Targeting Proteasome by Phenolic Compounds in Cancers

Nowadays, chemoprevention is considered as a promising approach for preventing premalignancy before transformation into invasive cancer. The development of drug is one of the biggest obstacles for prevention of cancer. The 26S proteasome is a proteolytic enzyme complex responsible for intracellular protein degradation especially in playing an important role for tumor growth. Phenolic compounds have multiple intracellular targets, one of which is the proteasome complex. Little attention has been devoted to studying the roles of natural antioxidants in the ubiquitin-proteasome pathway. The natural antioxidant polyphenolic compounds, methyl gallate, gallic acid, ellagic acid, and tannic acid from daily food, are known to inhibit certain carcinogen-induced cancers and effect on proteasome. In this review, the properties of polyphenolic compounds may provide cancer chemoprevention.