Turmeric has gained immense popularity over the years not just for the unique flavor it adds to dishes like curries, but also for its various health benefits. One of its most promising therapeutic applications is as a natural remedy for cancer. Although the anticancer potential of turmeric isn't new, a recent study published in Cancer Letters further proved the importance of this golden spice in understanding and treating cancer.
The team of American researchers evaluated the ability of curcumin, which is a polyphenol in turmeric, to target cancer stem cells that are assumed to be the primary cause of cancer tumor formation and malignancy. Unlike conventional cancer models used in previous studies, the cancer stem cell model suggests that only a small population of cancer cells drive the initiation, maintenance, and growth of tumors. These stem cells regularly undergo renewal and differentiation into other cancer cells, which no longer have the ability to regenerate themselves. Therefore, in this model, cancer stem cells that are not killed by treatments lead to the formation of more invasive and treatment-resistant tumors.
In this study, the researchers found that curcumin is more effective in eradicating cancer since unlike conventional treatments, this polyphenol also targets cancer stem cells. It can do so through various mechanisms of action, which include the following.
Regulation of cancer stem cell self-renewal pathway -- There are different pathways involved in the self-renewal of cancer stem cells. These include the Wnt/beta-catenin, sonic hedgehog 89 (SHH), and Notch pathways. The researchers found that curcumin can directly or indirectly interfere with these pathways in 12 different cancer cell lines
Modulation of microRNA -- The body contains microRNAs, which are short RNA sequences that don't encode for anything. These microRNAs regulate more than 33 percent of protein-coding genes by targeting and binding to their corresponding messenger RNAs so that these won't be expressed. In this study, the authors observed that curcumin altered microRNA expression in cancer stem cells so that they can't produce everything that they need for tumor formation and growth.
Direct anti-cancer activity -- Curcumin selectively targets cancer cells and programs their death. When used in conjunction with conventional anticancer agents, this effect becomes more evident and the damage typically caused by chemotherapy is no longer observed.