A Review On Biological Activities Of Azadirachta indica

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Review On Biological Activities Of Azadirachta indica


Neem has become valuable plant in the world which shows the solutions for hundreds to thousands problems. Azadirachta indica ( Neem ) is a rapidly growing evergreen well known tree found generally in various regions of world like America, Africa and India.This review article provides information mainly on various biological activities like Antiallergic, Antidermatic, Antibacterial, Antifungal, Anti-inflammatory, Insecticidal, larvicidal, Antimalarial, Antiulcer and other biological activities of neem plant and medicinal uses. Neem tree produces some active compounds which contains biological activities ,parts of Neem tree such as Root, bark, leaf, flower , seed and fruit togetherposseses biological activities Various compounds have been obtained from various parts of neem. Some of them have been studied for biological activity.


Neem, Medicinal Uses, Biological Activity, Azadirachta indica, Antimicrobial Activity


Azadirachta indica is rapidly growing evergreen plant found commonly in India, Africa and America [1]. It is used in Ayurvedic medicine from more than 400 years due to its medicinal characteristics. Neem is also called as ‘Arista’ in Sanskrit, a word that means Imperishable, Perfect & Complete [2]. Arista is the Sanskritname of neem tree meaning ‘reliver of stickness’ & hence is known as ‘sarbarogaribarini’. In India it is known as ‘Village dispensary ’. The importance of the Azadirachta indica (neem) tree has been admitby the US National Academy of sciences which publish a report in 1992 entiteled ‘Neem-a tree for solving global problems [3].

It gives maximum useful non-wood products[leaves, bark, , gum, oil, neem cake flowers, fruits, seed ] than any other tree species known to have Antiallergic, Antifungal, Antibiotic, Antidermatic, Antibacterial, Anti-inflammatory, Insecticidal, Larvicidal, Antimalarial, Antiulcer & other biological activities. Because of there activities neem has found several applications making it a green treasure [3].

The phytochemical screening has been under taken by various research workers in different countries of the world. The photoconstituents i.e. alkaloids, glycosides, flavonoids and saponins are antibiotic principles of neem plants. These antibiotic principles are actually the protective mechanism of the plants against different pathogens (Hafiza, 2000). [4].

Neem tree used to give treatment of a variety of physical oilments such as heart disease, diabetes, blood disorders, digestive and nervous disorders, parasites and possibly cancer. Moreover, Neem may also be used as spermicidal as well as mouthwash.

Taxonomic position of neem-

  • Order:- Rutales
  • Suborder:- Rutinal
  • Family :- Maliaceae
  • Subfamily:- Melioideae
  • Tribe:- Melieae
  • Genus:- Azadirachta
  • Species:- Indica

Biological Activities of Neem Plant-

  • Antibacterial Activity :-

Methanolic extract of A.Indica (neem) leaves was tested for its antibacterial, antisecretory and antihemarrhagic activity against vibrio cholera [5]. The hexane chloroform and methanol extracts of Azadirachta indica were screened for antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Micrococcus luteus, Bacillus subtilis Enterococcus faecalis and Streptococcus faecalis. It was reported that methanol extract was the most effective, chloroform moderately effective and hexane extract showed low antibacterial activity [6].

Oil extracted from leaves, seeds and bark gives a wide spectrum of antibacterial activity action against gram positive and gram negative microorganisms including M. tuberculosis and streptomycin resistant strains (Chopra et al 1956). The photoconstituents like alkaloids, spooning, steroids, tennis, crude glycosides and flavonoids of neem plants was tested for antibacterial activity against pathogenic strains of E.coli, Corynebacterium bovis and Staphylococcus aureus. [4]. The outcomes were also supported by Hymete et. al (2005) they reported that flavonoids compounds have antimicrobial activity. Hafiza et al (2002) reported that crude saponins also prevent the growth of the microbes.

