Curcumin is a component of turmeric, a spice that is harvested from the rhizomes of the root of a herbaceous perennial plant of the ginger family (Curcuma longa).1 Turmeric has been used for its medicinal properties for thousands of years, and is a commonly used spice in Asian and Indian foods.
Curcumin is purported to have multiple health-promoting effects, such as relieving inflammation, pain, and symptoms of metabolic syndromes. There are also claims that curcumin has anticancer properties.
There are multiple studies that suggest that curcumin has anticancer properties, but the majority of these were conducted in vitro.2,3 These studies suggest that curcumin inhibits cell proliferation and induces cell cycle arrest, apoptosis, and senescence — through various mechanisms, across multiple different types of cancer cell lines. Curcumin has been shown to decrease the expression of multiple different enzymes, transcription factors, inflammatory cytokines, growth factors, and other cell-signaling components that are important for cancer growth and progression.1
For example, a consistent finding across multiple studies of different cancer cell lines is that curcumin downregulates the expression of the transcription factor NF-κB, which is commonly highly expressed by cancer cells and is known to promote the development of cancer, metastasis, and tumor growth.2 In addition, curcumin arrests the cell cycle at the G1/S or G2/M phases by inhibition of different cyclins. Curcumin also induces apoptosis through caspase-dependent pathways, and decreases the expression of antiapoptotic proteins.
Curcumin has been evaluated in animal models of different cancer types.3 These studies have generally shown that curcumin has antiproliferative effects. For example, a mouse model of colorectal cancer (CRC) that was treated by intraperitoneal injection of curcumin or vehicle control demonstrated that curcumin prolonged life and inhibited tumor growth.4 These data also suggest that curcumin upregulated the miRNA miR-130a, which decreased the Wnt/β-catenin pathway and led to prolonged survival.
Studies in animal models of breast cancer demonstrated that curcumin also downregulates NF-κB, reduces metastasis, and inhibits angiogenic signaling resulting in decreased microvessel formation.5 Animal studies of pancreatic cancer have also demonstrated that curcumin inhibits tumor growth, suppresses proliferation, and reduces angiogenesis.6