Hope at the Root of the Walnut Tree—Investigating Potential Cancer-Fighting Medicines

By Armaan Singh

Imagine if the cure to devastating diseases like cancer, the second leading cause of death in the United States, was right under our noses. Leaves, bark, and the roots of many trees and plants contain life-saving medicines that have yet to be discovered. From 1960-1981, more than 30,00 plant samples were screened by the National Cancer Institute. Botanists were hired to collect plants from across the United States because scientists suspected that the natural world contained cancer-fighting compounds. For example, Taxol-derived from the bark of the Pacific Yew tree was discovered by Monroe E. Wall and Mansukh C. Wani at the Research Triangle Institute in North Carolina, in 1971 and since then has been used as a chemotherapy drug. From that momentous discovery, several others have been made from plants and trees. In nature, plants produce anti-fungal chemicals that are toxic to fungi and serve as a mechanism to defend themselves from attacks by micro-organisms. Human cells are similar to fungal cells. Interestingly, chemical compounds that are intended for plant defense also have an inhibitory effect on human cells—and this includes cancer cells. Currently, human trials for the treatment of prostate cancer are being conducted to investigate the efficacy of Plumbagin that is derived from the walnut tree. Diseases that have taken scientists and researchers decades to cure could potentially have a promising treatment from the roots of a walnut tree. Plumbagin is a naphthoquinone derivative of the Plumbago zeylanica which is an herbaceous plant with smooth stems and broad rounded leaves. These plants often grow in sub-tropical areas in the understory of monsoon forests. Plumbagin is also found in genera dosera which is one of the largest species of carnivorous plants that grows in wet habitats. It is also a component of black walnut drupes. Black walnut trees grow widely in the United States. Plumbagin often takes the appearance of a ye