|Some medicinal uses of neem as mentioned in ayurveda|
|Leprosy, eye problem, epistaxis, intestinal|
|worms, anorexia, biliousness, skin ulcers.||Leaf|
|Analgesic, alternative and curative of fever.||Bark|
|Bile suppression, elimination of intestinal||Flower|
|worms and phlegm.|
|Relieves piles, intestinal worms, urinary disorder,||Fruit|
|epistaxis, phlegm, eye problem, diabetes,|
|wounds and leprosy.|
|Relieves cough, asthma, piles, phantom||Twig|
|tumour, intestinal worms, spermatorrhoea,|
|obstinate urinary disorder, diabetes.|
|Effective against skin diseases like ringworms,||Gum|
|scabies, wounds and ulcers.|
|Leprosy and intestinal worms.||Seed pulp|
|Leprosy and intestinal worms.||Oil|
|Blood morbidity, biliary afflictions, itching,||Root, bark, leaf, flower|
|skin ulcer, burning sensation and leprosy.||and fruit together|
Anti-inflammatory, antipyretic and analgesic activities:
The chloroform extract of stem bark is effective against carrageenin. Inflammatory stomatitis in children is cured by the bark extract. Antipyretic activity has been reported in neem oil. A methanol extract of the leaves exerts antipyretic effect. The plant also possesses analgesic activity mediated through opioid receptors in laboratory animals. Anti-inflammatory and antipyretic activities in various extracts have been reviewed.
The aqueous extract of neem bark possesses anticomplement activity, acting both on the alternative as well as the classical pathway of complement activation in human serum. Recently, an aqueous extract of stem bark has been shown to enhance the immune response. The aqueous extract of leaf also possesses potent immunostimulant activity as evidenced by both humoral and cell-mediated responses. Leaf extract at 100 mg/kg after three weeks of oral administration causes higher IgM and IgG levels along with increased titer of antiovalbumin antibody. Neem oil has been shown to possess immunostimulant activity by selectively activating the cell-mediated immune mechanisms to elicit an enhanced response to subsequent mitogenic or antigenic challenge.
Aqueous extract of neem leaves significantly decreases blood sugar level and prevents adrenaline as well as glucose-induced hyperglycaemia. The aqueous leaf extract when orally fed, also produces hypoglycaemia and decreased blood glucose levels. Aqueous leaf extract also reduces hyperglycaemia in streptozotocin diabetes and the effect is possibly due to presence of a flavonoid, quercetin. A significant hypoglycaemic effect was also observed.
Neem leaf aqueous extract produces antiulcer effect by preventing mucus depletion and mast cell degranulation. An aqueous extract of neem bark has been shown from laboratory to possess highly potent antiacid secretory and antiulcer activity and the bioactive compound has been attributed to a glycoside.
Studies showed that intravaginal application of neem oil prior to coitus can prevent pregnancy. Antifertility effect of neem oil has also been studied and suggested to be a novel method of contraception. Oral administration of aqueous extract of neem leaf also shows antifertility effect. Purified neem seed extract (Praneem) has also been demonstrated to abrogate pregnancy. From the hexane extract of neem seed, an active fraction containing six components has been found to completely abrogate pregnancy when given orally up to a concentration of 10%, with no apparent side effect. The effect is possibly due to activation of cell-mediated immune reaction. The mechanism of action of neem oil appears to be non-hormonal, probably mediated through its spermicidal effect and may have less side effects than steroidal contraceptives.
Neem seed and leaf extracts are effective against malarial parasites. Components of the alcoholic extracts of leaves and seeds are effective against both chloroquin-resistant and sensitive strains of malarial parasite. Recently, neem seed extract and its purified fractions have been shown to inhibit growth and development of asexual and sexual stages of drugsensitive and resistant strains of the human malarial parasite.
Extracts of neem leaf, neem oil and seed kernels are effective against certain human fungi, including Trichophyton, Epidermophyton, Microsporum, Trichosporon, Geotricum and Candida. High antimycotic activity with extracts of different parts of neem has already been reported.
Oil from the leaves, seeds and bark possesses a wide spectrum of antibacterial action against Gram-negative and Gram-positive microorganisms, including M. tuberculosis and streptomycinresistant strains. it inhibits Vibrio cholerae, Klebsiella pneumoniae, M. tuberculosis and M. pyogenes. Antimicrobial effects of neem extract have been demonstrated against Streptococcus mutans and S. faecalis. NIM-76, a new vaginal contraceptive from neem oil showed inhibitory effect on the growth of various pathogens, including bacteria, fungi and virus. Recently, the antibacterial activity of neem seed oil was assessed against 14 strains of pathogenic bacteria.
