I’m not aware of a UK Hospital putting together an overview of the different herbs and tinctures that are sometimes mentioned as being beneficial for cancer patients. The Sloan Kettering Memorial Hospital is one of the biggest Cancer Hospitals in the USA and is also a Centre for Renal Cancer – they have an area on their website devoted to herbs and botanicals . They give the following details about any of the substances they have investigated….
Mechanism of Action
As an example and because it is mentioned often in connection with kidney cancer, this is part of what they say about the use of Essiac Tea……….. –
Essiac was developed in the 1920s by Rene Caisse, a Canadian nurse. It is a formulation of four botanicals: burdock root, sheep sorrel root, slippery elm bark, and rhubarb root (1) (2). Despite insufficient clinical evidence (13), many cancer patients use Essiac tea as an alternative treatment based on anecdotal evidence.
Essiac demonstrated antioxidant (12) and cytotoxic properties in vitro (6) (11), but stimulated growth of human breast cancercells both via estrogen receptor (ER) dependent and ER independent pathways (3). Data is conflicting on Essiac’s antiproliferative effects on prostate cancercells (7) (8). A retrospective study of breast cancer patients found that Essiac did not improve quality of life or mood (10). Well designed clinical trials are needed to evaluate Essiac.
Because Essiac inhibits cytochrome P450 (CYP450) enzymes (6), it can interfere with some chemotherapy drugs (4). Cancer patients should use caution.