Researchers from Cardiff University and partners in Uganda have developed an affordable, plant-based mosquito repellent using catnip oil, according to findings presented at the Society for Experimental Biology conference. Laboratory and field trials show the lotion is as effective as DEET, offering a sustainable, locally produced alternative to expensive imported synthetic repellents in malaria-endemic regions.
How does catnip oil repel mosquitoes?
The active ingredient in the repellent is nepetalactone, a chemical found in the essential oil of the catnip plant, Nepeta cataria. According to Dr. Simon Scofield, a senior lecturer at Cardiff University, nepetalactone acts as a potent natural insect repellent. While traditionally known for inducing euphoria in cats, the chemical effectively deters mosquitoes, which are primary vectors for malaria and other diseases in Sub-Saharan Africa.
Nepetalactone has been recognized for its insect-repelling properties for years, but pharmaceutical companies have historically avoided commercializing it because the natural compound cannot be patented.
Why is this a shift from current malaria prevention?
Currently, DEET is the most widely used active ingredient in commercial insect repellents. It functions by disrupting the sensors insects use to locate human skin. However, Dr. Scofield notes that DEET products are often prohibitively expensive for rural Ugandan subsistence farmers. By utilizing locally grown catnip, the project—led by the organization Community Enterprise Model for Plant Oil Production (CEMPOP)—creates a product that is both affordable and easy to manufacture within the community.
Comparison of Efficacy: Catnip vs. DEET
Researchers tested the efficacy of the catnip-based repellent, dubbed “DSK lotion” after local community leader Dison Stephen Kalebo, using two primary methods:
- Laboratory trials: A Y-tube olfactometer measured mosquito attraction to treated versus untreated skin under controlled conditions.
- Field trials: A “human landing catch assay” tracked the number of wild mosquitoes landing on participants in the Budaka district of Eastern Uganda.
According to Dr. Scofield, laboratory and field results indicate that a 6% concentration of catnip oil is just as effective as DEET, while a 2% concentration remains only marginally less effective.
What is the future of the DSK lotion project?
The project, a collaboration between Cardiff University, Makerere University, and Ugandan government officials, aims to transition from a grant-funded trial to a self-sustaining enterprise. The goal is to scale up production to provide a stable income for local workers while keeping the retail price low. Dr. Scofield suggests that the model could eventually expand beyond Uganda to other regions in Africa or even the global north, as the repellent also shows potential against other biting insects like midges and ticks.
Pro Tips for Sustainable Community Projects
To ensure long-term success, the project focuses on three pillars:
- Local Cultivation: Using crops that grow easily in the region to minimize supply chain costs.
- Community Involvement: Employing local workers and volunteers throughout the production cycle.
- Economic Circularity: Reinvesting profits back into the community to sustain production and distribution.
Frequently Asked Questions
Is catnip repellent safe to use on skin?
Yes, researchers report that the catnip-based lotion is safe for use. Additionally, users have noted that it possesses a more pleasant scent compared to the chemical odor of DEET.
Why hasn’t this been used before?
While the properties of nepetalactone are well-documented, the inability to patent a natural plant oil has historically discouraged large-scale investment from pharmaceutical companies.
Where is the DSK lotion currently available?
The lotion is currently being distributed for free during local trials in the Budaka district of Eastern Uganda as part of a community enterprise development program.
Interested in the intersection of public health and sustainable agriculture? Subscribe to our newsletter for the latest updates on community-led research projects and global health innovations.
