Phytochemicals modulate cancer aggressiveness: A review depicting the anticancer efficacy of dietary polyphenols and their combinations

Cancer is referred to as the “Emperor of all maladies” accounting for the second-highest mortality rates worldwide. Major factors associated with cancer lethality are uncontrolled proliferation, metastasis, and frequent recurrence. The conventional therapeutic drugs used in cancer therapy have been associated with numerous damaging side-effects that call for the use of alternative therapeutic options. The natural plant compounds (NPCs) have been found to be effective against diverse groups of diseases including cancer. Among the different types, the polyphenolic phytochemicals like curcumin, (−)epigallocatechin-3-gallate, Resveratrol, and nimbolide which are predominant parts of daily dietary intake have proved their potency in reducing the aggressive properties of cancer. Here, we have highlighted the mechanisms through which these NPCs influence growth, metastatic potential, and the drug-resistant behavior of different cancer types. Moreover, we have also emphasized on their function as modulators of the immune system as well as the metabolic properties of the tumor. The role of these phytochemicals in reducing cancer progression has been highlighted when administered unaided or in combination with similar group of compounds. Moreover, their ability to enhance the drug-sensitivity of cancer cells which accounts for their use in combination with conventional chemotherapeutics has also been discussed in this article. Therefore, co-administration of these phytochemicals with chemically similar group members or with conventional chemotherapeutics may prove to be an effective treatment strategy for cancer.