Program Item Details
TITLE: Dr. Kevin Smith, Assistant Professor in Chemistry and Biochemistry, University of Lethbridge
SUBJECT: #85 Stressing Plants to Produce Medicinal Compounds
SYNOPSIS: Today, the potential for developing new pharmaceuticals from plants seems endless. But 25 years ago, researchers couldn't seem to validate the medicinal qualities native cultures claimed for plants used in traditional healing. Dr. Kevin Smith, a phytochemist at the University of Lethbridge, believes he's found the method required to coax the medicinal compounds out of plants. And it involves stress!
AUDIO: Download Audio (mp3 format)
TRANSCRIPT:
Intro: It’s easy to tease Dr. Kevin Smith that he tortures plants. The growth chambers in his lab at the University of Lethbridge are designed to create stressful conditions for the echinechae and sage that he’s studying. What he’s interested in is producing the special compounds that give these plants their medicinal qualities.
Dr. Kevin Smith
KS: We essentially try to turn on the defense pathways within plants which are within nature turned on due to either pathogen attack or due to heavy metal situations where there’s high concentrations of heavy metals. So in the lab to simulate this, we either spray these plants with solutions of heavy metals and they believe they are under some form of attack and they produce these compounds to try to defend themselves. Or we actually treat them with pathogens. We culture and grow microbial pathogens that kill plants. And we treat the plants with those and see what kind of response we get.
CC: WHAT ARE THESE COMPOUNDS?
KS: The compounds have various structures. They go across all the different natural product pathways. Different plants produce different compounds. The one thing they have in common is they play a role in defense.
CC: WHAT PLANTS ARE YOU DEALING WITH?
KS: We’ve looked at a number of different plant species. A lot of them are plants that have been utilized in traditional medicine practices, either in other parts of the world or even in North America within the native population. We deal with three different species of echninea, a number of plants within the sage family. We‘ve recently started working with some plants that are strictly Chinese medicine-type plants to see what we can observe within those plants.
CC: IS THIS SOMETHING YOU’VE STARTED LOOKING AT FROM AN AGRICULTURE POINT OF VIEW AND IT’S KIND OF MOVED INTO THE MEDICINE SIDE OF THINGS?
KS: Yes, when we initiated this work, this was work we were focusing on, determining how plants were protecting themselves, so we could consider increasing harvestable yields and quality. And from that, it’s become a quest to look for these compounds as they might act as anti-microbial compounds in medicine and more recently, as anti-cancer and anti-inflammatory compounds.
CC: WHAT HAVE YOU FOUND OUT SO FAR?
KS: We have been able to show that by stressing these plants we can produce anti-microbial activity in a significant number of the plants. It’s not always difficult to isolate these compounds and identify them because they are produced in very small quantities.
It’s only been more recently that we’ve now started to take a look at these same extracts from plants and look at them in other biological systems, such as in cancer tissues. So far the anti-microbial work has gone well and we expect the anti-cancer work will go well. But that’s still in the early stages.
CC: WHAT IS GOING TO HAPPEN WITH THIS ANTI-CANCER WORK? YOU JUST SHOWED ME A NEW LAB THAT YOU’RE BUILDING THAT WILL DEAL WITH THIS?
KS: The lab that I was showing you was a lab for us to culture mammalian cells which require which require very sterile conditions to be able to deal with these cultures without contamination.
Our plan is now, if everything works is we’ll be able to isolate compounds and identify them and they will become target compounds for looking either at commercializing or at least as structures to start with in investigating new model compounds that we can use in anti-cancer therapy and anti-inflammatory therapy.
CC: TWENTY YEARS AGO A LOT OF THIS STUFF WAS REALLY POOH-POOHED IN TERMS OF THE HEALTH BENEFITS THAT PLANTS MIGHT HAVE. AND YET NOW, THAT’S EXACTLY WHERE RESEARCH IS BEING DONE AND THE PROMISE FOR NEW MEDICINES AND THAT IS COMING FROM. IT’S BEING LEGITIMIZED IN A SENSE. HOW HAVE YOU SEEN THINGS CHANGE AND WHY DO YOU THINK THIS CHANGE IS COMING ABOUT?
KS: Where we’ve seen it change as far as the public view has been that people are looking for alternatives to western medicines which have complications and which perhaps been used improper ways or to excess.
Where we’ve really looked at for our purposes is why might some of the answers that have come back from research 20 years ago or 25 years ago have come back to show that there isn’t anything to do with medicine? And its our feeling that when scientists have done a lot of these extractions from plants and found the extracts were not active, it’s actually because they’ve taken them into a different environment than those plants actually grow. And the plants don’t grow in a pristine environment where they’re unstressed. They grow out in a competitive environment, and sometimes it’s this competition for life that actually causes the plants to produce compounds that have special features, and features that we might be able to utilize as a medicine.
CC: TO TAKE THIS OUT OF THE LAB THEN AND TURN IT INTO SOMETHING THAT CAN BE COMMERCIALIZED, HOW ARE YOU GOING TO GO ABOUT STRESSING THESE PLANTS ON A LARGESCALE IN ORDER TO GET THE QUANITITEIS OF THE MATERIALS YOU NEED IN ORDER TO MAKE NEW MEDICINES?
KS: I’m not actually sure that at this stage that’s the way things will actually go. I’m not convinced at this point we can do this as an agricultural application. It may be that rather than stressing plants on a large agricultural scale and then isolating compounds or even using these in a more crude form as an alternative medicine, that may not be the best approach.
It may be that by doing the research and finding new target compounds that can be useful as anti-microbial agents or as anti-cancer agents or whatever, it just gives us target compounds that we can go back in and look at new medicines to manufacture. In a similar western way. But at least we understand what these medicines are doing and where they come from. About 50 percent of the medicines that we use have origins in plants. Either they’re produced by plants or a compound of a similar structure was produced in plants and gave us the idea to produce the current compounds.
CC: YOU’RE DEALING WITH JUST A HANDFUL OF PLANTS HERE. HOW BIG COULD THIS FIELD BE?
KS: I think it’s huge. We’ve investigated a lot of plants over the years as natural product chemists to look at the compounds that are constitutent, compounds that are produced all the time in these plants. But we haven’t looked at the compounds that are not normally produced that you actually have to turn them on via stress or some other pathway . So there’s about 250,000 plants that are considered flowering plants. And very few of these have been investigated in this ways. So there’s a lot of possibilities out there.
CC: WHAT’S NEXT?
KS: For us, as we move into the anti-cancer therapy stuff, we need to get the assays down so we can know what we’re seeing and be able to actually validate those activities. After that, as far as choosing plants, everything’s wide open at this point. We’re going to try to focus on plants that are native to Canada and especially western and southern Alberta, at least in the initial stages.
CC: THANK YOU VERY MUCH.
KS: Oh, you’re welcome.
Dr. Kevin Smith is an assistant professor in chemistry and biochemistry at the University of Lethbridge.
FEATURED LINK: Visit the University of Lethbridge website
FEATURED LINK: Homepage for Dr. Kevin Smith