A Gift of Science

This Giving Tuesday, learn more about how you can support scientific research on medicinal plants.

Me in the lab preparing samples of Brazilian peppertree fruit for analysis. Did you know that this plant is the source of two powerful antimicrobial molecules that we discovered?

Today is Giving Tuesday! By now, like me, you are probably overloaded with emails from various organizations asking for support—and this comes following days of sales ads. So, I’ll make this pitch short and simple. With more than 34,000 medicinal plants on Earth, we still know very little about the safety, efficacy, and translational potential of 99% of them! My research group is one of the few in the world with the tools, expertise, and scope of knowledge to undertake rigorous scientific research on highly chemically complex medicinal plants.

We search for new medicines from nature. If you’d like to support us in this effort, you can do so with a tax-deductible donation to my lab on this Emory University secure giving website. It is very important that you use this link which includes the appeal code W6CCQ and is designated to “Cassandra Quave, PhD Research; Center for the Study of Human Health”. Whether you can pledge $10 a month or a single donation of any size, every penny helps us in this effort!

What do we research in the lab?

This is a great question! Our overarching aim is to develop a better understanding of the pharmacological properties of plants and to record medicinal plant traditions before they are lost forever. I lead with a very interdisciplinary and translational angle to our work. I hope to see our discoveries move from the laboratory bench to the pharmacy shelves and we are gradually making headway in these efforts!

Why is this work important?

Many essential medicines were first discovered in plants. If you’ve ever taken an aspirin, thank a plant for that. Recovery from surgery is made tolerable thanks to the help of medicines from the opium poppy. Plants have given us life-saving cures for everything from cancer to heart disease, infection, and more. Our academic research has led to seven patents and the launch of two startup companies: PhytoTEK LLC and Verdant Scientific LLC. PhytoTEK is working on new eco-friendly bandages that combat bacterial biofilms in wounds, and Verdant Scientific is developing a first-in-class non-steroidal therapy to treat atopic dermatitis (eczema), a disease that affects 233 million people worldwide, with 43 million of these being children aged 1-4.

Where do we conduct field research?

We work in partnership with scientists across the globe, with a focus on collecting plant samples from global hotspots of biodiversity. There are 36 such hotspots, defined as regions with at least 1,500 endemic species (plants found only in that part of the world) and at least 70% of native vegetation loss. This means that these locales are home not only to the most biologically (and thus chemically) diverse plants but also to these imperiled ecosystems, and there is an urgency to study these plants before they are lost forever.

Why is traditional knowledge of medicinal plants disappearing?

As the world becomes more Westernized and communities become more embedded into the global economy, we are rapidly losing millennia-old traditions of plant uses for everything from food to construction and medicine. Further, language loss has accelerated this process.

What are some examples of lab studies we’ve conducted?

We have published more than 100 scientific publications, which have been cited in the work of other scientists more than 7,000 times! This indicates the importance of our findings to the scientific community. Here are just a few examples of research topics covered in the lab.

Antivirulence approaches to staphylococcal infections

Significant efforts of my lab at Emory are rooted in the study of small-molecule inhibitors of microbial virulence pathways. Beginning in graduate school, my work has focused on the discovery of virulence and pathogenesis inhibitors for MRSA. This research started with an ethnobotanical study of medicinal plants used in traditional medical treatments for skin and soft tissue infections (SSTIs) in rural Italian villages. The cited species were collected for my phytochemical analysis and assessed for growth inhibitory, anti-biofilm, and anti-virulence activity against clinical MRSA isolates for my NIH-funded projects. The anti-virulence study was the first to report the quorum-quenching activity of plant extracts in MRSA. The focus of our present work has not only been on identifying new quorum quenchers but also assessing and developing high-throughput technologies for anti-virulence drug discovery.

• Quave, C.L., J.T. Lyles, J.S. Kavanaugh, K. Nelson, C.P. Parlet, H.A. Crosby, K.P. Heilmann, A.R. Horswill. (2015) Castanea sativa (European Chestnut) leaf extracts rich in ursene and oleanene derivatives block Staphylococcus aureus virulence and pathogenesis without detectable resistance. PLoS ONE 10(8): e0136486. PMCID: PMC4546677

• Muhs, A., J.T. Lyles, C.P. Parlet, K. Nelson, J.S. Kavanaugh, A. R. Horswill, C.L. Quave. (2017) Virulence inhibitors from Brazilian Peppertree block quorum sensing and abate dermonecrosis in skin infection models. Sci Rep, 7: 42275. PMCID: PMC5301492

• Tang, H., G. Porras-Brenes, M. M. Brown, F. Chassagne, J.T. Lyles, J. Bacsa, A. Horswill, C.L. Quave (2020) Triterpenoid acids isolated from Schinus terebinthifolia fruits reduce Staphylococcus aureus virulence and abate dermonecrosis. Sci Rep, 10, 8046.  PMCID: PMC7229044.

