Ephedra. Artemisia. Yerba santa. Opium poppy.
A lot of well-known drugs start with roots in the ground. The San Diego Botanic Garden in Encinitas is leading an effort to make curative plants even better by exploring their genomes.
The Medicinal Plants Initiative began three years ago by the botanic garden. During that time, their collection of medicinal plants has quadrupled, according to Benjamin Naman, director of medicinal plants research.
He described the initiative as a partnership between plants, scholarship and the pharmaceutical industry.
“Here in San Diego county, we would have everything needed to go from a medicinal plant that’s out in the environment that’s been used by indigenous people for thousands of years,” Naman said. “Study them for chemistry, biology, their genetics, then actually translate those through the pharmaceutical pipeline into botanical drug products or Western medicines.”
There are more than 2,300 medicinal plants in their collection, Naman said. You can see them in a special greenhouse and in their medicinal garden, which is open to the public.
Offering one example, Naman said Native Americans in California used yerba santa for respiratory disorders, like asthma and bronchitis.
“The reason it’s even called yerba santa — that’s a Spanish name — is when the Spanish came they were introduced to this plant by the native people. And they found it was more effective at treating tuberculosis than any drug they had brought from Europe,” he said.
One of the goals of the medicinal plants initiative is to understand plants genetically. That’s where Todd Michael comes in.
He’s a genetic researcher at the Salk Institute and a partner in the project. He said the challenge is identifying genetic pathways that give a plant its curative chemicals.
“So we can say, “Yes! This plant has the genes that make this chemical,’” Michael said. For now, he said that kind of discovery is the object of the plants initiative.
“However, once we know that a specific plant makes something, in the future we can do some hybridization of plants to get new species that either grow well here or grow well in other conditions,” he said.
Another resident of the medical plant greenhouse is one that you will find growing in San Diego County. Ephedra, the source of ephedrine, is a stimulant that’s used for several ailments. Surgeons use it to prevent low blood pressure during anesthesia.
Michael suspects ephedra evolved to create its chemical machinery to prevent animals from eating it. He suggests critters that ate the organic stimulant ended up feeling tense and hyper.
"So now they know, 'Don’t eat that plant, It’ll make you crazy,'" he said.
Other plants, though we may see them as native and wild, have been influenced by the human hand. He said people have been breeding cannabis for at least 10,000 years.
“So we have definitely co-evolved with medicinal plants so that they make things that make us happy, so we continue to grow them,” Michael said.
Naman said he hopes their collection of healing plants will be a resource to scholars across the country who want to explore the subject.