Metabolic extract and ace tonic extracts of leaves of Azadirachtaindica were screened for antibacterial activity against two different bacterial strains i.e. E. coli and B. subtilus and it was reported that methanolic plant extracts showed maximum antibacterial activity as compared to acetonic plant extracts. [7]. El-Mahmood et al (2010) observed the antibacterial effects of crude extracts of neem seed against pathogenic involved in the infection of eyes and ear. The pure, Ethanol, acetone and methanol extracts of neem were screened against bacterial strains i.e. Ecolab, B. subtitles, Salmonella typhus, Pseudomonas, Staphylococcus aurous, and Klebsiellapneumoniae and Staphylococcus epidermitis for various antibacterial activity.

They reported that the neem extracts of acetone showed the maximum antibacterial activity as compared to other siolvent extracts [8]. Neemseed oil gives bactericidal activity against 14 pathogenic bacterial strains [9]. Crude aqueous and solvent extracts of neem were tried against 20 pathogenic bacterial strains, wherein crude extracts shows better outcomes [10]. Ethanolic extracts of neem leaves and stick of neem plant were screened for antibacterial activity on streptococcus mutans and it was reported that neem stick extracts had higher antibacterial properties than the leaves extracts. [11].

  • Antifungal Activity :-

The aqueous and ethanolic extracts of Azadirachta indicaleaves have been shown to have antidermatophytic activity when tested in vitro against 88 clinical isolates of dermatophytes using the agar dilution technique. The activity was more conspicuous in ethanolic extract as compared to that in aqueous extract [12]. Antifungal characteristics was tested using methanolic and acetone extracts of Azadirachta indicaagainst two different fungal strains i.e. Aspergillus niger and Aspergillusfumigatus and it was reported that methanolic plant extract gives maximum antifungal activity as compared to acetonic extracts [7]. The seed and leaf extracts of Azadirachta indica (Neem) were tested for antifungal activity against dermatophytes and the Minimum Inhibitory Concentration (MIC) of neem seed extracts was found to be lower than that of neem leaf when tested against different species of Trichophyton and Epidermatophyton floccosum [13].

Antifungal activity of aqueous ethanolic and ethyl acetone extracts of neem leaves on growth of some human pathogens.Aspergillus flavus, Candida albicans Aspergillus terreus, Aspergillus fumigates, Aspergillus niger, and Microsporum, gypseum in vitro using different concentration and it was reported that these extracts prevented the growth of the test pathogens and the effect gradually increased with increase in concentration [14]. Gedunin isolated from neem seed oil has been reported to have antifungal activity [15].Sulphur containing compounds such as cyclic trisulphide and tetrasulphide isolated from the stem distillate of fresh, matured neem leaves shows antifungal activity against Trichophyton mentagrophytes [16].

  • Antimalarial Activity:-

Ball shaped wood scrapings which is soaked in 5% neem oil (Azadirachta indica) diluted in acetone and placed in water storage overheadtanks controlled the breeding of anopheles stephensi and aedes aegypti in 45 days [17]. Nimbolide isolated from neem extracts shows the antimalarial activity by preventing the growth of plasmodium falciparum [18]. Gedunin isolated from neem seed oil has been reported to show antimalarial activities [19]. Both aqueous and alcohol extracts of bark and leaves of neem are effective antimalarial agents, particularly on chloroquine resistant strains (badam et al 1987) [20].

  • Antitumor and Antiviral Activity:-

Scientist in India, Europe and Japan have now found that limonoids and polysaccharides found in neem seed oil, bark and leaves reduced tumors and cancers and revealed effectiveness against lymphocytic leukemia. Mitotic inhibition activity by the leaf extract was abserved. Several conclusions have also highlighted the pronounced antiviral effect of aqueous extract of neem leaves against Small Pox, Fowl Pox, Polio and HSVas assessed by virus prevention assay (98-100). Aqueous extracts of neem leaf and a fraction from neem oil (Nim-76) have also been reported to suppress HIV and Polio Viruses [21].

  • Anti-inflammatory, Antipyretic and Analgesic Activities :-

The chloroform extract of stem bark shows effectiveness against carrageenin – induced pawaedema in rat and mouse ear Inflammation. Inflammatory stomatitis in children is treated by the bark extract. Antipyretic activity has been reported in neem oil. A methanol extract of the leaves exerts antipyretic effect in male rabbits. The plant also shows analgesic activity mediated through opioid receptors in laboratory animals. Antipyretic and Anti-inflammatory activities in various extracts have been reviewed [3].

