Background: Histone deacetylases (HDACs) are a group of histone modification enzymes with pivotal
role in disease pathogenesis especially in cancer development. Increased activity of certain types of HDACs and
positive effects of HDAC inhibition has been shown in several types of cancers. Furthermore, few HDAC inhibitors
have been approved by the FDA for cancer treatment, and this has generated interest in finding new HDAC
inhibitors as potential anti-cancer agents. Curcumin, a natural polyphenol extracted from turmeric, is a safe and
bioactive phytochemical with a wide range of molecular targets and pharmacological activities including promising
Methods: A systematic literature search using appropriate keywords was made to identify articles reporting the
modulatory effect of curcumin on HDACs in different types of cancer in vitro and in vivo.
Results: HDACs have emerged as novel targets of curcumin that their modulation may contribute to the putative
anti-cancer effects of curcumin. Curcumin inhibits HDAC activity, and down-regulates the expression of HDAC
types 1, 2, 3, 4, 5, 6, 8 and 11 in different cancer cell lines and mice, while the activity and expression of HDAC2
have been reported to be up-regulated by curcumin in COPD and heart failure models.
Conclusion: Available in vitro and in vivo data are encouraging and in favor of the HDAC inhibitory activity of
curcumin but clinical evidence on the efficacy of curcumin as an adjunct treatment in cancer patients is lacking.