The neem tree (Azadirachta indica), which grows in India and surrounding areas, has been called "Arishtha" Sanskrit for "reliever of sickness." Virtually every part of the tree is beneficial for healing and has been used medicinally for over 2000 years. In 1992, the U.S. National Academy of Sciences published a book entitled, "Neem - a tree for solving global problems." The extract has been used to treat a wide variety of illnesses.
Nimbidim, a major constituent of neem extract, has been shown to reduce inflammation in rats. A study at the Department of Pharmacology at Rajshahi Medical College in Bangladesh, researchers found that neem extract has a significant impact on inflammation, but less than popular steroid, dexamethasone.
Because of its anti-inflammatory effects, nimbidim has been shown to reverse signs of arthritis in rats. Research published in the 2004 issue of Phytotherapy Research found that nimbidim can help treat diseases due to inflammation.
A study in The Antiseptic in 1979 showed neem extract to be effective in treating eczema, scabies, ringworm, and some forms of dermatitis. The extract was applied topically, but better results were noted when injected into the muscle.
Studies with diabetic rats have shown neem extract to be effective in decreasing blood sugar levels and preventing glucose-induced high blood sugar, or hyperglycemia. A significant decrease in blood sugar was noted when fasting rabbits were given neem extract.
Due to the presence of a glycoside, neem extract shows the ability to inhibit the formation of ulcers in the stomach and intestines of rats.
In vitro studies show neem extract's spermicidal ability against monkey and human sperm. Oral administration of neem extract shows antifertility properties and further studies are needed to determine its ability to prevent conception.
Antifungal & Insecticide
Neem extract have been proven to be effective at killing a number of human fungi. In addition to its effectiveness against Candida, Microsporum, Trichosporium and other fungi, author James Walter, in his book, Biopesticides: Use and Delivery, states that neem oil "affects over 300 species of insects, including such important pests as armyworms, leafminers, aphids, whiteflies, psyllids, and numerous other insect pests" making neem oil a useful pesticide with a low impact on the environment and beneficial insects.
In test tube studies, neem extract has shown to be effective against M. tuberculosis and other Gram-negative and Gram-positive bacteria. A vaginal contraceptive has shown effectiveness against a number of bacteria, viruses and fungi.
One of neem extract's main constituents, sodium nimbidinate, has been shown to have diuretic effects in patients with congestive heart failure.
Neem extract's usefulness against malaria is legendary. Various forms of the plant have been used to treat malaria for centuries. Recent studies have shown neem extract's effectiveness against the malarial parasite P. falciparum.
Studies have found neem extract to have an antitumor polysaccharide that inhibits the growth of some tumors. While comprehensive clinical trials on humans are lacking, some human studies have shown neem extract's ability to interfere with the cell cycles of both leukemia and melanoma.