Failure and high systemic toxicity of conventional
cancer therapies have accelerated the focus on the search for newer agents, which could prevent and/or slow-down
cancer growth and have more human acceptability by being less or non-toxic.
Silymarin is one such agent, which has been extensively used since ages for the treatment of liver conditions, and thus has possibly the greatest patient acceptability. In recent years, increasing body of evidence has underscored the
cancer preventive efficacy of
silymarin in both in vitro and in vivo animal models of various epithelial
cancers. Apart from chemopreventive effects, other noteworthy aspects of
silymarin and its active constituent
silibinin in
cancer treatment include their capability to potentiate the efficacy of known chemotherapeutic drugs, as an inhibitor of
multidrug resistance-associated proteins and as an adjunct to the
cancer therapeutic drugs due to their organ-protective efficacy specifically liver, and immunostimulatory effects. Widespread use of
silymarin for liver health in humans and commercial availability of its formulations with increased bioavailability, further underscore the necessity of carrying out controlled clinical trials with these agents in
cancer patients. In this review, we will briefly discuss the outcomes of clinical trials being conducted by us and others in
cancer patients to provide insight into the clinical relevance of the observed chemopreventive effects of these agents in various epithelial
cancer models.