Phytoconstituents as Potential Anticancer Agents: Mechanisms, Evidence, and Therapeutic Prospects

Abstract

Cancer remains a major global health challenge despite advances in diagnosis and treatment. Conventional therapies such as chemotherapy and radiotherapy are often limited by systemic toxicity, resistance development, and damage to healthy tissues. Phytoconstituents, bioactive secondary metabolites derived from medicinal plants, have gained considerable attention as potential anticancer agents due to their multi-targeted mechanisms, relative safety, and chemopreventive properties. This study reviews the classification, molecular mechanisms, experimental evidence, clinical relevance, advantages, and limitations of phytoconstituents in cancer therapy. Evidence from in vitro, in vivo, and clinical studies indicates that compounds such as curcumin, resveratrol, epigallocatechin gallate (EGCG), genistein, sulforaphane, silymarin, vincristine, vinblastine, and paclitaxel modulate key signaling pathways including NF-κB, PI3K/Akt, MAPK, p53, VEGF, and STAT3. These compounds exert anticancer effects through apoptosis induction, cell cycle arrest, inhibition of angiogenesis, suppression of metastasis, epigenetic modulation, and targeting of cancer stem cells. Although limitations such as poor bioavailability and insufficient large-scale clinical validation persist, advancements in nanotechnology and targeted drug delivery systems offer promising solutions. Phytoconstituents represent a valuable bridge between traditional medicine and modern oncology and may contribute significantly to future cancer prevention and therapy strategies.