Comprehensive review of medicinal plants as green corrosion inhibitors and their role in safeguarding cultural heritage

Metal corrosion is a persistent global challenge, leading to substantial economic losses and safety concerns. In recent years, plant-based extracts containing bioactive compounds such as flavonoids, phenols, and alkaloids have gained attention as effective and environmentally friendly corrosion inhibitors. This review explored the growing interest in green inhibitors derived from natural sources, focusing on their inhibition performance, sustainability, and compatibility with different metallic systems. The review focused on key factors influencing their efficiency, including molecular structure, adsorption behavior, and environmental conditions. It also highlighted applications in protecting cultural heritage materials and the use of medicinal plant extracts as corrosion inhibitors. Additionally, relevant case studies are presented to demonstrate their practical applicability. In addition, commonly used evaluation techniques such as weight loss analysis, electrochemical methods, and surface characterization tools are summarized. The review discussed significant advancements reported over the past decade and highlights existing challenges, including variability in extract composition and stability issues, while outlining future prospects for the large-scale application of plant-derived corrosion inhibitors.