Therapeutic Potential of Naturally Occurring Lignans as Anticancer Agents

Cancer is a long-term and deadly pandemic that affects nearly a third of the world's population. Chemotherapy is currently the most common therapeutic treatment, but it is difficult to achieve satisfactory efficacy due to drug resistance and adverse effects.Natural products are becoming increasingly popular in cancer therapy due to their potent broad-spectrum anticancer potency and slight side effects. Lignans are complex diphenolic compounds comprising a family of secondary metabolites existing widely in plants. Naturally occurring lignans have the potential to act on cancer cells by a range of mechanisms of action and could inhibit the colony formation, arrest the cell cycle in different phases, induce apoptosis, and suppress migration, providing privileged scaffolds for the discovery of novel anticancer agents. In recent five years, a variety of naturally occurring lignans have been isolated and screened for their in vitro and/or in vivo anticancer efficacy, and some of them exhibited promising potential. This review has systematically summarized the resources, anticancer activity, and mechanisms of action of naturally occurring lignans, covering articles published between January 2017 and January 2022.