Preclinical Risk Assessment of Plant Lectins with Pharmacological Applications: A Narrative Review

Plants have been used for medicinal purposes both intuitively and based on traditional knowledge for centuries. Recently, however, there has been a significant increase in research focused on medicinal plants to meet the growing demands of the pharmaceutical industry. As a result, it has become essential to evaluate the safety of natural products for human use. This review examines in vitro and in vivo toxicity studies of lectins, a class of plant proteins with pharmacological applications. The reviewed data indicate that many of these proteins do not appear to be toxic to human and animal cells, nor when administered to rodents through oral, intraperitoneal, or intravenous routes. However, some lectins have shown toxicity under certain conditions, such as depending on the administration route, dose, and treatment duration. These adverse effects may include behavioral changes, antinutritional effects, hepatotoxicity, nephrotoxicity, pancreatic hypertrophy, allergic reactions, and even death. Therefore, it is crucial to prioritize toxicological studies to ensure the safety of these plant proteins as potential drug candidates in the future.