We use insect repellants to get rid of mosquitoes, cockroaches, etc. The widely used ingredient in those repellants is DEET (N, N-Diethyl-meta-Toluamide). It was shown to be very effective in repelling insects.
However, DEET, which is a synthetic chemical, has some shortcomings. First of all, it is toxic. It can cause encephalopathy in children. In addition, it was found that it can cause urticaria syndrome, anaphylaxis, hypertension and decreased heart rate. It also contributes to environmental pollution. Ultimately, it is harmful to humans and harmful to the environment.
Due to the above disadvantages, people have been searching for natural repellants that have no side effects. Plant essential oils were found to be a useful natural material as an alternative to synthetic.
There are some essential oils found in plants that are mixed into insect repellants.
Lemongrass (Cymbopogon citritus) is a tropical plant whose root is used in cooking. It contains citronellol, which is a material that can be used to repel mosquitoes. It can give 2 hours of repellent effect after spraying. This type of mosquito repellent can be found in most grocery store sales.
Neem oil from the neem tree (Indian lilac, Azadirachta Indica) is also used as an ingredient. Neem oil is very useful as it could be used to prevent and repel 200 types of insects. It is very unique that it is not harmful to friendly insects such as dragonflies, spiders, earthworms, frogs, etc. Of course, it is not harmful to human. In fact, the neem tree is the most useful plant as a source of essential oil to produce insect repellants.
The repellent properties of essential oils are associated with the presence of mono terpenoids and sesquiterpenes. Examples of terpenoids are alpha-pinene, limonene, citronellol, citronellal, camphor, thymol, etc.
Curry leaf was found to be a potential source of essential ingredient natural oil for the preparation of insect repellants. However, it is most famous for its use in culinary dishes, as it gives a special aroma and fragrance to food.
Scientific research found that curry leaf essential oil contains alpha-pinene and beta-myrcene. These two active ingredients have great potential to make curry leaf an essential oil source for insect repellants.
More efforts are needed to conduct more research and market curry leaf essential oil as an insect repellent.
