Synthesis and Structure–Activity Relationship Analysis of the Natural Flavone Acacetin as a Promising Anticancer Agent

Abstract

Flavonoids are diverse group of phytochemicals that are found in fruits, vegetables, and medicinal plants and exhibit wide range of pharmacological activities, including antioxidant, anti-inflammatory, antiviral, cardioprotective, neuroprotective, and anticancer activities. Among the subclasses of flavonoids, flavones have gained a lot of attention because of their therapeutic potential in solving problems associated with oxidative stress. A 2-phenylchromen-4-one skeleton structurally defines these compounds, and representative flavones such as apigenin and acacetin exhibit significant biological actions that can be attributed to their specific hydroxyl and methoxy substitution patterns. Acacetin (5,7-dihydroxy-4'-methoxyflavone) is naturally occurring flavone which may be isolated from such species as Turnera diffusa, Saussurea involucrata, and Robinia pseudoacacia. The compound exhibits unique physicochemical properties and high lipophilicity, which enable it to exert powerful anticancer action on various human cancer cell lines through the induction of apoptosis and cell cycle arrest. Mechanistic studies have shown that acacetin regulates both mitochondrial (intrinsic) and death receptor (extrinsic) apoptotic pathways, as well as p53-mediated signaling, which inhibit the proliferation, migration, angiogenesis, and metastasis of the cells. Structure-activity relationship studies have established the importance of a free hydroxyl group on the A-ring and a methoxy group on the B-ring for the maintenance of the cytotoxicity of acacetin. Alterations to these functional groups frequently result in diminished biological activity, underscoring the importance of maintaining the native substitution pattern for optimal therapeutic potential. Future research should focus on elucidating the detailed molecular interactions of acacetin with its cellular targets, characterizing its metabolic profile, and developing clinically viable derivatives.