An inteview with David Kinder. His Role: The professor of medical chemistry at Ohio Northern University helps discover new drugs.
1. What is it you do exactly?
I teach drug design in the college of pharmacy at Ohio Northern University. Iím a professor of medicinal chemistry. Basically, what we do in drug design is we do drug discovery guided by ethnobotany. We go out and look for plants that have activity against cancer. We test the compounds in the plant against cancer cell lines to see if there is any anti-cancer activity.
2. What is ethnobotany?
Ethnobotany is the study of native populations of people who live in an area who have used the plant materials for a specific reason. Someone has usually written that down somewhere. In my case, the plants were used by the Hopi Indians to treat cancer growths in the throat.
3. How long have you been testing plants for cancer activity and how often do you do fieldwork?
I took a sabbatical in 2004. The plant Iíve been working with primarily grows and blooms in the spring, and for that area, spring is in May. So, in the past eight years, Iíve been going out there every spring. I go yearly. You can only collect so much plant material at a time because it does not grow abundantly. Itís not endangered, but itís not plentiful either.
4. What plant are you working with?
Itís called the Cryptantha flava or the yellow hidden flower. Out in the West, the dust blows across the mesas, and because the dust and winds are pretty consistent, that dust builds up into lumps of soil. This plant likes to grow in those lumps. The soil is not very fertile though, so only 10 to 15 plants may grow in a 1- to 3-acre area.
5. Where do you go primarily to find these plants?
Iím doing my work primarily in two national parks ó Chaco Culture National Historical Park and Mesa Verde National Park. Those are in Colorado and New Mexico. Iím focused on the desert areas. I love hiking in the desert, but you have to be careful.
6. Can you tell me what your fieldwork is like when you are collecting the plants?
It takes me three to four days to find enough to have enough plant material to be useful in the laboratory. As a general rule, I only collect about 10 percent of whatís growing. Usually, there will be maybe 15 to 20 plants in an area, so that means I only take a few plants at a time from each area.
7. How do you test the plants once you are back at the laboratory?
For anti-cancer activity, we maintain cancer cell lines. These are live cells that were taken from the tumor of a patient, years ago. Someone was able to get the cells to grow outside of the body. We grow the cells in a cell culture called a culture media. We add compounds of the extract of the plant to that media to see what kind of activity we get. We add different compounds in differing amounts to different cultures, and if any of the cell cultures stop growing, that means there is anti-cancer activity.
8. Whatís the biggest challenge in this type of work?
Identifying the plants in the first place is the easy part. The real challenge is to figure out whatís in the plant that has the activity. The extract of a plant can have 200, maybe more, compounds. There are probably only one to two of those compounds that have the anti-cancer activity. So, we are trying to sort out which ones have the activity. Weíve been testing this plant for four years now, and we only have a fraction of the compounds tested. Complicating this, we just discovered this summer that two to three of the compounds have to work together for it to have the anti-cancer activity.
9. What is the process from taking those plant extract compounds to an actual drug people can use?
Wow ó well, thatís a long process. First, you have to show there is activity. The second step is to identify what compounds in the extract are giving that activity. Then a couple things happen. Usually, there is animal study. At that point, the compound could not work on an animal, but if it does, then someone does some pretesting, which means they figure out how the animalís body is using the compound. They look at if it is causing damage and if the activity is useful. In terms of getting a drug to use in a clinical study ó you have to approach the [Food and Drug Administration] to get an investigational new drug application which we call an IND. Presuming the FDA grants the IND, then they move on to testing it on people. This is the clinical trial stage. There are several levels of study, such as does it work and how well does it work and how useful is it to the general population. They then go back to the FDA with that information. The FDA goes over the information and then, if they OK it, it is then available in drug form. It often takes 10 years or more to develop a drug.