Azadirachta indica, a member of the Meliaceae family, is commonly known as neem. Coming from the mahogany family, it is called dogonyaro in Hausa and Yoruba; and aku shorop, ogwu iba or ogwu akom in Igbo. It is a large evergreen tree that grows up to 20m in height in tropical and semi-tropical regions of the world.
Different parts of neem tree contain many biologically active compounds, including triterpenoids, alkaloids, phenolic compounds, flavonoids, carotenoids, ketones and steroid. Phytochemicals such as quercetin and azadirachtin and liminoids such as nimbin, nimbinin, and nimbidin have been purified from the different parts of the plant. The leaves also contain ascorbic acid, various amino acids, and several other types of compounds.
Different parts of the plant, such as the leaves, stem, bark, roots, fruits and flowers may be prepared as capsule, tea, paste, powder, decoction, infusion or oil. The twigs can be chewed raw. The leaves may be taken alone or mixed with beverages. It may also be used in aromatherapy. Neem may be burnt to ward off insects.
Pharmacological actions and medicinal uses
Several studies have portrayed that neem has hepatoprotective, neuroprotective, nephroprotective, cardioprotective, immunostimulant, contraceptive, anti-inflammatory, antidiabetic, antimicrobial, antihelmintic, antitumor, insecticidal and pesticidal properties.
All parts of the neem tree, including, leaves, seeds, roots, bark and the flowers of the plant are used to cure different ailments, such as stomach ulcers, jaundice, a variety of infectious and parasitic diseases, including leprosy, chicken pox and warts.
The leaves are widely used to alleviate fever, especially from malaria attacks, intestinal complaints, dental problems, headache and heartburn. They are used as insect repellents, appetite stimulants and diuretics. The twig is used as toothbrush for reducing plaque and gingival inflammation.
Some studies have clearly shown that neem extracts can be potentially useful to control some foodborne pathogens and other spoilage organisms. Neem is commonly used to heal wounds because of its antiseptic properties and fatty acid content.
Studies confirm the antiviral activity of neem by showing that the bark extract extensively blocked HSV-1 entry into cells. Neem leaves can be used to treat infected eyes, asthma, cough and sore throats.
Neem also helps in strengthening hair quality and promotes growth of hair. The neem oil is believed to relieve skin dryness, skin itchiness and redness and treatment of such skin complaints as furuncles and eczema.
Adverse effects that could be attributed to neem include death in infants, allergic reactions, infertility, miscarriage, stomach irritation, increase in fatigue and low blood sugar.
The neem tree is now gaining more importance due to its wide potentialities for industrialisation and commercialisation in the areas of agriculture, cosmetics, medicine, toiletries and various industries. 15 neem trees within the staff quarters of LBRBA in Benue State yielded up to 605.7kg of fruits in six weeks.
The demand for neem products are increasing daily. Some companies are now using Neem products (Neem oil and leaves) for production of cosmetics like facial creams, nail polishes, nail oils, shampoos, conditioners etc. Neem twigs are sold in rural markets as toothbrush. Dried neem leaves, neem tea and neem plus vermonia tea are available for sale for as much as ₦1,000.00, ₦2,000.00.00 and ₦4,000.00, respectively
The neem tree is of great importance as fuel, additive to fertilizers, forage for ruminants and rabbits and for its anti-desertification properties. Neem is widely established in plantations to check desertification in Kano, Katsina and Jigawa States of Nigeria.
Great potentials abound for neem in pharmaceuticals, cosmetics, agriculture including livestock, and landscaping.