Horseradish Enzyme Could Help Make Anti-Cancer DrugsBy
An enzyme in horseradish could make it easier to produce life-saving
anti-cancer drugs, preliminary research suggests.
Service scientists devised a method that uses the enzyme
horseradish peroxidase in making cancer drugs known as chlorins.
Currently, chlorins are made in a costly multi-step process. The new
one-step method could save time and money.
ARS plant biochemist Franck Dayan made chlorins by combining the
horseradish enzyme and a chemical cousin of chlorophyll. Plants use
chlorophyll to turn light energy into food. But scientists doing
research studies frequently turn to chlorophylls cheap,
easier-to-use synthetic cousin, deuteroporphyrin IX. All plants use a
form of peroxidase to make cell walls, but the horseradish version is
extremely easy to extract.
Dayan is based at ARS
Products Utilization Research Unit in Oxford, Miss. He and ARS
colleagues work to find potential new medical, food and industrial
uses for chemicals naturally present in plants and other organisms.
Dayan came up with the new chlorin-making method--combining
peroxidase and deuteroporphyrin IX--partly from a suggestion by
medical researcher Nick Jacobs. Jacobs, with
School, initially recognized that deuteroporphyrin reacted with
horseradish peroxidase and wondered aloud whether the tactic would
of Mississippi School of Pharmacy will test human cell cultures
to ensure chlorins made this way are still effective photodynamic
Photodynamic compounds kill tumors when exposed to red light from
tiny lasers. First, the drug is injected and carried through the body
by blood proteins. Because cancer cells grow 10 times faster than
healthy cells, they take in much more of the drug than healthy cells.
After a few days, a physician shines a red laser light on the tumor.
Nearby healthy cells-- transparent to the red light--are unaffected.
But the chlorin molecules in the tumor cells are energized by red
light and produce free radical oxygen molecules that destroy them.
Scientific contact: Franck E. Dayan, ARS
Products Utilization Research Unit, Oxford, Miss., phone (601)
232-1036, fax (601) 232-1035, firstname.lastname@example.org.