Dietary Bioactive Compounds in Cancer Chemoprevention: Targeting Apoptosis, Angiogenesis, and Metastasis

Abstract

Cancer chemoprevention—the use of natural or synthetic agents to prevent, delay or reverse carcinogenesis—has become an attractive complement to treatment, and diet is its most accessible instrument. Epidemiological and preclinical evidence consistently links diets rich in fruits, vegetables, spices and tea with reduced cancer risk, an effect attributed to their bioactive constituents: polyphenols, flavonoids, carotenoids, isothiocyanates and organosulfur compounds. This review examines how dietary bioactive compounds—curcumin, epigallocatechin gallate (EGCG), resveratrol, sulforaphane, quercetin, genistein, lycopene and anthocyanins—exert chemopreventive activity by targeting three interconnected hallmarks of malignancy: apoptosis, angiogenesis and metastasis. Acting across the initiation, promotion and progression stages of carcinogenesis, these compounds restore apoptotic competence (up-regulating pro-apoptotic Bax and caspases, down-regulating anti-apoptotic Bcl-2, and reactivating p53), suppress tumour angiogenesis (reducing VEGF and HIF-1α and microvessel density), and blunt metastasis (inhibiting matrix metalloproteinases MMP-2/9 and the epithelial–mesenchymal transition). Their defining feature is multi-target, pleiotropic action: a single dietary molecule typically engages all three processes, matching the multifactorial nature of cancer.
Compiled data indicate 40–60% reductions in key angiogenic and metastatic markers in preclinical models, and several compounds—curcumin, EGCG, lycopene and folate among them—have advanced to clinical chemoprevention trials, albeit with variable results. The principal limitation, poor oral bioavailability, is increasingly addressed by nanoformulation. The review concludes that dietary bioactive compounds are rational, mechanistically grounded chemopreventive agents whose translation depends on standardisation, improved delivery and rigorous trials in defined high-risk populations.