Chemopreventive and anti-cancer efficacy of silibinin against growth and progression of lung cancer

Abstract

The use of systemic chemotherapeutic drugs and molecular-targeted therapies in the treatment of patients with locally advanced or metastatic lung cancer has its limitations due to the associated acute and cumulative dose limiting toxicities and acquisition of drug resistance. Prevention and therapeutic intervention by dietary agents including nutraceuticals which are non-toxic, cost-effective, and physiologically bioavailable, are emerging approaches in lung cancer management. In this regard, silibinin, a natural flavonolignan, has been rigorously evaluated for the prevention and growth control of lung cancer through extensive in vitro and in vivo studies. Successful studies conducted so far, have established that silibinin is effective both alone and in combination with other agents (e.g., chemotherapeutic and epigenetic agents) in significantly inhibiting the growth of lung cancer cells. In vivo, its effects have been shown to be mediated through inhibition of proliferation, angiogenesis and epigenetic-related events. Therefore, the present review focuses on encompassing the efficacy and mechanisms of silibinin against lung cancer.

Fig. 1

Milk Thistle. (A) Silybum marianum (Milk Thistle) plant, Family: Asteraceae. (B) Seeds of Milk thistle plant. (C) Chemical structure of silibinin - the principle bioactive constituent of silymarin (milk thistle extract) isolated from the dried fruits and seeds of milk thistle.

Fig. 2

Major molecular targets of silibinin involved in its efficacy against epithelial cancers. *, Key molecules that are targeted by silibinin in its chemopreventive and anti-cancer efficacy against lung cancer.