The 2005 LPI Prize for Health Research was awarded on May 18, 2005, at the 3rd Diet and Optimum Health Conference to Paul Talalay, M.D., who is the John Jacob Abel Distinguished Service Professor of Pharmacology and Molecular Sciences at Johns Hopkins University in Baltimore, Maryland. Born and raised in England, Dr. Talalay earned a B.S. in Biophysics from MIT and an M.D. from Yale. He worked at the University of Chicago with Nobel Laureate Dr. Charles Huggins before joining Johns Hopkins in 1963. Dr. Talalay was elected to the National Academy of Sciences in 1987 and serves as Associate Editor of Cancer Research. He has published over 200 scientific papers.
As the Director of the Department of Pharmacology and Experimental Therapeutics at Johns Hopkins from 1963 to 1974, Dr. Talalay was instrumental in developing its world-renowned reputation. Stimulated by Huggins's work on hormone-responsive tumors, Dr. Talalay worked initially on steroid metabolism and found that one steroid-metabolizing enzyme on which he had been working was glutathione transferase, which helps protect the body from carcinogens and oxidant damage. In the late 1970s, Dr. Talalay demonstrated that the anticancer effect of the antioxidant food additives BHA and BHT was due to their induction of phase 2 enzymes in the liver that block carcinogenesis. This led to the search for naturally occurring inducers of phase 2 enzymes.
In a 1992 paper, Dr. Talalay reported that a phytochemical called sulforaphane, which is an isothiocyanate especially abundant in the cruciferous vegetable broccoli, is a potent inducer of phase 2 enzymes in cultured cells and mice. Sulforaphane and other isothiocyanates have also been found to inhibit chemically-induced carcinogenesis in animals. Sulforaphane induces enzymes, including quinone reductase and the antioxidant glutathione S-transferase, that can detoxify carcinogens and prevent toxic electrophiles from damaging DNA. Dr. Talalay developed a novel quantitative assay to screen for natural inducers of quinone reductase, which was published in the Proceedings of the National Academy of Sciences USA in 1992 and has been widely applied. In fact, this assay was used to identify sulforaphane as a putative anticancer phytochemical. Additionally, Dr. Talalay showed for the first time how many inducers of phase 2 enzymes also induce endogenous antioxidant defenses. Dr. Talalay found that the amount of sulforaphane in broccoli is quite variable, which led him to focus on broccoli sprouts as a reproducibly high source.
Several nomination letters noted a parallel between Dr. Talalay's research and that of Linus Pauling, both of whom "spent early years in basic molecular studies and later brought the rigor and insight from this experience to bear on larger problems of health and nutrition." Dr. Talalay was saluted for his pragmatic research strategies, the practical application of his work to public health, and for helping us to understand what phytochemicals may be partly responsible for the cancer chemoprotection afforded by a regular intake of vegetables, as demonstrated by epidemiological studies, and how these substances work. Nominators also cited Dr. Talalay's devotion to young scientists and sustained mentorship. Dr. Talalay continues to work on the complicated molecular mechanisms involved in cancer chemoprotection by sulforaphane and related substances and has recently reported the antibiotic effect of sulforaphane against H. pylori, the bacterium associated with gastric ulcers and cancer.