• Salam, A.M., G. Porras, Y-S.K. Cho, M.M. Brown, C.J. Risener, L. Marquez, J.T. Lyles, J. Bacsa, A.R. Horswill, C.L. Quave. (2021) Castaneroxy A from the leaves of Castanea sativa inhibits virulence in Staphylococcus aureus. Front Pharmacol, 12, 1487. PMCID: PMC8274328

Characterization of microbial pathogenesis in clinical populations

My group has undertaken work to characterize phenotypic variation in clinical isolates to better understand the basic science behind virulence pathways and the clinical exhibition of disease, with particular focus on atopic dermatitis and recurrent urinary tract infections.

• Su, M., J.T. Lyles, R. Petit, J.M. Peterson, M. Hargita, H. Tang, C. Solis-Lemus, C.L. Quave, T.D. Read. (2020) Genomic analysis of variability in Delta-toxin levels between Staphylococcus aureus strains. PeerJ 8:e8717. PMCID: PMC7100594

• Gurnee, E., M. Xu, C.J. Risener, K. Lehman, K. Nelson. R.A. Swerlick, C.L. Quave. (2021). Staphylococcal hemolytic potential is correlated with increased severity of atopic dermatitis in children and young adults. J Invest Derm S0022-202X(20)32391-5. PMID: 33359627

• Falk, K., S. Satola, F. Chassagne, G. Northington, C.L. Quave. (2021). Biofilm production by uropathogens in postmenopausal women with recurrent and isolated urinary tract infection. Female Pelvic Medicine and Reconstructive Surgery doi: 10.1097/SPV.0000000000001124. PMID: 34768258

Isolation and structural elucidation of natural products

In the search for novel bioactive compounds to fight infectious diseases, my laboratory has isolated and resolved the structures of bioactive natural products, including novel and known compounds that previously lacked complete structural conformation data. This work illustrates our skills in the authentication of wild plants, the bioassay-guided fractionation of natural products, and structural elucidation using the tools of mass spectrometry, NMR, and X-ray crystallography.

• Lavoie, S., A.M. Sweeney-Jones, N. Mojib, B. Dale, K. Gagaring, C.W. McNamara, C.L. Quave, K. Soapi, J. Kubanek. (2019) Antibacterial Oligomeric Polyphenols from the Green Alga Cladophora socialis. J Org Chem.84(9):5035-5045. PMCID: PMC6503470.

• Dettweiler, M, L. Marquez, M. Lin, A.M. Sweeney-Jones, B.K. Chhetri, D.V. Zurawski, J. Kubanek, C.L. Quave. (2020) Pentagalloyl glucose from Schinus terebinthifolia inhibits growth of carbapenem-resistant Acinetobacter baumannii. Sci Rep.10(1):15340. PMCID: PMC7501240.

• Dettweiler, M., L. Marquez, M. Bao, C.L. Quave. (2020). Quantifying synergy in the bioassay-guided fractionation of natural product extracts. PLoS One 15(8): e0235723. PMCID:  PMC7428089

• Zeiler, M.J., G.M. Connors, G.M. Durling, A.G. Oliver, L. Marquez, R. Melander, C.L. Quave, C.C. Melander. (2022) Synthesis, Stereochemical Confirmation, and Derivatization of a Clerodane Diterpene That Sensitizes Methicillin-Resistant Staphylococcus aureus to β-Lactam Antibiotics. Angewandte Chemie, e202117458, PMCID: PMC9007873

Anti-infective drug discovery

Discoveries based on my research have been used in patent filings with the aim of promoting translation into future clinical applications. Other discoveries have contributed towards investigation of the safety and efficacy of common herbal preparations for public use.

• Marquez, L., Y. Lee, D. Duncan, L. Whitesell, L.E. Cowen, C. Quave. Potent Antifungal Activity of Penta-O-galloyl-β-d-Glucose against Drug-Resistant Candida albicans, Candida auris, and Other Non-albicans Candida Species. ACS Infect Dis. 9(9):1685-1694. PMCID: PMC10496123

• Dettweiler M., R.J. Melander, G. Porras, C. Risener, L. Marquez, T. Samarakoon, C. Melander, C.L. Quave. A Clerodane Diterpene from Callicarpa americana Resensitizes Methicillin-Resistant Staphylococcus aureus to β-Lactam Antibiotics. ACS Infect Dis. 2020 Jul 10;6(7):1667-1673. PMCID: PMC8183163

• Pineau, R.M., S. Hanson, J.T. Lyles, C.L. Quave. (2019) Chemical characterization and anti-acne activity of Callicarpa americana. Front Pharmacol, 10 (1206): 1-12. PMCID: PMC6803531.

