General info
A tree belonging to the mahogany family known as the "free tree" because of its ability to "free the soil." Popular in the Philippines, more for its insecticidal properties (pang-lamok) than for its medicinal applications. In India, it is considered the most useful traditional medicinal plant, and commericially beneficial as each part of the tree has some medicinal property.

Botany
Medium-sized tree growing to 15 meters high, with wide spreading branches formiing an oval crown. Leaves are pinnately compound. The drooping leaflets are 1 cm long, paired, lanceolate, acuminate with serrated margins. The blade is shiny dark green on the upper surface and pale green on the underside. Flowers are numerous, small, white and fragrant.

Distribution
Not widespread in the Philippines.
A good shade tree.
Propagated by seeds.

Chemical constituents and properties
• From the seed is produced a bitter fixed oil, nimbidin, known as "Oil of Margosa" or neem oil.
• Neem seeds yield a fix oil of glycerides and bitter compounds including nimbin, nimbinin and nimbidol.
• Neem bark and leaves contain tannin and oil.
• Azadirachtin, the insecticide constitutent of the seeds, is biodegradable, non-mutagenic, and nontoxic to birds, fish, and warm-blooded animals. The EPA has approved a neem formulation (Margosan-O) as a pesticide for limited use on nonfood crops
• Antiinflammatory (nimbidin, sodium nimbidate, gallic acid, catechin, polysachharides).
• Antiarthritic, hypoglycemic, antipyretic, hypoglycemic, diuretic, anti-gastric ulcer (nimbidin)
• Antifungal (nimbidin, gedunin, cyclic trisulfide)
• Antibacterial (nimbidin, nimbolide, mahmoodin, margolone, margolonone, isomargolonone)
• Spermicidal (nimbin, nimbidin)
• Antimalarial (nimbolidfe, gedunin, azadirachtin)
• Antitumor (polysaccharides)
• Immunomodulatory (NB-II peptoglycan, gallic acid, epicatechin, catechin)
• Hepatoprotective (aequeous extract of neem leaf)
• Antioxidant (neem seed extract)

Parts used and preparation
Whole plant.
.
Uses
Folkloric
Poultice of leaves for swollen glands, brusies and sprains.
Fresh leaf-tea used for malaria.
Tree and root barks have been used for malaria, jaundice, and for intestinal parasitism.
Edible pulp of the fruit used for hemorrhoids.
Ayurvedic medicine
Leaf- leprosy, intestinal parasites, eye problems, skin ulcers
Bark - pain and fever.
Flower - bile suppression, intestinal worms and phlegm.
Fruit - piles, intestinal worms, urinary disorder, nose bleeding , phlegm, eye problem, diabetes, wounds and leprosy.
Twig - cough, asthma, piles, intestinal worms, spermatorrhoea, urinary disorders, diabetes.
Gum - ringworms,scabies, wounds and ulcers.
Seed pulp and oil- leprosy and intestinal worms.
Others
Young tender branches are chewed for toothbrushing use.
Leaf's oil is used as a local antiseptic and insecticide.
Neem oil may be useful for gingivitis.
In the rural areas, burning of leaves and seeds used as mosquito repellant.
Neem oil has been shown to possess some spermicidal and contraceptive properties when used intravaginally.
Use of neem oil in animals showed lowering of glucose
Commercial use
Neem extracts used in the manufacture of toothpaste for its antibacterial properties.
Fresh seed oil has a strong garlic odor and is an ingredient for insect sprays.

Studies
• Studies have suggested hypoglycemic, antiulcer, antifertility, antimalarial, antifungal, antibacterial, antiviral, anticancer and antioxidant effects.
• Effect of essential oils from two Nigerian medicinal plants (Azadirachta indica and Morinda lucida) on growth and aflatoxin B1 production in maize grain by a toxigenic Aspergillus flavus: Oils from A indica completely suppressed aflatoxin synthesis.
• Lipid Effects / Antiviral: Effect of Supplemental Garlic and Neem Leaves in Broiler Feeds on Blood Cholesterol, Triglycerids and Antibody Titer: Study showed neem had greater potential than garlic in reducing cholesterol, triglycerides and increasing the antibody titers against viruses.
• Antibacterial / Anticariogenic: Study showed Neem bark constituents have the ability to suppress growth of cariogenic bacteria (Streptococcus sobrinus).
• Anti-ulcer: (1) Mechanism of antiulcer effect of Neem (Azadirachta indica) leaf extract: effect on H+-K+-ATPase, oxidative damage and apoptosis: Study suggests antiulcer activity is achieved by blocking acid secretionn through inhibition of H+K+ATPase and preventing oxidative damage and apoptosis. (2) Study of A indica in albino rats showed significant inhibition of basal and histamine-induced gastric acid secretion. Cimetidine seemed to augment AI inhibition of gastric acid secretion. (3) Study of neem bark extract showed therapeutic potential in controlling gastric hypersecretion and gastroesophageal and gastroduodenal ulcers. (4) Study showed neem extract to have a regenerative potential in ethanol-induced mucosal damage in the stomach and ileum and may be adopted in the management of gastrointestinal ulcer disorders.
• Anti-candidal: Anticandidal activity of Azadirachta indica: Study suggested hexane and alcoholic extracts to have anticandidal potential.
• Antiplaque Activity: A study was done on the effectiveness of neem leaf extract against plaque formation. Results showed the dental gel containing neem extract significantly reduced the plaque index and bacterial count of S mutans and Lactobacillus species compared with commercial chlorhexidine gluconate mouthwash as control.
• Antidermatophytic Activity: A study showed the neem seed extract has high antidermatophytic properties and supports the alternative use of neem oil in the treatment of various skin infections.
• Biosorbent Activity: A study showed the effectiveness of the Neem leaf powder as a biosorbent for removing dyes like Congo Red from water.
• Hypoglycemic / Antidiabetic Activity: (1) In a study of 30 known or less known hypoglycemic medicinal plants in folk medicine, Azadirachta indica was one of 24 samples (18th or 24) that was observed to have significant blood glucose lowering activities. (2) Study on the aqueous extracts of C roseus, Azadirachta indica and A sativum indicated significant antidiabetic activity, supporting its traditional use in Ayurveda for therapy of diabetes.
• Hepatoprotective Activity: A study showed A indica leaf extract showed hepatoprotective effects against paracetamol-induced hepatic damage probably through its antioxidant activity.
• Anti-Fertility Activity / Rodent Control: A study showed Neem seed extract can be used as an anti-fertility agent on baits to control harmful agricultural rodents.

Toxicity Studies
• Acute Toxicity Study of Neem Oil: Study of neem oil by oral route in rats and rabbits showed dose-related pharmacotoxic symptoms along with biochemical and histopatholocial indices of toxicity, with the changes in the lungs and CNS as target organs of toxicity.

Availability
Wildcrafted.
Available in cybermarkets as supplements, oil, cakes, extracts, and organic manure.