International Journal of Pharmacognosy and Life Science 2020; 1(1): 38-41

E-ISSN: 2707-2835
P-ISSN: 2707-2827
IJPLS 2020; 1(1): 38-41 Pharmacological activities of neem (Azadirachta
Received: 21-11-2019
Accepted: 23-12-2019 indica): A review
Shakib Uzzaman
Department of Pharmacy Shakib Uzzaman
Varendra University
Rajshahi, Bangladesh
DOI: https://doi.org/10.33545/27072827.2020.v1.i1a.8

Abstract
Azadirachta indica, commonly known as neem, has attracted worldwide prominence in recent years,
owing to its wide range of medicinal properties. Neem has been extensively used in Ayurveda, Unani
and Homoeopathic medicine and has become a cynosure of modern medicine. Neem elaborates a vast
array of biologically active compounds that are chemically diverse and structurally complex. More than
140 compounds have been isolated from different parts of neem. Neem possesses anti-diabetic, anti-
oxidant, anti-viral, anti-inflammatory properties. Various effects like antibacterial, anti-fungal,
anthelmintic, anti- parasitic, anticancer, anti HIV, antibone resorption, antispasmodic, antipyretic,
antidiarrheal, immunomodulation, hypolipidemic, anti-microbial, hepatoprotective, gastro protective
have also been studied.

Keywords: Neem, anticancer, antidiabetic, antimicrobial, antimalarial.

1. Introduction
Neem is a natural herb that comes from the neem tree, other names for which include
Azadirachta indica and Indian lilac. The extract comes from the seeds of the tree and has
many different traditional uses. Neem is known for its pesticidal and insecticidal properties,
but people also use it in hair and dental products. All parts of the neem tree- leaves, flowers,
seeds, fruits, roots and bark have been used traditionally for the treatment of inflammation,
infections, fever, skin diseases and dental disorders. The medicinal utilities have been
described especially for neem leaf. Neem leaf and its constituents have been demonstrated to
exhibit immunomodulatory, anti-inflammatory, antihyperglycaemic, antiulcer, antimalarial,
antifungal, antibacterial, antiviral, antioxidant, antimutagenic and anticarcinogenic
properties. This review summarises the wide range of pharmacological activities of neem
leaf.

2. Synonyms of Azadirachat Indica

 Azadirachta indica var. minor Valeton
 Azadirachta indica var. siamensis Valeton
 Azadirachta indica subsp. vartakii Kothari, Londhe & N.P. Singh
 Melia azadirachta L.
 Melia indica (A. Juss.) Brandis

3. Taxonomical Classification
 Kingdom: Plantae
 Subkingdom: Tracheobionta
 Division: Magnoliophyta
 Class: Eudicot
 Subclass: Rosidae
 Order: Sapindales
 Family: Meliaceae
Corresponding Author:
 Genus: Azadirachta
Shakib Uzzaman
Department of Pharmacy  Species: A. indica
Varendra University
Rajshahi, Bangladesh

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4. Plant description Various parts of the neem tree have been used as traditional
Neem is a fast-growing tree that can reach a height of 15–20 Ayurvedic medicine in India. Neem oil and the bark and leaf
metres (49–66 ft), and rarely 35–40 metres (115–131 ft). It extracts have been therapeutically used as folk medicine to
is evergreen, but in severe drought it may shed most or control leprosy, intestinal helminthiasis, respiratory
nearly all of its leaves. The branches are wide and disorders, constipation and also as a general health
spreading. The fairly dense crown is roundish and may promoter. Its use for the treatment of rheumatism, chronic
reach a diameter of 20–25 metres (66–82 ft). The neem tree syphilitic sores and indolent ulcer has also been evident.
is very similar in appearance to its relative, the Chinaberry Neem oil finds use to control various skin infections. Bark,
(Melia azedarach). leaf, root, flower and fruit together cure blood morbidity,
biliary afflictions, itching, skin ulcers, burning sensations
5. Neem compound, Source & Biological Activity and pthysis.

