Milk Thistle (Silybum marianum) as a tool for helping with Cancer (anticancer research)

Milk thistle (Silybum marianum) is an herb that is increasingly used in oncology research and treatment settings. Historically, it has been used to treat liver and biliary disorders and has been used in detoxification and cleansing protocols. However, milk thistle is increasingly being investigated for its use in adult and pediatric populations for oncology indications. Possible indications during cancer treatment include cleansing and detoxification after chemotherapy, preventing hepatotoxicity during chemotherapy, treating hepatotoxicity after chemotherapy, and potentiating chemotherapy and radiation therapy as an adjunctive treatment. Milk thistle may also have applications in ameliorating long-term hepatic and cardiovascular effects of cancer treatment. Preliminary studies are investigating its use as a chemopreventive agent and possibly to treat cancer directly. Much of milk thistle's current clinical use grows out of historical uses but is informed by an increasing number of clinical trials and animal studies. This article provides an overview of the current clinical applications of milk thistle in the oncology setting, including guidelines on commonly used forms and doses.

Silymarin contains a group of closely-related flavonolignan compounds including silibinin, and is extracted from Silybum marianum species, also called milk thistle. Silymarin has been shown to protect the liver in both experimental models and clinical studies. The chemopreventive activity of silymarin has shown some efficacy against cancer both in vitro and in vivo. Silymarin can modulate apoptosis in vitro and survival in vivo, by interfering with the expression of cell cycle regulators and apoptosis-associated proteins. In addition to its anti-metastatic activity, silymarin has also been reported to exhibit anti-inflammatory activity. The chemoprotective effects of silymarin and silibinin (its major constituent) suggest they could be applied to reduce the side effects and increase the anti-cancer effects of chemotherapy and radiotherapy in various cancer types, especially in gastrointestinal cancers. This review examines the recent studies and summarizes the mechanistic pathways and down-stream targets of silymarin in the therapy of gastrointestinal cancer.