The timer starts. Cassandra Quave has exactly two minutes and one PowerPoint slide to explain her work as a medical ethnobotanist at Emory University, a feat that took 12 hours to accomplish in the audio version of her memoir, The Plant Hunter. It’s the Thursday before Labor Day—the evening launch of the joyful controlled chaos of Dragon Con 2023. Science Track devotees fill the seats of a small conference room in the Hyatt Regency.
This track puts the “science” in sci-fi. Cosplayers are scattered throughout the audience, wearing capes, hats, and gowns. One woman is clad in very realistic garb of Fremen from the desert planet in Dune.
Quave begins her “lightning talk” at a fast clip; as both a professor and a podcast host, she knows how to squeeze information into short time slots. “So, in my lab, we look for new molecules from nature. We are drug hunters. ‘Plant hunters’ has a better ring to it, but really, we’re looking for new medicines,” Quave says.
She recounts how she trekked in the Balkans, Southern Italy, the Sahara, and the Amazon, collecting wild plants and turning their leaves and roots into extracts, “kind of like how you make your coffee every morning.” To up the drama, she mentions that she nicknamed her lab freezer Atropos, “after the Greek Fate that cuts the thread of life—because I have thousands of things in there that will absolutely kill you.”
Quave, 45, associate professor of dermatology at Emory University School of Medicine, researches plants that have been used by traditional healers and are known to have therapeutic properties. More than 34,000 medicinal plants have been used throughout history, and each contains thousands of different molecules. Her lab works to identify which molecules—or combinations of molecules—provide the benefit.
Also, plants aren’t just tools for healing. Quave targets their potency at preventing infections—by targeting the bacteria, viruses, and fungi that have plagued humankind for millennia and are becoming resistant to modern drug therapies.
It’s a daunting task, but Quave and her team have made impressive finds. They’ve identified extracts from tall goldenrod and eagle fern that block the infectivity of SARS-CoV-2, the virus that causes Covid. They’ve found compounds from the Brazilian peppertree, the American beautyberry, and the European chestnut that inhibit the spread of drug-resistant bacteria. Working in collaboration with a lab at the University of Toronto, Quave recently reported antifungal activity of Brazilian peppertree compounds against the multidrug-resistant Candida genus, the most common culprit in human fungal infections. She cofounded two biotech start-ups, PhytoTEK and Verdant Scientific, to develop antibacterial products from her discoveries.
Quave is aware that most people think of plants as the source of a different sort of drug—cannabis, hallucinogenic mushrooms, or opium poppies, to name a few. Meanwhile, scientists often discount healing techniques of Indigenous peoples or the potential for plant-based medical breakthroughs, even though they are the origin of many common medicines. For example, willow bark was used as a pain remedy by ancient Egyptians. Salicin, its active ingredient, is the foundation for acetylsalicylic acid, commonly known as aspirin.
Quave began educating the public about her field in 2011 with lectures and videos on a YouTube channel called TeachEthnobotany, and in 2019, she launched a podcast on the cultural and scientific value of plants, called Foodie Pharmacology. She also posts a biweekly newsletter on Substack called Nature’s Pharmacy, which describes the science behind medicinal plants.
When Covid hit and she heard that some people were promoting oleandrin and cinchona bark as treatments—which can actually be toxic—she saw a greater need to lend her expertise through articles and media interviews. In 2022, the National Academies of Sciences, Engineering, and Medicine recognized her work with an Eric and Wendy Schmidt Award for Excellence in Science Communication.
Quave has advocated for more federal funding to combat antimicrobial resistance, which the Centers for Disease Control and Prevention calls “an urgent global public health threat.” It’s a mission that doesn’t get enough public attention, says Wes Kim, director of global public health programs for the American Society for Microbiology. “She’s doing double duty in terms of being a scientist and bringing awareness,” he says. “As a professor, she’s training the next generation of drug discoverers.”
Her passion for plants extends beyond the lab and the field. For Quave, this issue is deeply personal. She was born with abnormalities in her lower right leg. In hopes of providing better mobility, doctors amputated her leg below the knee when she turned three. But a Staphylococcus aureus infection took hold after the surgery. Quick action—antibiotics and another surgery to cut away damaged tissue—saved her life. Since then, S. aureus strains have emerged worldwide that are resistant to almost all antibiotics.
Quave has endured many other surgeries and infections and learned to live with pain, but her disability hasn’t hindered her. She grew up playing in the piney woods of Arcadia, Florida, and she became intrigued with plant-based remedies during a college summer at an Amazonian research camp in Peru, where she worked under the tutelage of a traditional healer. Prosthetics enable her to trek up mountain trails and through swamps, often with students in tow.
She tends a lush garden at her home in Decatur, where she lives with her husband and their four tween- and teenaged children. She grows medicinal specimens along with vegetables, berries, herbs, and wildflowers. She also curates the Emory University Herbarium, a collection of about 24,000 preserved plant specimens from Georgia and around the world, and teaches in Emory’s Center for the Study of Human Health.
Quave was preparing for a book tour in 2021 when she found a way to turn her prosthetic into another educational tool—through customized covers with diagrams of chestnut leaves, St. John’s wort, and ojé fig and their healing molecules. Now when she speaks, she often invites people to stare at her leg. “It is like a tattoo,” she says at the close of her Dragon Con talk. “So, I’m not gonna take it off—I’d fall over. I have the chemical structures of the plants we’ve studied, so take a gander if you’re interested.” Those who approach learn just a little bit more about why the next great medical advances might come from nature.
This article appears in our December 2023 issue.