Aqueous leaf extract offers antiviral activity against Vaccinia virus, Chikungenya and measles virus. The antiviral and virucidal effects of the methanolic extract of neem leaves (NCL-11) have recently been demonstrated against group-B Coxsackie viruses. NCL-11 inhibits plaque formation in different antigenic types of Coxsackie virus B at a concentration of 1 mg/ml at 96 h. Further studies indicated that NCL-11 is most effective in Coxsackie virus B-4 as a virusidal agent, in addition to its interference at the early events of its replication.
Neem may exert its chemopreventive effect in the oral mucosa by modulation of glutathione and its metabolizing enzymes. That neem leaf extract exerts its protective effect in Nmethyl-N-nitro-N-nitrosoguanidine (MNNG) (a carcinogenic material)-induced oxidative stress has also been demonstrated by the reduced formation of lipid peroxides and enhanced level of antioxidants and detoxifying enzymes in the stomach, a primary target organ for MNNG as well as in the liver and in circulation.
The aqueous extract of neem leaf was found to offer protection against paracetamolinduced liver necrosis in rats. The elevated levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma glutamyl transpeptidase (GGT) indicative of liver damage, were found to be significantly reduced on administration of the neem leaf aqueous extract.
The antioxidant activity of neem seed extract has been demonstrated during horsegrain germination, which is associated with low levels of lipooxygenase activity and lipid peroxides. An antioxidant principle has also been isolated, which is a potent inhibitor of plant lipooxygenases.
Effect on central nervous system:
Varying degrees of central nervous system (CNS) depressant activity was observed with the leaf extract. Fractions of acetone extract of leaf showed significant CNS depressant activity. Leaf extract up to a dose of 200 mg/kg body weight produces significant anxiolytic activity. The crude ethanolic extract of stem bark and root bark showed hypotensive, spasmolytic and diuretic activities.
|Some bioactive compounds from neem|
|Neem compound||Source||Biological activity|
|Gallic acid, epicatechin||Anti-inflammatory and|
|Cyclic trisulphide and|
Clinical studies with the dried neem leaf extract indicated its effectiveness to cure ringworm, eczema and scabies. Lotion derived from neem leaf, when locally applied, can cure these dermatological diseases within 3–4 days in acute stage or a fortnight in chronic case. A paste prepared with neem and turmeric was found to be effective in the treatment of scabies in nearly 814 people. In 97% of cases, the paste was found to cure scabies within 3–15 days of treatment without any adverse effect. Neem leaf extract has been prescribed for oral use for the treatment of malaria by Indian ayurvedic practitioners from time immemorial. Dried neem leaves in the form of tea are used by the people of Nigeria and Haiti to treat this disease. Recently, a clinical trial has been carried out to see the efficacy of neem extract to control hyperlipidemia in a group of malarial patients severely infected with. The lipid level, especially cholesterol, was found to be lower during therapy when compared to non-malaria patients. This is a report on malaria patients being treated with the neem extract on plasma lipid level during infection. Several clinical studies have been reported with the neem oil. Application of neem oil on the hair has been shown to kill head lice. Reports are available regarding the use of neem to treat patients suffering from various forms of cancer. One patient with parotid tumour and another with epidermoid carcinoma have responded successfully when treated with neem seed oil. Although in trials neem oil has been shown to have antimicrobial effect to inhibit many species of pathogenic bacteria, including S.aureus and Salmonella typhora, it has not been considered as antibiotic due to some limitations. Considerable clinical trials have been done on the antifertility effect of neem oil. NIM-76, a refined product from neem oil, was studied in 10 human volunteers, where intravaginal application before sexual intercourse could prevent pregnancy with no adverse effect on vagina, cervix and uterus. After demonstrating the antifertility effect of intrauterine neem oil treatment (IUNT) in bonnet monkeys with no apparent side effects, phase I clinical trials were conducted on Praneem Vilci (PV)105, a purified neem oil preparation on eighteen healthy tubectomized women to evaluate the safety after a single intrauterine instillation of PV and to determine the effects of its coadministration on anti-hCG response to the heterospecies dimer (HSD) hCG vaccine. Haematological and biochemical profiles, mid-luteal serum progesterone level and ovulatory status were determined before and after intrauterine treatment with PV. Except one woman showing nonspecific endometritis, no significant adverse effect was observed in other women and all women receiving PV and HSD vaccine produced antibodies against hCG. The data suggested that intrauterine treatment of PV is safe. The authors are unaware whether phase II and phase III clinical trials have been carried out. A polyherbal pessary (Praneem polyherbal pessary) has been developed using some purified ingredients from neem leaves, Sapindus mukerossi and Mencitrata oil, which shows spermicidal action in vitro on human sperm and in vivo on post-coital tests in women. The formulation also has antimicrobial activity. Phase I clinical trials have been completed in India, Egypt and the Dominician Republic. These indicate the safety of its use with beneficial action in invaginosis due to microbial infection. In most women, the pessary also prevented migration of sperm into the cervical mucus. Praneem pessary has thus potential for the development of contraceptive devices.