Neem

Scientific Name(s): Azadirachta indica A. Juss.
Common Name(s): Arishtha, Margosa, Neem, Nim, Nimba, Nimbatiktam, Praneem

Medically reviewed by Drugs.com. Last updated on Aug 13, 2021.

Clinical Overview

Use

Limited clinical trials exist to support therapeutic claims. Neem has been used as an insecticide, insect repellent, and oral dentifrice, and in traditional medicine to treat malaria, diabetes, worms, and cardiovascular and skin diseases. It reportedly has contraceptive, antiulcer, and fungicidal properties, as well as applications relevant to cancer.

Dosing

There are inadequate clinical trials to support specific therapeutic doses of neem.

Contraindications

Specific contraindications have not been identified. The use of oral neem oil in children cannot be supported due to reported deaths.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking. Avoid use.

Interactions

None well documented.

Adverse Reactions

Research reveals few or no adverse reactions in adults with the use of neem at normal doses.

Toxicology

Neem oil (made from neem seeds) contains low concentrations of aflatoxin that are poisonous in large doses. In a case report of a 35-year-old woman, bilateral vision loss occurred 5 days after consumption of approximately 150 mL of neem oil.

Severe poisoning in infants from neem oil have been reported.

Scientific Family

• Meliaceae

Botany

The neem (formerly known as Melia azadirachta L.) is a large evergreen tree that grows up to 20 m in height, with spreading branches that form a broad crown. The plant is found throughout India and neighboring regions, where it is cultivated commercially. The plant is often confused with Melia azedarach L., the chinaberry or Persian lilac.1, 2 Leaves grow alternately with leaflets containing 8 to 19 leaves.2 The tree yields high-quality timber and a commercial gum.

History

Almost every part of the neem tree is used in traditional medicine (eg, Ayurveda, Unani, Siddha, Amchi) in many countries, with some 700 preparations described. The stem, root bark, and young fruits are used as a tonic and astringent, and the bark has been used as an analgesic and to treat malaria and cutaneous diseases. The tender leaves have been used in the treatment of worm infections, ulcers, and cardiovascular diseases, as well as in the treatment of leprosy. Indian farmers have used the leaves for hundreds of years as a pesticide and insect repellent.3, 4, 5

Chemistry

The seed kernels of neem yield about 10% of a fixed oil, comprised primarily of glycerides. The yellow, bitter oil has a garlic-like odor and contains approximately 2% of bitter principles including azadirachtin, azadiradione, azadirone, gedunin, nimbidin, nimbin, ninmbolide, nimbinin, nimbidol, margolene, mahmoodin, salanin, meldenin, vepinin, and other related limonoid triterpenes. Azadirachtin is the most active insecticidal component of neem, with a yield of about 5 g from 2 kg of seeds.2, 3, 6, 7, 8, 9, 10, 11 All parts of the tree yield beta-sitosterol. The leaves also contain quercetin, gallic acid, catechin, carotenes, and ascorbic acid.2 Low concentrations of aflatoxin have been reported.