Engineering Podophyllotoxin Biosynthesis in Different Plant Systems

Abstract: Podophyllotoxin (PDXn) is a naturally occurring aryl tetralin lactone lignan extensively recognized as a natural precursor for synthesizing important chemotherapeutic drugs such as etoposide, teniposide, and etopophos. These derivatives are valuable in treating various cancers, enhancing the compound's global pharmaceutical significance. Podophyllotoxin is predominantly isolated from endangered plant species of the genus Podophyllum, leading to critical endangerment due to unsustainable harvesting practices for industrial purposes. Its complex molecular structure, low extraction yields, and high production costs make chemical synthesis economically impractical, highlighting the urgent need to identify alternative and sustainable natural sources. This review focuses on methods that overcome the limitations of traditional extraction, including plant cell cultures, hairy root transformation, and media optimization. The application of immobilization, elicitation, and various scale-up methodologies to enhance PDXn production is critically evaluated. Additionally, the review emphasizes the significance of metabolic engineering strategies involving key genes and enzymes to manipulate and enhance biosynthetic pathway flux, facilitating improved yields across diverse host systems. Furthermore, the review discusses process bottlenecks encountered during the biotechnological production of podophyllotoxin and outlines future directions and recommendations necessary for achieving viable commercial-scale production. The paper aims to review recent (2015–2025) achievements in P. hexandrum research to synthesize data on podophyllotoxin's historical development, mechanisms of action, cell culture approaches and limitations, metabolic engineering pathways, and the importance of podophyllotoxin and its derivatives as antitumor drugs and their delivery systems. By highlighting these advancements and challenges, the review contributes to the development of sustainable, economically feasible, and environmentally friendly strategies for large-scale podophyllotoxin production.