Green tea may prevent Velcade from working effectively

It turned out to be really interesting and newsworthy so I tweeted about it, since quite a few cancer survivors and advocacy groups follow me and thought it might be helpful. I also meant to write a more detailed post about it later that day, but sadly events intervened. Shame on me, as I would have got the scoop before the major news organisations.

Green tea has long been thought to offer health benefits and many people enjoy it as opposed to iced tea, coffee or sodas. The researchers, from USC in Los Angeles, were curious to investigate the anti-cancer effects of the green tea but what they found was more than they bargained for:

"The anticancer potency of green tea and its individual components is being intensely investigated, and some cancer patients already self-medicate with this 'miracle herb' in hopes of augmenting the anticancer outcome of their chemotherapy. Bortezomib (Velcade) is a proteasome inhibitor in clinical use for multiple myeloma. Here, we investigated whether the combination of these compounds would yield increased antitumor efficacy in multiple myeloma and glioblastoma cell lines in vitro and in vivo. Unexpectedly, we discovered that various green tea constituents, in particular (-)-epigallocatechin gallate (EGCG) and other polyphenols with 1,2-benzenediol moieties, effectively prevented tumor cell death induced by bortezomib in vitro and in vivo."

The results were noticeable enough (100% inactivation) to suggest that green tea polyphenols may have the potential to negate the therapeutic efficacy of bortezomib by preventing its boronic unit on the molecule from interacting with the cancer cell. Green tea supplements are also available in health food stores in the US in capsules containing up to 50 times as much polyphenol as a single cup of tea. They have already been associated with liver and kidney damage.

Patients undergoing Velcade treatment may well find that consumption of green tea products contraindicated with this therapy. It will be interesting to see if abstinence from green tea products improves the drugs efficacy, which is usually around 30% of patients who respond to treatment.

By Pharma Strategy Blog.