A Comprehensive Review on the Anticancer Activity of Plant Peptides and Their Mechanisms of Action

Plant-derived peptides have become one of the most promising classes of compounds in cancer research due to their specificity, safety, and different therapeutic actions. Generally, plant peptides have a size of 2 to 100 amino acids, and they can be extracted from different parts of the plant including leaves, seeds, stems, and roots. The present review brings together more than 300 prominent plant peptides, their sources, structural classes, extraction methods, anticancer effects, and mechanisms of action. We show the cytotoxicity of plant peptides against a wide range of human cancer cell lines (such as MCF-7, A549, HL-60, and HCT-116), as well as their effectiveness in preclinical animal models of cancer, where they resulted in lesser tumor growth and metastasis. Moreover, we go into the anticancer activity of plant peptides and reveal the interconnectedness of apoptosis, cell cycle arrest, angiogenesis inhibition, metastasis suppression, and the modulation of signaling pathways as some of the mechanisms through which plant peptides perform. In addition to their therapeutic potential, many of these peptides are derived from edible plant sources and can be delivered through functional foods or dietary supplements, offering a promising avenue for cancer prevention and adjunctive nutritional support. The review also touches upon the major hurdles in peptide drug development at present, such as stability, oral bioavailability, and large-scale production, while at the same time giving future perspectives that include bioengineering, nanotechnology-based delivery systems, and combination therapies for translating these natural products into clinical oncotherapeutics and health-promoting foods.