| Latin Names |
English Names |
Sanskrit Names |
Hindi Names |
Azadirachta indica
A. Juss.
/
Melia azadirachta
Linn. (Meliaceae).
|
Indian Lilac, Margosa Tree, Neem Tree |
Nimba |
Nim, Nimb |
|
| |
 Habitat
It is commonly found throughout the greater part of
India and often cultivated. Though not a forest-tree, it is
generally found to grow wild.
Morphology Description (Habit) |
A large, evergreen tree, with
long, spreading branches forming a broad crown. The bark is
grey and rough; the leaves are alternate, the leaflets 8-19,
glossy and bluntly serrate; the flowers are white or
pale-yellow, small, scented, numerous and found in long,
axillary panicles; the drupes are yellow on ripening,
aromatic, oblong and smooth, with a single exalbuminous
seed.
Principal Constituents
The alcoholic extract of the fresh stem and bark yielded the
bitter principles nimbin, nimbinin, and nimbidin. The
alcoholic extract of the air-dried rootbark yielded nimbin
and nimbidin. Another terpenic constituent, identical with
sugiol, is reported to be present in the stem and bark.
Petrol-ether soluble fraction of the alcoholic extract of
the stem-bark yielded an essential oil (0.02%), having
characteristics similar to the oil isolated from the
blossoms. All parts of the plant yield ß-sitosterol1.
The leaves contain nimbin, nimbinene, 6-desacetylnimbinene,
nimbandiol, nimbolide and quercetin. The presence of ß-sitosterol,
n-hexacosanol and nonacosane is also reported2.
The diterpenoids margolone, nimbogone, nimbonolone and
mimbolinin have been isolated from the plant3.
Pharmacology
A crude extract of the leaves was studied for its effects on
the cardiovascualar system of anesthetized guinea pigs and
rabbits. The extract (200mg/kg) decreased the heart-rate of
the rabbit from 280 to 150 beats/min. It also exhibited a
weak anti-arrhythmic activity in rabbit against ouabain-induced
dysrhythmia4.
The leaves are reported to possess antifertility properties.
The powder of the leaves at the dose level of 20mg, 40mg and
60mg/rat/day for 24 days exhibited spermicidal activity. The
leaves are said to be used as an anthelmintic. The aqueous
extract of leaves exhibited anti-ulcer and anti-inflammatory
activity. The water soluble portion of the alcoholic extract
of the leaves was found to possess a significant blood sugar
lowering effect in glucose-fed and adrenaline-induced
hyperglycemic rats but failed to show such effect in normal
and streptozotocin induced diabetic rats. The freshly
prepared leaf extract at low doses (10, 20, 50, 100 and
200mg/kg) produced a significant anti-anxiety effect whereas
at higher doses (400mg and 800mg/kg) it did not show the
activity. The acetone extract of leaves exhibited CNS
depression, a reduction of blood pressure as well as heart
rate without showing diuretic activity5.
Laboratory trials on rats have shown that the oil from the
seed kernal and nimbidol in a dose of 8mg/kg body wt possess
anti-arthritic action6.
Clinical studies
Clinical trials were conducted on 9 patients of congestive
heart failure with anasarca to study the diuretic effect of
sodium nimbidinate. 250mg were administered daily by deep
intra-muscular injection in the gluteal region. The
injections were repeated for 2-13 days with an average of
about 5 injections per patient. Four other patients were
also studied as controls on the same lines with bed rest,
low sodium diet and adequate digitalization without any
diuretic. Eight of the patients showed a definite diuretic
response. The control group did not show any diuresis. No
toxic reaction was noted except local discomfort or slight
pain7.
Clinical trials were conducted on 12 cases of congestive
cardiac failure with sodium nimbidinate for diuretic
activity. Encouraging diuretic activity was observed with
good response in 4 cases. There was no significant toxicity8.
Toxicity
A study of the toxicity of nimbidin on frogs showed that the
average lethal dose was estimated at 0.25mg/g body wt.
Indications
Neem extracts have been reported to possess anti-diabetic,
anti-bacterial and anti-viral properties. The stem, root,
bark and young fruits are reported to possess astringent,
tonic and anti-periodic properties. The bark is reported to
be beneficial in malarial fever and useful in cutaneous
diseases.
References
- Indian Pat. NO.13343, 1927; Bhattacharji et. al., J
sci industr Res, 1953, 12B, 154; Mitra et. al., ibid, 12B,
152; Sengupta et. al., Chem & Ind, 1958, 861; Narasimhan,
Chem & Ind, 1957, 661.
- Ketkar, 1976, 208; Troup, I, 180; Dastur, Useful
Plants, 39; Mitra, C R , 6, 9, 64; Christopher, loc. cit.;
Murthy, Indian Fmg, N S, 1957-58, 7(9), 9; Macmillan, 29;
Basu & 6 Chakraborty, J Indian chem Soc, 1968, 45, 466;
Chem Abstr,1981, 95, 111715; Awasthi & Mitra,
Phytochemistry, 1971, 10, 2842; Nutritive Value of Indian
Foods, 69; Dakshinamurti, Curr Sci, 1954, 23, 125.
- Hanson, Nat Prod Rep, 1991, 54, 6.
- Mitra, C R, 64, 96; Tyagi et. al., Nagarjun 1977-78,
21(4), 5; Basu, J Bombay nat Hist Soc, 1955-56, 53, 743;
Rao et. al., Indian J med Res, 1969, 57, 495; Joshi &
Magar, J sci industr Res, 1952, 11B, 261; Banerjee &
Sanyal, Proc Indian Sci Congr, 1956, pt. III, 348;
Shrivastava & Singh, Indian Drugs, 1981-82, 19, 245;
Dictionary org Compds, V, 688; Thompson & Anderson, J
pharm Sci, 1978, 67, 1467.
- Qamar et.al., Pakist J Industr Res, 1989, 32, 600;
Vedavathy et. al., Int J Pharmacogn 1991, 29, 113;
Bhattarai, ibid, 1992, 30, 145; Shaikh, Curr Sci, 1993,
64, 688; Garg, et. al., Planta Med, 1993, 59, 215 Alam et.
al., Fitoterapia, 1990, 61, 240; Chattopadhyay & Maitra,
ibid, 1993, 64, 332; El-Hawary & Kholief, Arch Pharm Res,
1990, 13, 108; Handa, 1992, 63, 3; Jaiswal et. al., Indian
J. Exp Biol, 1994, 32, 484; Chattopadhyay et. al., ibid,
1992, 738; Singh et. al., ibid, 1990, 61, 164.
- Dastur, Useful Plants, 40; Mitra, Indian Oilseeds J,
1956-57, 1, 256;Information from Dr C R Mitra, NBRI,
Lucknow; Shankaranarayanan & Sirsi, Indian J Pharm, 1961,
23, 53.
- Shah et. al., Ind. J. Med. Sci., 1958, 12, 150.
- Shah et. al., J. Assoc. Physician India, 1959, 7, 235.
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