Extracts of Devil's Club (Oplopanax horridus) Exert Therapeutic Efficacy in Experimental Models of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a group of hematological malignancies defined by expanded clonal populations of immature progenitors (blasts) of myeloid phenotype in blood and bone marrow. Given a typical poor prognostic outlook, there is great need for novel agents with anti‐AML activity. Devil's club (Oplopanax horridus) is one of the most significant medicinal plants used among the indigenous people of Southeast Alaska and the coastal Pacific Northwest, with different linguistic groups utilizing various parts of the plant to treat many different conditions including cancer. Studies identifying medically relevant components in Devil's club are limited. For this research study, samples were extracted in 70% ethanol before in vitro analysis, to assess effects on AML cell line viability as well as to study regulation of tyrosine phosphorylation and cysteine oxidation. The root extract displayed better in vitro anti‐AML efficacy in addition to a noted anti‐tyrosine kinase activity independent of an antioxidant effect. In vivo therapeutic studies using an immunocompetent murine model of AML further demonstrated that Devil's club root extract improved the murine survival while decreasing immunosuppressive regulatory T cells and improving CD8+ T‐cell functionality. This study defines for the first time an anti‐AML efficacy for extracts of Devil's club. Copyright © 2014 John Wiley & Sons, Ltd.