Fig: Neem Leaves Fig: Neem buds and flowers

Table 1: Shows the Neem compound, Source & Biological Activity

Neem compound Source Biological activity
Anti-inflammatory, Antiarthritic, Antipyretic, Hypoglycaemic,
Nimbidin Seed oil
Antigastric ulcer, Spermicidal Antifungal, Antibacterial, Diuretic.
Sodium nimbidate Anti-inflammatory.
Nimbin Seed oil Spermicidal.
Nimbolide Seed oil Antibacterial, Antimalarial
Gedunin Seed oil Antifungal, Antimalarial
Azadirachtin Seed Antimalarial
Mahmoodin Seed oil Antibacterial.
Gallic acid, (–) epicatechin and catechin Bark Anti-inflammatory, immunomodulatory.
Margolone , margolonone and isomargolonone Bark Antibacterial
Cyclic trisulphide and cyclic tetrasulphide Leaf Antifungal
Polysaccharides Anti-inflammatory
Polysaccharides GIa , GIb Bark Antitumour
Polysaccharides GIIa , GIIIa Bark Anti-inflammatory
NB-II peptidoglycan Bark Immunomodulatory

6. Pharmacological uses Conclusion: The present study concludes that NSO exhibits
 Antidiabetic significant anti-inflammatory action.
The oral effective dose of A. indica leaf extract (400 mg/kg
body weight [b.wt]) was given once daily for 30 days to  Hepatoprotective
high-fat diet-induced diabetic rats. At the end of the The aim of this study was to investigate the hepatoprotective
experimental period, fasting blood glucose, oral glucose role of azadirachtin-A in carbon tetrachloride (CCl4)
tolerance, serum lipid profile, and the levels of insulin induced hepatotoxicity in rats. The group allotment for the
signaling molecules, glycogen, glucose oxidation in animals used in the hepatoprotective study included a
gastrocnemius muscle were assessed vehicle treatment group, CCl4 (1 mL · (kg body mass)(-1))
treatment group, silymarin (100 μg · (kg body mass)(-1) ·
 Anti-inflammatory day(-1)) + CCl4 treatment group, and groups treated with
NSO in the dose of 0.25 ml/kg body weight did not show different doses of azadirachtin-A (100 or 200 μg · (kg body
any significant anti-inflammatory activity. NSO showed mass)(-1) · day(-1)) + CCl4. On the 9th day, blood was
increased inhibition of paw edema with the progressive obtained for measuring the biochemical parameters, and
increase in dose from 0.25 ml to 2 ml/kg body weight. At liver tissue was obtained for pathological examination. The
the dose of 2 ml/kg body weight, NSO showed maximum acute toxicity test with azadirachtin-A (500, 1000, or 2000
(53.14%) inhibition of edema at 4 th hour of carrageenan μg· (kg body mass)(-1)) indicated no mortality after 14 days
injection. Aspirin in the dose of 200 mg/kg body weight of treatment; further, there was no change in behavior, food
showed maximum inhibition of hind paw edema.

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International Journal of Pharmacognosy and Life Science http://www.pharmacognosyjournal.com

consumption, or organ mass. However with the higher dose, effects and possible teratogenic effects on the foetuses. All
some hematological parameters showed changes. the groups were control-matched.

