kim JK, Park SY, et al. Chaga mushroom (Inonotus obliquus) induces G0/G1 arrest and apoptosis in human hepatoma HepG2 cells. World J Gastroenterol. 2008;14:511–517.
Jasenka Piljac Zegarac is a scientist and freelance writer. She holds a PhD in biology and a BS degree in biochemistry, and contributes on a regular basis to several health and science blogs. She may be contacted for assistance with a variety of science and medical writing projects. You can find Jasenka on LinkedIn.