Can plants grow your meds? U of G researchers think so

Plants have long been used as traditional remedies, but now their many health benefits could be used for major medications such as insulin, cancer treatments and life-saving vaccines.

Even though the Canadian Food Inspection Agency has said, “There is no commercial plant molecular farming in Canada to date, Jennifer Geddes-McAlister, professor in the College of Biological Science at the University of Guelph believes there is no reason plants should not be making drugs right now.

“In theory, it should already be happening,” Geddes-McAlister said in a recent U of G news release. “Because the promise is there. The setup and infrastructure are there. The research is there. The biggest hurdle is reducing variability in drug production.”

Molecular pharming uses plants, rather than animal cells and materials, to produce pharmaceuticals.

U of G researchers have recently confirmed molecular mechanisms that could turn molecular pharming research into industrial and commercial realities. 

According to the university news release, in a recent study published in Plant Biotechnology Journal, researchers investigated a plant-bacteria production system that produces trastuzumab, an antibody used in breast cancer treatment.

Led by Geddes-McAlister and then-PhD student Nicholas Prudhomme, the study found key proteins and metabolites were produced during the process.

This gives manufacturers the molecular insights that could one day see plant-based drugs produced at a full industrial scale.  

According to the release, COVID-19 has exposed the need for vaccines to be produced quickly and at a mass scale. Plants have been identified as a promising way forward, able to shorten production times from months to days. 

Cutting down costly animal media and materials, such as fetal bovine serum, a main ingredient required to grow most cells, or even the chicken eggs used to create the flu vaccine, plant-based production systems are estimated to be only 68 percent of the cost of current production methods. Research labs have been able to produce vaccines for the seasonal flu or COVID-19, or for insulin, cancer treatments, hormones and even cosmetic products. They could even make medicine in space.  

Also, plant-based drugs have appeal for other reasons including religious, diet and lifestyle preferences. 

“The molecular side of research done at U of G gives a foundation to improve molecular pharming,” Geddes-McAlister said.  “This project is quite exciting because it gives some suggestions and highlights as to how to make the production system better and more cost effective, with a higher production of drugs in the end.” 

Geddes-McAlister says this isn’t the same thing as a GMO.  

“It’s not a genetically modified system,” she says. “When you infiltrate the plants with the bacteria, you capitalize on a natural disease that occurs in plants in the wild. You’re facilitating that process, but it’s done through a vacuum.”

Another benefit to the method beyond cost savings and speed is reduced risk of allergens. Because animal cells add modifications to proteins, there can be unwanted immune reactions caused by the final product. There is less risk with the plant N. benthamiana which doesn’t even produce pollen. 

In Geddes-McAlister’s study, the team used innovative technologies associated with proteomics, the study of proteins in a biological system, and metabolomics which is the study of metabolites produced by the plant. 

They’ve found the enzymes that destroy the drugs before they can be harvested. Looking at the proteins and metabolites that appear also tells a story about what’s happening “under the hood” of the plant–bacteria system, so that each step may be improved upon. 

“Proteomics and metabolomics give you new insight into how things are happening,” Geddes-McAlister said. “We wouldn’t have identified those enzymes that degrade the drug without looking at the proteins.” 

Meeting industrial standards would also involve a study across different seasons by looking at the production of the drug, and how its qualities and quantities change over time.

Despite longer-term obstacles needing to be cleared, the day of plant-based drugs on shelves seems like it is “anticipated in the near future.”

“Instead of letting the plant sit for seven days to produce the drug, I’d like to see what happens when we let them sit for three days, and then collect,” Geddes-McAlister said.

 “In theory, this doubles the amount of material and halves the amount of time.”