An evidence-based exploration of rosemary, chicken curry, and the fight against Bundibugyo virus
The Spice Route
Let’s stay with that field nurse in the remote village for a moment. She’s already considered Prunella vulgaris tea with black pepper—a cheap, scalable, culturally acceptable adjunct. But now she’s looking at the spice rack. Specifically, she’s looking at rosemary.
And she’s thinking about chicken curry.
Here’s why this matters. In East Africa, rosemary isn’t an exotic import—it’s a kitchen staple. In the highlands of Kenya, locals lean on rosemary, thyme, and ginger root to flavor beef, chicken, and vegetable soups. Kuku Paka—an East African chicken curry that hails from Kenya, Tanzania, and Uganda—is a creamy coconut curry infused with garlic, ginger, chilies, and spices. Rosemary shows up in marinades, in spice blends, and on the grill.
So here’s the question: if Prunella vulgaris—a plant in the same botanical family (Lamiaceae) as rosemary—showed antiviral potential against Ebola in a lab, what about rosemary itself?
And more practically: what if the intervention wasn’t a separate tea, but something already integrated into daily life—like a spiced chicken curry?
The Lab Evidence: What We Know About Rosemary
Rosemary (Rosmarinus officinalis L., also known as Salvia rosmarinus) is in high demand in the food and drink industries due to its distinct organoleptic properties. It’s also been studied for its biological activity.
A 2021 study evaluated both the essential oil and an alcoholic extract of rosemary leaves for their chemical composition, genotoxicity, antimicrobial, antiviral, and antioxidant properties. The main volatile compounds in the essential oil were eucalyptol (40.1%), camphor (12.4%), and α-pinene (12.9%). The extract’s main ingredients included gallocatechin and—here’s where it gets interesting—rosmarinic acid.
Both the essential oil and the extract showed antiviral activity against Adenovirus 35. The pharmacologically validated medicinal properties of rosemary include antibacterial, antioxidant, and antiviral effects. Rosemary extracts contain a variety of active components with physiological functions including antioxidant, antibacterial, antiviral, and anticancer properties.
But here’s the catch: there is no direct, published research on rosemary extract against Ebola virus. None. Zero. The antiviral studies on rosemary have been conducted against adenovirus, HIV, hepatitis B virus, and enterovirus 71—not Ebola.
The Rosmarinic Acid Question
This is where we need to be careful—and where the science gets subtle.
Rosmarinic acid is a major compound in both Prunella vulgaris and rosemary. It has documented antiviral effects against a range of viruses. It’s also a powerful antioxidant.
So if rosmarinic acid is the common link, and Prunella vulgaris extract showed anti-Ebola activity, then rosemary—which also contains rosmarinic acid—might theoretically have similar potential, right?
Not so fast.
A 2021 study specifically investigated whether rosmarinic acid was responsible for the anti-Ebola activity observed in an extract of Perilla frutescens (another plant in the Lamiaceae family). The results were telling: rosmarinic acid did not reveal significant antiviral activities. The researchers concluded that “perhaps other less abundant active components or a combination of these compounds may be responsible for the extract’s antiviral activity”.
In other words: rosmarinic acid is not the Ebola-fighting compound we’re looking for. The active component in Prunella vulgaris that showed anti-Ebola activity remains unidentified. It could be something else entirely—something that rosemary may or may not contain.
The Bioavailability Question
Even if rosemary did contain the right compound, we’d still face the same challenge we discussed with Prunella vulgaris: getting it into the bloodstream.
Research on herbs and spices shows that certain phytochemicals unique to specific herbs—like piperine in black pepper and carnosic acid in rosemary—are metabolized after intake and can remain in the circulation for extended periods. In contrast, others are cleared more rapidly, often within a few hours.
Carnosic acid—one of rosemary’s signature compounds—has a pharmacokinetic profile worth noting. When consumed, carnosic acid glucuronide and carnosol glucuronide concentrations were still increasing at 24 hours after consumption. In other words, rosemary’s metabolites hang around. This is a significant advantage over compounds that clear within hours.
But—and this is a big but— we don’t know if carnosic acid has any activity against Ebola. There’s no research on that. None.
The Practical Reality: Rosemary in the Diet
Let’s bring this back to the field.
In East Africa, rosemary is already present in the diet. It’s used in chicken curry marinades, in grilled chicken (kuku choma), and in soups. It’s not an imported supplement that requires special logistics—it’s a spice that grows in the highlands.