  • Male Antifertility Activity :-

The neem seed oil (NSO) and leaf extracts used as powerful spermicide and significantly prevented spermatogenesis, decreased sperm mobility, count and cessation of fertility. These conditions were reversed by the withdrawal of neem products 4-6 weeks later. No Indicative or important effect on loss of libidoor potency. Furthermore, NSO possess abortifacient and anti-implantation properties. Sinha et al (1984) found spermatozoa of human and rhesus monkey were immotile and die within 30 minutes of contact with NSO in an intravaginal dose of 1 ml. Vaginal biopsy showed no side effect, while radio-isotope studies indicate non-absorption in the vagina and non-antiovulatory (sinha et al 1984). These findings enabled neem oil formulation “sensal” which is used as a powerful contraceptive in India [20].

  • Antiulcer Activity :-

A significant antiulcer effect was observed with nimbidin in preventingacetylsalicyclic acid, indomethacin, streets or serotonin-induced gastric lesions as well as histamine or cysteamine induced duodenal ulcers [22], [23]. Garg et al, have also reported an antiulcer effect of neem leaf extract and the inhibition of mucus depletion and most cell defragmentation as possible mechanism. A phenolic glycoside has been obtained by Bandyopadhyay et al, as an active constituent, whose characterization and mechanism are under investigation. Therefore, Azadirachta indicaoffersanother option for a safer and an effective antiulcer drug [24].

  • Biological activities of some neem compounds :-

Various compounds have been isolated from various parts of neem. Some of them have been studied for biological activity given in Table 1. [44], [45]

Sr. No.

Compound Name


Biological activity




Seed oil









Antigastric ulcer











Sodium nimbidate





Seed oil





Seed oil





Seed oil







Seed oil







Seed oil




Gallic acid (-) epicatechin and catechin






Margolone, mergolonone and isomargolonone





Cyclic trisulphide and cyclic tetrasulphide









Polysaccharides G1A, G1B





Polysaccharides G2A, G3A





NB-2 peptidoglucan




Fig. Table 1 [44], [45]

  • Medicinal Uses Of Neem:-

Neem plant shows the large number of medicinal uses. The non-wood products of neem like flowers, leaves, bark, fruits, seeds (oil, cake), and gum also find various uses. The Neem plant shows various biological activities like antibacterial, antifungal, insecticidal and other activities. Some of the medicinal uses of various parts of neem as mentioned in ayurveda given in Table 2. [45]


Medicinal uses


Leprosy, eye problem, epistaxis, intestinal worms, anorexia, biliousness, skin ulcers


Analgesic, alternative and curative of fever


Bile suppression elimination of intestinal worms and phlegm


Relieves piles, intestinal worms, urinary disorders, epitaxis ,phlegm, eye problem, diabetes , wounds and leprosy


Relieves cough,asthma,piles,phantom tumor, intestinal worms, spermatorrhea, obstinate urinary disorders, diabetes


Effective against skin diseases like ring worms, scrabies, wounds and ulcers

Seed pulp

Leprosy and intestinal worms


Leprosy and intestinal worms

Root, bark, leaf, flower and fruit together

Blood morbidity, ulcers, burning, biliary afflictions, leprosy, skin sensation and itching

Fig. Table 2 .[45]

  • Conclusion:-

Azadirachta indica(Neem) plant acts as a medicinal plant have been found effective in the treatment of bacterial , fungal, viral and other diseases and revealed the antibacterial, antifungal, antiviral, antimalarial, antiulcer and other biological activities. Due to increasing antibiotic resistance in microorganisms and side effects of synthetic antibiotics neem plant are now growing popularity in the treatment of many infections. Neem plant is considered as clinically effective and safer alternatives to the synthetic antibiotics.

Extensive research in the area of isolation and characterization of the active principles of neem plant is essential so that better, safer and cost effective drugs for curing various diseases and infections can be developed.