Dr. Oesterheld's Note: Here is the latest in vitro investigation of an herbal drug, Essiac for it inhibitory effects on P450 cytochromes. In Canada it is used as a tea originally developed by the Ojibwa tribe and used for the treatment of cancer and as an antioxidant. It is composed of four herbs Arctium lappa (burdock root) Rumex acetosella (sheep sorrel), Ulmus rubra (inner bark of the slippery elm) and Rheum officinale (Indian rhubarb). Recent clinical studies of it use in breast cancer to improve mood states has not be shown to be effective (Zick et al 2006) nor to be effective in an invov model of prostate cancer (Eberding et al 2007).

Anticancer Res. 2007 Nov-Dec;27(6B):3875-82
In vitro analysis of the herbal compound Essiac.
Seely D, Kennedy DA, Myers SP, Cheras PA, Lin D, Li R, Cattley T, Brent PA, Mills E, Leonard BJ.

Department of Research and Clinical Epidemiology, The Canadian College of Naturopathic Medicine, Toronto, ON, Canada. dseely@ccnm.edu

BACKGROUND

Despite the recommendation of the Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative, little research has been published on the widely used herbal compound Essiac. We aimed to address this deficiency by conducting a series of assays to determine some of the purported activities of Essiac in vitro.

MATERIALS AND METHODS

The activity of Essiac was measured using established assays to assess anti-oxidant, fibrinolytic, anti-microbial, anti-inflammatory, immune modulation, cell-specific cytotoxicity, and impact on cytochrome P450 (CYP450) enzyme pathways.

RESULTS

Essiac exhibited significant antioxidant activity in the ABTS assay. A 20-fold dilution of Essiac also exhibited significant immunomodulatory effects, specifically through stimulation of granulocyte phagocytosis, increases in CD8+ cell activation, and moderately inhibiting inflammatory pathways. Essiac exhibited significant cell-specific cytotoxicity towards ovarian epithelial carcinoma cells (A2780). Importantly, a 20-fold dilution of Essiac showed significant inhibition of several CYP450 enzymes, most notably CYP1A2 (37%) and CYP2C19 (24%). Essiac demonstrated dose- dependent inhibition of clot fibrinolysis.

CONCLUSION

In vitro analysis of Essiac indicates significant antioxidant and immunomodulatory properties, as well as neoplastic cell specific cytotoxicity consistent with the historical properties ascribed to this compound. Importantly, significant CYP450 and fibrinolysis inhibition were also observed. This is the first comprehensive investigation of the in vitro effects of Essiac.