If someone wanted to “activate” rosemary’s potential, the same logic applies as with Prunella vulgaris:
The Hypothesis: What If?
Let’s play this out. Suppose a field team wanted to test whether rosemary—already present in the local diet—could offer any adjunct benefit. Here’s what the logic might look like:
- Rosemary is already consumed in East African communities through dishes like kuku paka and grilled chicken.
- Rosemary contains bioactive compounds with documented antiviral activity against other viruses.
- Carnosic acid, a major rosemary compound, persists in the circulation for extended periods—a pharmacokinetic advantage over many other phytochemicals.
- Black pepper, already used in East African cuisine, could potentially enhance bioavailability of other compounds.
The gap: We have no evidence that any rosemary compound has activity against Ebola. We don’t know if carnosic acid—or any other rosemary compound—binds to the Ebola glycoprotein, blocks viral entry, or inhibits replication. The rosmarinic acid dead-end is a cautionary tale: just because a compound is in the same family doesn’t mean it does the same thing.
The Comparative Table
The Bottom Line
Rosemary is a fascinating plant with documented antiviral properties. It contains compounds that persist in the body longer than many other phytochemicals. It’s already part of East African cuisine, making it a culturally integrated, logistically simple candidate for any “couldn’t hurt, might help” intervention.
But the evidence gap is real. There is no research on rosemary against Ebola. None. The rosmarinic acid story—where a major compound looked promising but turned out not to be the active agent—should give us pause. We don’t know what works, and we don’t know if rosemary has it.
If a community is already eating rosemary-spiced chicken curry, there’s no harm in that. It’s food. It’s delicious. It’s culturally appropriate. But it would be scientifically dishonest to present it as an Ebola intervention—even an adjunct one—without evidence.
The Prunella vulgaris tea, for all its weaknesses, at least has a published study showing activity against Ebola in a lab. Rosemary does not.
The Field Recommendation
- Don’t replace the Prunella vulgaris tea protocol with rosemary. The tea has lab evidence; rosemary does not.
- Don’t discourage rosemary consumption. It’s already in the diet, it’s safe, and it may have general health benefits.
- Do document traditional rosemary use in outbreak-affected communities. If there are anecdotes about health outcomes, they should be recorded—not as evidence, but as hypothesis-generating data.
- Do consider rosemary as a potential candidate for future research—but only after the active compound in Prunella vulgaris is identified and tested.
The Bigger Picture
This exercise—examining rosemary in chicken curry—reveals something important about outbreak response in resource-limited settings. The most effective interventions are often the ones that already fit into daily life. They don’t require new behaviors, new supply chains, or new cultural negotiations. They just require a slight nudge: add a little more of this spice, drink this tea with your meals.
The challenge is that “fits into daily life” and “has evidence against Ebola” rarely overlap. The Prunella vulgaris tea has evidence but requires behavior change. Rosemary chicken curry requires no behavior change but has no evidence.
The ideal intervention would be something that combines both: a culturally integrated food or beverage with documented anti-Ebola activity. We’re not there yet. But we’re getting closer.
References
- Christopoulou SD, Androutsopoulou C, Hahalis P, et al. Rosmarinus officinalis L. (rosemary) extract and essential oil as drink ingredients: An evaluation of their chemical composition, genotoxicity, antimicrobial, antiviral, and antioxidant properties. Foods. 2021;10(12):3143.
- Zhang X, Ao Z, Bello A, et al. Characterization of the inhibitory effect of an extract of Prunella vulgaris on Ebola virus glycoprotein (GP)-mediated virus entry and infection. Antiviral Research. 2016;127:20-31.
- Liu CH, et al. The methanolic extract of Perilla frutescens robustly restricts Ebola virus glycoprotein-mediated entry. Viruses. 2021;13(9):1793.
- Huang Y, Petersen KS, Kris-Etherton PM, et al. Phytochemicals from herbs and spices: Their absorption, metabolism, and relationship to clinical outcomes. Nutrition Reviews. 2024;84(Supplement_1):29.
- Herrera MOF, Cangui-Panchi SP. Natural products and their derivatives against the Ebola virus. Revista Cubana de Investigaciones Biomédicas. 2024;43:e2325.
- Kenyan Food Journal. Spicing up Kenya: The role of aromatics in Kenyan cuisine. 2025.
- Kuku Paka (East-African chicken curry) recipes and references.