Curcumin and lung cancer—a review

Curcumin (diferuloylmethane) is the most important component of the spice turmeric and is derived from the rhizome of the East Indian plant Curcuma longa. Curcumin has been used extensively in Ayurvedic medicine for centuries, as it is nontoxic and has a variety of therapeutic properties including antioxidant, analgesic, anti-inflammatory, and antiseptic activities. Recently, curcumin has been widely studied for its anticancer properties via its effects on a variety of biological pathways involved in apoptosis, tumor proliferation, chemo- and radiotherapy sensitization, tumor invasion, and metastases. Curcumin can be an effective adjunct in treating solid organ tumors due to its properties of regulating oncogenes like p53, egr-1, c-myc, bcl-XL, etc.; transcription factors like NF-kB, STAT-3, and AP-1; protein kinases like MAPK; and enzymes like COX and LOX. Lung cancer is the most common malignancy worldwide and a leading cause of cancer-related deaths. Seventy-five percent of lung cancer presents at an advanced stage where the existing treatment is not very effective and may result in tremendous patient morbidity. As a result, there is a significant interest in developing adjunctive chemotherapies to augment currently available treatment protocols, which may allow decreased side effects and toxicity without compromising therapeutic efficacy. Curcumin is one such potential candidate, and this review presents an overview of the current in vitro and in vivo studies of curcumin in lung cancer.