Basil: Nature’s remedy for sleepingsickness

AFRICAN trypanosomiasis has continued to
threaten human health and economical
development.
African trypanosomes cause human
sleeping sickness and livestock
trypanosomiasis in sub-Saharan Africa.
Trypanosome, the causative parasite, is
most prevalent in Africa and has been
responsible to a great extent for the under
development, poverty and suffering in
many parts of Africa.
Up to 80 per cent of the Nigerian land mass
is infested by the vector of the parasite,
tsetse fly and with increase in the menace
of tsetse fly, drug resistance to common
drugs, lack of effective vaccine against
trypanosomiasis, there is an urgent need
for the development of new, cheap, safe
and easy-toadminister drugs for the
treatment of African trypanosomiasis for
both human and animals.
However, among the indigenes of
trypanosome prevalent areas, there are
several claims of medicinal plants with
possible therapeutic activities, which have
not been proved scientifically.
Nevertheless, a number of African medicinal
plants have been evaluated for their effect
on trypanosome, the causative parasite for
sleeping sickness.
The water extract of the leaf of Ocimum
gratissimumis (referred to as Efirin in
Yoruba) is one of such plants that
traditionally were used in the treatment of
African trypanosomiasis. Researchers
evaluating its usefulness in the treatment of
African trypanosomiasis found out its water
extract was effective against
trypanosomes.
Ocimum gratissimum belongs to the plant
family Lamiaceae. It is known as Efinrin
ajase in Yoruba, Ebavbokho in Bini, Aai
doya ta gida in Hausa and Nchuanwu in
Igbo. It is also commonly called Sweet basil.
The leaves are used locally for soup. It is
also used to treat cases of stomach upset
and diarrhoea.
The 2009 study, published in the African
Journal of Traditional Medicine was carried
out by Dr. Chukunyere Nwosu from the
Department of Veterinary Microbiology and
Parasitology, University of Maiduguri; Dr.
Roland Agbede from the Department of
Veterinary Parasitology and Entomology,
Ahmadu and Dr. M. Adamu from the
Department of Veterinary Parasitology and
Entomology, University of Agriculture,
Makurdi, Benue State.
In the study, dry leaves of Sweet basil were
ground into fine powder before a water
extract of the leaves was made from it.
Twenty albino rats were used for the study.
Fifteen of the rats were infected with
trypanosome. The animals were examined
daily for the presence of trypanosome for
the first two days after treatment and
thereafter every two days for 28 days.
They found that treatment with the extract
resulted in a reduction in the level of
trypanosome between days 10 and 18 after
they became infected, demonstrating that
the water extract of the leaf of Sweet basil
at the concentrations used significantly kill
trypanosome under laboratory conditions.
According to the researchers, although the
extract did not significantly reduce the level
of the germ responsible for the disease, it
prolonged the survival time in the infected
rats. They wrote: “The ability of the water
extract of Sweet basil to inhibit parasite
activity in vitro and modify the course of
the disease in vivo may be due to the
presence of some active principles in the
leaf extract such as alkaloids, flavanoids.
In conclusion, they suggested that the
folkloric medicinal use of the aqueous
extract of Sweet basil has no correlation
with scientific data, and as such no possible
therapeutic basis.
Dissotis rotundifolia is a medicinal plant
which is widely used in Nupe
ethnomedicine for treatment of
trypanosomiasis. It is referred to as
ajagunmoransin in Yoruba. It was against
this background that Drs. Abdullahi Mann,
Barnabas Banji, Nda-Umar Abdukadir and
Mohammed Gbate from the Federal
Polytechnic Bida, Niger State collaborated
with Dr. Evans C. Egwim from Federal
University of Technology Minna,Niger State
and J. T. Ekanem from University of Ilorin,
Kwara State, set to work on this plant.
In the 2009 study documented in the
African Journal of Biochemistry Research,
they suggested that extracts from the
leaves of Dissotis rotundifolia may be a
novel solution to trypanosomiasis. They
found that when by the infected animal
drank water laced with extracts made from
the leaves of Dissotis rotundifolia and
when the extract was passed into the veins
of the animal both reduced the amount of
the Trypanosome in the tested animals used
for the study by 66.7 and 78.4 per cent
respectively.
However, the crude extract at high
concentration (800mg/kg) was able to
paralyse or kill the parasite completely
within 45 s when tried on Trypanosoma
directly under laboratory conditions.
Meanwhile, Butyrospermum paradoxum
stem bark, commonly used in the traditional
treatment of various diseases including
animal and human trypanosomosis in
north-eastern Nigeria, is also able to
completely suppress or reduce the level of
Trypanosoma and the severity of the
attendant disease, so helping to enhance
survival of the rats infected with
Trypanosoma congolense and
Trypanosoma brucei.
Butyrospermum paradoxum is called
Emigidi in Yoruba. Shea butter is derived
from this plant.
The results of this study in Journal of
Ethnopharmacology also suggested that
the folkloric medicinal application of the
extracts of Butyrospermum paradoxum
has a scientific basis.
Other studies have also found neem, garlic,
Sclerocarya birrea, Commiphora kerstingii
and Khaya senegalensis (African
mahogany) useful in the control of the
germ that causes sleeping sickness.
Commiphora kerstingii is referred to as
garkuwarwuta or gurzun dali. Sclerocarya
birrea is popularly called Craw-craw vine in
Nigeria.