Potential of Green-Synthesized Silver Nanoparticles from Herbal Plants as Anticancer Therapy: A Systematic Review of Anticancer Effectiveness

Cancer is a leading cause of mortality worldwide due to uncontrolled proliferation, resistance to apoptosis, and metastasis. Chemotherapy and radiotherapy have improved survival, but the effectiveness is limited by toxicity and drug resistance. This condition has prompted the exploration of herbal medicines and nanotechnology-based alternatives. Green-synthesized silver nanoparticles (AgNPs), produced using phytochemical-rich plant extracts, are promising anticancer agents because of the eco-friendly synthesis, biocompatibility, and multitargeted effects. Therefore, this systematic review, following PRISMA 2020 guidelines, analyzed 26 in vitro studies published between 2015 and 2025 from PubMed, ScienceDirect, Taylor & Francis, Hindawi, and ProQuest. Evidence consistently showed selective cytotoxicity of green-synthesized AgNPs against cancer cells while sparing normal cells. Reported mechanisms included apoptosis induction through mitochondrial pathways, reactive oxygen species generation, cell cycle arrest, DNA damage, and inhibition of angiogenesis and metastasis. Smaller nanoparticles had higher potency, signifying the role of size and surface chemistry in therapeutic performance. In conclusion, green-synthesized AgNPs show considerable potential as novel anticancer nanomedicines. However, most evidence is limited to in vitro studies, with significant heterogeneity in synthesis methods. Standardized protocols, in vivo validation, and clinical examinations are required before clinical translation can be achieved.