Potential anticancer properties of the water extract of Inontus obliquus by induction of apoptosis in melanoma B16-F10 cells

Ethnopharmacological relevance: Inonotus obliquus (Chaga mushroom), one of the widely known medicinal mushrooms, has been used to treat various cancers in Russia and most of Baltic countries for many centuries. Aim of the study: To examine the anti-proliferative effects of Inonotus obliquus extract on melanoma B16-F10 cells. Furthermore, to assess the anti-tumor effect of Inonotus obliquus extract in vivo in Balb/c mice. Materials and methods: The water extract of Inonotus obliquus was studied for anti-proliferative effects on the growth and morphology of B16-F10 melanoma cells and for anti-tumor effect using in vivo in Balb/c mice. Results: Inonotus obliquus extract not only inhibited the growth of B16-F10 cells by causing cell cycle arrest at G(0)/G(1) phase and apoptosis, but also induced cell differentiation. These effects were associated with the down-regulation of pRb, p53 and p27 expression levels, and further showed that Inonotus obliquus extract resulted in a G(0)/G(1) cell cycle arrest with reduction of cyclin E/D1 and Cdk 2/4 expression levels. Furthermore, the anti-tumor effect of Inonotus obliquus extract was assessed in vivo in Balb/c mice. Intraperitoneal administration of Inonotus obliquus extract significantly inhibited the growth of tumor mass in 1316410 cells implanted mice, resulting in a 3-fold (relative to the positive control, 'p < 0.05) inhibit at dose of 20 mg/kg/day for 10 days. Conclusion: This study showed that the water extract of Inonotus obliquus mushroom exhibited a potential anticancer activity against B16-F10 melanoma cells in vitro and in vivo through the inhibition of proliferation and induction of differentiation and apoptosis of cancer cells. (C) 2008 Published by Elsevier Ireland Ltd.