A novel research project led by Dr. Susan Mooberry is exploring this question, and early test results indicate that it’s certainly possible.
Dr. Mooberry directs a cancer drug discovery program at the Southwest Foundation for Biomedical Research in San Antonio, where she studies numerous types of plant and marine life in the search for new compounds to provide more effective, less toxic ways to fight cancer.
Over the past few years, she has found promising results with compounds derived from such exotic sources as the tropical Bat Flower plant and a marine sponge known as the chocolate sponge or mushroom sponge.
Now she has set her sights on plants that thrive in Texas, thinking that the same chemical properties that give Texas plants their hardiness might also be useful in fighting cancer. “We’re looking at things that are tough, plants that are drought resistant, deer resistant, resistant to mildew and other fungi,” Dr. Mooberry said. “These are some hints we’re taking from nature. For example, why don’t deer eat certain plants? Well, they probably taste bad. Why do they taste bad? It must be something in their chemistry. Maybe something about that chemistry could be useful in fighting cancer, and that is what we’re trying to find out.”
So far, lab results show that her hunch is a good one. “We have evaluated 300 extracts thus far, and 11 percent of them were highly active against cancer cells,” said Dr. Mooberry. “This is the highest ‘hit’ rate that we have ever seen in plant extracts, suggesting that the plants of Texas might be an excellent source for new antitumor agents.”
Donor support, local collaborations enable novel research
This novel research began two summers ago, after Dr. Mooberry’s laboratory received a pilot study grant from the Southwest Foundation Forum, which works to raise funds for and public awareness of the research done at SFBR. Since that time, partial funding for the project’s continuation have been awarded by the Amon G. Carter Foundation, the W.B. and E.G. Stuart Trust, The William Randolph Hearst Foundation the and the Joe and Jesse Crump Foundation. The Helen Freeborn Kerr Foundation and the Shelby Rae Tengg Foundation also provided funding for equipment that facilitates this and other cancer drug discovery efforts in Dr. Mooberry’s laboratory.
With this enabling support, Dr. Mooberry and fellow researcher Evelyn Jackson set about the task of collecting approximately 100 plant samples during the summer of 2004, mostly from their own backyards, including Texas sage, American beauty berry, Turk’s cap, Salvia gregii, and Nandina.
Then in 2005, Dr. Mooberry began a new collaboration with the San Antonio Botanical Garden, a facility of the San Antonio Parks and Recreation Department, giving her access to an additional 200 specimens.
“With its extensive collection of Texas plants, including its new native plant trail, the Botanical Garden offers an ideal site for collecting samples,” Dr. Mooberry said. “This has been a fabulous collaboration.”
Dr. Mooberry explained the importance of having direct access to a large variety of plants, which allows her to collect fresh samples. “We do things a little bit differently from others in the plant community in that we use our material fresh,” she said. “In the field, we actually put it in a cooler to keep it fresh and out of the sun. As soon as we bring it back to the laboratory, it’s immediately frozen. We are retaining the chemical diversity by freeze-drying, whereas, sometimes if you dry things [conventionally], that diversity can be lost.”
Lauren Clark, a botany student from the University of Texas at Austin, and Mildred Abodakpi, a student from St. Mary’s University in San Antonio, have come on board during their summer breaks to assist with plant collection and identification of voucher specimens.
Mooberry and Jackson have then used a high-tech device called a “super-critical fluid extractor” to pull three different types of extracts from each plant sample.
“With these different kinds of extracts, we try to maximize the chemistry that we extract out of the plants,” Dr. Mooberry said. “We’re running various assays that can predict potential anti-cancer activity. So even though we might be looking at some plants that other groups have previously studied, our methods combining the use of fresh material and our specific biological assays provide the opportunity for some new findings.”