• Dettweiler, M., J.T. Lyles, K. Nelson, B. Dale, R.M. Reddinger, D. Zurawski, and C.L. Quave. (2019). American Civil War plant medicines inhibit growth, biofilm formation, and quorum sensing by multidrug-resistant bacteria. Sci Rep, DOI: 10.1038/s41598-019-44242-y. PMCID: PMC6531439.

• Carrol, D., F. Chassagne, M. Dettweiler, C.L. Quave. (2020) Antibacterial activity of plant species used for oral health against Porphyromonas gingivalis. PLoS One 15(10): e0239316. PMCID: PMC7544490.

• Risener, C.J., S. Woo, T. Samarakoon, M. Caputo, E. Edwards, K. Klepzig, W. Applequist, K. Zandi, S.L. Goh, J.A. Downs-Bowen, R.F. Schinazi, C.L. Quave. (2023) Botanical inhibitors of SARS-CoV-2 viral entry: a phylogenetic perspective. Sci Rep. 13(1):1244. PMCID: PMC9868516

Medical ethnobotany of medicinal and food plants

In addition to my laboratory activities, field research is an essential component of my research portfolio. Indeed, through engagement in field research, I have identified several sources of novel anti-infective compositions and traditional food practices for laboratory investigation. Understanding how people interact with wild medicinal plants is central to the ethnobotanical approach to drug discovery. I adhere to the Convention on Biological Diversity and Nagoya Protocol principles on equitable access and benefit-sharing. In addition to supporting scientific research in these countries, we also work diligently to promote research capacity building with our international partners.

• Quave, C.L. and A. Pieroni (2014) Fermented foods for food sovereignty and food security in the Balkans: A case study of the Gorani people of northeastern Albania. J Ethnobiol 34(1): 28-43.

• Quave, C.L. and A. Pieroni. (2015). A reservoir of ethnobotanical knowledge informs resilient food security and health strategies in the Balkans. Nat Plants DOI: 10.1038/NPLANTS.2014.21 PMID: 27246758

• Quave, C.L. and A. Saitta. (2016) Forty-five years later: The shifting dynamic of traditional ecological knowledge Pantelleria Island, Italy. Econ Bot 70(4): 380-393.

• Schultz, F., G. Anywar, B. Wack, C.L. Quave, L.-A. Garbe. (2020) Ethnobotanical survey and literature assessment of selected medicinal plants traditionally used in the rural Greater Mpigi region of Uganda. J Ethnopharm, 256: 112742. PMID: 32224196

Meet the research group!

The composition of our research group is constantly changing as new trainees come and established ones go on to launch their careers. My trainees have transitioned to leading their own academic and government research labs, working in the biotech industry, and practicing medicine with clinical research as a cornerstone of their practice. Here’s a list of our 2023 team members:

• Lab director/PI: Cassandra Quave, PhD

• Lab manager: Nadia Aziz

• Medical Fellow: Amanda Paquet, MD

• Postdoctoral fellows: Sunmin Woo, PhD and Na-mi Kim, PhD

• Fulbright scholar: Aygun Israyilova, PhD

• Herbarium collections manager: Tharanga Samarakoon, PhD

• Medical student: Jade Howard and Tsvetomira Peykova

• Graduate students: Lewis Marquez, Caitlin Risener, Isabel Daher, and William Crandall

• Research specialist: Marco Caputo

• Honors student: Ben Kittleson

• Undergraduate students: Sloane Donovan, Paul Sprowl, Monica Duan, Ayesha Faheem, Benjamin Ryu

The Takeaway

Your gift—no matter the amount—can be of great assistance in helping my lab reach our research goals and:

• Train the next generation of cutting-edge scientists;

• Record and preserve traditional knowledge of traditional medical practices;

• Perform rigorous scientific studies on the safety and efficacy of medicinal plants; and

• Disseminate the science behind how herbs work to the scientific community and the public.

If you prefer to send a gift through standard mail, print a gift form, add the appeal code W6CCQ to Cassandra Quave Research, and send it with your check to:

Office of Gift Accounting
Emory University
1762 Clifton Road, Suite 2400
Atlanta, GA 30322

Or you can call 404.712.GIVE (4483) to make your gift over the phone.

If you have a more complex gift plan of stock, a donor advised fund, giving through your estate, or IRA, please call 404.712.GIVE (4483) for assistance. Thank you for your support!

Yours in health, Dr. Quave

---

Cassandra L. Quave, Ph.D. is a scientist, author, speaker, podcast host, wife, mother, explorer, and professor at Emory University School of Medicine. She teaches college courses and leads a group of research scientists studying medicinal plants to find new life-saving drugs from nature. She hosts the Foodie Pharmacology podcast and writes the Nature’s Pharmacy newsletter to share the science behind natural medicines. To support her effort, consider a paid or founding subscription, with founding members receiving an autographed 1st edition hardcover copy of her book, The Plant Hunter.

---

Available in hardcover, paperback, audio, and e-book formats!