Neem:
The Wonder Tree
By
Dr. Rahman
The
neem tree (Azadirachta indica) is regarded as one of mother nature's
gift to the world. In India, it is commonly found in house compounds
in both villages and cities.
Green twigs are used as toothbrushes to combat teeth decay. Its
extracts have a powerful pesticidal activity and are used by both
households and farmers to control a wide variety of pests (insects,
fungi, bacteria, viruses, nematodes, rodents etc.). These extracts
have considerable antiseptic affects and are used as a skin care
agent in soaps and shampoos. The leaves are often mixed with rice
and consumed as a cure all and prophylactic against bacterial
and helminthic infections. Neem leaf pastes are used to repair
scarred skins arising from the effects of chickenpox.
The
pesticidal and medicinal properties of extracts from the neem
tree have been exploited for at least the last 2500 years.
Neem extracts
Sanskrit texts dating back to the sixth century BC, document the
microbicidal and prophylactic effects of neem extracts. Charaka
in the 6th Century BC recommended the oral consumption of neem
extracts to ward off pimples, leprosy and edema.
Neem extracts have also been shown to be effective against nematode
pests. Neem cake, the by product from neem seed processing appears
to be effective on nematodes, snails and certain fungi. The neem
tree and its extracts surprisingly appear to be benign to bees
and other nectar feeding insects. Seed extracts are not known
to have any toxic effect on plants, mammals and birds and in fact
in studies by the US EPA, no LD-501
could be established even at high doses.
Neem-leaf smoke
Sushruta in the 5th century BC recommended the use of neem-leaf
smoke for fumigation and maintenance of general hygiene. He also
recommended it as a "krimihara", an agent effective
against insects, grubs and maggots and detailed the ability of
neem leaves to cure gangrenous and otherwise difficult to cure
wounds.
Biochemical
factory
The neem tree appears to be a biochemical factory producing a
mixture of over 135 biologically active compounds. As a pesticide,
the oil from neem seeds are believed to break the life cycle of
pests and deters them from feeding and hatching. Studies have
shown that active compounds in the oil inhibited the secretion
of hormones into the blood inhibiting the molting and reproductive
function in insects.
Neem oil
Neem
oil is known to be active on over 400 insect pests. It has for
example been found to be effective against fleas, head lice, ticks,
termites, plague locusts, mosquitoes and sheep blow flies. It
is believed to be particularly active against chewing and sucking
insects such as caterpillars and beetle larvae.
These
remarkable properties have attracted considerable interest from
both researchers and pharmaceutical companies. This renewed interest
in neem created no more than amusement in India where the beneficial
properties of neem have been known for countless generations.
Patent's and Trademark's
Grace Horticultural Products, a unit of Grace Specialty Chemicals
(USA) acquired the patent and trademark rights to produce and
sell insecticidal neem extracts. Their product, Margosan-O Concentrate,
is protected under US patent No. 5124349.
Not a new invention
In
1995, a group led by Mr. Jeremy Rifkin, president of the Foundation
of Economic Trends in the US, Dr. Vandana Shiva of the Research
Foundation for Science Technology and Natural Resource Policy
and Professor, Nanjundaswamy of the Karnataka Rajya Ryot Sangha
in India contested the decision of the US Patent and Trademark
Office. They claim that the neem product has long been used as
a pesticide in India and is not a new invention as claimed under
the patent. They claim that Grace's patent does not satisfy the
criterion that the invention must not be obvious to one of ordinary
skill in the art. They assert that the Grace process only slightly
differs from that used by farmers in India.
Grace
on the other hand claims that its patent relates to a formulation
based on neem-seed extract. They assert their formulation overcomes
the problems associated with the instability of azadirachtin,
the primary active pesticidal ingredient from the plant, in traditionally
used water or alcohol based emulsions. Further the awarding of
patents based on the purification or modification of naturally
occurring substances is not new. For example, in 1979, the US
Court of Customs and Patent Appeals reversed a decision by the
Patent and Trademark Office to award a patent for a compound purified
from strawberries. In fact, more than 40 patents have already
been award for inventions relating to a compound found in neem
seeds alone.
Reproduced
with permission Mr. Milan Mehta
Top
LD50
1. An LD50 value is the amount of a solid or liquid
material that it takes to kill 50% of test animals in one dose.
Neem Advice
Neem should not be taken by anyone (male or female) who is
pregnant or trying to conceive.
It also contains compounds similar to those in aspirin and should
not be used to treat children with fevers.
While people in some countries use neem oil internally, we definitely
do not recommended taking neem oil in this manner.
Within those limitations, neem is generally considered to be one
of the safest medicinal herbs available.
The FDA
The FDA's Office of Special Nutritionals maintains an extensive
database of adverse affects from herbal medications which does
not include any references to neem that would indicate potential
problems.
U.S. Environmental Protection
Even the Extension Toxicology Network documentation for using
neem as a pesticide shows that it is "relatively non-toxic" and
caused no significant problems even at the extraordinary high
dosages fed to laboratory rats as part of the approval process
required by the U.S. Environmental Protection Agency.
