The Neem Tree: Nature's Bio-Defense at its Best

One of the speakers this week was Dr. Peter Radtke, PhD and CEO of JustNeem. JustNeem is a corporation based in the Triangle that produces skin care products made from neem that is sourced from Mauritania, where they support neem planting and reforestation. The presentation explained the medical and environmental uses of neem, and the economic and social benefits of neem plantations. neem can survive temperatures up to 40°c and salinity up to a third of sea water, giving it the ability to grow in Sub Saharan Africa, and even desert countries like Saudi Arabia. This unique ability to survive in hostile environments makes it an ideal candidate for reforestation and dune stabilization, thus providing a source of livelihood in underdeveloped desert countries.

The medicinal properties of neem come from its remarkable array of bioactive compounds. Dr. Radtke explained his realization of how this came to be – that all living things are in a constant fight for survival, and the defenses that the neem tree has evolved can be harnessed to fight our own potential pathogens. Almost every part of the neem tree’s body has bioactive compounds. These compounds have anti-viral, anti-fungal, anti-bacterial, and anti-inflammatory properties among others. Each component has a somewhat different mode of action, so no pathogen has been able to evolve resistance against them.

When questioned about whether anyone has tried to create synthetic compounds based on the bioactive molecules, Dr. Radtke remarked that he is grateful that nobody has succeeded – a synthetic molecule working independently would eventually lead to the development of resistance. The amazing thing about these bioactive components are that they are toxic to pathogens that are detrimental to human health and economics, but have been found safe for other organisms so far. Neem has been used extensively in the Indian subcontinent for thousands of years without any toxic effects on humans.

The question of neem’s persistence in the environment was also raised. With a half-life of about two weeks, these compounds are safe but short-lived. A sun protectant vehicle and certain delivery methods can extend its half-life in the environment.

There was a final discussion about the veterinary use of neem. Its bitter taste, lack of toxicity and medicinal properties make it an ideal product for certain veterinary uses, such as a flea repellant in young animals, or wound healing for wild and large animals. 

Post authored by Dipika Kadaba, veterinarian and graduate student at Duke University's Nicholas School of the Environment.