Green Synthesized Herbal Nanoparticles in Cancer Therapy: Emerging Trends, Current Challenges, and Future Perspectives

Abstract

Cancer is a major global health challenge, and conventional treatments such as chemotherapy,
radiotherapy, and surgery often face limitations including poor selectivity, severe side effects, and
drug resistance. Green-synthesized herbal nanoparticles have emerged as a promising alternative
because they combine the therapeutic potential of nanotechnology with the biocompatibility of plant-
derived compounds. These nanoparticles are produced using herbal extracts that act as natural
reducing and stabilizing agents, making synthesis more sustainable, cost-effective, and
environmentally friendly. Compared with chemically synthesized nanocarriers, herbal nanoparticles
may offer lower toxicity, improved surface functionality, and added antioxidant, anti-inflammatory,
and anticancer properties. The review explains how reaction conditions such as pH, temperature,
extract concentration, and reaction time influence nanoparticle size, shape, stability, and biological
activity. Mechanistically, green-synthesized nanoparticles exert anticancer effects through cellular
uptake, reactive oxygen species generation, mitochondrial dysfunction, DNA damage, cell cycle
arrest, apoptosis activation, and inhibition of metastasis and angiogenesis. The review further
discusses emerging trends such as active targeting, theranostics, combination therapy, and tumor
microenvironment modulation. However, clinical translation is limited by batch variability, scalability
issues, long-term safety concerns, and regulatory challenges. Future progress will likely depend on
standardized synthesis, improved in vivo studies, and the integration of artificial intelligence and
personalized medicine to develop reproducible and clinically useful nanoplatforms for cancer therapy.