 Anti-hemorrhagic  Antibacterial
The minimum inhibitory concentration reached by 50% The neem NE at lower concentration (0.7–1 mg/mL) is
(MIC50) and 90% (MIC90), and minimum bactericidal found to be nontoxic while it is toxic at higher
concentration for the extract were 2.5, > 5, and 10 mg/ml, concentrations (1.2–2 mg/mL). The oxidative stress induced
respectively. Neem extract showed antisecretory activity on by the neem NE is evidenced by the depletion of catalase,
Vibrio cholerae induced fluid secretion in mouse intestine SOD, and GSH levels in human lymphocytes. Neem NE
with inhibition values of 27.7%, 41.1%, 43.3%, 57.0%, and showed a significant increase in DNA damage when
77.9% at doses of 100, 200, 300, 450 and 1800 mg/kg, compared to control in human lymphocytes (P<0.05). The
respectively. Oral administration of the extract inhibited NE is an effective antibacterial agent against the bacterial
hemorrhage induced by Vibrio cholerae in mouse intestine pathogen V. vulnificus, and it was found to be nontoxic at
at a dose > or = 300 mg/kg. The results obtained in this lower concentrations to human lymphocytes.
study give some scientific support to the uses of neem
employed by the indigenous people in India employed for  Antifungal
the treatment of diarrhea and dreadful disease cholera. Neem (Azadirachta indica) extract (NE) and NE combined
with copper sulfate and boric acid (NECB) were examined
 Analgesic and Antipyretic for their protective effect against fungal deterioration of
The anti-inflammatory effect of aqueous extract of neem mango (Mangifera indica) and rain tree (Albizia saman)
leaf (400 mg/kg body weight) was compared with that of wood. Growth of the white-rot fungus Schizophyllum
dexamethasone (0.75 mg, intraperitoneally) by commune was completely inhibited on solid medium
administering one hour before the formalin injection and containing 1.8% (w/w) NE or 5% (w/w) NECB. The
once daily for 7 days in rats. The percentage of inhibition of average weight losses of NE and NECB treated wood blocks
paw edema in case of neem after 3, 6 hours, on day 3, 7 inoculated with S. commune were respectively 4.7% and
after formalin injection were 28, 40, 45, 58% respectively 3.3% for M. indica and 4.1% and 3.0% for A. saman.
and that in case of dexamethasone after 3, 6 hours, on day 3,
7 after formalin injection were 43, 58, 61, 65% respectively.  Antiviral
The reduction was statistically significant in each case The antiviral and virucidal effect of methanolic extract
(p<0.001). The present study suggests that anti- fraction of leaves of neem (Azadirachta indica A. Juss)
inflammatory effect of neem extract is less than that (NCL-11) was studied regarding its activity and possible
produced by dexamethasone. mechanism of action against Coxsackie B group of viruses.
NCL-11 inhibited plaque formation in 6 antigenic types of
 Kidney damage Coxsackie virus B at a concentration of 1000
The results obtained in this study showed the aqueous crude micrograms/ml at 96 hrs. 'in vitro'. Additionally virus
extract of neem (A. indica) leaves exerted a dose-dependent inactivation, yield reduction and effect of time of addition
protective activity of renal damage induced by P. berghei. It assays suggested that NCL-11 was most effective against
was most effective at the dose levels of 1,000 and coxsackie virus B-4 as a virucidal agent besides interfering
2,000 mg/kg. This plant can be recommended for use since at an early event of its replicative cycle. The evidence
it possessed a high protective effect against malaria and can suggested that presence of a battery of compounds besides
be obtained at relatively no cost from nature. flavonoids, triterpenoids and their glycosides in NCL-11
have antiviral action for coxsackie B group of viruses 'in
 Anti-ulcer vitro.' The minimal inhibitory concentrations were not toxic
The antiulcer effect of aqueous extracts of the leaves of the to Vero (African green monkey kidney), cells; subtoxic
neem tree was investigated in rats exposed to 2-h cold- concentration was 8,000 micrograms/ml and cytotoxic
restraint stress or given ethanol orally for 1 h. Extracts were concentration 10,000 micrograms/ml, which was confirmed
administered in doses of 10, 40, or 160 mg leaf/kg body by trypan blue dye exclusion test.
weight, either as single- or five-dose pretreatment regimens.
Neem dose-dependently reduced gastric ulcer severity in  Immunoregulation
rats subjected to stress and also decreased ethanol provoked The aqueous extract of neem bark and leaf also possesses
gastric mucosal damage. anticomplement and immunostimulant activity. Neem oil
has been shown to possess activity by selectively activating
 Antibone resorption the cell-mediated immune mechanisms to elicit an enhanced
Adult female Sprague-Dawley rats, weighing between 140– response to subsequent mitogenic or antigenic challenge.
180g were used. There were 3 main experimental groups.
Group 1 rats received 1 g/kg of alcoholic extract of Neem 7. Hyoglycaemic
flower by gavage for 3 weeks and the effect on estrous cycle Aqueous extract of neem leaves significantly decreases
studied. Group 2 rats were administered 1 g/kg of Neem blood sugar level and prevents adrenaline as well as
flower alcoholic extract at 9 a.m. and at 6 p.m. on proestrus glucose-induced hyperglycaemia. Recently, hypoglycaemic
and the effect on the number of ova shed on the morning of effect was observed with leaf extract and seed oil, in normal
estrus observed. Rats in Group 3 were treated with 1 g/kg of as well as alloxan-induced diabetic rabbits.
alcoholic extract of Neem flower on days 1 to 5 postcoitum,
and observation was made for anti-implantion / abortifacient  Antioxidant activity

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